What have we learned from Turkish familial hypercholesterolemia registries (A-HIT1 and A-HIT2)?

Background and aims: Familial hypercholesterolemia (FH) is a common genetic disease of high-level cholesterol leading to premature atherosclerosis. One of the key aspects to overcome FH burden is the generation of large-scale reliable data in terms of registries. This manuscript underlines the important results of nation-wide Turkish FH registries (A-HIT1 and A-HIT2). Methods: A-HIT1 is a survey of homozygous FH patients undergoing low density lipoprotein (LDL) apheresis (LA). A-HIT2 is a registry of adult FH patients (homozygous and heterozygous) admitted to outpatient clinics. Both registries used clinical diagnosis of FH. Results: A-HIT1 evaluated 88 patients (27 ± 11 years, 41 women) in 19 centers. All patients were receiving regular LA. There was a 7.37 ± 7.1-year delay between diagnosis and initiation of LA. LDL-cholesterol levels reached the target only in 5 cases. Mean frequency of apheresis sessions was 19 ± 13 days. None of the centers had a standardized approach for LA. Mean frequency of apheresis sessions was every 19 ± 13 (7–90) days. Only 2 centers were aware of the target LDL levels. A–HIT2 enrolled 1071 FH patients (53 ± 8 years, 606 women) from 31 outpatients clinics specialized in cardiology (27), internal medicine (1), and endocrinology (3); 96.4% were heterozygous. 459 patients were on statin treatment. LDL targets were attained in 23 patients (2.1% of the whole population, 5% receiving statin) on treatment. However, 66% of statin-receiving patients were on intense doses of statins. Awareness of FH was 9.5% in the whole patient population. Conclusions: The first nationwide FH registries revealed that FH is still undertreated even in specialized centers in Turkey. Additional effective treatment regiments are urgently needed.