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

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). 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). 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.