Background Congenital heart disease with severe pulmonary arterial hypertension (SPAH),previously thought to have irreversible pulmonary vascular disease (PVD),has been recently successfully corrected using diagnostic treatment and repair strategy by our surgery team.This study aimed to evaluate the midterm results of a selected cohort of older patients with nonrestrictive ventricular septal defect (VSD) and SPAH using diagnostic treatment and repair strategy.Methods The records of 56 patients older than six years with nonrestrictive VSD and SPAH undergoing diagnostic treatment and repair strategy from 2006 to 2012 were retrospectively reviewed.All patients received advanced pulmonary arterial hypertension (PAH) therapy and radical repairs were performed when transcutaneous oxygen saturation (SPO2) increased up to 93％.Results There were no operative deaths.SPO2 and baseline six-minute walk test (SMWT) distance of all selected patients increased significantly and mean pulmonary artery pressure (MPAP) regressed significantly after diagnostic treatment and at late follow-up (P ＜0.01).The incidence of late postoperative PAH was seen in six (10.7％) patients and by Logistic regression analysis,early postoperative PAH was an independent risk factor related to late postoperative PAH.Conclusions Diagnostic treatment and repair strategy was effective and safe for treatment of nonrestrictive VSD and SPAH and the midterm results were excellent.Diagnostic treatment strategy was effective in assessing the reversibility of SPAH in older patients associated with nonrestrictive VSD and the PVD in these selective patients is generally reversible.