Perioperative management of pulmonary arterial hypertension in children undergoing congenital heart surgery: a systematic review and meta-analysis

Background
Children with pre-existing pulmonary arterial hypertension (PAH) undergoing surgery for congenital heart disease (CHD) are at an increased risk of morbidity and mortality, primarily due to complications associated with increased pulmonary arterial pressures. Despite the clinical significance of this risk, no comprehensive review of perioperative strategies to manage pre-existing PAH in paediatric CHD patients undergoing cardiac surgery exists. This systematic review aims to address this gap.

Methods
A comprehensive systematic literature search was conducted on Scopus, Medline, Embase, PubMed, Cochrane Library and grey literature; studies were screened using eligibility criteria. Data was extracted using a pre-tested standard form and the methodological quality appraised using the RoB 2 tool. A meta-analysis was used to analyse, summarise, and interpret the extracted data.

Results
Ten randomised controlled studies were included in this review, comprising 520 patients, ages ranged from 0.21 to 13.8 years across 6 countries. All studies reported a greater decrease in postoperative mean pulmonary arterial pressure (mPAP) in the intervention groups compared to the control groups. Although perioperative management did not significantly reduce postoperative PAP (pooled mean difference, -0.44; 95% CI: -4.62-3.73; I² = 88.73%), their use resulted in statistically significant decreases in mean ICU stays (pooled mean difference, -1.08; 95% CI: -1.90-0.25, p-value = 0.01; I² = 86.21%) and ventilation times (pooled mean difference, -13.29; 95% CI: -25.78 -0.80, p - value = 0.04; I² = 97.47%) compared to controls. Sildenafil was the most used intervention, with a significantly greater reduction in PAP compared to other management strategies (pooled mean difference, -6.27; 95% CI: -8.982- -3.57, p-value < 0.001; I² = 49.84%). Among studies reporting pulmonary hypertensive crises and mortality, the prevalence of pulmonary hypertensive crises was 6.18% in the control group versus 3.43% in the treatment group. Mortality rates were 1.27% in the control group and 0.54% in the treatment group, respectively.

Conclusions
PAH Perioperative management strategies yielded no reductions in postoperative mPAP, but significantly reduced other key clinical outcomes including mean ICU stay and ventilation times in children undergoing cardiac surgery for CHD. Integrating perioperative interventions in the management of PAH may improve overall clinical outcomes, despite minimal impact on mPAP.