Gastrointestinal complications after cardiac surgery: a retrospective case-control study and risk score development

Gastrointestinal (GI) complications after cardiac surgery, although uncommon (0.4-3%), are associated with high mortality rates (13-63%). This study aimed to describes outcomes of GI complications and propose a risk score predicting their occurrence.

We conducted a retrospective case-control study including 8,544 patients undergoing cardiac surgery between 2005 and 2019. GI complications-defined as bleeding, ischemia/perforation, obstruction, or pancreatitis-were used to select cases for 1:2 propensity score matching with controls. Multivariable logistic regression was performed to determine independent predictors of a composite endpoint (postoperative pulmonary, renal, and cardiac complications). A GI complication risk score was then developed.

After matching, 162 patients were analyzed (54 GI group, 108 controls). Smokers and patients with significant coronary artery disease were more frequent in the GI group (p = 0.0049 and p = 0.0013). GI complications included ischemia (50.6%), hemorrhage (31.5%), pancreatitis (3.7%), and obstruction (14.8%), with 24.1% occurring as part of multiorgan failure. Overall mortality in the GI group was 38.8% compared with 0.9% in controls (p < 0.0001). Independent predictors of the composite endpoint were GI complications, NYHA class >2, and preoperative acute myocardial ischemia. The risk score, incorporating smoking, age, chronic kidney disease, and mitral valve replacement, showed good discrimination (area under the curve 0.735, 95% CI 0.653-0.816) and calibration (Hosmer-Lemeshow p = 0.934).

Mortality remains high among patients who develop GI complications after cardiac surgery, regardless of treatment modality. This risk score represents a potentially valuable tool for identifying patients at increased risk and underscores the importance of close monitoring and timely intervention in this population.