Polymorphism Gln27Glu of β2 Adrenergic Receptors in Patients with Ischaemic Cardiomyopath

Background: Polymorphisms of the Adrenergic Receptors (ARs) might affect the development and progression of Heart Failure (HF) and the response to treatment with β-blockade therapy. Objective: To examine the role of the Gln27Glu polymorphism of β2-AR in HF development and to assess the hypothesis that Gln27Glu is associated with coronary artery disease in patients with ischaemic HF. Methods: In this case control study we enrolled 155 consecutive patients with symptomatic HF of ischaemic aetiology with impaired Left Ventricular Ejection Fraction (LVEF) ≤35%. The control group consisted of 133 patients with no obstructive coronary artery disease and or evidence of HF. Results: Concerning HF and control subjects there was no significant differences in the prevalence of Gln27Gln homozygotes (46 vs. 44%, p=0.82). In HF patients concerning the differences in patient characteristics between allele categories (Gln27Gln vs. Gln27Glu/Glu27Glu) there was no difference in risk factors, LVEF, treatment, the clinical status and NYHA categorization of patients, and in the prevalence of multi-vessel coronary artery disease. Interestingly, participants homozygous for Gln had significant higher prevalence of previous myocardial infarction (Gln27Gln vs. Gln27Glu/Glu27Glu: 77 vs. 23%, p=0.02). Conclusion: The present study shows that the Gln27Gln genotype of β2-AR is the most predominant while the Glu27Glu is the least prevalent in our HF population. There was no difference in the prevalence of polymorphism Gln27Glu between HF patients and control subjects. However, the presence of Glu allele was associated with lower myocardial infarction rate. Keywords: Adrenergic receptor, heart failure, polymorphism, myocardial infarction, β- blockers, Gln27Glu polymorphism.