Abstract 13144: Comparison of Risk Scores for the Prediction of Stroke in African Americans: Findings From the Jackson Heart Study

Abstract

Introduction: Evidence from existing cohort studies supports the prediction of incident coronary heart disease and stroke using 10-year cardiovascular disease (CVD) risk scores and the American Heart Association/American Stroke Association’s cardiovascular health (CVH) metric. Hypothesis: The predictive ability would be similar between the two scoring systems for incident stroke among African-American participants of the Jackson Heart Study. Methods: We included all participants with complete scoring information at baseline who had no history of stroke (n=4,140). We used Kaplan-Meier methods to calculate the cumulative incidence of stroke, and estimated hazard ratios and 95% confidence intervals (CI) for stroke according to CVD risk and CVH score. We compared the discrimination of the two models according to the Harrell c-index and predicted versus observed stroke risk calibration plots. Results: The average age of the participants was 54.5 years, and 65% were female. The cumulative incidence of stroke increased across worsening categories of CVD risk and CVH (Figure). A one-unit increase in CVD risk increased the hazard of stroke (1.07, 1.06-1.08), while each one-unit increase in CVH corresponded to a decreased hazard of stroke (0.76, 0.69-0.83). As evidenced by the c-statistics, the CVH model was less discriminating than the CVD risk model 0.59 (0.55-0.64) versus 0.79 (0.76-0.83). However, both models had poor calibration in the uppermost and lowermost deciles of risk. Conclusions: While the CVD risk model was more discriminating than the CVH model, both scores were associated with incident stroke in a dose-response fashion. The CVH score has the advantage of simplicity in application to broad patient populations. However, by including estimates of physical activity and diet, the CVH provides a basis from which to make recommendations on behavior change. Figure. Kaplan-Meier curves for incident stroke by categories of CVD risk (left) and CVH (right).