Background: Tricuspid valve regurgitation is an inherent part of Ebstein's anomaly, yet whether the severity of the regurgitation further impairs exercise capacity and contributes to long-term morbidity on top of the lesion severity per se is unknown.
Methods: To evaluate for this potential effect, we included 30 patients with Ebstein's anomaly who did not undergo any form of surgical interventions and had a cardiopulmonary exercise test and echocardiographic studies in this retrospective analysis. Echocardiographic studies and cardiopulmonary exercise tests were critically reviewed for lesion severity grade, tricuspid regurgitation degree, and exercise parameters. Cardiac-related hospitalisations were recorded from computerised medical records and during clinic visits.
Results: Fourteen patients (47%) had moderate and 8 (27%) had severe regurgitation. Patients with ≥ moderate regurgitation exhibited significantly lower exercise capacity (median % predicted maximal oxygen consumption, 62 versus 79%, p = 0.03) and venilatory efficiency at exercise. When stratifying exercise results by regurgitation degree, a stepwise decrease in oxygen consumption and ventilatory efficiency with increasing regurgitation severity was observed, regardless of the anatomic lesion severity. During a median follow-up of 4.6 years, > moderate tricuspid regurgitation was associated with significantly lower cumulative probability of freedom from cardiac hospitalisations.
Conclusions: We report that among non-operated Ebstein's anomaly patients, greater tricuspid regurgitation severity was associated with worse exercise capacity and with overall higher probability of cardiac-related hospitalisations independent from the underlying lesion severity.
Keywords: Ebstein’s anomaly; exercise; tricuspid regurgitation.