Association of beta-adrenergic receptor polymorphisms and mortality in carvedilol-treated chronic heart-failure patients

Pharmacogenetics can be used as a tool for stratified pharmacological therapy in cardiovascular medicine. We investigated whether a predefined combination of the Arg389Gly polymorphism in the adrenergic β(1) -receptor gene (ADRB1) and the Gln27Glu polymorphism in the adrenergic β(2) -receptor gene (ADRB2) could predict survival in carvedilol- and metoprolol-treated chronic heart failure (HF) patients.

Five hundred and eighty-six HF patients (carvedilol n= 82, metoprolol n= 195) were genotyped for ADRB1 Arg389Gly (rs1801253) and ADRB2 Gln27Glu (rs1042714). The end-point was all-cause mortality, and median follow-up time was 6.7 years. Patients were classified into two functional genotype groups: group 1 combination of Arg389-homozygous and Gln27-carrier (46%) and group 2 any other genotype combination (54%). Results were fitted in two multivariate Cox models.

There was a significant interaction between functional genotype group and carvedilol treatment (adjusted(1) P= 0.033, adjusted(2) P= 0.040). Patients treated with carvedilol had shorter survival in functional genotype group 1 (P= 0.004; adjusted(1) hazard ratio (HR) 2.67, 95% CI 1.27, 5.59, P= 0.010; adjusted(2) HR 2.05, 95% CI 1.06, 3.95, P= 0.033). There was no interaction between genotype group and metoprolol treatment (P= 0.61), and there was no difference in overall survival between genotype groups (P= 0.69).

A combination of ADRB1 Arg389-homozygous and ADRB2 Gln27-carrier in HF patients treated with carvedilol was associated with a two-fold increase in mortality relative to all other genotype combinations. There was no difference in survival in metoprolol-treated HF patients between genotype groups. Patients in genotype group 1 may benefit more from metoprolol than carvedilol treatment.