Association of Preoperative Oxygen Saturation and McGoon Ratio With Early Prognosis of Tetralogy of Fallot: A Propensity Score-Matched Analysis.

Abstract

Aim: Tetralogy of Fallot (TOF) is the most common cyanotic heart disease. This study aimed to demonstrate the effects of preoperative oxygen saturation on the early prognosis of TOF and identify risk factors associated with early complications.

Method: A cohort of 1,138 patients who were diagnosed and underwent one-stage surgical repair in this hospital were retrospectively included in this study. The cohort was divided into three groups according to preoperative oxygen saturation: group 1 (≤75%, n=275), group 2 (75%-85%, n=339), and group 3 (≥85, n=524).

Results: There were 16 early deaths (16 of 1,138) and no late deaths in this study. The total mortality rate was 1.41%, which was not significantly different among the three groups. Major adverse events (MAE)-including death, extracorporeal membrane oxygenation assistance, delayed sternal closure, and re-operation during hospitalisation-were reported in 11.81% of patients in group 1, 7.93% in group 2, and 5.61% in group 3 (p=0.008). Multivariable risk analysis showed that atrial septal defect fenestration (p=0.002), aortic cross-clamp time (p=0.027), and McGoon ratio (p=0.046) were associated with MAE. By propensity score matching, the lower McGoon ratio was significantly related to MAE.

Conclusions: The surgical outcomes were acceptable, with low mortality and MAE rates. The McGoon ratio, not oxygen saturation, presented as a determining factor of MAE.