Acute kidney injury is an independent risk factor for myocardial injury after noncardiac surgery in critical patients

Abstract

BackgroundMyocardial injury after noncardiac surgery (MINS) contributes to mortality and morbidity. However, risk factors accelerating its development remain unclear. The aim of this study was to identify the incidence and risk factors of MINS. MethodsA retrospective and observational cohort study of critical patients (n=1087) after noncardiac surgery was carried out at a large and tertiary university hospital from January 2012 to January 2013. The clinical data including medical history as well as intraoperative and postoperative variables were recorded. The primary outcome was the occurrence of MINS. Secondary outcomes included 30-day all-cause mortality and the incidence of 30-day major adverse cardiac events (MACE) after surgery. The risk factors of MINS in critical patients were analyzed using logistic regression. ResultsMINS had occurred in 188 (17.3%) of the 1087 critical patients. Fifty-seven patients (5.2%) had postoperative acute kidney injury (AKI), wherein stage 1 accounted for 82.5% (47/57), stage 2 accounted for 12.3% (7/57), and stage 3 accounted for 5.3% (3/57). The independent risk factors of MINS in critical patients were emergency surgery (odds ratio [OR], 2.64; 95% confidence interval [CI], 1.60-4.35; P<.001), a longer time of operation (OR, 1.10; 95% CI, 1.03-1.17; P=.004), postoperative AKI (OR, 2.09; 95% CI, 1.15-3.79; P=.015), vasopressor drugs used within 24 hours after operation (OR, 2.27; 95% CI, 1.40-3.67; P=.001), and a higher Acute Physiology and Chronic Health Evaluation II score (OR, 1.05; 95% CI, 1.02-1.08; P=.002). All-cause mortality and MACE after surgery were not related to postoperative AKI (P=.544 for mortality; P=.663 for MACE). ConclusionsThe incidence of MINS in critical patients is high. Postoperative AKI is an independent risk factor of MINS in critical patients. It is recommended that postoperative kidney functions be routinely assessed in all critical patients after noncardiac surgery.