Shifting Paradigms: Exercise Testing as a Metric of Long-Term Success in Surgery for Ebstein Anomaly

Optimum timing for surgery in asymptomatic/mildly symptomatic adult patients with Ebstein anomaly remains uncertain. This study assessed the association between preoperative cardiopulmonary exercise testing (CPET) and mortality, and longitudinal changes in CPET.

A retrospective review was conducted of consecutive adult patients with Ebstein anomaly who had tricuspid surgery between 2007 and 2018 with preoperative CPET. Primary outcome was all-cause mortality and secondary outcomes included changes in CPET.

The cohort included 116 patient, of whom 94 (81.1%) were New York Heart Association Functional Class I/II. Median age was 39.6 years, and 75 (64.7%) were women. There were 44 (37.9%) with ≥1 prior sternotomies, 58 (50%) underwent Cone repair, and 55 (47.5%) had tricuspid replacement. Median percentage predicted peak oxygen consumption (Vo₂) was 62%, and ventilatory efficiency was 30 L/min/min. Fifteen (12.9%) had severe right ventricle dysfunction, and median left ventricular ejection fraction was 58%. At a median follow-up of 9.8 years, there were 8 deaths. Ventilatory efficiency trended to be associated with mortality (P = .075) on univariate analysis and was the largest contributor to prediction of mortality in machine learning random forest models. Thirty-three patients had CPET at a median of 2.9 years after surgery. There was significant improvement in ventilatory efficiency (30 L/min/L/min preoperatively vs 27 L/min/L/min postoperatively, P = .015).

In those with minimal or no symptoms, ventilatory efficiency is one of the most important variables in predicting mortality after surgery. Patients may have improved ventilatory efficiency after tricuspid surgery for Ebstein anomaly. These findings highlight the role of CPET in optimizing timing of surgery.