Development and Validation of Risk Prediction Models for Cardiovascular Events in Black Adults

Abstract

IMPORTANCE Cardiovascular risk assessment is a fundamental component of prevention of cardiovascular disease (CVD). However, commonly used prediction models have been formulated in primarily or exclusively white populations. Whether risk assessment in black adults is dissimilar to that in white adults is uncertain. OBJECTIVES To develop and validate risk prediction models for CVD incidence in black adults, incorporating standard risk factors, biomarkers, and subclinical disease. DESIGN, SETTING, AND PARTICIPANTS The Jackson Heart Study (JHS), a longitudinal community-based study of 5301 black adults in Jackson, Mississippi. Inclusive study dates were the date of a participant’s first visit (September 2000 to March 2004) to December 31, 2011. The median (75th percentile) follow-up was 9.1 (9.7) years. The dates of the analysis were August 2013 to May 2015. Measurements included standard risk factors, including age, sex, body mass index, systolic and diastolic blood pressure, ratio of fasting total cholesterol to high-density lipoprotein cholesterol, estimated glomerular filtration rate, antihypertensive therapy, diabetes mellitus, and smoking; blood biomarkers; and subclinical disease measures, including ankle-brachial index, carotid intimal-medial thickness, and echocardiographic left ventricular hypertrophy and systolic dysfunction. MAIN OUTCOMES AND MEASURES Incident CVD event was defined as the first occurrence of myocardial infarction, coronary heart disease death, congestive heart failure, stroke, incident angina, or intermittent claudication. Model performance was compared with the American College of Cardiology/American Heart Association (ACC/AHA) CVD risk algorithm and the Framingham Risk Score (FHS) refitted to the JHS data and evaluated in the Atherosclerosis Risk in Communities (ARIC) and Multi-Ethnic Study of Atherosclerosis cohorts. RESULTS The study cohort comprised 3689 participants with mean (SD) age at baseline was 53 (11) years, and 64.8% (n = 2390) were female. Over a median of 9.1 years, 270 participants (166 women) experienced a first CVD event. A simple combination of standard CVD risk factors, B-type natriuretic peptide, and ankle-brachial index (model 6) yielded modest improvement over a model without B-type natriuretic peptide and ankle-brachial index (C statistic, 0.79; 95% CI, 0.75–0.83 [relative integrated discrimination improvement, 0.22; 95% CI, 0.15–0.30]). However, the reclassification improvement was not substantially different between model 6 and the ACC/AHA CVD Pooled Cohort risk equations or between model 6 and the FHS. The models discriminated reasonably well in the ARIC and Multi-Ethnic Study of Atherosclerosis data (C statistic range, 0.70–0.77). CONCLUSIONS AND RELEVANCE Our findings using the JHS data in the present study are valuable because they confirm that current FHS and ACC/AHA risk algorithms work well in black individuals and are not easily improved on. A unique risk calculator for black adults may not be necessary.

Increased Proximal Aortic Diameter is Associated With Risk of Cardiovascular Events and All‐Cause Mortality in Blacks The Jackson Heart Study

“…First, around 37% of all the JHS participants were excluded from this study mainly because of missing antihypertensive medication variable and missing echo parameters. Antihypertensive medication use is a significant risk factor for cardiovascular events in this population 29. Therefore, we excluded those participants.…”

Subclinical Atherosclerosis, Statin Eligibility, and Outcomes in African American Individuals

“…Collectively, the findings in our work provide therapeutic context to recent work from Fox and colleagues in JHS. Fox et al demonstrated good calibration and risk discrimination of CVD risk estimates in African Americans using PCE, not significantly improved with biomarker or ancillary imaging 22 . Several key differences between the work from Fox et al and ours merit mention.…”

“…First, we sought to extend prior work in Caucasians 7 by fitting Cox proportional hazards regression models and estimating annualized event rates for incident CVD as a function of statin eligibility by newer ACC/AHA guidelines versus ATP-III. Event rates were calculated per 1000 patient-years of follow-up, analogous to a recently published study 22 . In the subgroup of 1790 individuals with CT imaging, we examined whether the presence of CAC by CT imaging would be associated with CVD risk independent of statin eligibility by newer ACC/AHA guidelines.…”

Using Predicted Cardiovascular Disease Risk in Conjunction With Blood Pressure to Guide Antihypertensive Medication Treatment

“…A number of other risk prediction models have been developed across a variety of study groups (18,22–25). Although the Pooled Cohort risk equations have exhibited good test properties in several studies, the choice of equation to estimate CVD risk in a specific setting relates to validation data showing good discrimination and calibration in the patients of interest (26–29). …”