Changes in Exercise Performance After Surgery for Ebstein Anomaly and Impact on Long-term Survival

J. Afoke, E. Stephens, T. Allison, T. Chopko, C. Briggs, B. Curran, A. Todd, L. Burchill, H. Connolly, A. Egbe, C. Jain, W. Miranda, J. Dearani
Mayo Clinic, Rochester, Minnesota

Purpose: Although operative techniques for Ebstein anomaly have evolved, the optimum timing for surgery in adult patients remains unclear. Cardiopulmonary exercise testing (CPET) is used to objectively quantify functional status. We sought to evaluate whether pre-operative CPET is associated with survival after surgery in these patients and longitudinal changes after surgery.

Methods: Retrospective review was performed of consecutive adult patients (≥18 years) with Ebstein anomaly who had tricuspid surgery between 2007 and 2018 and pre-operative CPET. Clinical and mortality data were collected from chart review and our institutional database. Primary outcome was post-surgical all cause mortality and univariable analysis was performed to identify associated variables. Secondary outcome was changes in CPET parameters after surgery.

Results: The cohort included 116 patients. Ninety four patients (81.1%) were NYHA Class I or II. Median age was 40 (IQR 28, 52) years, 75 patients (64.7%) were female, 33 (28.4%) had prior atrial fibrillation or flutter, 15 (12.9%) had pre-operative pacemaker. Forty four patients (38%) had one or more prior sternotomy, 58 (50%) underwent cone repair, 3 (2.6%) had other repair techniques, 55 (47.5%) had tricuspid replacement.

Median percentage predicted peak VO2 (ppVO2) was 62% (51, 74) and ventilatory equivalent of carbon dioxide (VE/VCO2) was 30 (26, 33) l/min/min. Median left ventricular ejection fraction was 58% (55, 63). Fourteen patients (12.2%) had severe RV systolic dysfunction and 83 (72.2%) had severe RV dilation. At median follow up of 9.8 (1.8, 13.1) years, there were 8 deaths. On the univariable analysis, VE/VCO2 tended to be associated with mortality (HR 1.12, 0.99-1.28, p=0.075).

33 patients had CPET at a median of 2.9 (2.0, 3.5) years after surgery including 15 patients with cone repair and 18 patients had primary sternotomy. There was no significant change in ppVO2 (62 (51, 74) pre-operatively vs 71% (63, 81) post-operatively, p=0.27), but significant decrease in VE/VCO2 (30 (26, 33) pre-operatively vs 27 (26, 29) l/min/l/min post-operatively, p=0.015).

Conclusion: At mid-term follow up, there is improvement in ventilatory efficiency, but not in peak VO2 in patients with Ebstein anomaly undergoing tricuspid surgery, Even in patients with no or minimal symptoms, pre-operative VE/VCO2 may influence long term survival after surgery. This suggests a role for cardiopulmonary exercise testing in guiding timing of surgery for Ebstein anomaly and risk stratifying patients following operation.

Identify the source of the funding for this research project: No external funding