Factors associated with exercise capacity in patients with a systemic right ventricle

Abstract

Systemic right ventricle (SRV) is a rare and complex congenital heart disease (CHD). Patients with a SVR present with a significant decrease of their exercise capacity. We aimed atidentifying clinical and paraclinicalfactors associated with maximum oxygen uptake (VO2 max ) in adults with SRV. This multicentre cross-sectional study was performed from in 2017 in three French tertiary care CHD centres. Adult patients with a D-transposition of the great artery (d-TGA) or a congenitally corrected TGA (cc-TGA) were included. Demographic, clinical, laboratory and imaging data were collected. Univariate and multivariate analyses were performed to identify predictors of impaired VO2max, as measured by cardiopulmonary exercise test (CPET). A total of 111 patients were included in the study (85% d-TGA, median age 37.2 ± 8.2 years). Most patients presented with impaired physical capacity (mean VO2 max of 23.3 ± 6.9 ml/kg/min, representing 68.4 ± 16.6% of predicted values) and muscular deconditioning (mean ventilatory anaerobic threshold (VAT) of 32.7% ± 10.9% of the predicted values). In univariate analysis, VO2 max correlated with professional status, NYHA functional class, BNP level, the type of SRV, SRV systolic dysfunction, the severity of tricuspid regurgitation, the presence of a pacemaker or an implantable defibrillator, the VAT, the maximum load, and the maximal heart rate during exercise. In multivariate analysis, the VO2 max remained affected by the NYHA functional class. The final multivariate model explained 49% of the variability of VO2 max . NYHA functional class is the strongest predictor of impaired exercise capacity in adult patients with SRV.