Ø. Risum - Academia.edu (original) (raw)
Papers by Ø. Risum
Scandinavian Cardiovascular Journal, 2000
Sudden heart arrest (HA) in the early phase after aorto coronary bypass surgery represents a seri... more Sudden heart arrest (HA) in the early phase after aorto coronary bypass surgery represents a serious event necessitating resuscitation, and for those who survive usually also an extra stay in the coronary care unit. Since such episodes of heart standstill may be related to conduction defects, a study was conducted to determine whether the duration of the QRS complex on the preoperative ECG is a marker for this morbid event. A cohort of 1011 consecutive patients operated on between 1982 and 1986 and followed to January 1st, 1993 were included in the study. Incidence of lethal or non-lethal HA during the first 4 weeks after surgery was considered as the primary endpoint and total mortality as the secondary endpoint. The incidence of HA was 40/1011 = 4%, with the majority of events (60%) being lethal. Independent risk factors of HA using the multivariate logistic model were previous coronary artery bypass surgery, presence of mitral regurgitation, left ventricular ejection fraction and the intraoperative cross-clamp time of aorta. Adjusting for the effect of confounder variables showed that the gradient effect of QRS complex duration on the endpoint HA was still present (p = 0.012). The duration of the QRS complex taken from the preoperative ECG had a gradient effect on the incidence of HA. With a baseline level of QRS <70 ms, the following odds ratios (OR) for HA were found: OR = 1.38 (95% CI 0.60-3.31) for QRS 70-80 ms; OR = 2.27 (95% CI 0.87-5.90) for QRS >90-120 ms; and OR = 3.38 (95% CI 1.06-11.50) for QRS > 120 ms, when adjusting for the risk factors. Cumulative survival at 5 years after surgery was 28+/-7.1% for patients experiencing HA versus 87+/-1.2% for patients free from this event. Our results underline the importance of the QRS complex duration as a preoperative marker for HA after aorta coronary bypass surgery, when adjusting for other risk factors. Although the one-year survival is poor for patients experiencing HA, there is no increase in mortality during the late follow-up.
The International Journal of Artificial Organs, 1988
A study on a cohort of 839 patients with valvular heart replacement between June 1977 and May 198... more A study on a cohort of 839 patients with valvular heart replacement between June 1977 and May 1985 showed that the linearized rates of systemic emboli and thrombotic obstruction were 1.4/100 pts/year for Aortic Valve Replacement (AVR), 2.2/100 pts./year for Mitral Valve Replacement, and 3.00/100 pts./year for Double Valve Replacement (DVR). The 5-year free-from-thromboembolism (TE) survival was 95% for AVR and 92% for MVR. The hazard function (the instantaneous risk) for TE peaked in the first six months after operation for AVR and MVR. Another analysis using the Cox regression model to estimate risk factors of systemic emboli and thrombotic obstruction pinpointed two factors in the AVR group: presence of aortic regurgitation (AR) and age at operation. In the MVR group the sole predictor covariate was sex of the patients, with a higher hazard for females. Our results underline the importance of patient-related factors besides the type of prosthesis as predictors of morbidity from TE.
European Journal of Cardio-Thoracic Surgery, 1996
The long-term results of 1025 patients, 912 men and 113 women, undergoing coronary artery bypass ... more The long-term results of 1025 patients, 912 men and 113 women, undergoing coronary artery bypass grafting (CABG) at the Cardiovascular Unit of Rikshospitalet, Oslo, between 1982 and 1986, were analyzed on factors associated with the return of angina pectoris and of non-fatal post CABG myocardial infarction. The closing date was 1st January 1993, with a mean follow-up time of 7.4 years. Recurrent angina pectoris was experienced by 118 (11.6%) patients and 102 (10%) patients experienced non-fatal post CABG myocardial infarction during the observation period. Altogether 30 possible risk factors were analyzed. The cumulative incidence of recurrent angina was initially low after operation, followed by a rise after 4 years. One, 5 and 10 years after the operation, survival free from angina rates were 97.8%, 91.8% and 80.6%, respectively. The cumulative incidence of post CABG myocardial infarction was also low initially, followed by a rise after 4 years. The survival free of non-fatal post CABG myocadial infarction rate was 98.9%, 96% and 83.5%, at 1, 5 and 10 years after surgery, respectively. The incremental risk factor of recurrent angina pectoris was hypertension. The independent risk factors of non-fatal post CABG myocardial infarction were hypertension and preoperative stenosis of the left-sided, versus rightsided, coronary arteries. The study emphasizes the favorable effect of coronary bypass surgery on the functional outcome in patients with symptomatic coronary artery disease.
European Heart Journal, 1996
Objective To study the pre-operative level of left ventricular ejection fraction that may be indi... more Objective To study the pre-operative level of left ventricular ejection fraction that may be indicative of an increased risk of early and late mortality and of recurrent angina pectoris and late non-fatal myocardial infarction. Material and methods A total of 934 patients with known left ventricular ejection fraction, 80 women and 854 men, were submitted to coronary artery bypass grafting at the Cardiovascular Unit of Rikshospitalet, Oslo, between August 1982 and December 1986. The closing date was the 1st of January 1993, with a mean follow-up of time of 7-4 years. The patients were divided in to four subgroups according to their level of left ventricular ejection fraction: 40%, 41-60%, 61-80% and >80%. The left ventricular ejection fraction varied from 13-98%. A chi-square test of linear trend was used to calculate the relative risk between the different subgroups. Cumulative survival was determined using survival curves. Conclusion When the left ventricular ejection fraction was 40% or lower, there was a substantial increase in the risk of early mortality in patients submitted to coronary artery bypass grafting. As for the risk of late mortality, there was a practically linear increase in risk with falling values of left ventricular ejection fraction. We found no difference in risk of developing recurrent angina pectoris or of late non-fatal myocardial infarction related to values of left ventricular ejection fraction.
Cardiovascular Surgery, 1995
A total of IOZS patients who had coronary bypass surgery at the Surgical Department A, Rikshospit... more A total of IOZS patients who had coronary bypass surgery at the Surgical Department A, Rikshospitalet, Oslo. between 1982 and 1966, were analysed for factors associated with early mortality and long-term survival. The cumulative follow-up time accounted for 6553 patient-years: the median follow-up was 6.45 years and ranged from the day of admission to IO years. In total, 31 patients (3%) died within 30 days of surgery. Some 30 possible risk factors were analysed. Univariate analysis followed by a multiiariate analysis defined six independent risk factors for early mortality. These were lack of sinus rhythm, previous heart surgery, mitral regurgitation, left main stem stenosis, unstable angina, and an elevated left ventricular end-diastolic pressure. Estimation of attributable risk showed that these factors could identify all patients who died early. Independent risk factors for late death were: lack of sinus rhythm, resection of a left ventricular aneurysm, left main stem stenosis, New York Heart Association (NYHA) class N on admission, an elevated end-diastolic pressure, and prolonged cross-ciamping time. The attributable risk analysis showed that independent risk factors for total mortaiii explained only about half of the patients who died. This appeared to be because of the competing effect of non-cardiac mortality. Results of the study show that risk factors for early mortality are good indicators for the outcome of coronary artery bypass surgery, identif+jng all deaths, whereas long-term mortality cannot be predii. Stratlfkation of independent risk factors allows a better comparison of mortality in different centres, and also better qualii control of bypass surgery.
European Journal of Cardio-Thoracic Surgery, 1997
Objecti6e: We wished to analyse early mortality, postoperative low-output syndrome needing intra-... more Objecti6e: We wished to analyse early mortality, postoperative low-output syndrome needing intra-aortic balloon pumping support (IABP), total mortality, recurrent angina pectoris and total non-fatal myocardial infarction in women compared with men. Also, the standard mortality ratio (SMR) was estimated to compare the mortality data to the general Norwegian population of comparable sex and age. Methods: A total of 1025 patients; 113 women and 912 men, were submitted to coronary artery bypass surgery at Rikshospitalet, Oslo between August 1982 and December 1986. The patients were followed up until the 1st of January 1993, representing a mean follow-up time of 7.4 years. An exposed/non-exposed cohort study design was used. A power study was carried out. The standardized mortality ratios for women and men were calculated after adjusting for age and sex. Results: Crude odds ratio (OR C) of early mortality was 2.0 with a 95% confidence limit (CL 95%) of 0.7-5.4. Odds ratio of low output syndrome needing intra-aortic balloon support was 1.7 (CL 95% = 0.8-4.2). Statistical significance was not achieved for these end-points. Women did not run an increased hazard of total mortality (OR C = 0.9; CL 95% = 0.5-1.5), recurrent angina pectoris (OR C =1.4; CL 95% =0.8-2.4) or of total non-fatal myocardial infarction (OR C = 0.8; CL 95% = 0.4-1.6) when compared with men. Adjusting for confounders did not significantly alter the results. When matched on sex and age and compared to the normal Norwegian population, we found an increased SMR in both men (2.5; CL 95% = 2.2-2.9) and women (4.1; CL 95% = 2.2-4.9). Conclusion: The risk of early mortality and low-output syndrome needing intra-aortic balloon support tended to be higher in women compared with men. Women did not run an increased risk of total mortality, recurrent angina or of total non-fatal myocardial infarction. The standard mortality ratio was increased in both men and women, but in particular higher in women, suggesting a more aggressive course of coronary artery disease in operated women than in operated men. However, this difference did not show in the long term follow-up, due to the beneficial effect of coronary artery bypass surgery in both men and women.
Critical Care, 2001
Introduction: Coronary artery bypass grafting is the gold standard for myocardial revascularizati... more Introduction: Coronary artery bypass grafting is the gold standard for myocardial revascularization. Coronary revasculariza-tion with the heart beating avoids cardiopulmonary bypass and its complications, but requires active participation by the
Tidsskrift for Den norske legeforening, Nov 30, 1998
A total of 113 women and 912 men were submitted to coronary artery bypass surgery at Surgical Dep... more A total of 113 women and 912 men were submitted to coronary artery bypass surgery at Surgical Department A, Rikshospitalet between August 1982 and December 1986 and followed till January 1993. We found no difference in early mortality, recurrent angina pectoris or non-fatal myocardial infarction in diabetic patients compared to nondiabetic patients. However, total mortality was 1.87 times higher in the diabetic group. For patients with ejection fraction < or = 40%, early mortality was 10.2 times higher than for the reference group. For total mortality we found a practically linear relationship between increased mortality and falling ejection fraction values. We found no relationship between ejection fraction and recurrent angina and non-fatal myocardial infarction, neither did we find any difference in mortality and morbidity between women and men. Although a somewhat higher mortality and morbidity rate must be expected for high-risk patients, they seem to profit to the same exte...
Tidsskrift for Den norske legeforening, Oct 20, 1998
This cohort study includes 1,025 patients operated between 1982 and 1986 at Rikshospitalet, the N... more This cohort study includes 1,025 patients operated between 1982 and 1986 at Rikshospitalet, the National Hospital of Norway, 912 men and 113 women. The closing date was 1 January 1993. A total of 31 patients (3%) died within 30 days of operation. Independent risk factors were atrial fibrillation, previous heart surgery, mitral insufficiency, left main stem stenosis, unstable angina pectoris and elevated end-diastolic pressure. Among the 164 patients (16%) who died more than 30 days after operation, the independent risk factors of total mortality were atrial fibrillation, concomitant resection of left ventricular aneurysm, left main stem stenosis, NYHA functional class IV on admission, elevated end-diastolic pressure and prolonged cross-clamping time. Recurrent angina pectoris was experienced by 146 patients (14.2%) while 102 patients had non-fatal myocardial infarction. The cumulative incidence of these conditions was initially low, but began to increase four year after operation. T...
Tidsskrift for den Norske laegeforening : tidsskrift for praktisk medicin, ny raekke, 1998
This cohort study includes 1,025 patients operated between 1982 and 1986 at Rikshospitalet, the N... more This cohort study includes 1,025 patients operated between 1982 and 1986 at Rikshospitalet, the National Hospital of Norway, 912 men and 113 women. The closing date was 1 January 1993. A total of 31 patients (3%) died within 30 days of operation. Independent risk factors were atrial fibrillation, previous heart surgery, mitral insufficiency, left main stem stenosis, unstable angina pectoris and elevated end-diastolic pressure. Among the 164 patients (16%) who died more than 30 days after operation, the independent risk factors of total mortality were atrial fibrillation, concomitant resection of left ventricular aneurysm, left main stem stenosis, NYHA functional class IV on admission, elevated end-diastolic pressure and prolonged cross-clamping time. Recurrent angina pectoris was experienced by 146 patients (14.2%) while 102 patients had non-fatal myocardial infarction. The cumulative incidence of these conditions was initially low, but began to increase four year after operation. T...
A total of 113 women and 912 men were submitted to coronary artery bypass surgery at Surgical Dep... more A total of 113 women and 912 men were submitted to coronary artery bypass surgery at Surgical Department A, Rikshospitalet between August 1982 and December 1986 and followed till January 1993. We found no difference in early mortality, recurrent angina pectoris or non-fatal myocardial infarction in diabetic patients compared to nondiabetic patients. However, total mortality was 1.87 times higher in the diabetic group. For patients with ejection fraction < or = 40%, early mortality was 10.2 times higher than for the reference group. For total mortality we found a practically linear relationship between increased mortality and falling ejection fraction values. We found no relationship between ejection fraction and recurrent angina and non-fatal myocardial infarction, neither did we find any difference in mortality and morbidity between women and men. Although a somewhat higher mortality and morbidity rate must be expected for high-risk patients, they seem to profit to the same exte...
Tidsskrift for den Norske lægeforening : tidsskrift for praktisk medicin, ny række, Jan 30, 1998
A total of 113 women and 912 men were submitted to coronary artery bypass surgery at Surgical Dep... more A total of 113 women and 912 men were submitted to coronary artery bypass surgery at Surgical Department A, Rikshospitalet between August 1982 and December 1986 and followed till January 1993. We found no difference in early mortality, recurrent angina pectoris or non-fatal myocardial infarction in diabetic patients compared to nondiabetic patients. However, total mortality was 1.87 times higher in the diabetic group. For patients with ejection fraction < or = 40%, early mortality was 10.2 times higher than for the reference group. For total mortality we found a practically linear relationship between increased mortality and falling ejection fraction values. We found no relationship between ejection fraction and recurrent angina and non-fatal myocardial infarction, neither did we find any difference in mortality and morbidity between women and men. Although a somewhat higher mortality and morbidity rate must be expected for high-risk patients, they seem to profit to the same exte...
Tidsskrift for den Norske lægeforening : tidsskrift for praktisk medicin, ny række, Jan 20, 1998
This cohort study includes 1,025 patients operated between 1982 and 1986 at Rikshospitalet, the N... more This cohort study includes 1,025 patients operated between 1982 and 1986 at Rikshospitalet, the National Hospital of Norway, 912 men and 113 women. The closing date was 1 January 1993. A total of 31 patients (3%) died within 30 days of operation. Independent risk factors were atrial fibrillation, previous heart surgery, mitral insufficiency, left main stem stenosis, unstable angina pectoris and elevated end-diastolic pressure. Among the 164 patients (16%) who died more than 30 days after operation, the independent risk factors of total mortality were atrial fibrillation, concomitant resection of left ventricular aneurysm, left main stem stenosis, NYHA functional class IV on admission, elevated end-diastolic pressure and prolonged cross-clamping time. Recurrent angina pectoris was experienced by 146 patients (14.2%) while 102 patients had non-fatal myocardial infarction. The cumulative incidence of these conditions was initially low, but began to increase four year after operation. T...
Cardiovascular Surgery
A total of 1025 patients who had coronary bypass surgery at the Surgical Department A, Rikshospit... more A total of 1025 patients who had coronary bypass surgery at the Surgical Department A, Rikshospitalet, Oslo, between 1982 and 1986, were analysed for factors associated with early mortality and long-term survival. The cumulative follow-up time accounted for 6553 patient-years; the median follow-up was 6.45 years and ranged from the day of admission to 10 years. In total, 31 patients (3%) died within 30 days of surgery. Some 30 possible risk factors were analysed. Univariate analysis followed by a multivariate analysis defined six independent risk factors for early mortality. These were lack of sinus rhythm, previous heart surgery, mitral regurgitation, left main stem stenosis, unstable angina, and an elevated left ventricular end-diastolic pressure. Estimation of attributable risk showed that these factors could identify all patients who died early. Independent risk factors for late death were: lack of sinus rhythm, resection of a left ventricular aneurysm, left main stem stenosis, New York Heart Association (NYHA) class IV on admission, an elevated end-diastolic pressure, and prolonged cross-clamping time. The attributable risk analysis showed that independent risk factors for total mortality explained only about half of the patients who died. This appeared to be because of the competing effect of non-cardiac mortality. Results of the study show that risk factors for early mortality are good indicators for the outcome of coronary artery bypass surgery, identifying all deaths, whereas long-term mortality cannot be predicted. Stratification of independent risk factors allows a better comparison of mortality in different centres, and also better quality control of bypass surgery.
Scandinavian Cardiovascular Journal, 2000
Sudden heart arrest (HA) in the early phase after aorto coronary bypass surgery represents a seri... more Sudden heart arrest (HA) in the early phase after aorto coronary bypass surgery represents a serious event necessitating resuscitation, and for those who survive usually also an extra stay in the coronary care unit. Since such episodes of heart standstill may be related to conduction defects, a study was conducted to determine whether the duration of the QRS complex on the preoperative ECG is a marker for this morbid event. A cohort of 1011 consecutive patients operated on between 1982 and 1986 and followed to January 1st, 1993 were included in the study. Incidence of lethal or non-lethal HA during the first 4 weeks after surgery was considered as the primary endpoint and total mortality as the secondary endpoint. The incidence of HA was 40/1011 = 4%, with the majority of events (60%) being lethal. Independent risk factors of HA using the multivariate logistic model were previous coronary artery bypass surgery, presence of mitral regurgitation, left ventricular ejection fraction and the intraoperative cross-clamp time of aorta. Adjusting for the effect of confounder variables showed that the gradient effect of QRS complex duration on the endpoint HA was still present (p = 0.012). The duration of the QRS complex taken from the preoperative ECG had a gradient effect on the incidence of HA. With a baseline level of QRS <70 ms, the following odds ratios (OR) for HA were found: OR = 1.38 (95% CI 0.60-3.31) for QRS 70-80 ms; OR = 2.27 (95% CI 0.87-5.90) for QRS >90-120 ms; and OR = 3.38 (95% CI 1.06-11.50) for QRS > 120 ms, when adjusting for the risk factors. Cumulative survival at 5 years after surgery was 28+/-7.1% for patients experiencing HA versus 87+/-1.2% for patients free from this event. Our results underline the importance of the QRS complex duration as a preoperative marker for HA after aorta coronary bypass surgery, when adjusting for other risk factors. Although the one-year survival is poor for patients experiencing HA, there is no increase in mortality during the late follow-up.
Tidsskrift for Den norske legeforening
This cohort study includes 1,025 patients operated between 1982 and 1986 at Rikshospitalet, the N... more This cohort study includes 1,025 patients operated between 1982 and 1986 at Rikshospitalet, the National Hospital of Norway, 912 men and 113 women. The closing date was 1 January 1993. A total of 31 patients (3%) died within 30 days of operation. Independent risk factors were atrial fibrillation, previous heart surgery, mitral insufficiency, left main stem stenosis, unstable angina pectoris and elevated end-diastolic pressure. Among the 164 patients (16%) who died more than 30 days after operation, the independent risk factors of total mortality were atrial fibrillation, concomitant resection of left ventricular aneurysm, left main stem stenosis, NYHA functional class IV on admission, elevated end-diastolic pressure and prolonged cross-clamping time. Recurrent angina pectoris was experienced by 146 patients (14.2%) while 102 patients had non-fatal myocardial infarction. The cumulative incidence of these conditions was initially low, but began to increase four year after operation. T...
European Journal of Cardio-Thoracic Surgery, 1996
The long-term results of 1025 patients, 912 men and 113 women, undergoing coronary artery bypass ... more The long-term results of 1025 patients, 912 men and 113 women, undergoing coronary artery bypass grafting (CABG) at the Cardiovascular Unit of Rikshospitalet, Oslo, between 1982 and 1986, were analyzed on factors associated with the return of angina pectoris and of non-fatal post CABG myocardial infarction. The closing date was 1st January 1993, with a mean follow-up time of 7.4 years. Recurrent angina pectoris was experienced by 118 (11.6%) patients and 102 (10%) patients experienced non-fatal post CABG myocardial infarction during the observation period. Altogether 30 possible risk factors were analyzed. The cumulative incidence of recurrent angina was initially low after operation, followed by a rise after 4 years. One, 5 and 10 years after the operation, survival free from angina rates were 97.8%, 91.8% and 80.6%, respectively. The cumulative inci-dence of post CABG myocardial infarction was also low initially, followed by a rise after 4 years. The survival free of non-fatal post CABG myocadial infarction rate was 98.9%, 96% and 83.5%, at 1, 5 and 10 years after surgery, respectively. The incremental risk factor of recurrent angina pectoris was hypertension. The independent risk factors of non-fatal post CABG myocardial infarction were hypertension and preoperative stenosis of the left-sided, versus rightsided, coronary arteries. The study emphasizes the favorable effect of coronary bypass surgery on the functional outcome in patients with symptomatic coronary artery disease. [Eur J Cardio-thorac Surg (1996) 10:173-178]
Scandinavian Cardiovascular Journal, 2000
Sudden heart arrest (HA) in the early phase after aorto coronary bypass surgery represents a seri... more Sudden heart arrest (HA) in the early phase after aorto coronary bypass surgery represents a serious event necessitating resuscitation, and for those who survive usually also an extra stay in the coronary care unit. Since such episodes of heart standstill may be related to conduction defects, a study was conducted to determine whether the duration of the QRS complex on the preoperative ECG is a marker for this morbid event. A cohort of 1011 consecutive patients operated on between 1982 and 1986 and followed to January 1st, 1993 were included in the study. Incidence of lethal or non-lethal HA during the first 4 weeks after surgery was considered as the primary endpoint and total mortality as the secondary endpoint. The incidence of HA was 40/1011 = 4%, with the majority of events (60%) being lethal. Independent risk factors of HA using the multivariate logistic model were previous coronary artery bypass surgery, presence of mitral regurgitation, left ventricular ejection fraction and the intraoperative cross-clamp time of aorta. Adjusting for the effect of confounder variables showed that the gradient effect of QRS complex duration on the endpoint HA was still present (p = 0.012). The duration of the QRS complex taken from the preoperative ECG had a gradient effect on the incidence of HA. With a baseline level of QRS <70 ms, the following odds ratios (OR) for HA were found: OR = 1.38 (95% CI 0.60-3.31) for QRS 70-80 ms; OR = 2.27 (95% CI 0.87-5.90) for QRS >90-120 ms; and OR = 3.38 (95% CI 1.06-11.50) for QRS > 120 ms, when adjusting for the risk factors. Cumulative survival at 5 years after surgery was 28+/-7.1% for patients experiencing HA versus 87+/-1.2% for patients free from this event. Our results underline the importance of the QRS complex duration as a preoperative marker for HA after aorta coronary bypass surgery, when adjusting for other risk factors. Although the one-year survival is poor for patients experiencing HA, there is no increase in mortality during the late follow-up.
The International Journal of Artificial Organs, 1988
A study on a cohort of 839 patients with valvular heart replacement between June 1977 and May 198... more A study on a cohort of 839 patients with valvular heart replacement between June 1977 and May 1985 showed that the linearized rates of systemic emboli and thrombotic obstruction were 1.4/100 pts/year for Aortic Valve Replacement (AVR), 2.2/100 pts./year for Mitral Valve Replacement, and 3.00/100 pts./year for Double Valve Replacement (DVR). The 5-year free-from-thromboembolism (TE) survival was 95% for AVR and 92% for MVR. The hazard function (the instantaneous risk) for TE peaked in the first six months after operation for AVR and MVR. Another analysis using the Cox regression model to estimate risk factors of systemic emboli and thrombotic obstruction pinpointed two factors in the AVR group: presence of aortic regurgitation (AR) and age at operation. In the MVR group the sole predictor covariate was sex of the patients, with a higher hazard for females. Our results underline the importance of patient-related factors besides the type of prosthesis as predictors of morbidity from TE.
European Journal of Cardio-Thoracic Surgery, 1996
The long-term results of 1025 patients, 912 men and 113 women, undergoing coronary artery bypass ... more The long-term results of 1025 patients, 912 men and 113 women, undergoing coronary artery bypass grafting (CABG) at the Cardiovascular Unit of Rikshospitalet, Oslo, between 1982 and 1986, were analyzed on factors associated with the return of angina pectoris and of non-fatal post CABG myocardial infarction. The closing date was 1st January 1993, with a mean follow-up time of 7.4 years. Recurrent angina pectoris was experienced by 118 (11.6%) patients and 102 (10%) patients experienced non-fatal post CABG myocardial infarction during the observation period. Altogether 30 possible risk factors were analyzed. The cumulative incidence of recurrent angina was initially low after operation, followed by a rise after 4 years. One, 5 and 10 years after the operation, survival free from angina rates were 97.8%, 91.8% and 80.6%, respectively. The cumulative incidence of post CABG myocardial infarction was also low initially, followed by a rise after 4 years. The survival free of non-fatal post CABG myocadial infarction rate was 98.9%, 96% and 83.5%, at 1, 5 and 10 years after surgery, respectively. The incremental risk factor of recurrent angina pectoris was hypertension. The independent risk factors of non-fatal post CABG myocardial infarction were hypertension and preoperative stenosis of the left-sided, versus rightsided, coronary arteries. The study emphasizes the favorable effect of coronary bypass surgery on the functional outcome in patients with symptomatic coronary artery disease.
European Heart Journal, 1996
Objective To study the pre-operative level of left ventricular ejection fraction that may be indi... more Objective To study the pre-operative level of left ventricular ejection fraction that may be indicative of an increased risk of early and late mortality and of recurrent angina pectoris and late non-fatal myocardial infarction. Material and methods A total of 934 patients with known left ventricular ejection fraction, 80 women and 854 men, were submitted to coronary artery bypass grafting at the Cardiovascular Unit of Rikshospitalet, Oslo, between August 1982 and December 1986. The closing date was the 1st of January 1993, with a mean follow-up of time of 7-4 years. The patients were divided in to four subgroups according to their level of left ventricular ejection fraction: 40%, 41-60%, 61-80% and >80%. The left ventricular ejection fraction varied from 13-98%. A chi-square test of linear trend was used to calculate the relative risk between the different subgroups. Cumulative survival was determined using survival curves. Conclusion When the left ventricular ejection fraction was 40% or lower, there was a substantial increase in the risk of early mortality in patients submitted to coronary artery bypass grafting. As for the risk of late mortality, there was a practically linear increase in risk with falling values of left ventricular ejection fraction. We found no difference in risk of developing recurrent angina pectoris or of late non-fatal myocardial infarction related to values of left ventricular ejection fraction.
Cardiovascular Surgery, 1995
A total of IOZS patients who had coronary bypass surgery at the Surgical Department A, Rikshospit... more A total of IOZS patients who had coronary bypass surgery at the Surgical Department A, Rikshospitalet, Oslo. between 1982 and 1966, were analysed for factors associated with early mortality and long-term survival. The cumulative follow-up time accounted for 6553 patient-years: the median follow-up was 6.45 years and ranged from the day of admission to IO years. In total, 31 patients (3%) died within 30 days of surgery. Some 30 possible risk factors were analysed. Univariate analysis followed by a multiiariate analysis defined six independent risk factors for early mortality. These were lack of sinus rhythm, previous heart surgery, mitral regurgitation, left main stem stenosis, unstable angina, and an elevated left ventricular end-diastolic pressure. Estimation of attributable risk showed that these factors could identify all patients who died early. Independent risk factors for late death were: lack of sinus rhythm, resection of a left ventricular aneurysm, left main stem stenosis, New York Heart Association (NYHA) class N on admission, an elevated end-diastolic pressure, and prolonged cross-ciamping time. The attributable risk analysis showed that independent risk factors for total mortaiii explained only about half of the patients who died. This appeared to be because of the competing effect of non-cardiac mortality. Results of the study show that risk factors for early mortality are good indicators for the outcome of coronary artery bypass surgery, identif+jng all deaths, whereas long-term mortality cannot be predii. Stratlfkation of independent risk factors allows a better comparison of mortality in different centres, and also better qualii control of bypass surgery.
European Journal of Cardio-Thoracic Surgery, 1997
Objecti6e: We wished to analyse early mortality, postoperative low-output syndrome needing intra-... more Objecti6e: We wished to analyse early mortality, postoperative low-output syndrome needing intra-aortic balloon pumping support (IABP), total mortality, recurrent angina pectoris and total non-fatal myocardial infarction in women compared with men. Also, the standard mortality ratio (SMR) was estimated to compare the mortality data to the general Norwegian population of comparable sex and age. Methods: A total of 1025 patients; 113 women and 912 men, were submitted to coronary artery bypass surgery at Rikshospitalet, Oslo between August 1982 and December 1986. The patients were followed up until the 1st of January 1993, representing a mean follow-up time of 7.4 years. An exposed/non-exposed cohort study design was used. A power study was carried out. The standardized mortality ratios for women and men were calculated after adjusting for age and sex. Results: Crude odds ratio (OR C) of early mortality was 2.0 with a 95% confidence limit (CL 95%) of 0.7-5.4. Odds ratio of low output syndrome needing intra-aortic balloon support was 1.7 (CL 95% = 0.8-4.2). Statistical significance was not achieved for these end-points. Women did not run an increased hazard of total mortality (OR C = 0.9; CL 95% = 0.5-1.5), recurrent angina pectoris (OR C =1.4; CL 95% =0.8-2.4) or of total non-fatal myocardial infarction (OR C = 0.8; CL 95% = 0.4-1.6) when compared with men. Adjusting for confounders did not significantly alter the results. When matched on sex and age and compared to the normal Norwegian population, we found an increased SMR in both men (2.5; CL 95% = 2.2-2.9) and women (4.1; CL 95% = 2.2-4.9). Conclusion: The risk of early mortality and low-output syndrome needing intra-aortic balloon support tended to be higher in women compared with men. Women did not run an increased risk of total mortality, recurrent angina or of total non-fatal myocardial infarction. The standard mortality ratio was increased in both men and women, but in particular higher in women, suggesting a more aggressive course of coronary artery disease in operated women than in operated men. However, this difference did not show in the long term follow-up, due to the beneficial effect of coronary artery bypass surgery in both men and women.
Critical Care, 2001
Introduction: Coronary artery bypass grafting is the gold standard for myocardial revascularizati... more Introduction: Coronary artery bypass grafting is the gold standard for myocardial revascularization. Coronary revasculariza-tion with the heart beating avoids cardiopulmonary bypass and its complications, but requires active participation by the
Tidsskrift for Den norske legeforening, Nov 30, 1998
A total of 113 women and 912 men were submitted to coronary artery bypass surgery at Surgical Dep... more A total of 113 women and 912 men were submitted to coronary artery bypass surgery at Surgical Department A, Rikshospitalet between August 1982 and December 1986 and followed till January 1993. We found no difference in early mortality, recurrent angina pectoris or non-fatal myocardial infarction in diabetic patients compared to nondiabetic patients. However, total mortality was 1.87 times higher in the diabetic group. For patients with ejection fraction < or = 40%, early mortality was 10.2 times higher than for the reference group. For total mortality we found a practically linear relationship between increased mortality and falling ejection fraction values. We found no relationship between ejection fraction and recurrent angina and non-fatal myocardial infarction, neither did we find any difference in mortality and morbidity between women and men. Although a somewhat higher mortality and morbidity rate must be expected for high-risk patients, they seem to profit to the same exte...
Tidsskrift for Den norske legeforening, Oct 20, 1998
This cohort study includes 1,025 patients operated between 1982 and 1986 at Rikshospitalet, the N... more This cohort study includes 1,025 patients operated between 1982 and 1986 at Rikshospitalet, the National Hospital of Norway, 912 men and 113 women. The closing date was 1 January 1993. A total of 31 patients (3%) died within 30 days of operation. Independent risk factors were atrial fibrillation, previous heart surgery, mitral insufficiency, left main stem stenosis, unstable angina pectoris and elevated end-diastolic pressure. Among the 164 patients (16%) who died more than 30 days after operation, the independent risk factors of total mortality were atrial fibrillation, concomitant resection of left ventricular aneurysm, left main stem stenosis, NYHA functional class IV on admission, elevated end-diastolic pressure and prolonged cross-clamping time. Recurrent angina pectoris was experienced by 146 patients (14.2%) while 102 patients had non-fatal myocardial infarction. The cumulative incidence of these conditions was initially low, but began to increase four year after operation. T...
Tidsskrift for den Norske laegeforening : tidsskrift for praktisk medicin, ny raekke, 1998
This cohort study includes 1,025 patients operated between 1982 and 1986 at Rikshospitalet, the N... more This cohort study includes 1,025 patients operated between 1982 and 1986 at Rikshospitalet, the National Hospital of Norway, 912 men and 113 women. The closing date was 1 January 1993. A total of 31 patients (3%) died within 30 days of operation. Independent risk factors were atrial fibrillation, previous heart surgery, mitral insufficiency, left main stem stenosis, unstable angina pectoris and elevated end-diastolic pressure. Among the 164 patients (16%) who died more than 30 days after operation, the independent risk factors of total mortality were atrial fibrillation, concomitant resection of left ventricular aneurysm, left main stem stenosis, NYHA functional class IV on admission, elevated end-diastolic pressure and prolonged cross-clamping time. Recurrent angina pectoris was experienced by 146 patients (14.2%) while 102 patients had non-fatal myocardial infarction. The cumulative incidence of these conditions was initially low, but began to increase four year after operation. T...
A total of 113 women and 912 men were submitted to coronary artery bypass surgery at Surgical Dep... more A total of 113 women and 912 men were submitted to coronary artery bypass surgery at Surgical Department A, Rikshospitalet between August 1982 and December 1986 and followed till January 1993. We found no difference in early mortality, recurrent angina pectoris or non-fatal myocardial infarction in diabetic patients compared to nondiabetic patients. However, total mortality was 1.87 times higher in the diabetic group. For patients with ejection fraction < or = 40%, early mortality was 10.2 times higher than for the reference group. For total mortality we found a practically linear relationship between increased mortality and falling ejection fraction values. We found no relationship between ejection fraction and recurrent angina and non-fatal myocardial infarction, neither did we find any difference in mortality and morbidity between women and men. Although a somewhat higher mortality and morbidity rate must be expected for high-risk patients, they seem to profit to the same exte...
Tidsskrift for den Norske lægeforening : tidsskrift for praktisk medicin, ny række, Jan 30, 1998
A total of 113 women and 912 men were submitted to coronary artery bypass surgery at Surgical Dep... more A total of 113 women and 912 men were submitted to coronary artery bypass surgery at Surgical Department A, Rikshospitalet between August 1982 and December 1986 and followed till January 1993. We found no difference in early mortality, recurrent angina pectoris or non-fatal myocardial infarction in diabetic patients compared to nondiabetic patients. However, total mortality was 1.87 times higher in the diabetic group. For patients with ejection fraction < or = 40%, early mortality was 10.2 times higher than for the reference group. For total mortality we found a practically linear relationship between increased mortality and falling ejection fraction values. We found no relationship between ejection fraction and recurrent angina and non-fatal myocardial infarction, neither did we find any difference in mortality and morbidity between women and men. Although a somewhat higher mortality and morbidity rate must be expected for high-risk patients, they seem to profit to the same exte...
Tidsskrift for den Norske lægeforening : tidsskrift for praktisk medicin, ny række, Jan 20, 1998
This cohort study includes 1,025 patients operated between 1982 and 1986 at Rikshospitalet, the N... more This cohort study includes 1,025 patients operated between 1982 and 1986 at Rikshospitalet, the National Hospital of Norway, 912 men and 113 women. The closing date was 1 January 1993. A total of 31 patients (3%) died within 30 days of operation. Independent risk factors were atrial fibrillation, previous heart surgery, mitral insufficiency, left main stem stenosis, unstable angina pectoris and elevated end-diastolic pressure. Among the 164 patients (16%) who died more than 30 days after operation, the independent risk factors of total mortality were atrial fibrillation, concomitant resection of left ventricular aneurysm, left main stem stenosis, NYHA functional class IV on admission, elevated end-diastolic pressure and prolonged cross-clamping time. Recurrent angina pectoris was experienced by 146 patients (14.2%) while 102 patients had non-fatal myocardial infarction. The cumulative incidence of these conditions was initially low, but began to increase four year after operation. T...
Cardiovascular Surgery
A total of 1025 patients who had coronary bypass surgery at the Surgical Department A, Rikshospit... more A total of 1025 patients who had coronary bypass surgery at the Surgical Department A, Rikshospitalet, Oslo, between 1982 and 1986, were analysed for factors associated with early mortality and long-term survival. The cumulative follow-up time accounted for 6553 patient-years; the median follow-up was 6.45 years and ranged from the day of admission to 10 years. In total, 31 patients (3%) died within 30 days of surgery. Some 30 possible risk factors were analysed. Univariate analysis followed by a multivariate analysis defined six independent risk factors for early mortality. These were lack of sinus rhythm, previous heart surgery, mitral regurgitation, left main stem stenosis, unstable angina, and an elevated left ventricular end-diastolic pressure. Estimation of attributable risk showed that these factors could identify all patients who died early. Independent risk factors for late death were: lack of sinus rhythm, resection of a left ventricular aneurysm, left main stem stenosis, New York Heart Association (NYHA) class IV on admission, an elevated end-diastolic pressure, and prolonged cross-clamping time. The attributable risk analysis showed that independent risk factors for total mortality explained only about half of the patients who died. This appeared to be because of the competing effect of non-cardiac mortality. Results of the study show that risk factors for early mortality are good indicators for the outcome of coronary artery bypass surgery, identifying all deaths, whereas long-term mortality cannot be predicted. Stratification of independent risk factors allows a better comparison of mortality in different centres, and also better quality control of bypass surgery.
Scandinavian Cardiovascular Journal, 2000
Sudden heart arrest (HA) in the early phase after aorto coronary bypass surgery represents a seri... more Sudden heart arrest (HA) in the early phase after aorto coronary bypass surgery represents a serious event necessitating resuscitation, and for those who survive usually also an extra stay in the coronary care unit. Since such episodes of heart standstill may be related to conduction defects, a study was conducted to determine whether the duration of the QRS complex on the preoperative ECG is a marker for this morbid event. A cohort of 1011 consecutive patients operated on between 1982 and 1986 and followed to January 1st, 1993 were included in the study. Incidence of lethal or non-lethal HA during the first 4 weeks after surgery was considered as the primary endpoint and total mortality as the secondary endpoint. The incidence of HA was 40/1011 = 4%, with the majority of events (60%) being lethal. Independent risk factors of HA using the multivariate logistic model were previous coronary artery bypass surgery, presence of mitral regurgitation, left ventricular ejection fraction and the intraoperative cross-clamp time of aorta. Adjusting for the effect of confounder variables showed that the gradient effect of QRS complex duration on the endpoint HA was still present (p = 0.012). The duration of the QRS complex taken from the preoperative ECG had a gradient effect on the incidence of HA. With a baseline level of QRS <70 ms, the following odds ratios (OR) for HA were found: OR = 1.38 (95% CI 0.60-3.31) for QRS 70-80 ms; OR = 2.27 (95% CI 0.87-5.90) for QRS >90-120 ms; and OR = 3.38 (95% CI 1.06-11.50) for QRS > 120 ms, when adjusting for the risk factors. Cumulative survival at 5 years after surgery was 28+/-7.1% for patients experiencing HA versus 87+/-1.2% for patients free from this event. Our results underline the importance of the QRS complex duration as a preoperative marker for HA after aorta coronary bypass surgery, when adjusting for other risk factors. Although the one-year survival is poor for patients experiencing HA, there is no increase in mortality during the late follow-up.
Tidsskrift for Den norske legeforening
This cohort study includes 1,025 patients operated between 1982 and 1986 at Rikshospitalet, the N... more This cohort study includes 1,025 patients operated between 1982 and 1986 at Rikshospitalet, the National Hospital of Norway, 912 men and 113 women. The closing date was 1 January 1993. A total of 31 patients (3%) died within 30 days of operation. Independent risk factors were atrial fibrillation, previous heart surgery, mitral insufficiency, left main stem stenosis, unstable angina pectoris and elevated end-diastolic pressure. Among the 164 patients (16%) who died more than 30 days after operation, the independent risk factors of total mortality were atrial fibrillation, concomitant resection of left ventricular aneurysm, left main stem stenosis, NYHA functional class IV on admission, elevated end-diastolic pressure and prolonged cross-clamping time. Recurrent angina pectoris was experienced by 146 patients (14.2%) while 102 patients had non-fatal myocardial infarction. The cumulative incidence of these conditions was initially low, but began to increase four year after operation. T...
European Journal of Cardio-Thoracic Surgery, 1996
The long-term results of 1025 patients, 912 men and 113 women, undergoing coronary artery bypass ... more The long-term results of 1025 patients, 912 men and 113 women, undergoing coronary artery bypass grafting (CABG) at the Cardiovascular Unit of Rikshospitalet, Oslo, between 1982 and 1986, were analyzed on factors associated with the return of angina pectoris and of non-fatal post CABG myocardial infarction. The closing date was 1st January 1993, with a mean follow-up time of 7.4 years. Recurrent angina pectoris was experienced by 118 (11.6%) patients and 102 (10%) patients experienced non-fatal post CABG myocardial infarction during the observation period. Altogether 30 possible risk factors were analyzed. The cumulative incidence of recurrent angina was initially low after operation, followed by a rise after 4 years. One, 5 and 10 years after the operation, survival free from angina rates were 97.8%, 91.8% and 80.6%, respectively. The cumulative inci-dence of post CABG myocardial infarction was also low initially, followed by a rise after 4 years. The survival free of non-fatal post CABG myocadial infarction rate was 98.9%, 96% and 83.5%, at 1, 5 and 10 years after surgery, respectively. The incremental risk factor of recurrent angina pectoris was hypertension. The independent risk factors of non-fatal post CABG myocardial infarction were hypertension and preoperative stenosis of the left-sided, versus rightsided, coronary arteries. The study emphasizes the favorable effect of coronary bypass surgery on the functional outcome in patients with symptomatic coronary artery disease. [Eur J Cardio-thorac Surg (1996) 10:173-178]