Meta-analysis of the performances of contemporary risk models in cardiac surgery for infective endocarditis

Abstract Background Risk scores play important roles in the decision-making for cardiac surgery, but remain under-studied in the setting of infective endocarditis (IE) when there is often a high risk of adverse outcomes. Several IE-specific risk scores have been developed recently, but there is a paucity of external validation studies. We aimed to pool the performance of current risk models applied to IE surgery. Methods Ovid Medline, Ovid Embase and Cochrane Library were comprehensively searched following PRISMA guidelines for eligible studies. Standard meta-analysis techniques using random effects models were used to pool the discriminative and calibration performance of risk scores for predicting operative mortality after IE surgery. Results Amongst 620 studies and 50 full-text articles screened, 17 studies reporting 12 risk scores and totaling 6337 patients were included. Amongst traditional risk scores, EuroSCORE I, EuroSCORE II, and STS IE score had pooled areas under curve (95%CI) of 0.727 (0.700.754), 0.753 (0.731-0.775), and 0.695 (0.645-0.746) (Table1). However, EuroSCORE II significantly over-estimated operative mortality while EuroSCORE I had good calibration with pooled Peto’s odds ratio (95%CI) of 2.47 (1.22-5.01) and 1.00 (0.74-1.36) respectively. Amongst IE-specific scores, areas under curve (95%CI) was highest for the ANCLA score 0.838 (0.803-0.873) and lowest for the COSTA score 0.641 (0.573-0.710). Conclusion Most contemporary risk score had moderate discriminative ability for operative mortality after IE surgery, with the IE-specific ANCLA score performing the best. However, there is room for improving the performance of current risk models, along with need for further external validation studies and calibration assessment, especially for IE-specific scores.