Kiani Jawad, Agarwal Sunil Kumar, Kamireddy Swapna, Adelstein Evan, Saba Samir
Cardiac Electrophysiology Section, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania 15213, USA.
Tex Heart Inst J. 2013;40(3):268-73.
Cardiac resynchronization therapy, when added to optimal medical therapy, increases longevity in symptomatic congestive heart failure patients with left ventricular ejection fractions (LVEF)≤0.35 and QRS durations>120 ms. Cardiac resynchronization therapy is also associated with electrical and mechanical reverse remodeling. We examined whether reverse remodeling predicts increased survival rates in non-trial settings. Recipients of cardiac resynchronization therapy and defibrillators (n=112; 78 men; mean age, 69±11 yr) underwent repeat echocardiography and electrocardiography at least 90 days after device implantation. Forty patients had mechanical responses of at least 0.05 improvement in absolute LVEF; 56 had electrical responses (any narrowing of biventricular-paced QRS duration compared with the electrocardiogram immediately after therapy). During a mean follow-up period of 3.1±1.7 years, 55 patients died. The average death rate per 100 person-years was lower among mechanical responders than nonresponders (9.2% vs 23.9%; P=0.009); the unadjusted hazard ratio was 0.39 (95% confidence interval [CI], 0.19-0.79). In a multivariate model adjusted for age, sex, baseline LVEF, and QRS duration, mechanical responders had 60% better survival than nonresponders (hazard ratio=0.40; 95% CI, 0.21-0.79; P=0.008). No difference in survival was observed in electrical response. In our association of absolute change in LVEF over the observed range with death (using restricted cubic splines), we observed a linear relationship with survival. In patients given cardiac resynchronization therapy, mechanical but not electrical remodeling was associated with better survival rates, suggesting that mechanical remodeling underlies this therapy's mechanism of conferring a survival benefit.
心脏再同步治疗联合最佳药物治疗时，可延长症状性充血性心力衰竭且左心室射血分数（LVEF）≤0.35及QRS时限>120 ms患者的寿命。心脏再同步治疗还与电和机械逆向重构相关。我们研究了在非试验环境中逆向重构是否可预测生存率提高。接受心脏再同步治疗和除颤器治疗的患者（n = 112；78名男性；平均年龄69±11岁）在装置植入后至少90天接受重复超声心动图和心电图检查。40例患者机械反应表现为绝对LVEF至少改善0.05；56例有电学反应（与治疗后即刻心电图相比，双心室起搏QRS时限有任何缩窄）。在平均3.1±1.7年的随访期内，55例患者死亡。机械反应者每100人年的平均死亡率低于无反应者（9.2%对23.9%；P = 0.009）；未校正的风险比为0.39（95%置信区间[CI]，0.19 - 0.79）。在根据年龄、性别、基线LVEF和QRS时限校正的多变量模型中，机械反应者的生存率比无反应者高60%（风险比 = 0.40；95% CI，0.21 - 0.79；P = 0.008）。在电学反应方面未观察到生存率差异。在我们将观察范围内LVEF的绝对变化与死亡关联（使用受限立方样条）时，我们观察到与生存率呈线性关系。在接受心脏再同步治疗的患者中，机械而非电学重构与更高的生存率相关，提示机械重构是该治疗带来生存获益机制的基础。
