Association of β1 and β2-adrenoceptor Polymorphisms With the Demand of Inotropic Catecholamine Support Following Coronary Artery Bypass Grafting in Iranian Population

Background: Hemodynamic instability is a common complication in the first hours following cardiac surgery and inotropic catecholamine support is an acceptable treatment strategy for its management. β1 and β2-adrenoceptors (β1 and β2 AR) are mediated the positive inotropic and chronotropic responses of the heart to catecholamines. Previous evidence has suggested an association between β1 and β2AR polymorphisms and cardiac response and change in receptor signaling. The aim of this study was evaluating the relationship between β1 and β2AR polymorphisms with demand of catecholamine inotropic support among coronary artery bypass grafting (CABG) patients.Methods: One hundred ninety-eight consecutive patients who underwent CABG with cardiopulmonary bypass were included in this study. We assessed hemodynamic parameters, dose and duration of inotropic support according to β1 and β2AR genotypes in post-operative period. DNA genotyping were assessed through polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and PCR genotyping results were confirmed by direct DNA sequencing. Results: The our results indicated that patients carrying one or two alleles of the Arg389-β1AR variant required significantly shorter inotropic support time compared with patients homozygous for the Gly389-β1AR (p=0.003). Finally, neither β1AR polymorphisms nor Arg16Gly-β2AR polymorphism are associated with catecholamines-induced hemodynamic effects.Conclusion: These findings suggest that genetic variability in the β1 and β2AR polymorphisms may not be a major determinant of cardiac responses to catecholamine treatment in Iranian population. However, larger scale studies with different ethnicities are needed for confirmation.