Six-Minute Walk Test Could Help Guide Heart Failure Treatment
Depending on performance, patient response to antiarrhythmic agent or ICD therapy varies
TUESDAY, April 15, 2014 (HealthDay News) -- Distance achieved in the six-minute walk test may be a practical measure of functional capacity that guides selection of therapy for patients with heart failure, according to research published online April 9 in the Journal of the American College of Cardiology.
Daniel P. Fishbein, M.D., of Duke University in Durham, N.C., and colleagues conducted a six-minute walk test in 2,397 patients with heart failure prior to random assignment in the Sudden Cardiac Death in Heart Failure Trial (SCD-HeFT). The researchers assessed the association between the distance on the six-minute walk test and mortality according to treatment selection.
The researchers found that risk of mortality for preventive therapy with an implantable cardioverter defibrillator (ICD) versus placebo according to hazard ratio [HR] for tertiles of distance on the six-minute walk test was 0.42 (95 percent confidence interval [CI], 0.26 to 0.66) for the top tertile, greater than 386 m; 0.57 (95 percent CI, 0.39 to 0.83) for the middle tertile, 288 to 386 m; and 1.02 (95 percent CI, 0.75 to 1.39) for the bottom tertile, less than 288 m. The corresponding HRs for amiodarone therapy versus placebo were 0.68 (95 percent CI, 0.46 to 1.02) for the top tertile, 0.86 (95 percent CI, 0.61 to 1.21) for the middle tertile, and 1.56 (95 percent CI, 1.17 to 2.09) for the bottom tertile of distance on the six-minute walk test. In a secondary analysis of cause-specific mortality, ICD therapy reduced arrhythmic mortality in the top two tertiles of the six-minute walk test but had no effect on heart failure mortality.
"In summary, patients with a six-minute walk distance of less than 288 meters did not derive benefit from either prophylactic implantable cardioverter defibrillator implantation or amiodarone therapy," the authors write.
Several pharmaceutical companies contributed funding to the SCD-HeFT trial.