Predicting long-term mortality after Fontan procedures: A risk score based on 6707 patients from 28 studies.

Background: Reported long-term outcome measures vary greatly between studies in Fontan patients making comprehensive appraisal of mortality hazard challenging. We sought to create a clinical risk score to assist monitoring of Fontan patients in the outpatient setting.

Methods: A systematic review was conducted to evaluate risk factors for long-term (beyond the first postoperative year) mortality in Fontan patients. Studies were eligible for inclusion if ≥90 patients were included or ≥20 long-term mortalities we reported. Risk factors for long-term mortality were determined. The pooled hazard ratios were used to create components of a clinical score for long-term mortality using meta-analysis techniques.

Results: Twenty-eight studies were included. The total number of patients was 6707 with an average follow-up of 8.23 ± 5.42 years. There were 1000 deaths. Thirty-five risk factors for late mortality were identified and classified into 9 categories and their relative hazards were used to derive the initial components of a weighted, practical and clinically based Fontan risk score (ranging from 0 to 100). The final score included 8 risk factors: anatomic risk factors, elevated preoperative pulmonary artery pressure, atriopulmonary Fontan, heart failure symptoms, arrhythmia, moderate/severe ventricular dysfunction or atrioventricular valve regurgitation, protein losing enteropathy, and end organ disease (cirrhosis or renal insufficiency).

Conclusion: In patients with Fontan circulation, the influence of readily available risk factors can be quantified in an integer score to predict long-term mortality. Prospective validation and refinement of this risk score will be undertaken.