Familial hypercholesterolemia (FH) is a common genetic disorder causing accelerated atherosclerosis and premature cardiovascular disease. The aim of this study was to examine the prevalence and prognostic significance of possible FH in patients with myocardial infarction (MI).
By individual-level linkage of data from the Eastern Danish Heart Registry and national administrative registries, a study population of patients referred for coronary angiography due to MI was selected. The study population was divided into "unlikely FH" and "possible FH" based on the Dutch Lipid Clinic Network criteria, which included a plasma low-density lipoprotein cholesterol (LDL-C) and age for onset of cardiac disease. A score of =3 points was used as the cutpoint between the 2 groups. Among the study population of 13,174 MI patients, 1,281 (9.7%) had possible FH. These patients were younger (59.1 vs 65.7 years, P = .0001), had similar levels of comorbidities, and were treated more aggressively with cholesterol-lowering drugs compared with patients with unlikely FH. During a median of 3.3 years of follow-up, the unadjusted and adjusted event rates of recurrent MI were higher in patients with possible FH compared with unlikely FH (16% vs 11%, adjusted hazard ratio 1.28, 95% CI 1.09-1.51, P = .003.). Differences in adjusted all-cause mortality were not statistically significant (17% vs 23%, adjusted hazard ratio 0.89 [0.74-1.04], P = .1).
We found that MI patients with possible FH have higher risk of recurrent MI but similar risk of mortality compared with unlikely FH patients. Further studies on secondary prevention are warranted.