Unexpected Cardiac Computed Tomography Findings in Patients With Postoperative Myocardial Injury

BACKGROUND: Postoperative myocardial injury (PMI) is a strong predictor of mortality after noncardiac surgery. PMI is believed to be attributable to coronary artery disease (CAD), yet its etiology is largely unclear. We aimed to quantify the prevalence of significant CAD in patients with and without PMI using coronary computed tomography angiography (CCTA). METHODS: This prospective cohort study included patients of 60 years or older without a history of cardiac disease and with and without PMI after intermediate-to high-risk noncardiac surgery. PMI was defined as any serum troponin I level >= 60 ng/L on the first 3 postoperative days. Main exclusion criteria were known cardiac disease and postoperative ischemic symptoms or electrocardiography abnormalities. Noninvasive imaging consisted of a postoperative CCTA. Main outcome was CAD defined as >50% coronary stenosis on CCTA. RESULTS: The analysis included 66 patients. Median peak troponin levels in the PMI (n = 46) and control group (n = 20) were 150 (interquartile range, 120-298) vs 15 (interquartile range, 10-31) ng/L (P < .01). CAD was found in 23 patients with PMI (50%) vs 3 without PMI (15%; relative risk, 3.3; 95% confidence interval, 1.1-9.8). Remarkably, pulmonary embolism was present in 15 patients with PMI (33%) versus in 4 without PMI (20%; relative risk, 1.6; 95% confidence interval, 0.6-4.3). None of the patients died within 30 days. CONCLUSIONS: In patients without a history of cardiac disease, PMI after noncardiac surgery was associated with CAD. In addition, a clinically silent pulmonary embolism was found in one-third of patients with PMI. This urges further research to improve clinical workup using imaging and may have important clinical implications.