The cardiovascular event reduction tool (CERT) - A simplified cardiac riskprediction model developed from The West of Scotland Coronary Prevention Study (WOSCOPS)

The clinical decision to treat hypercholesterolemia is premised an an aware ness of patient risk, and cardiac risk prediction models offer a practical means of determining such risk. However, these models are based on observat ional cohorts where estimates of the treatment benefit are largely inferred . The West of Scotland Coronary Prevention Study (WOSCOPS) provides an oppo rtunity to develop a risk-benefit prediction model from the actual observed primary event reduction seen in the trial. Five-year Cox model risk estima tes were derived from all WOSCOPS subjects (n = 6,595 men, aged 45 to 64 ye ars old at baseline) using factors previously shown to be predictive of def inite fatal coronary heart disease or nonfatal myocardial infarction. Model risk factors included age, diastolic blood pressure, fetal cholesterol/hig h-density lipoprotein ratio (TC/HDL), current smoking, diabetes, family his tory of fatal coronary heart disease, nitrate use or angina, and treatment (placebo/40-mg pravastatin), All risk factors were expressed as categorical variables to facilitate risk assessment. Risk estimates were incorporated into a simple, hand-held slide rule or risk tool, Risk estimates were ident ified for 5-year age bands (45 to 65 years), 4 categories of TC/HDL ratio ( <5.5, 5.5 to <6.5, 6.5 to <7.5, greater than or equal to 7.5), 2 levels of diastolic blood pressure (<90, greater than or equal to 90 mm Hg), from 0 t o 3 additional risk factors (current smoking, diabetes, family history of p remature fatal coronary heart disease, nitrate use or angina), and pravasta tin treatment. Five-year risk estimates ranged from 2% in very low-risk sub jects to 61% in the very high-risk subjects. Risk reduction due to pravasta tin treatment averaged 31%. Thus, the Cardiovascular Event Reduction Tool ( CERT) is a risk prediction model derived from the WOSCOPS trial. Its use wi ll help physicians identify patients who will benefit from cholesterol redu ction, (C)2000 by Excerpta Medica, Inc.