Risk factors and outcomes of prolonged cardiopulmonary bypass time in surgery for adult congenital heart disease: A single-center study from a low-middle-income country

BACKGROUND: Prolonged cardiopulmonary bypass time (prolonged CPBT; PCPBT) during operations for adult congenital heart disease (ACHD) may lead to worse postoperative outcomes, which could add a significant burden to hospitals in developing countries. This study aimed to identify risk factors and outcomes of PCPBT in patients undergoing operations for ACHD. METHODS: This retrospective study included all adult patients (≥18 years) who underwent cardiac surgery with cardiopulmonary bypass for their congenital heart defect from 2011-2016 at a tertiary-care private hospital in Pakistan. Prolonged CPBT was defined as CPBT>120 minutes (65th percentile). RESULTS: This study included 166 patients (53.6% males) with a mean age of 32.05±12.11 years. Comorbid disease was present in 59.0% of patients. Most patients underwent atrial septal defect repair (42.2%). Atotal of 58 (34.9%) of patients had a PCPBT. Postoperative complications occurred in 38.6% of patients. Multivariable analysis adjusted for age, gender and RACHS-1 Categories showed that mild preoperative left ventricular (LV) dysfunction was associated with PCPBT (OR=3.137 [95% CI: 1.003-9.818]), while obesity was found to be protective (0.346 [0.130-0.923]). PCPBT was also associated with a longer duration of ventilation (1.298 [1.005-1.676]), longer cardiac ICUstay (1.204 [1.061- 1.367]) and longer hospital stay (1.120 [1.005-1.247]). CONCLUSIONS: While mild preoperative LV dysfunction was associated with PCPBT, obesity was found to be protective. Postoperatively, PCPBT was associated with longer duration of ventilation, cardiac ICUstay, and hospital stay. Operations with shorter CPBT may help minimize the occurrence and impact of these postoperative adverse outcomes especially in resource-constrained developing countries.