Thr164Ile polymorphism of beta 2-adrenergic receptor negatively modulates cardiac contractility: implications for prognosis in patients with idiopathic dilated cardiomyopathy
Abstrakt
Beta 2-adrenergic receptor Thr164lle (threonine (Thr) is replaced by an isoleucine (Ile) at codon 164) polymorphism was postulated to contribute to lower exercise tolerance and poor prognosis in patients with congestive heart failure. However, heart failure is associated with several abnormalities of beta receptor signalling, and underlying mechanisms are not clear.
To investigate whether Thr164lle polymorphism negatively modulates myocardial contractile performance and is associated with adverse long-term prognosis of patients with congestive heart failure. Conclusions: The b2-adrenergic Thr164lle polymorphism directly modulates adrenergic-mediated cardiac responses in patients with normal and failing myocardium.
Furthermore, blunted beta 2 adrenergic-mediated myocardial contractile response in patients with Ile-164 variant seems to adversely modulate the course of congestive heart failure.