Sildenafil for congenital heart diseases induced pulmonary hypertension, a meta-analysis of randomized controlled trials

BackgroundSildenafil was first prescribed for angina pectoris and then for erectile dysfunction from its effects on vascular smooth muscle relaxation and vasodilatation. Recently, sildenafil has been proposed for congenital heart diseases induced pulmonary hypertension, which constitutes a huge burden on children's health and can attribute to fatal complications due to presence of unoxygenated blood in the systemic circulation. Therefore, our meta-analysis aims to further investigate the safety and efficacy of sildenafil on children population.MethodsWe searched the following electronic databases: PubMed, Cochrane CENTRAL, WOS, Embase, and Scopus from inception to April 20th, 2022. Randomized controlled trials that assess the efficacy of using sildenafil in comparison to a placebo or any other vasodilator drug were eligible for inclusion. The inverse variance method was used to pool study effect estimates using the random effect model. Effect sizes are provided in the form of mean difference (MD) with 95% confidence intervals (CI).ResultsOur study included 14 studies with (n = 849 children) with a mean age of 7.9 months old. Sildenafil showed a statistically significant decrease over placebo in mean and systolic pulmonary artery pressure (PAP) with MD -7.42 (95%CI [-13.13, -1.71], P = 0.01) and -8.02 (95%CI [-11.16, -4.88], P < 0.0001), respectively. Sildenafil revealed a decrease in mean aortic pressure and pulmonary artery/aortic pressure ratio over placebo with MD -0.34 (95%CI [-2.42, 1.73], P = 0.75) and MD -0.10 (95%CI [-0.11, -0.09], P < 0.00001), respectively. Regarding post corrective operations parameters, sildenafil had a statistically significant lower mechanical ventilation time, intensive care unit stay, and hospital stay over placebo with MD -19.43 (95%CI [-31.04, -7.81], s = 0.001), MD -34.85 (95%CI [-50.84, -18.87], P < 0.00001), and MD -41.87 (95%CI [-79.41, -4.33], P = 0.03), respectively. Nevertheless, no difference in mortality rates between sildenafil and placebo with OR 0.25 (95%CI 0.05, 1.30], P = 0.10) or tadalafil with OR 1 (95%CI 0.06, 17.12], P = 1).ConclusionSildenafil is a well-tolerated treatment in congenital heart diseases induced pulmonary hypertension, as it has proven its efficacy not only in lowering both PAP mean and systolic but also in reducing the ventilation time, intensive care unit and hospital stay with no difference observed regarding mortality rates.