Impact of Tricuspid Valve Regurgitation Severity on Exercise Performance among Adults with Unoperated Ebstein’s Anomaly

Background and Aims The majority of patients with unoperated Ebstein’s anomaly have reduced exercise capacity. Lesion severity index (LSI), as evaluated in imaging studies, and maximal oxygen consumption (VO2 max), as evaluated in cardiopulmonary exercise tests (CPETs), were shown to correlate well in this patient population, indicating a close relationship between the anatomy and the exercise capacity . Tricuspid regurgitation (TR) is common in Ebstein’s anomaly, yet whether its severity pertains an additional impact on exercise parameters is unknown. Our aim was therefore to evaluate for a relationship between TR severity and various exercise parameters in adult patients with unoperated Ebstein’s anomaly.
Methods CPET and imaging studies of thirty patients at a median age of 34 years (22-45) with unoperated Ebstein’s anomaly and without intracardiac shunts were evaluated. Imaging studies (echo in all patients, MRI in 9) were evaluated for LSI, TR degree, and cardiac chamber sizes. CPETs were evaluated for VO2 max, VE/VCO2 slope, heart rate reserve, FVC and FEV1.
Results Twenty-two patients (73%) had LSI>3 and 21 (70%) had > moderate TR. LSI and TR severity moderately correlated (p for correlation=0.2(. Patients with >moderate TR had significantly lower % predicted VO2 max (median, 62% vs 79%, p=0.01) and steeper VE VCO2 slopes (median, 36 vs 29, p<0.001). Patients with LSI 2 and 3 who had> moderate TR had lower % predicted VO2 max and steeper VE VCO2 slopes as compared to those with
Conclusions Adults with unoperated Ebstein anomaly and> moderate TR showed worse cardiac performance and abnormal pulmonary blood flow patterns at exercise. Moderate or severe TR was associated with worse CPET parameters among patients with LSI of up to 3, yet in patients with more severe form of disease, the degree of TR was not associated with further reduction in exercise parameters.