Polymorphisme génétique des récepteurs bêta-adrénergiques et mortalité dans l'ischémie myocardique

The genetic polymorphism of beta-2 adrenergic receptors (B2AR) could play a major role in the pronostic of patients with a coronary heart disease. Two recent epidemiological studies could support this hypothesis. In 597 patients treated by a betablocker and followed for 3 years after a myocardial infarction or an acute coronary syndrome, the death rate was 5.4 times higher in homozygous Arg 16 and Gln 27 B2AR genotypes than in heterozygous or homozygous Gly 16 and Glu 27 B2AR genotypes. The beta-1 adrenergic receptor (B1AR) genetic polymorphism did not modify mortality. In a second study, in a prospective cohort of 5249 patients aged ≥65 years, the incidence of sudden cardiac death was 1.56 times higher in patients with homozygous Gln 27 B2AR than in heterozygous or homozygous Glu 27 B2AR genotype. This result was confirmed by a case-control study (155 cases of sudden cardiac death versus 144 control subjects). These data suggest that B2AR genetic polymorphism should be systematicaly studied in clinical trials in myocardial ischemia, with or without congestive heart failure.