Impact of Genetic Testing Among Patients With Familial Hypercholesterolemia on Adverse Cardiovascular Events　― The Hokuriku-Plus Familial Hypercholesterolemia Registry Study ―

BACKGROUND: We aimed to clarify the impact of genetic testing on major adverse cardiovascular events (MACE) among patients with heterozygous familial hypercholesterolemia (HeFH) using data from the Hokuriku-plus FH Registry (UMIN000038210). METHODS AND RESULTS: In all, 431 patients were enrolled in the study, with a median follow-up of 3.9 years. The primary outcome was time to first MACE, defined as cardiovascular death, non-fatal myocardial infarction, coronary revascularization, or non-fatal stroke. Using Cox proportional hazards regression models, we examined whether undergoing genetic testing was associated with a reduced risk of MACE. Among the 431 patients, sufficient data were available for 386 with HeFH, of whom 202 (52.3%) underwent genetic testing. Low-density lipoprotein cholesterol (LDL-C) levels at follow-up were significantly lower in group that underwent genetic testing than in the group that did not (median 102 vs. 130 mg/dL, respectively; P<0.001). During follow-up, 23 MACE occurred (18 in the non-testing group and 5 in the genetic testing group). Notably, undergoing genetic testing was significantly associated with a reduced risk of MACE, even after adjusting for LDL-C levels (hazard ratio 0.66; 95% confidence interval 0.20-0.92; P=0.033). CONCLUSIONS: Genetic testing in patients with HeFH was associated with a reduced risk of MACE independent of LDL-C. Randomized controlled trials will be needed to clarify whether providing genetic testing can reduce MACE among patients with HeFH.