Long-term outcomes of patients with single ventricle who do not undergo Fontan palliation

Background

Patients with single ventricle (SV) without Fontan palliation are uncommon, and their long-term outcomes remain unclear.

Methods

Retrospective study of 35 adult patients with SV without Fontan from two tertiary centers. Primary outcome was mortality.

Results

Median age at first follow-up was 31 years (IQR: 20–40). Most common defect was double inlet left ventricle (34%), and 69% had left ventricular morphology. Patients were unoperated (46%), had systemic-to-pulmonary artery shunt (31%) or bidirectional cavopulmonary shunt (23%) as final palliation. Most common reasons for not progressing to Fontan palliation were pulmonary vascular disease (54%), patient refusal (17%), Fontan takedown (14%), and hypoplastic pulmonary arteries (11%). Baseline mean hemoglobin was 195 ± 29 g/L, mean O₂ saturation 83 ± 6.9%, and 4 patients in NYHA Class III‒IV. After a mean follow-up of 10 ± 8.3 years, there were 9 deaths with heart failure being the leading cause (n = 6). Age-adjusted survival of these adult SV survivors was 73% and 53% at 40 and 50 years of age, respectively. Deceased patients more frequently had renal impairment (50% vs 0%) and QRS prolongation (75% vs 16%) at baseline (all p < 0.05). During follow-up, 40% had a new arrhythmia (atrial: n = 14, ventricular: n = 3), 34% had one or more hospitalizations for heart failure, and 17% had a stroke. A greater proportion of patients with pre-existing or new atrial/ventricular arrhythmia died compared to those without (42% vs 6%, p = 0.02).

Conclusions

Patients with SV without Fontan have high mortality and a substantial burden of cardiovascular complications, particularly arrhythmia. QRS prolongation and renal impairment were associated with mortality.