Discordance between Framingham Risk Score and atherosclerotic plaque burden

Abstract

Clinical predictors are routinely used to identify individuals who may benefit from aggressive risk factor modification. However, clinical predictors cannot account for all genetic and environmental variables. The objective of this study is to investigate the association of Framingham Risk Score (FRS) with computed tomography angiography (CTA) measures of coronary atherosclerosis. Consecutive patients who underwent CTA were prospectively enrolled and categorized according to clinical predictors such as FRS and pre-test probability for obstructive coronary artery disease (CAD). Atherosclerotic calcific and non-calcific plaques were assessed. Of the 1507 patients without a history of diabetes mellitus, myocardial infarction, and not on statin therapy, coronary atherosclerosis was present in 63.5% of the patients. Of the 1173 patients with low and intermediate FRS, atherosclerotic plaque was visually present in 47.6 and 72.7% of the patients, respectively. A higher proportion of low FRS patients had isolated non-calcific plaque (14.8%) compared with patients in the intermediate (10.1%) or high (7.2%) FRS groups, and 11.7% of high FRS patients had no visual evidence of plaque. The correlation between FRS and plaque was fair (r = 0.48; P < 0.001). Although clinical variables are predictive of CAD events, CTA identified coronary atherosclerosis in a significant proportion of patients with low to intermediate FRS, and a small minority of patients with high FRS had no evidence of atherosclerosis. Prospective studies are required to determine the potential value of identifying coronary atherosclerosis using CTA and to assess whether modifying therapies based on these results are warranted.