Objectives: Bi-ventricular congenital heart disease with pulmonary hypertension may not be operable. Although there are several clinical features that suggest operability, the definitive method to determine operability is to measure the pulmonary vascular resistance index (PVRI). ‘Cut-offs’ for operability, reported in the literature, range from 5 to 10.3 Wood Units per m2 (WU.m2). The object of our study was to determine the optimal PVRI cut-off for operability in CHD with pulmonary hypertension. Methods: We performed at systematic search of Google scholar and PubMed between January 1st 1966 to August 12th 2024. English language studies that examined how preoperative PVRI related to operative mortality and long-term post-operative mortality, were included. The most externally valid study was chosen using the proximal similarity model to determine the optimal PVRI cut-off indicating inoperability. Results: Six hundred and thirty four results were retrieved. Eleven full-text papers were examined; 2 papers were included. PVRI cut-offs ranged from 7 to 10.3 WU.m2. The PVRI cut-off in the most externally valid paper was 10.3 WU.m2. Conclusion: The optimal PVRI cut-off indicating inoperability of CHD with pulmonary hypertension is 10.3 WU.m2. This cut-off was after administration of 100% inhaled oxygen and is referred to as the PVRIO.

Keywords: Congenital heart disease operability pulmonary vascular resistance index