Differences in estimates for 10-year risk of cardiovascular disease in Black versus White individuals with identical risk factor profiles using pooled cohort equations: an in silico cohort study

Abstract

Background: Sex-specific and race-specific pooled cohort equations (PCEs) are recommended for estimating the 10-year risk of cardiovascular disease, with an absolute risk of more than 7·5% indicating a clinical decision threshold. We compared differences between Black and White individuals in PCE-estimated absolute cardiovascular disease risk across various plausible risk factor combinations with the aim of evaluating if using the PCE might result in different clinical decisions in Black versus White individuals with identical risk profiles.

Methods: We generated in silico patient risk profiles by combining numerical risk factors (age [5-year intervals], total cholesterol [20-mg/dl intervals], HDL cholesterol [5-mg/dl intervals], systolic blood pressure [10-mm Hg intervals]) and binary risk factors (smoking, diabetes, and antihypertensive treatment). We compared PCE-estimated 10-year cardiovascular disease risk in Black versus White individuals with identical risk profiles. We did similar comparisons using eligible participants in the Framingham Heart Study (FHS) third generation cohort and the National Health and Nutrition Examination Survey (NHANES) 2017-18.

Findings: For our in silico analysis, we evaluated 29 515 risk factor combinations for women and 30 565 for men, after excluding profiles that generated 10-year cardiovascular disease risk estimates below 1% or above 30%. There were 6357 risk profiles associated with 10-year cardiovascular disease risk above 7·5% for Black men but not for White men (median risk difference [RD] 6·25%, range 0·15-22·8; median relative risk [RR] 2·40, range 1·02-12·6). There were 391 profiles with 10-year cardiovascular disease risk above 7·5% for White men but not Black men (median RD 2·68%, range 0·07-16·9%; median RR 1·42, range 1·01-3·57). There were 6543 risk profiles associated with 10-year estimated cardiovascular disease risk above 7·5% for Black women but not for White women (median RD 6·14%, range 0·35-26·8%; median RR 2·29, range 1·05-12·6). There were 318 profiles with 10-year cardiovascular disease risk above 7·5% for White women but not Black women (median RD 3·71%, range 0·22-20·1%; median RR 1·66, range 1·03-5·46). For the population-based samples, we calculated the PCE-based 10-year cardiovascular disease risk for 1272 eligible participants (378 women; median age 48 years [IQR 44-52]; 100% White) in the FHS third generation cohort and 550 participants (223 women [36·8% Black] and 327 men [40·4% Black]; median age 61 years [IQR 52-67]) in the NHANES cohort. The population-based samples showed similar risk differences to that of the in silico analyses.

Interpretation: The PCE might generate substantially divergent cardiovascular disease risk estimates for Black versus White individuals with identical risk profiles, which could introduce race-related variations in clinical recommendations for cardiovascular disease prevention.

Funding: US National Institutes of Health.

Figure 1:. Distributions of risk differences and risk ratios for Black versus White men with divergent risks

(A) Differences in PCE-based 10-year cardiovascular disease risk in men when absolute cardiovascular disease risk exceeds 7·5% in Black but not in White men. (B) Relative risks (Black vs White men) for 10-year incidence of cardiovascular disease when PCE-based absolute risk exceeds 7·5% in Black but not in White men. (C) Differences in PCE-based 10-year cardiovascular disease risk in men when absolute cardiovascular disease risk exceeds 7·5% in White but not in Black men. (D) Relative risks (White vs Black men) for 10-year incidence of cardiovascular disease when PCE-based absolute risk exceeds 7·5% in White but not in Black men. PCE=pooled cohort equation.

Figure 2:. Distributions of risk differences and risk ratios for Black versus White women with divergent risks

(A) Differences in PCE-based 10-year cardiovascular disease risk in women when absolute cardiovascular disease risk exceeds 7·5% in Black but not in White women. (B) Relative risks (Black vs White women) for 10-year incidence of cardiovascular disease when PCE-based absolute risk exceeds 7·5% in Black but not in White women. (C) Differences in PCE-based 10-year cardiovascular disease risk in women when absolute cardiovascular disease risk exceeds 7·5% in White but not in Black women. (D) Relative risks (White vs Black women) for 10-year incidence of cardiovascular disease when PCE-based absolute risk exceeds 7·5% in White but not in Black women. PCE=pooled cohort equation.

Figure 3:. Distribution of risk differences in PCE-based 10-year cardiovascular disease risk for White versus Black individuals, Framingham Heart Study

Counterfactuals refers to theoretical participants who have the same risk factor combinations as the actual Framingham Heart Study participants (factual) but belong to the comparison race of interest. (A) Risk differences when absolute cardiovascular disease risk does not exceed 7·5% in White men but exceeds this threshold in their Black counterfactuals. (B) Risk differences when absolute cardiovascular disease risk exceeds 7·5% in White men but does not exceed this threshold in their Black counterfactuals. (C) Risk differences when absolute cardiovascular disease risk does not exceed 7·5% in White women but exceeds this threshold in their Black counterfactuals. (D) Risk differences when absolute cardiovascular disease risk exceeds 7·5% in White women but does not exceed this threshold in their Black counterfactuals. PCE=pooled cohort equation.