Researchers have developed a more accurate way to predict the risk of developing cardiovascular disease among women, according to a study in the issue of JAMA.
"In the decade between 1956 and 1966, investigators in Framingham, Mass., defined age, hypertension (high blood pressure), smoking, diabetes and hyperlipidemia (high cholesterol levels) as major determinants of coronary heart disease and coined the term coronary risk factors," according to background information provided by the authors. "Over time, these markers were codified into global risk scores for assessment of cardiovascular risk. However, for women, up to 20 percent of all coronary events occur in the absence of these major risk factors, whereas many women with traditional risk factors do not experience coronary events." The authors note that although understanding of cardiovascular disease has changed dramatically in the past half-century, the algorithms (predictive models) for women are largely unchanged from those recommended 40 years ago.
Paul M Ridker, M.D., M.P.H., from Brigham and Women's Hospital, Boston, and colleagues, developed and validated cardiovascular risk algorithms for women based on a large set of traditional and new risk factors. The researchers assessed 35 risk factors among 24,558 initially healthy women (free of cardiovascular disease and cancer at the beginning of the study) 45 years or older from the Women's Health Study who were followed up for a median of 10.2 years for incident (new) cardiovascular events, such as myocardial infarction (heart attack), ischemic stroke, coronary revascularization, and cardiovascular deaths. The researchers used data among a randomly selected two-thirds of the women (n = 16,400) to develop new algorithms that were then tested to compare observed and predicted outcomes in the remaining one-third of women (n = 8,158). The new algorithms are called the Reynolds Risk Score and the clinically simplified model for non-diabetic women includes age, systolic blood pressure, current smoking, total and HDL cholesterol, high sensitivity C-reactive protein (CRP) and parental history of myocardial infarction before age 60.
"In these analyses, large proportions of women with 10-year risk estimates of 5 percent to less than 10 percent or of 10 percent to less than 20 percent based on current ATP-III (Adult Treatment Panel III) risk scores were reclassified at either higher or lower risk of total cardiovascular disease when either of the new algorithms was used," the researchers found.
"We developed, validated and demonstrated highly improved accuracy of two clinical algorithms for global cardiovascular risk prediction that reclassified 40 percent to 50 percent of women at intermediate risk into higher- or lower-risk categories," the authors write. "As 8 to 10 million U.S. women have an ATP-III estimated 10-year risk between 5 percent and 20 percent, application of these data could have an immediate effect on cardiovascular prevention," the authors conclude.