Abstract 20440: Cardiovascular Events in a Physical Activity Intervention as Compared to a Successful Aging Intervention: The LIFE Study Randomized Trial

Abstract

Background: There is little clinical trial evidence that sustained physical activity can prevent cardiovascular disease (CVD) in older adults. The LIFE Study was a multi-center randomized trial comparing sustained, structured physical activity (PA) to health education/successful aging (SA) to prevent mobility disability in older sedentary men and women. Cardiovascular morbidity and mortality was a secondary endpoint. Methods: Eligible participants (N=1635, 67% women, aged 70-89 years) were randomized to PA vs. SA. Eligibility criteria included being sedentary with a score <10/12 on a short physical performance battery (SPPB), indicating higher risk for disability. Prevalent CVD was 30% at baseline. The PA intervention was a structured moderate intensity program, predominantly aerobic (walking), with resistance and flexibility exercises, at least five days weekly, 2x per week on site for 2.6 years on average. The SA intervention consisted of weekly health education sessions for six months, then monthly. CVD was assessed every 6 months, including fatal and non-fatal MI, angina, stroke and transient ischemic attack, peripheral artery disease including abdominal aortic aneurysm and all revascularizations. Hospital records were reviewed and adjudicated for CVD events by committee. Silent MI was assessed by ECG at 18 and 36 months. Results: Incident CVD occurred in 14.4% (n=118/818) of PA and 13.8% (113/817) of SA participants (HR=1.07, 95%CI=0.82-1.38. Using a narrower endpoint of MI, stroke or cardiovascular death, rates were 8.9% in PA and 8.7% in PA groups respectively with HR = 1.04 (95% CI=0.75-1.45). There were no significant differences in rates of incident vs. recurrent CVD. Among participants with SPPB <8, CVD rates were 13.8% in PA vs 17.7% in SA with HR = 0.74 (95%CI=0.51-1.08), compared to 14.8% vs.10.5% (HR = 1.54 (95%CI=1.06-2.24) among those with SPPB of 8 or 9 (p for interaction = 0.007). Conclusions: Among participants in the LIFE Study, an aerobically-based, moderately intensive PA program did not reduce cardiovascular events overall. However, the intervention was more protective in lower functioning participants. Hypotheses to explain differences by functional status could be addressed with continued follow-up.