Prevalence of familial hypercholesterolemia in patients with acute coronary syndrome in Japan: Results of the EXPLORE-J study

Abstract Background and aims Prevalence of familial hypercholesterolemia (FH), a common genetic disorder with a high risk for coronary artery disease (CAD), is high among CAD patients; however, data on FH prevalence among acute coronary syndrome (ACS) patients are limited. EXPLORE-J is the largest registry to diagnose FH among Japanese ACS patients using the 2012 Japan Atherosclerosis Society guidelines. Methods This prospective study consecutively recruited patients between April 2015 and August 2016 at 59 sites. Low-density lipoprotein cholesterol (LDL-C) levels, family history of premature CAD, presence of tendon xanthomas, and Achilles tendon radiograms were recorded at baseline. The prevalence rate of FH in patients with ACS was estimated with 95% CI. Results Of 1944 analyzed patients (mean age, 66.0 years; men, 80.3%), 52 (2.7% [95% CI: 2.0–3.5]) had FH. Thirty-one (1.6%) had LDL-C ≥180 mg/dL and Achilles tendon thickness (ATT) ≥9 mm, 8 (0.4%) had LDL-C ≥180 mg/dL and family history of premature CAD, 10 (0.5%) had ATT ≥9 mm and family history of premature CAD, and 3 (0.2%) met all the criteria. FH patients were younger than those without FH (59.5 [12.5] vs. 66.2 [12.1] years; p vs. 2.1% [1.4–3.0]) had FH. Conclusions FH prevalence is at least five-fold higher in ACS patients than in the general population, especially in patients with premature ACS onset and ATT ≥9 mm. FH screening in ACS patients is therefore clinically important and critical.