Use of the 6-Min Walk Distance to Identify聽Variations in Treatment Benefits From聽Implantable Cardioverter-Defibrillator and聽Amiodarone: Results From the SCD-HeFT (Sudden Cardiac Death in聽Heart聽Failure Trial)

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• 作者：Daniel P. Fishbein ; MD^&lowast ; ; ^{dfish@u.washington.edu" class="auth_mail} ; Anne S. Hellkamp ; MS^&dagger ; ; Daniel B. Mark ; MD ; MPH^&Dagger ; ; Mary Norine Walsh ; MD^§ ; ; Jeanne E. Poole ; MD^&lowast ; ; Jill Anderson ; BSN ; RN^鈥?/sup> ; George Johnson ; BSEE^鈥?/sup> ; Kerry L. Lee ; PhD^&dagger ; ; Gust H. Bardy ; MD^&lowast ; ; ^鈥?/sup> ; for the SCD-HeFT Investigators
• 关键词：6-min walk ; amiodarone ; congestive heart failure ; implantable cardioverter-defibrillator ; sudden cardiac death
• 刊名：Journal of the American College of Cardiology
• 出版年：17 June 2014
• 年：2014
• 卷：63
• 期：23
• 页码：2560-2568
• 全文大小：808 K

文摘

The purpose of this study was to determine if 6-min walk test data assists in treatment decisions for patients with heart failure.

Background

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.

Methods

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.

Results

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.

Conclusions

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)