Abstract 19569: High-sensitive Troponin T Cut-off Value for Myocardial Infarction After Vascular Surgery

Abstract

Introduction: Isolated high sensitive cardiac troponin T (hsTnT) elevations after vascular surgery are frequent and may lead to over diagnosis of myocardial infarction (MI). The aim of our study was to determine the accuracy of the current hsTnT cut-off value in the setting of acute coronary syndrome (ACS) after vascular surgery. Methods: Between August 2012 and March 2014, we included 337 consecutive patients submitted to arterial vascular surgery for which cardiac perioperative evaluation was requested. Perioperative surveillance included 12-lead electrocardiogram and hsTnT measurements on the three days following surgery. Patients were followed-up by cardiologists until hospital discharge and monitored for ACS. A receiver operating characteristics (ROC) curve analysis was performed to determine the hsTnT cut-off value with better accuracy for the diagnosis of perioperative ACS. Results: Of the 337 patients included, 240 (71.2%) presented hsTnT elevation above the manufacturer-provided cut-off value (0.014 ng/ml), whereas 22 (6.5%) fulfilled criteria for ACS. Median post-operative peak hsTnT of ACS patients were 0.215 ng/ml (IQR 0.043-0.493 ng/ml), versus 0.02 ng/ml (IQR 0.012-0.038 ng/ml) in patients that did not have events (P<0.001). After performing a ROC curve analysis (AUC = 0.876), we found that the manufacture-provided cutoff hsTnT value yielded a sensitivity of 100% and specificity of only 35% for diagnosis of perioperative ACS. A new hsTnT cutoff value of 0.0415 ng/ml was obtained with 86.4% sensitivity and 77% specificity for the diagnosis of perioperative ACS. Ninety-two patients (27.3%) had hsTnT elevations above the proposed new cutoff. Conclusion: A different hsTnT cutoff value of 0.0415 ng/ml is proposed and could be more useful for the diagnosis of perioperative ACS.