Department of Medicine, Division of Cardiology, University of Washington, Seattle, Washington.
Department of Statistics, Duke Clinical Research Institute, Duke University, Durham, North Carolina.
J Am Coll Cardiol. 2014 Jun 17;63(23):2560-2568. doi: 10.1016/j.jacc.2014.02.602. Epub 2014 Apr 9.
The purpose of this study was to determine if 6-min walk test data assists in treatment decisions for patients with heart failure.
In the SCD-HeFT (Sudden Cardiac Death in Heart Failure Trial), a pre-specified subgroup analysis showed that patients with New York Heart Association functional class III symptoms did not benefit from implantable cardioverter-defibrillator (ICD) therapy and appeared to be harmed by amiodarone, whereas New York Heart Association functional class II patients obtained significant survival benefit from ICD. We postulated that a more objective measure of functional capacity, such as 6-min walk (6MW) distance, might provide a better tool for selecting these preventive therapies.
A 6MW test was performed before randomization in 2,397 patients. Median follow-up was 45.5 months. All-cause mortality was the primary endpoint, with cause-specific mortality (heart failure, arrhythmic) examined in secondary analyses.
The hazard ratios (HRs) for ICD therapy compared to placebo were estimated within tertiles of baseline 6MW distance: HR: 0.42 (95% confidence interval [CI]: 0.26 to 0.66) for 6MW distance >386 m (top tertile); HR: 0.57 (95% CI: 0.39 to 0.83) for 6MW distance 288 to 386 m (middle tertile); and HR: 1.02 (95% CI: 0.75 to 1.39) for 6MW distance <288 m (bottom tertile). The corresponding HRs for amiodarone compared to placebo were 0.68 (95% CI: 0.46 to 1.02) for the top, 0.86 (95% CI: 0.61 to 1.21) for the middle, and 1.56 (95% CI: 1.17 to 2.09) for the bottom tertile. The 6MW distance was inversely related to heart failure-related mortality but not to arrhythmic mortality. ICD therapy reduced arrhythmic mortality in the top 2 tertiles of 6MW, but had no effect on heart failure mortality.
A baseline 6MW distance <288 m identified a subgroup of SCD-HeFT patients who were harmed by amiodarone therapy and did not benefit from ICD. (Sudden Cardiac Death in Heart Failure Trial [SCD-HeFT]; NCT00000609).
本研究旨在确定 6 分钟步行试验数据是否有助于心力衰竭患者的治疗决策。
在 SCD-HeFT（心力衰竭中的心脏性猝死试验）中，一项预先指定的亚组分析表明，纽约心脏协会功能 III 级症状的患者不能从植入式心脏复律除颤器（ICD）治疗中获益，而且似乎会因胺碘酮而受到损害，而纽约心脏协会功能 II 级患者则从 ICD 中获得显著的生存获益。我们推测，更客观的功能能力测量，如 6 分钟步行（6MW）距离，可能是选择这些预防治疗的更好工具。
在 2397 名患者中进行了随机分组前的 6MW 测试。中位随访时间为 45.5 个月。全因死亡率是主要终点，在次要分析中检查了特定原因死亡率（心力衰竭、心律失常）。
根据基线 6MW 距离的三分位数，估计了与安慰剂相比 ICD 治疗的风险比（HR）：6MW 距离>386m（最高三分位）的 HR：0.42（95%置信区间[CI]：0.26 至 0.66）；6MW 距离 288 至 386m（中间三分位）的 HR：0.57（95%CI：0.39 至 0.83）；6MW 距离<288m（最低三分位）的 HR：1.02（95%CI：0.75 至 1.39）。与安慰剂相比，胺碘酮的相应 HR 分别为最高三分位的 0.68（95%CI：0.46 至 1.02）、中间三分位的 0.86（95%CI：0.61 至 1.21）和最低三分位的 1.56（95%CI：1.17 至 2.09）。6MW 距离与心力衰竭相关死亡率呈负相关，但与心律失常死亡率无关。ICD 治疗降低了 6MW 前两个三分位的心律失常死亡率，但对心力衰竭死亡率没有影响。
基线 6MW 距离<288m 确定了 SCD-HeFT 患者亚组，他们因胺碘酮治疗而受到损害，并且不能从 ICD 中获益。（心力衰竭中的心脏性猝死试验[SCD-HeFT]；NCT00000609）。
