Pulmonary Vasodilator Therapy in Patients With Fontan Circulation: A Meta-Analysis.

Background and objectives: The effect of pulmonary vasodilator therapy on patients with Fontan circulation remains unclear. This study aims to assess its impact on exercise capacity and hemodynamic parameters in this population.

Methods: We searched PubMed, Embase, and the Cochrane Library for relevant studies up to November 2023. Pooled outcomes were used to evaluate the efficacy of pulmonary vasodilators in Fontan patients.

Results: A total of 18 studies with 667 patients were included. Exercise capacity was assessed in 14 studies (526 patients). Pulmonary vasodilator therapy improved oxygen consumption anaerobic threshold (VO₂AT; MD, 1.12 mL/min/kg; 95% CI, 0.35 to 1.89; p=0.004) and Ve/VCO₂ slope (MD, -1.14; 95% CI, -1.97 to -0.31; p=0.007) during exercise. No significant differences were found among drug classes regarding peak oxygen consumption, Ve/VCO₂, or VO₂AT. Invasive hemodynamics were evaluated in 6 studies (126 patients). Pulmonary vasodilators significantly reduced mean pulmonary arterial pressure (MD, -2.28 mmHg; p=0.02), pulmonary vascular resistance (MD, -0.91 WU*m²; p=0.01), and improved pulmonary flow (MD, 0.46 L/min/m²; p=0.02).

Conclusions: Pulmonary vasodilator therapy appears beneficial for exercise capacity and pulmonary hemodynamics in Fontan patients. More randomized controlled trials are needed to confirm these findings.