Comparison of high-sensitivity cardiac troponin I and T for the prediction of cardiac complications after non-cardiac surgery.

BACKGROUND: We aimed to directly compare preoperative high-sensitivity cardiac troponin (hs-cTn) I and T concentration for the prediction of major cardiac complications after non-cardiac surgery. METHODS: We measured hs-cTnI and hs-cTnT preoperatively in a blinded fashion in 1022 patients undergoing non-cardiac surgery. The primary endpoint was a composite of major cardiac complications including cardiac death, cardiac arrest, myocardial infarction, clinically relevant arrhythmias, and acute heart failure within 30 days. We hypothesized that the type of surgery may impact on the predictive accuracy of hs-cTnI/T and stratified all analyses according to the type of surgery. RESULTS: Major cardiac complications occurred in 108 (11%) patients, 58/243 (24%) patients undergoing vascular surgery and 50/779 (6%, P < .001) patients undergoing non-vascular surgery. Using regulatory-approved 99th percentile cut-off concentrations, preoperative hs-cTnI elevations were less than one-fifth as common as preoperative hs-cTnT elevations (P < .001). Among patients undergoing vascular surgery, preoperative hs-cTnI concentrations, but not hs-cTnT, was an independent predictor of cardiac complications (adjusted odds ratio (aOR) 1.5, 95% confidence interval (95% CI) 1.0-2.1). The area under the receiver-operating characteristics curve (AUC) was 0.67 (95% CI, 0.59-0.75) for hs-cTnI versus 0.59 (95% CI 0.51-0.67, P = .012) for hs-cTnT. In contrast, among patients undergoing non-vascular surgery both preoperative hs-cTnI and hs-cTnT were independent predictors of the primary endpoint (aOR 1.6, 95% CI 1.3-2.0, and aOR 3.0, 95% CI 2.0-4.6, respectively) and showed higher predictive accuracy (AUC 0.77, 95% CI, 0.71-0.83, and 0.79, 95% CI 0.73-0.85, P = ns). CONCLUSIONS: Preoperative hs-cTnI and hs-cTnT concentrations predict major cardiac complications after non-vascular surgery, while, in patients undergoing vascular surgery, hs-cTnI may have better accuracy.

Prediction of major cardiac events after vascular surgery.

OBJECTIVE: Predicting cardiac events is essential to provide patients with the best medical care and to assess the risk-benefit ratio of surgical procedures. The aim of our study was to evaluate the performance of the Revised Cardiac Risk Index (Lee) and the Vascular Study Group of New England Cardiac Risk Index (VSG) scores for the prediction of major cardiac events in unselected patients undergoing arterial surgery and to determine whether the inclusion of additional risk factors improved their accuracy. METHODS: The study prospectively enrolled 954 consecutive patients undergoing arterial vascular surgery, and the Lee and VSG scores were calculated. Receiver operating characteristic curves for each cardiac risk score were constructed and the areas under the curve (AUCs) compared. Two logistic regression models were done to determine new variables related to the occurrence of major cardiac events (myocardial infarction, heart failure, arrhythmias, and cardiac arrest). RESULTS: Cardiac events occurred in 120 (12.6%) patients. Both scores underestimated the rate of cardiac events across all risk strata. The VSG score had AUC of 0.63 (95% confidence interval [CI], 0.58-0.68), which was higher than the AUC of the Lee score (0.58; 95% CI, 0.52-0.63; P = .03). Addition of preoperative anemia significantly improved the accuracy of the Lee score to an AUC of 0.61 (95% CI, 0.58-0.67; P = .002) but not that of the VSG score. CONCLUSIONS: The Lee and VSG scores have low accuracy and underestimate the risk of major perioperative cardiac events in unselected patients undergoing vascular surgery. The Lee score's accuracy can be increased by adding preoperative anemia. Underestimation of major cardiac complications may lead to incorrect risk-benefit assessments regarding the planned operation.

Myocardial injury after noncardiac surgery: a large, international, prospective cohort study establishing diagnostic criteria, characteristics, predictors, and 30-day outcomes.

BACKGROUND: Myocardial injury after noncardiac surgery (MINS) was defined as prognostically relevant myocardial injury due to ischemia that occurs during or within 30 days after noncardiac surgery. The study's four objectives were to determine the diagnostic criteria, characteristics, predictors, and 30-day outcomes of MINS. METHODS: In this international, prospective cohort study of 15,065 patients aged 45 yr or older who underwent in-patient noncardiac surgery, troponin T was measured during the first 3 postoperative days. Patients with a troponin T level of 0.04 ng/ml or greater (elevated "abnormal" laboratory threshold) were assessed for ischemic features (i.e., ischemic symptoms and electrocardiography findings). Patients adjudicated as having a nonischemic troponin elevation (e.g., sepsis) were excluded. To establish diagnostic criteria for MINS, the authors used Cox regression analyses in which the dependent variable was 30-day mortality (260 deaths) and independent variables included preoperative variables, perioperative complications, and potential MINS diagnostic criteria. RESULTS: An elevated troponin after noncardiac surgery, irrespective of the presence of an ischemic feature, independently predicted 30-day mortality. Therefore, the authors' diagnostic criterion for MINS was a peak troponin T level of 0.03 ng/ml or greater judged due to myocardial ischemia. MINS was an independent predictor of 30-day mortality (adjusted hazard ratio, 3.87; 95% CI, 2.96-5.08) and had the highest population-attributable risk (34.0%, 95% CI, 26.6-41.5) of the perioperative complications. Twelve hundred patients (8.0%) suffered MINS, and 58.2% of these patients would not have fulfilled the universal definition of myocardial infarction. Only 15.8% of patients with MINS experienced an ischemic symptom. CONCLUSION: Among adults undergoing noncardiac surgery, MINS is common and associated with substantial mortality.