External validation of pooled cohort equations using systolic blood pressure intervention trial data

Abstract

Objective

The risk of atherosclerotic cardiovascular disease (ASCVD) is estimated using the American College of Cardiology (ACC)/American Heart Association (AHA) Pooled Cohort Equations (PCEs). However, the accuracy of this tool remains controversial, particularly among patients who are recommended statin therapy according to the ACC/AHA guidelines. We performed external validation of PCEs among patients eligible for statin therapy using data from the systolic blood pressure intervention trial (SPRINT).

Results

Our study included 4057 patients from among the 9361 patients in SPRINT. The mean patient age was 64.5 years, and the median predicted 10-year risks of ASCVD were 17.2% and 12.3% for men and women, respectively. Over a median follow-up of 3.3 years, 133 primary events (including 23 cardiovascular deaths) were noted, whereas 304 events were predicted by the PCEs. The PCEs demonstrated poor calibration (Hosmer–Lemeshow test, p < 0.001) and overestimated the probability consistently. Additionally, they showed moderate discrimination [area under the curve: 0.65 (95% confidence interval, 0.60–0.69)]. This study demonstrates that PCEs might overestimate the risk of ASCVD in patients who are recommended statin therapy.