Comparison of risk scores for the prediction of stroke in African Americans: Findings from the Jackson Heart Study.

BACKGROUND: 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. METHODS: We included all Jackson Heart Study participants with complete scoring information at the baseline study visit (2000-2004) who had no history of stroke (n = 4,140). We used Kaplan-Meier methods to calculate the cumulative incidence of stroke and used Cox models to estimate hazard ratios and 95% CIs for stroke according to CVD risk and CVH score. We compared the discrimination of the 2 models according to the Harrell c index and plotted predicted vs observed stroke risk calibration plots for each of the 2 models. RESULTS: The median age of the African American participants was 54.5 years, and 65% were female. The cumulative incidence of stroke increased across worsening categories of CVD risk and CVH. A 1-unit increase in CVD risk increased the hazard of stroke (1.07, 1.06-1.08), whereas each 1-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] vs 0.79 [0.76-0.83]). CONCLUSIONS: Both scores were associated with incident stroke in a dose-response fashion; however, the CVD risk model was more discriminating than the CVH model. The CVH score may still be preferable for its simplicity in application to broad patient populations and public health efforts.

Depressive Symptoms and Risk of Cardiovascular Events in Blacks: Findings From the Jackson Heart Study.

BACKGROUND: Most studies of depression and cardiovascular risk have been conducted in white populations. We investigated this association in a community-based cohort of blacks. METHODS AND RESULTS: We used data from the Jackson Heart Study to investigate associations of baseline depressive symptoms between 2000 and 2004 with incident stroke and coronary heart disease (CHD) during 10 years. We used Kaplan-Meier estimates and Cox proportional hazards models to assess cardiovascular event risk using 3 exposure variables: any depressive symptoms (Center for Epidemiological Studies Depression score ≥16); none (score <16), minor (score 16 to <21), and major depression (score≥21); and Center for Epidemiological Studies Depression score per 1-SD increase. Models were adjusted for a stroke or CHD risk score and behavioral risk factors. Of 3309 participants with no stroke history, 738 (22.3%) had baseline depressive symptoms. A similar proportion with no previous CHD had baseline depressive symptoms (21.8%). The unadjusted 10-year risk of stroke was similar among participants with any compared with no depressive symptoms (3.7% versus 2.6%; P=0.12). Unadjusted CHD rates were higher among participants with depressive symptoms (5.6% versus 3.6%; P=0.03), and differences persisted after adjustment for clinical and behavioral risk factors but not after adjustment for coping strategies. In adjusted models comparing major versus no depressive symptoms, patients with major depressive symptoms had a 2-fold greater hazard of stroke (hazard ratio, 1.95; 95% confidence interval, 1.02-3.71; P=0.04). In continuous models, a 1-SD increase in Center for Epidemiological Studies Depression score was associated with a 30% increase in adjusted incident stroke risk (P=0.04). Similar associations were observed for incident CHD in models adjusted for clinical and behavioral risk factors, but associations were not significant after adjustment for coping strategies. CONCLUSIONS: In a community-based cohort of blacks, major depressive symptoms were associated with greater risks of incident stroke and CHD after adjustment for clinical and behavioral risk factors.