Diastolic Pulmonary Arterial Pressure as a Prognostic Indicator for Closure of Atrial Septal Defect with Severe Pulmonary Arterial Hypertension

Background: In patients with atrial septal defect (ASD) and severe pulmonary arterial hypertension (PAH), diastolic pulmonary arterial pressure (DPAP) correlates closely with pulmonary vascular resistance (PVR) and can reflect the severity of pulmonary vascular disease. However, it is unclear whether DPAP has potential to become a prognostic indicator for closure of ASD with severe PAH. Objectives: This study was performed to investigate the prognostic implication of DPAP in patients with ASD and severe PAH. Methods: Among 232 patients with ASD and severe PAH (systolic pulmonary arterial pressure (SPAP)≥70 mm Hg measured with right heart catheterization), 85 patients (21M/64F) undergoing closure of ASD were followed up. Doppler-calculated SPAP was recorded to identify the normalized post-operative PAP (SPAP<40 mm Hg). According to the cut-off value of DPAP from a ROC curve, two subsets were classified: low-DPAP (<25 mm Hg, n=31) and high-DPAP (≥25 mm Hg, n=54). Results: After closure of ASD, normalization of PAP occurred in 71% of patients with low-DPAP and 7.4% of patients with high-DPAP (P<0.001). Upon adjustment for PVR and SPAP/systolic aortic pressure, the hazard ratio of post-operative persistent PAH for high-DPAP was 4.48 (95%CI: 2.04-9.81, P<0.001). The follow-up (3.6 ± 1.3 years) demonstrated that normalized post-operative PAP tended to occur in patients with low-DPAP (Log Rank, P<0.001). Conclusions: In patients with ASD and severe PAH, low-DPAP has the potential to become a predictor for the normalized post-operative PAP.