Sex-specific troponin and creatine kinase thresholds after coronary bypass surgery

Background: The impact of sex-differences on the release of cardiac biomarkers after coronary artery bypass grafting (CABG) remains unknown. The aim of our study was to (1) investigate the impact of sex-differences in cardiac biomarker release after CABG and (2) determine sex-specific thresholds for high-sensitivity cardiac troponin (hs-cTn) and creatine kinase-myocardial band (CK-MB) associated with 30-day major adverse cardiovascular events (MACE) and mortality. Methods: A consecutive cohort of 3687 patients, comprising 643 women (17.4%) and 3044 men (82.6%), undergoing CABG from 2008 to 2021 in 2 tertiary university centers with serial postoperative cTn and CK-MB measurement was analyzed. The composite primary outcome was MACE at 30 days. Secondary end points were 30-day mortality and 5-year mortality and MACE. Sex-specific thresholds for cTn and CK-MB were determined. Results: Lower levels of cTn were found in women after CABG (69.18 vs 77.57 times the upper reference limit [URL]; P <. 001). The optimal threshold value for cTn was calculated at 94.36 times the URL for female patients and 206.07 times the URL for male patients to predict 30-day MACE. Female patients missed by a general threshold had increased risk for MACE or death within 30 days (cTn: MACE: odds ratio [OR], 3.78; 95% CI, 1.03-13.08; P =. 035; death: OR, 4.98; 95% CI, 1.20-20.61; P =. 027; CK-MB: MACE: OR, 10.04; 95% CI, 2.07-48.75; P <. 001; death: OR 13.59; 95% CI, 2.66-69.47; P =. 002). Conclusions: We provide evidence for sex-specific differences in the outcome and biomarker release after CABG. Sex-specific cutoffs are necessary for the diagnosis of perioperative myocardial injury to improve outcomes of women after CABG.