Left Ventricular Reverse Remodeling but Not Clinical Improvement Predicts Long-Term Survival After Cardiac Resynchronization Therapy

Abstract

Background-In patients with severe heart failure and dilated cardiomyopathy, cardiac resynchronization therapy (CRT) improves left ventricular (LV) systolic function associated with LV reverse remodeling and favorable 1-year survival. However, it is unknown whether LV reverse remodeling translates into a better long-term prognosis and what extent of reverse remodeling is clinically relevant, which were investigated in this study. Methods and Results-Patients (nϭ141) with advanced heart failure (meanϮSD age, 64Ϯ11 years; 73% men) who received CRT were followed up for a mean (ϮSD) of 695Ϯ491 days. The extent of reduction in LV end-systolic volume (LVESV) at 3 to 6 months relative to baseline was examined for its predictive value on long-term clinical outcome. The cutoff value for LV reverse remodeling in predicting mortality was derived from the receiver operating characteristic curve. Then the relation between potential predictors of mortality and heart failure hospitalizations were compared by Kaplan-Meier survival analysis, followed by Cox regression analysis. There were 22 (15.6%) deaths, mostly due to heart failure or sudden cardiac death. The receiver operating characteristic curve found that a reduction in LVESV of Ն9.5% had a sensitivity of 70% and specificity of 70% in predicting all-cause mortality and of 87% and 69%, respectively, for cardiovascular mortality. With this cutoff value, there were 87 (61.7%) responders to reverse remodeling. In Kaplan-Meier survival analysis, responders had significantly lower all-cause morality (6.9% versus 30.6%, log-rank 2 ϭ13.26, Pϭ0.0003), cardiovascular mortality (2.3% versus 24.1%, log-rank 2 ϭ17.1, PϽ0.0001), and heart failure events (11.5% versus 33.3%, log-rank 2 ϭ8.71, Pϭ0.0032) than nonresponders. In the Cox regression analysis model, the change in LVESV was the single most important predictor of all-cause (␤ϭ1.048, 95% confidence intervalϭ1.019 to 1.078, Pϭ0.001) and cardiovascular (␤ϭ1.072, 95% confidence intervalϭ1.033 to 1.112, PϽ0.001) mortality. Clinical parameters were unable to predict any outcome event. Conclusions-A reduction in LVESV of 10% signifies clinically relevant reverse remodeling, which is a strong predictor of lower long-term mortality and heart failure events. This study suggests that assessing volumetric changes after an intervention in patients with heart failure provides information predictive of natural history outcomes. (Circulation. 2005;112:1580-1586.)

Optimal site selection and image fusion guidance technology to facilitate cardiac resynchronization therapy

“…Cardiac resynchronization therapy (CRT), by pacing the left (LV) and right (RV) ventricles to re-coordinate cardiac electrical activation and produce a synchronous contraction, has emerged as one of the few effective treatments for HF [2,3]. However, at present 30% of patients fail to respond clinically through improved quality of life, exercise capacity and New York Heart Association (NYHA) functional classification of HF and up to 50% show no beneficial changes in cardiac function [3]. Suboptimal LV lead position is a common culprit when evaluating poor outcomes after CRT [4–7].…”

Cardiac resynchronization therapy outcomes in patients under nonoptimal medical therapy

“…However, on the other hand, CRT promotes LV reverse remodeling and a decrease in LVESV exceeding 15% has been shown to have a clinical impact on mortality and morbidity reduction in asymptomatic or symptomatic patients 25, 26, 27. According to our results, mildly or asymptomatic patients might benefit from CRT in clinical outcomes by exhibiting a reduction in HF hospitalizations or mortality when the standard therapy for HF (ACEI/ARB and/or BB) does not improve LVEF beyond 35%‐40%, independent of HF symptoms.…”

Biventricular pacing in heart failure: right is not wrong!

“…A positive association between each of the above component requirements for successful acute resynchronization and a favorable long-term outcome has been demonstrated in other small and mostly retrospective studies [8][9][10]. In the longer term, the acute salutary effect of CRT on LV dyssynchrony appears to be associated with chronic LV reverse remodeling and improved prognosis [11]. Thus, the mere presence of LV dyssynchrony at baseline may not translate into a benefit of CRT, but rather a constellation of conditions should be met to make the dyssynchrony remediable.…”