Background: Even after excellent repair of aortic coarctation without restenosis there are limitations in exercise capacity at long-term follow-up. This study was performed to assess the contribution of inherited genomic polymorphisms to exercise capacity in patients without restenosis.
Patients and methods: 122 patients aged 17-72 years, 46 female, 76 male, seen 2-27 years after repair of aortic coarctation with a residual brachial-ankle-gradient ≤20 mmHg were investigated. Genomic polymorphism of angiotensin converting enzyme (ACE I/D), angiotensinogen (AGT, c.704C > T), angiotensin II receptor type 1 (AGTR1, c.1166A > C), endothelin 1 (EDN1, EDN1/ex5-c.5665G > T), G protein (GNB3, c.825C > T), and two polymorphisms each of the ß1-adrenoreceptor (ADRB1, c.145G > A and c.1165C > G), ß2-adrenoreceptor (ADRB2, c.46A > G and c.79C > G), and endothelial NO synthase (NOS3, intron 4 I/D and NOS3, c.894G > T) were determined by PCR amplification and fragment length analysis. Exercise capacity was determined by an upright bicycle exercise test.
Results: Only the c.46A > G polymorphism of the ADRB2 (p = 0.024) and the c.704T > C AGT polymorphism (p = 0.042) were positively correlated with peak workload. Patients with one or especially two polymorphic alleles showed a significant higher exercise performance compared with those patients homozygous for the wild type.
Conclusions: In contrast to a previous study in heart failure patients, after coarctation repair adults had a better exercise capacity with the G allele of the ß2-receptor c.46A > G polymorphism. Therefore, the exercise capacity of coarctation patients does not profit from an enhanced down regulation of their beta receptors.