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Background: In the major trials of cardiac resynchronization therapy (CRT), the survival benefit of the therapy, relative to control subjects, increases with QRS duration. In the non-CRT heart failure population, however, a wide QRS duration is associated with a shorter survival. Relative survival benefit from a therapy, however, is not synonymous with a longer absolute survival. We sought to determine whether baseline QRS duration relates to the absolute survival after CRT., Methods and Results: In this prospective, longitudinal, observational study, 3,319 consecutive patients undergoing CRT (QRS 120-149 ms 26%, QRS 150-199 ms 58%, and QRS ≥200 ms 16%) were assessed in relation to mortality over 10 years. Overall mortality rates (per 100 patient-years) were 9.2%, 9.3%, and 13.3% in the 3 groups, respectively (all P < .001). Cardiac mortality rates were 6.2, 6.0, and 9.9 per 100 patient-years, respectively (all P < .001). Compared with the QRS 120-149 ms group, cardiac mortality was highest in the QRS ≥200 ms group (hazard ratio [HR] 1.72 [95% CI 1.35-2.19], P < .001), independent of age, gender, New York Heart Association class, presence of atrial fibrillation, heart failure etiology, and left ventricular ejection fraction. Median survival after CRT was longest in patients with a width of QRS 120-149 ms and shortest in patients with a QRS ≥200 ms (P < .001). In multivariable analyses, a QRS ≥200 ms emerged as a powerful independent predictor of both overall (HR 1.44 [95% CI 1.07-1.94], P = .017) and cardiac mortality (HR 1.59 [95% CI 1.14-2.24], P = .007)., Conclusions: At long-term follow-up, absolute overall and cardiac survival after CRT is similar in patients with a preimplant QRS duration of 120 to 149 ms and 150 to 199 ms but markedly shorter in patients with a QRS ≥200 ms., (© 2014.)

Objectives: The purpose of this study is to determine whether, in patients with atrial fibrillation (AF) undergoing cardiac resynchronization therapy (CRT), atrioventricular junction ablation (AVJA) is associated with a better outcome than treatment with rate-slowing drugs., Background: Different trials have demonstrated that CRT is effective in treating heart failure (HF) patients who are in sinus rhythm (SR). No trials have addressed whether CRT confers similar benefits on AF patients, with or without AVJA., Methods: The clinical outcomes of CRT for patients with permanent AF undergoing CRT combined with either AVJA (n = 443) or rate-slowing drugs (n = 895) were compared with those of SR patients (n = 6,046)., Results: Median follow-up was 37 months. Total mortality (6.8 vs. 6.1 per 100 person-years) and cardiac mortality (4.2 vs. 4.0) were similar for patients with AF+AVJA and patients in SR (both p = NS). In contrast, the AF+drugs group had a higher total and cardiac mortality than the SR group and the AF+AVJA group (11.3 and 8.1, respectively; p < 0.001). On multivariable analysis, AF+AVJA had total mortality (hazard ratio [HR]: 0.93, 95% confidence interval [CI]: 0.74 to 1.67) and cardiac mortality (HR: 0.88, 95% CI: 0.66 to 1.17) similar to that of the SR group, independent of known confounders. The AF+drugs group, however, had a higher total mortality (HR: 1.52, 95% CI: 1.26 to 1.82) and cardiac mortality (HR: 1.57, 95% CI: 1.27 to 1.94) than both the SR group and the AF+AVJA group (both p < 0.001)., Conclusions: Long-term survival after CRT among patients with AF+AVJA is similar to that observed among patients in SR. Mortality is higher for AF patients treated with rate-slowing drugs., (Copyright © 2013 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Objective: To analyze whether left ventricular dyssynchrony (LVD) at baseline is predictive for long-term outcome in heart failure (CHF) patients with left ventricular (LV) dysfunction and conduction disturbances treated with cardiac resynchronization therapy (CRT)., Methods: In 535 consecutive individuals with CHF scheduled for implantation of a CRT device, LVD was assessed by tissue Doppler imaging (TDI), defined as an electromechanical delay (EMD) difference of ≥40 ms in 2 opposed left ventricular wall regions (septal vs. lateral, anterior vs. inferior). All-cause mortality, heart transplantation, or assist device implantation was defined as combined primary end point. Secondary end points were measures of reverse LV remodeling and of symptomatic improvement., Results: Mean follow-up was 68 ± 36 [range: 4-150] months. LVD at baseline was present in 308 patients (61%). Of these, 24% reached the combined primary endpoint in contrast to 58% of patients without LVD (p < 0.001). Furthermore, patients with LVD showed pronounced improvement of all secondary end point parameters. In our cohort LVD was an independent predictor for outcome (hazard ratio [95% CI]: 0.30 [0.21-0.42], p < 0.001)., Conclusions: LVD at baseline as assessed by TDI is associated with a more pronounced clinical improvement and is a predictor for transplant-free long-term survival in CRT recipients., (© 2013.)

Background: Until now, there is no consensus regarding the definition of a clinical response to cardiac resynchronization therapy (CRT) in patients with chronic heart failure (CHF) and systolic left ventricular (LV) dysfunction. The aim of this study was to evaluate if echocardiography is predictive for an objective improvement in exercise capacity during long-term follow-up of CRT., Methods: Each patient underwent echocardiography and spiroergometry both at baseline and at last follow-up. Left ventricular dyssynchrony (LVD) before CRT was defined by tissue Doppler imaging (TDI) as intra-LV delay ≥40 msec (septal-lateral or anterior-posterior). Clinical response to CRT was defined as increase of peakVO2 or as increase of maximal workload >10% as compared to baseline., Results: Mean follow-up was 69 ± 37 months. From the 238 consecutive patients included in the study, 141 (59%) were classified as clinical responders and 97 (41%) as nonresponders. Baseline data of responders and nonresponders were comparable. However, clinical responders showed more often LVD (64%) than nonresponders (42%, P = 0.004). On multivariate regression analysis, nonischemic origin of CHF (β-coefficient in the final model 0.1, P = 0.04) and LVD at baseline (β-coefficient in the final model 0.2, P < 0.001) were independently associated with clinical response during long-term follow-up. Patients with LVD at baseline had significant more often an improvement of left ventricular ejection fraction >10% (P = 0.02) and a reduction of left ventricular end-diastolic diameter (LVEDD) >10% (P < 0.01) than patients without LVD at baseline., Conclusions: LVD at baseline as assessed by a straightforward echocardiographic approach predicts the long-term clinical response to CRT and is associated with a more pronounced reverse LV remodeling., (© 2013, Wiley Periodicals, Inc.)

We sought to determine whether correction of mechanical left ventricular (LV) dyssynchrony as defined by tissue Doppler imaging (TDI) is predictive for transplant-free long-term survival in patients (pts.) undergoing cardiac resynchronization therapy (CRT). In 76 CRT recipients TDI curves from the septal, lateral, anterior, and inferior basal LV were obtained at baseline and after 6 ± 4 months. A time difference between regional electromechanical delays (EMD) of ≥40 ms was considered dyssynchronous. At follow-up, pts. were classified as TDI-responders (TDI-R: dyssynchrony at baseline, corrected by CRT) versus non-responders (TDI-NR: either not dyssynchronous at baseline, or persisting dyssynchrony). Pts. were then followed by standard echocardiography over 21 ± 6 months and were re-classified as LV remodelers (LV-R: LV volume reduction of >10%) versus non-remodelers (LV-NR). The end-point during clinical long-term follow-up of 65 ± 38 months was all-cause mortality or heart transplantation. 44 out of the 76 pts. (58%) were classified as TDI-R, 32 (42%) as TDI-NR. Significant reverse LV remodeling was observed in 41 (54%) pts., while 35 (46%) did not improve LV size and function. TDI-R was associated with LV-R in 35 pts. (85%; P < 0.001). During long-term follow-up, 38 pts. (50%) reached the end point, 11 (30%) in the TDI-R group, and 27 (70%) in the TDI-NR group (P < 0.0003). Mechanical resynchronization as defined by TDI translates into a significant survival benefit in CRT recipients.