Absolute and attributable risks of heart failure incidence in relation to optimal risk factors.

BACKGROUND: Epidemiological studies have shown that a large proportion of coronary heart disease and stroke events are explained by borderline or elevated risk factors and that adults with optimal risk factors greatly avoid these events. The degree to which this applies to heart failure incidence is not well documented.

METHODS AND RESULTS: We categorized baseline (1987-1989) risk factors in the Atherosclerosis Risk in Communities Study cohort (n=13,460, aged 45 to 64 years) into optimal, borderline, and elevated groups based on national guidelines, using a 4-factor score (blood pressure, plasma cholesterol, diabetes, and smoking) and a 5-factor score (which included body mass). Incidence of hospitalized heart failure (n=1344) was identified over a 16-year period. Only 4.9% of the cohort at baseline had all optimal risk factors based on the 4-factor score and 2.6% using the 5-factor score. Compared with participants with any elevated risk factor using the 4-factor score, the age-, sex-, and race-adjusted relative hazard for heart failure events was 0.18 (95% CI, 0.10 to 0.32) for those with all optimal risk factors and 0.35 (95% CI, 0.30 to 0.41) for those with only borderline risk factors. A population-attributable fraction estimate suggested that having at least 1 of the 4 risk factors, elevated or borderline, accounted for 77.1% of heart failure events. For the 5-factor score, that percentage was 88.8%.

CONCLUSIONS: Middle-aged adults with optimal (low) risk factors have low incidence rates of heart failure, which supports redoubled efforts to prevent risk factor development in the first place.