The development or persistence of pulmonary arterial hypertension (PAH) after atrial septal defect (ASD) closure at adult age is associated with a poor prognosis. The objective of this review was to investigate the prevalence of PAH before and after ASD closure and to identify factors that are associated with PAH.

EMBASE and MEDLINE databases were searched for publications until March 2017. All studies reporting the prevalence of PAH or data on pulmonary artery pressures both before and after surgical or percutaneous ASD closure in an adult population (≥16 years of age) were included. Papers were methodologically checked and data was visualized in tables, bar charts and plots.

A total of 30 papers were included. The prevalence of PAH ranged from 29% to 73% before ASD closure and from 5% to 50% after closure; being highest in older studies, small study cohorts, and studies with high rates of loss to follow-up. The pooled systolic pulmonary artery pressure (PAP) was 43±13 before ASD closure and 32±10 after closure. The overall mean PAP was 34±10 before closure and 28±8 after closure. Studies with a higher mean PAP before closure and a higher mean age of the study cohort reported greater PAP reductions.

The prevalence of PAH and mean pulmonary pressures decreased in all studies, regardless of the mean age or pulmonary pressures of the cohort. The reported prevalence of PAH after ASD closure is substantial, although widely varying (5%-50%), which is likely affected by selection of the study cohort.