Background: We carried out a retrospective data review of patients with systemic to pulmonary shunts that underwent surgical repair between February 1990 and February 2012 in order to assess preoperative pulmonary vascular dynamic risk factors for predicting early and late deaths due presumably to pulmonary vascular disease. Methods and Results: A total of 1024 cases of congenital systemic-to-pulmonary shunt and advanced pulmonary vascular disease beyond infancy and early childhood were closed surgically. The mean follow up duration was 8.5 +/- 5.5 (range 0.7 to 20) years. Sixty-one in-hospital deaths (5.96%, 61/1024) occurred after the shunt closure procedure and there were 46 late deaths, yielding 107 total deaths. We analyzed preoperative pulmonary vascular resistance index (PVRI), pulmonary vascular resistance index on pure oxygen challenge (PVRIO), difference between PVRI and PVRIO (PVRID), Qp:Qs, and Rp:Rs as individual risk predictors. The results showed that these individual factors all predicted in-hospital death and total death with PVRIO showing better performance than other risk factors. A multivariable Cox regression model was built, and suggested that PVRID and Qp: Qs were informative factors for predicting survival time from late death and closure of congenital septal defects was safe with a PVRIO<10.3 WU.m(2) and PVRID>7.3 WU.m(2) on 100% oxygen. Conclusions: All 4 variables, PVRI, PVRIO, PVRID and Qp:Qs, should be considered in deciding surgical closure of congenital septal defects and a PVRIO<10.3 WU.m(2) and PVRID>7.3 WU.m(2) on 100% oxygen are associated with a favorable risk benefit profile for the procedure.