Impact of family history of coronary artery disease in young individuals (from the CONFIRM registry).

Although family history (FH) of coronary artery disease (CAD) is considered a risk factor for future cardiovascular events, the prevalence, extent, severity, and prognosis of young patients with FH of CAD have been inadequately studied. From 27,125 consecutive patients who underwent coronary computed tomographic angiography, 6,308 young patients (men aged <55 years and women aged <65 years) without known CAD were identified. Obstructive CAD was defined as >50% stenosis in a coronary artery >2 mm diameter. Risk-adjusted logistic regression, Kaplan-Meier, and Cox proportional-hazards models were used to compare patients with and without FH of CAD. Compared with subjects without FH of CAD, those with FH of CAD (FH+) had higher prevalences of any CAD (40% vs 30%, p <0.001) and obstructive CAD (11% vs 7%, p <0.001), with multivariate odds of FH+ increasing the likelihood of obstructive CAD by 71% (p <0.001). After a mean follow-up period of 2 ± 1 years (42 myocardial infarctions and 39 all-cause deaths), FH+ patients experienced higher annual rates of myocardial infarction (0.5% vs 0.2%, log-rank p = 0.001), with a positive FH the strongest predictor of myocardial infarction (hazard ratio 2.6, 95% confidence interval 1.4 to 4.8, p = 0.002). In conclusion, young FH+ patients have higher presence, extent, and severity of CAD, which are associated with increased risk for myocardial infarction. Compared with other clinical CAD risk factors, positive FH in young patients is the strongest clinical predictor of future unheralded myocardial infarction.