Geometrical and electrical predictors of cardiac resynchronization therapy response (original) (raw)
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.
Pacing and Clinical Electrophysiology, 2007
To examine the long-term effects of cardiac resynchronization therapy (CRT) in patients presenting with heart failure (HF) and QRS ≤120 ms. Methods: This was a prospective, longitudinal study of 376 patients [mean age = 65 years, mean left ventricular (LV) ejection fraction (EF) = 29%, mean QRS duration =165 ms, mean distance covered during a 6-minute hall walk (6-MHW) = 325 m], who underwent successful implantation of CRT systems. The QRS duration at baseline was ≤120 ms in 45 patients (12%) who were not pre-selected by echocardiographic criteria of dyssynchrony, and >120 ms in the remaining 331 patients. The baseline characteristics of the 2 groups were similar. We evaluated indices of cardiac function, percentage of responders, and survival rates over a mean 28-month follow-up. Results: Both groups experienced similar long-term increases in 6-MHW, and decreases in New York Heart Association functional class and LV end-systolic volume (all comparisons P < 0.0001 in both groups). Time interaction of changes in LVEF and percentage of responders were significantly different (P = 0.03 and P = 0.004, respectively), in favor of the narrow QRS group, where the changes were sustained and persisted at 2 and 3 years. The long-term death rate from HF was lower in the group with narrow than in the group with wide QRS complex (P = 0.04; log-rank test). Conclusions: CRT confers considerable long-term clinical, functional, and survival benefits in patients presenting with HF and narrow QRS, not preselected by echocardiographic criteria of dyssynchrony. Caution is advised before denying CRT to these patients on the basis of QRS width only. (PACE 2007
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.
Revista Portuguesa de Cardiologia (English Edition), 2019
The aim of this study was to document clinical practice in Portugal regarding the use of electronic cardiac devices in patients with heart failure (HF) and reduced left ventricular ejection fraction (LVEF). Methods: The Síncrone study was an observational prospective multicenter registry conducted in 16 centers in Portugal between 2006 and 2014. It included adult patients with a diagnosis of HF, LVEF <35% and indication for implantable cardioverter-defibrillator (ICD) and/or cardiac resynchronization therapy (CRT) devices, according to the recommendations of the European Society of Cardiology at the beginning of the study. Patients were followed for one year according to the practice of each center. Results: A total of 486 patients were included in the registry, half of whom received an ICD and the other half a CRT pacemaker (CRT-P) or CRT defibrillator (CRT-D). Mean age was 65±12 years and the most frequent causes of HF were ischemic (47%) and idiopathic dilated cardiomyopathy (28%). Overall mortality at one year was 3.6% and the hospitalization rate was 11%, significantly higher in patients with CRT-P/CRT-D than with ICD (17% vs. 5.6%, p<0.001). Patients who received CRT-P/CRT-D experienced significant reductions in QRS duration (160±21 vs. 141±24 ms, p<0.001) as well as improvement in New York Heart Association functional class.
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.
Journal of Cardiovascular Translational Research, 2016
Cardiac resynchronization therapy (CRT) is a wellknown treatment modality for patients with a reduced left ventricular ejection fraction accompanied by a ventricular conduction delay. However, a large proportion of patients does not benefit from this therapy. Better patient selection may importantly reduce the number of non-responders. Here, we review the strengths and weaknesses of the electrocardiogram (ECG) markers currently being used in guidelines for patient selection, e.g., QRS duration and morphology. We shed light on the current knowledge on the underlying electrical substrate and the mechanism of action of CRT. Finally, we discuss potentially better ECG-based biomarkers for CRT candidate selection, of which the vectorcardiogram may have high potential. Keywords Electrocardiography. Vectorcardiography. Cardiac mapping. Cardiac resynchronization therapy. Left bundle-branch block Abbreviations LV Left ventricle EF Ejection fraction LBBB Left bundle-branch block CRT Cardiac resynchronization therapy HF Heart failure ECG Electrocardiogram ECGi Electrocardiographic imaging BiV Biventricular Associate Editor Craig Stolen oversaw the review of this article Elien B. Engels and Masih Mafi-Rad contributed equally to this work.