Physical Activity, Measured with Implanted Devices, Predicts Patient Outcome in Chronic Heart Failure
Background—Physical activity (PA) predicts cardiovascular mortality in the population at large. Less is known about its prognostic value in chronic heart failure (CHF) patients (pts).
Methods and Results—Data from 836 patients with implanted defibrillators without (ICD) or with cardiac resynchronization therapy (CRT-D) enrolled in the Sensitivity of the InSync Sentry OptiVol feature for the prediction of Heart Failure (SENSE-HF) Study1 and the Diagnostic Outcome Trial in Heart Failure (DOT-HF) were pooled. Devices continuously measured and stored total daily active time (single-axis accelerometer). Early PA (average daily activity over the earliest 30-day study period), was studied as a predictor of time to death or HF related hospital admission (primary endpoint). Data from 781 pts were analyzed (65±10 years, 85% men, left ventricular ejection fraction: 26±7%). Older age, shorter height, ischemic aetiology, peripheral artery disease, atrial fibrillation, diabetes, rales, peripheral oedema, higher New York Heart Association class, lower diastolic blood pressure and no angiotensin II receptor blockers /angiotensin converting enzyme inhibitor use were associated with reduced early PA. The primary endpoint occurred in 135 pts (15±7 months follow-up). In multivariable analysis including baseline variables, early PA predicted death or HF hospitalization, with a 4% reduction in risk for each 10 minutes/day additional activity (hazard ratio, HR=0.96; confidence interval, CI:0.94-0.98; p=0.0002 compared to a model with the same baseline variables but without PA). PA also predicted death (HR=0.93, CI:0.90-0.96, p<0.0001) and HF hospitalization (HR=0.97, CI:0.95-0.99, p=0.011).
Conclusions—Early PA, averaged over a 30-day window early after ICD or CRT-D implant in CHF pts, predicted death or HF hospitalization, as well as mortality and HF hospitalization separately, accounting for baseline HF severity.
- Received May 6, 2013.
- Accepted January 30, 2014.