Transposition of great arteries in developing world: Early mortality and predictive factors

Introduction

Transposition of great arteries (TGA) is a prevalent congenital heart defect presenting a diagnostic and therapeutic emergency. Its immediate prognosis is currently much improved by initial palliative treatment. However, in the absence of early complementary surgical repair, the prognosis remains extremely poor, with a high rate of mortality.

Objective

In this study, we sought to investigate the preoperative in-hospital mortality of newborns with TGA born in Sfax in Tunisia, a developing country with limited resources where surgical repair is not possible and most children undergo surgery abroad.

Methods

Monocentric retrospective analysis of all newborns with TGA hospitalized in CHU Hedi Chaker of Sfax in Tunisia during 2014–2022. Infants with simple TGA (± small VSD) and with complex TGA (large VSD, pulmonary stenosis or aortic coarctation) were included. Factors associated with preoperative in-hospital mortality were analyzed.

Results

The study included 51 patients divided into two groups: group I, 42 cases of simple TGA and group II, 9 cases with complex TGA. The overall preoperative mortality was 19.6% (10 of 51 patients) and it did not differ significantly between the two groups (group I 21.4% vs. group II 11%, P = 0.667). The mean age of death was 19 days (IQR = [8–44]). The mean time of death after diagnosis of TGA was 11 days with the earliest death occurring within the first 24 hours after diagnosis and the latest 36 days later. Major hypoxemia and infections were main causes of death, responsible of 90% of all deaths. Early mortality was significantly associated with a lower birth weight (2885 vs. 3317; P = 0.014) with a higher rate in female patients. On the other hand, age of discovery (P = 0.429) and antenatal diagnosis of TGA (P = 0.537) were not significantly associated with preoperative mortality. However, this is statistically insignificant result due to the limited prenatal detection (6%). No ultrasound predictive factor was identified with a higher rate of early death in the presence of incongruence between the pulmonary artery and the aorta (27.3% vs. 17.5%, P = 0.47) and in cases of banana-like LV shape (33.3% vs. 18.8%, P = 0.537). Failed balloon atrial septostomy was significantly associated with early mortality (75% vs. 16%; P = 0.028).

Conclusion

In our study, lower birth weight and insufficient interatrial shunt were independent factors predicting preoperative early death in TGA patients.