Framingham Risk Score Inadequately Predicts Cardiac Risk in Young Patients Presenting with a First Myocardial Infarction

Introduction: The Framingham Risk Score (FRS) is a well-validated epidemiologic tool used to assess the risk for a first cardiac event. Because young patients presenting with a first myocardial infarction (MI) tend to have less significant risk profiles compared with older patients, we hypothesized that FRS may underestimate cardiac risk in these patients. Materials and Methods: We studied 1267 patients between January 2002 and November 2007 presenting with a first MI. Patients with pre-existing diabetes mellitus and vascular disease were excluded. FRS was calculated for each patient. Patients were divided based on their age: group A (<40 years), group B (40 to 64 years) and group C (>= 65 years). Results: The mean age was 54.7 +/- 11 years, 88.4% of the patients were males. Younger patients were more likely to be assigned with lower scores. Based on FRS, 63.0%, 29.3% and 14.2% of group A, B and C patients were classified as low risk (10-year risk for cardiac events<10%) respectively, P <0.001. The sensitivity of FRS in identifying at least intermediate risk subjects (10-year risk for cardiac events >10%) was 37.0% in group A vs 85.8% in group C (P <0.001). The incidence of newly diagnosed diabetes mellitus was higher in younger patients (12.0% vs 13.2% vs 7.1% in groups A, B and C respectively, P = 0.027). Conclusions: FRS inadequately predicts cardiac risk in young patients presenting with a first MI. This could be because a significant proportion of these young patients have undiagnosed diabetes mellitus, a coronary artery disease risk equivalent.