Lack of Association Between Adrenergic Receptor Genotypes and Survival in Heart Failure Patients Treated With Carvedilol or Metoprolol

ObjectivesThis study investigated the role of adrenergic receptor genetics on transplant-free survival in heart failure (HF).BackgroundDiscordant results exist for genetic associations between adrenergic receptor alleles and end points of β-blocker response in HF patients.MethodsWe identified 637 patients enrolled in 2 U.S. cardiovascular genetic registries with HF and left ventricular systolic dysfunction who were discharged on β-blocker, angiotensin-converting enzyme inhibitor (ACEI) or angiotensin II receptor blocker (ARB), and diuretic medications. End points were determined through the national Social Security Death Master File and transplant records. We genotyped 5 polymorphisms in 3 genes: ADRB1 (S49G, R389G), ADRB2 (G16R, Q27E), and ADRA2C (Del322-325) using 5′ nuclease assays and performed a multivariable clinical-genetic analysis.ResultsA total of 190 events (29.8%) occurred over a median follow-up of 1,070 days. Multivariable analysis showed a significant effect of 4 clinical factors on survival: age (p = 0.006), gender (p = 0.005), ejection fraction (p = 0.0002), and hemoglobin (p = 0.00010). There was no significant effect of the polymorphisms or haplotypes analyzed on survival.ConclusionsGenotypes and haplotypes of ADRB1, ADRB2, and ADRA2C did not significantly affect survival in metoprolol-treated or carvedilol-treated HF patients in this study. These results complement the findings of 2 similarly designed previous studies, but do not replicate an association of ADRB2 haplotypes and survival. All 3 studies differ from a survival benefit reported for bucindolol-treated homozygous ADRB1 R389 individuals. This may be attributable to a drug-specific interaction between genotype and outcome with bucindolol that does not seem to occur with metoprolol or carvedilol.