Geometrical and electrical predictors of cardiac resynchronization therapy response (original) (raw)
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European Heart Journal, 2005
Aims Cardiac resynchronization therapy (CRT) is an effective treatment for refractory congestive heart failure (CHF). However, up to 30% of patients do not respond to CRT. The aim of this study was to identify clinical and electrocardiographic (ECG) predictors of a positive response to CRT. Methods and results This retrospective study included 139 consecutive patients successfully implanted with a CRT device (mean age, 68+9 years, 113 men). At baseline, 69% of patients were in New York Heart Association (NYHA) functional class III, and 31% in class IV, mean left ventricular ejection fraction was 21 + 6%, and mean QRS duration was 188 + 28 ms. In each patient, left and right ventricular leads were placed to attain the shortest QRS duration during biventricular stimulation. Patients were classified at 6 months as responders to CRT (n ¼ 100) if they were alive, they had not been re-hospitalized for management of CHF, and the NYHA class had decreased by 1 point, and/or peak VO 2 or 6 min hall-walk increased by .10%. All others were classified as non-responders (n ¼ 38; one patient was lost to follow-up). Uni-and multivariate logistic regression analyses were performed to detect a pre-or intra-operative predictor of a positive response to CRT. Among multiple demographic, clinical, and ECG variables, the amount of QRS shortening (DQRS) associated with biventricular stimulation was the only independent predictor of a positive (37 + 23 ms) vs. negative (11 + 23 ms) response to CRT (P , 0.001). Conclusion A positive response to CRT was observed in 73% of patients at 6 months and predicted only by DQRS.
Cardiac-Resynchronization Therapy in Heart Failure with a Narrow QRS Complex
New England Journal of Medicine, 2013
BACKGROUND Cardiac-resynchronization therapy (CRT) reduces morbidity and mortality in chronic systolic heart failure with a wide QRS complex. Mechanical dyssynchrony also occurs in patients with a narrow QRS complex, which suggests the potential usefulness of CRT in such patients. METHODS We conducted a randomized trial involving 115 centers to evaluate the effect of CRT in patients with New York Heart Association class III or IV heart failure, a left ventricular ejection fraction of 35% or less, a QRS duration of less than 130 msec, and echocardiographic evidence of left ventricular dyssynchrony. All patients underwent device implantation and were randomly assigned to have CRT capability turned on or off. The primary efficacy outcome was the composite of death from any cause or first hospitalization for worsening heart failure. RESULTS On March 13, 2013, the study was stopped for futility on the recommendation of the data and safety monitoring board. At study closure, the 809 patients who had undergone randomization had been followed for a mean of 19.4 months. The primary outcome occurred in 116 of 404 patients in the CRT group, as compared with 102 of 405 in the control group (28.7% vs. 25.2%; hazard ratio, 1.20; 95% confidence interval [CI], 0.92 to 1.57; P = 0.15). There were 45 deaths in the CRT group and 26 in the control group (11.1% vs. 6.4%; hazard ratio, 1.81; 95% CI, 1.11 to 2.93; P = 0.02). CONCLUSIONS In patients with systolic heart failure and a QRS duration of less than 130 msec, CRT does not reduce the rate of death or hospitalization for heart failure and may increase mortality. (Funded by Biotronik and GE Healthcare; EchoCRT ClinicalTrials.gov number, NCT00683696.
Predictors of response to cardiac resynchronization therapy in chronic heart failure patients
Egyptian Heart Journal, 2016
Cardiac resynchronization therapy (CRT) is established in the management patients with moderate to severe symptoms due to left ventricular systolic dysfunction who present with signs of electrical dyssynchrony. There is wide variability in the clinical response and improvement in LVEF with CRT. Prediction of response to CRT is an important goal in order to tailor this therapy to patients most apt to derive benefit. Aim: The aim of the study was to assess and identify the best predictors of CRT response. Patients and methods: The study included 170 consecutive heart failure (HF) patients in New York Heart Association (NYHA) functional class III or IV and LVEF 6 35%. Routine device and clinical follow-up, as well as CRT optimization, were performed at baseline and at 3-month intervals. Responders were defined as having an absolute reduction in left ventricular end-systolic diameter >15% and an improvement in LVEF >10%. Results: 170 patients were included [71.1% men; mean age 68.8 ± 9.7 years; 159 patients NYHA class III, 11 patients ambulatory NYHA class IV; 91 patients had non-ischemic cardiomyopathy (ICM)-79 patients had ICM; 55.3% of patients had LBBB; mean QRS duration 145 ± 25 ms; left ventricular ejection fraction 28.38 ± 7.2]. CRT-P was implanted in 65 patients and CRT-D was implanted in 105 patients. CRT response was achieved in 114 patients (67.1%). Mean LVEF improved from 28.38 ± 7.2% to 35.46 ± 9.3% (p = 0.001), mean LV end-diastolic diameter reduced from 67.91 ± 8.7 to 64.95 ± 8.9 mm (p < 0.001), and mean LV end-systolic diameter reduced from 57.02 ± 8.8 to 52.42 ± 9.9 mm (p < 0.001). Responders had significantly wider baseline QRS duration, lower BMI, lower baseline serum creatinine level, smaller baseline RV diastolic dimension and significantly greater tricuspid annular peak systolic excursion (TAPSE) value. In multi-nominal regression analysis to identify the pre-implantation predictors of response, QRS duration >150 ms, non-ICM, TAPSE >15 mm, sinus rhythm, the absence of COPD and the absence of renal disease were the independent predictors of CRT response. We generated a new CRT score to predict responders to CRT. The score consists of maximum 9 points. The CRT response rate has been markedly different according to the CRT score: CRT response rate was 97.5% patients with CRT score >6 vs 40.7% if CRT score <6, p < 0.001. Conclusion: Only some of the commonly
A novel electrocardiographic predictor of clinical response to cardiac resynchronization therapy
Europace, 2013
A wide QRS with left bundle branch block pattern is usually required for cardiac resynchronization therapy (CRT) in patients with dilated cardiomyopathy. However, 30% of patients do not benefit from CRT. We evaluated whether a detailed analysis of QRS complex can improve prediction of CRT success. Methods and results We studied 51 patients (67.3 + 9.5 years, 36 males) with classical indication to CRT. Twelve-lead electrocardiogram (ECG) (50 mm/s, 0.05 mV/mm) was obtained before and 3 months after CRT. The following ECG intervals were measured in leads V1 and V6: (i) total QRS duration; (ii) QRS onset-R wave peak; (iii) R wave peakS wave peak (RS-V1 and RS-V6); (iv) S wave peak-QRS end; and (v) difference between QR in V6 and in V1. Patients were considered as responder when left ventricular ejection fraction (LVEF) increased by ≥5% and New York Heart Association class by ≥1 after 3 months of CRT. Of ECG intervals, only basal RS-V1 was longer in responders (n ¼ 36) compared with non-responders (52.9 + 11.8 vs. 44.0 + 12.6 ms, P ¼ 0.021). Among patients with RS-V1 ≥45 ms 83% responded to CRT vs. 33% of those with RS-V1 , 45 ms (P , 0.001). RS-V1 ≥ 45 ms was independently associated with response to CRT in multivariable analysis (odds ratio 9.8; P ¼ 0.002). A reduction of RS-V1 ≥ 10 ms by CRT also significantly predicted clinical response. RS-V1 shortening correlated with improvement in LVEF (r ¼ 20.45; P , 0.001) and in MS (r ¼ 0.46; P , 0.001). Conclusion Our data point out that RS-V1 interval and its changes with CRT may help to identify patients who are most likely to benefit from CRT.
Echocardiographic Criteria for CRT Patient Selection: Is There Still a Role?
Cardiac resynchronization therapy (CRT) is a relatively new therapeutic option for patients with systolic heart failure (HF) and electrocardiographic evidence of dyssynchrony. However, with current selection guidelines, still a proportion of patients do not respond to this interventional therapy. Several echocardiographic criteria have been proposed to address this issue, but research so far has failed to provide a single and simple measurement with adequate accuracy for CRT candidate selection. While investigation for this subject is still under way, new possible roles of echocardiography in CRT implementation arise, such as assistance in selecting the site of left ventricular (LV) pacing lead and optimizing CRT device programming during follow up visits.