Background: Pulmonary arterial hypertension (PAH) after shunt closure is associated with a poor prognosis. The aim of this study was to assess retrospectively the hemodynamics of patients developing PAH after shunt closure.
Methods: Hemodynamic data obtained by right heart catheterization (RHC) performed at baseline and after shunt closure were analyzed.
Results: Twenty-two patients, 13 with atrial septal defect (ASD), 6 with ventricular septal defect (VSD), 1 with patent ductus arteriosus, 1 with both ASD and VSD, and 1 with complete atrio-ventricular canal have been considered. The mean age at closure was 25.3±20.1 years (range of 3 months to 56.7 years), and the mean age at PAH diagnosis was 37.0±20.8 years (range of 5 to 61.2 years). The time delay between shunt closure and PAH diagnosis was 140.2±100.2 months. At baseline RHC, hemodynamic data were as follows: pulmonary vascular resistance (PVR) of 8.6±2.6 Wood units, PVR index (PVRi) of 10.1±2.7 Wood units∗m(2), mean pulmonary arterial pressure of 43.7±9.7 mmHg, PVR to systemic vascular resistance ratio (PVR/SVR) of 0.70±0.23, and Qp/Qs of 1.6±0.4. In particular, 18/22 (81%) had PVR≥5 Wood units, 21/22 (95%) PVRi≥6 Wood units∗m(2), 21/22 (95%) PVR/SVR≥0.33, and 11/22 (50%) Qp/Qs≤1.5. During the follow-up, 5/22 (22%) patients died and one patient underwent successful double lung transplantation.
Conclusions: High baseline values of PVR (≥5 Wood units), PVRi (≥6 Wood units∗m(2)) and PVR/SVR (≥0.33) are common findings in patients who develop PAH late after shunt closure. Large prospective clinical trials are needed to establish the safe limits for shunt closure.
Keywords: Congenital heart diseases; Hemodynamics; Pulmonary hypertension.