Tricuspid valve surgery improves cardiac output and exercise performance in patients with Ebstein's anomaly

Background: Clinical, hemodynamic and functional effects of tricuspid valve surgery in patients with Ebstein's anomaly are not well understood. Methods: Sixteen patients (median age of 27.7 years) were examined before and eight months after surgery by means of echocardiography, cardiovascular magnetic resonance (CMR) and cardiopulmonary exercise testing. Results: Peak work load (1.87 to 2.0 W/kg; p = 0.026), maximum oxygen uptake (21 to 22 ml/kg/min; p = 0.034) as well as cardiac output (2.7 to 2.9 l/min/m²; p = 0.035) increased postoperatively. The reduction of tricuspid regurgitation led to a higher pulmonary stroke volume (29 to 42 ml/m², p = 0.005) and augmented the left ventricular (LV) volume (55 to 63 ml/min/m²; p = 0.001) with a trend to better ejection fraction (61 to 64%; p = 0.083). Right ventricular (RV) volume index (124 to 108 ml/m2; p = 0.034) and ejection fraction (50 to 42%; p = 0.036) decreased on CMR. Echocardiographic measurements of RV function also decreased (tricuspid annular plane systolic excursion 2.3 to 1.7; p = 0.002; isovolumic acceleration 0.98 to 0.65; p = 0.004; and 2-d longitudinal global strain - 19.3 to - 16.25; p = 0.006). Conclusion: Tricuspid valve surgery improves exercise capacity in patients with Ebstein's anomaly. The reduction of tricuspid regurgitation decreases the volume of the right ventricle and increases pulmonary antegrade flow. As a result LV volume and cardiac output increase. This hemodynamic benefit occurs despite the preload dependent reduction in RV volume and ejection fraction.