Validation of the pooled cohort risk score in an Asian population – a retrospective cohort study

Abstract

BackgroundThe Pooled Cohort Risk Equation was introduced by the American College of Cardiology (ACC) and American Heart Association (AHA) 2013 in their Blood Cholesterol Guideline to estimate the 10-year atherosclerotic cardiovascular disease (ASCVD) risk. However, absence of Asian ethnicity in the contemporary cohorts and limited studies to examine the use of the risk score limit the applicability of the equation in an Asian population. This study examines the validity of the pooled cohort risk score in a primary care setting and compares the cardiovascular risk using both the pooled cohort risk score and the Framingham General Cardiovascular Disease (CVD) risk score.MethodsThis is a 10-year retrospective cohort study of randomly selected patients aged 40–79 years. Baseline demographic data, co-morbidities and cardiovascular (CV) risk parameters were captured from patient records in 1998. Pooled cohort risk score and Framingham General CVD risk score for each patient were computed. All ASCVD events (nonfatal myocardial infarction, coronary heart disease (CHD) death, fatal and nonfatal stroke) occurring from 1998–2007 were recorded.ResultsA total of 922 patients were studied. In 1998, mean age was 57.5 ± 8.8 years with 66.7% female. There were 47% diabetic patients and 59.9% patients receiving anti-hypertensive treatment. More than 98% of patients with pooled cohort risk score ≥7.5% had FRS >10%. A total of 45 CVD events occurred, 22 (7.2%) in males and 23 (3.7%) in females. The median pooled cohort risk score for the population was 10.1 (IQR 4.7-20.6) while the actual ASCVD events that occurred was 4.9% (45/922). Our study showed moderate discrimination with AUC of 0.63. There was good calibration with Hosmer-Lemeshow test χ2 = 12.6, P = 0.12.ConclusionsThe pooled cohort risk score appears to overestimate CV risk but this apparent over-prediction could be a result of treatment. In the absence of a validated score in an untreated population, the pooled cohort risk score appears to be appropriate for use in a primary care setting.

Association of Lipid Profiles With 10-Year Atherosclerotic Cardiovascular Disease Risk: Study Among Subjects in Sleman District of Yogyakarta Indonesia

“…During the writing process of this study, there is no reference of the ASCVD risk information for Indonesian subjects. According to a reference, the ASCVD risk method appeared to overestimate absolute ASCVD risk as the observed events were less than predicted [8]. A similar finding in an external calibration on ASCVD risk, the result showed that the method in 15 cohort studies, reanalyzed studies, or external calibration overestimated the ASCVD risk in almost all studies.…”

“…The ASCVD risk showed moderate discrimination and good calibration in an Asian population. The moderate discrimination due to the high prevalence of ASCVD risk factors was improved with clustering of higher risk patients, whereas fewer patients were needed among the patients with lower risk [8]. Therefore in a general population of subjects with a wider range of ASCVD risk, the risk prediction using PCE method may give a better discrimination [8,9].…”

Treatment use in prognostic model research: a systematic review of cardiovascular prognostic studies

“…In addition, many articles reported a low prevalence of statin use at study baseline; in those situations, it may have been assumed that treatment would not have greatly influenced the predicted probabilities. However, treatment use can greatly change over time, as shown by one study validating the AHA/ACC Pooled Cohort Equations [16], which reported increases in antihypertensive medication use and statin use from 59.9 to 82.4% and 9.7 to 63.7%, respectively, over a 10-year follow-up period (1998)(1999)(2000)(2001)(2002)(2003)(2004)(2005)(2006)(2007) [17]. Second, while only nine articles reported that data on treatments were not available in their studies, it might be that more studies were unable to obtain such data, especially follow-up information, as this may be more costly or difficult to collect.…”

High-sensitivity cardiac troponin I and incident coronary heart disease among asymptomatic older adults

“…We considered three risk categories, <10% (low), 10–20% (intermediate) and >20% (high). We did not consider the 2013 American College of Cardiology / American Heart Association (ACC/AHA) Pooled Cohort Equation17 because it was developed including stroke and because it has been shown to overestimate cardiovascular disease (CVD) risk, particularly in Asian populations 18…”