Abstract P339: Benefits of Achieving Optimal Risk Factor Levels for the Primary Prevention of Cardiovascular Disease in Elderly Men

Abstract

Context: Most cardiovascular disease (CVD) occurs after age 65. The additive benefits of aggressive risk factor management with advancing age are not well established. Objective: Evaluate the relationship between the intensity of control of 4 modifiable risk factors [smoking, non-high density lipoprotein cholesterol (non-HDL-C), blood pressure, and aspirin use] and the risk of CVD in a primary prevention population of men ≥65 years. Methods: The study population was comprised of 4203 U.S. male physicians from the Physicians' Health Study who in 1997 were aged ≥65 years, free of CVD and diabetes, and had lipids available. The primary endpoint was first of any CVD event, defined as cardiovascular death, non-fatal myocardial infarction, angina, coronary revascularization, non-fatal stroke, transient ischemic attack, carotid artery surgery, and other peripheral vascular disease surgery. Age and risk factor adjusted Cox proportional hazard models were adjusted for competing causes of death. Results: Mean age was 73 years and 96% were nonsmokers; 28% experienced a CVD event during the mean 9 year follow-up. Few had optimal levels of all 4 modifiable risk factors (6%): 18% had an untreated non-HDL-C<130 mg/dl; 54% had an untreated blood pressure <140/90 mm Hg; and 51% used aspirin; <1% had none of the 4 risk factors controlled. Compared to when all 4 risk factors were controlled (6%), CVD risk increased by 55% when 3 of 4 risk factors (36%) were controlled (event rate 25%; HR 1.55, 95% CI 1.08-2.22), 75% when 2 of 4 risk factors (44%) were controlled (event rate 28%; HR 1.74, 95% CI 1.22-2.49), and more than doubled when 1 of 4 risk factors (14%) were controlled (event rate 35%; HR 2.29, 95% CI 1.57-3.34); p for trend p=0.0002. The number-needed to control to prevent one CVD event over 9 years ranged from 4 to 11 depending on the number of risk factors controlled. Conclusion: In elderly men, not smoking, control of non-HDL-C and blood pressure, and aspirin use conferred substantial protection against incident CVD events. Nonetheless, the CVD event remained high even in those with well-controlled risk factors ≥65, emphasizing the need for optimal risk factor control throughout adulthood.