Clinical Outcomes of Patients With Atrial Septal Defect and Pulmonary Arterial Hypertension

Background Indications for atrial septal defect (ASD) closure in patients with pulmonary arterial hypertension (PAH) have not been established. We evaluated medium-term outcomes in such patients with regard to the effect of ASD closure and prognostic predictors. Methods This single-center retrospective study included 39 patients with pulmonary vascular resistance (PVR) ≥ 2 Wood units (WU). The primary adverse outcome was defined as a composite of major cardiovascular events, including cardiac death or hospitalization for heart failure. Results Of the 39 patients, 32 underwent shunt closure, whereas 7 did not. Among patients with PVR ≥ 5 WU, over a median follow-up of 3.8 years, 3-year clinical event rates were 27.3% (3/11) in the closure group ( n = 11) and 14.3% (1/7) in the no-closure group ( n = 7); the difference was not statistically significant. The maximal velocity of tricuspid regurgitation significantly decreased during follow-up in the closure group; no significant change was observed in the no-closure group. In patients with PVR ≥ 5 WU, systemic arterial oxygen saturation (SaO 2 ) showed a significant association with the primary composite outcome; ASD closure and PVR were not. Among patients with PVR ≥ 5 WU who underwent ASD closure, those with SaO 2 < 93% ( n = 4) had a significantly higher rate of adverse outcomes than those with SaO 2 ≥ 93% ( n = 7) (hazard ratio, 17.8; P = .014), whereas no composite adverse events occurred in patients with SaO 2 ≥ 93%. Conclusions In patients with ASD and severe PAH, SaO 2 < 93% showed a significant association with adverse outcomes and may complement PVR in risk stratification. These exploratory findings require prospective validation.