METHODS: We undertook an international, prospective study of 15,103 patients ≥45 years of age who had inpatient noncardiac surgery; 3,092 underwent orthopaedic surgery. Non-high-sensitivity TnT assays were performed on postoperative days 0, 1, 2, and 3. Among orthopaedic patients, we determined (1) the prognostic relevance of the MINS diagnostic criteria, (2) the 30-day mortality rate for those with and without MINS, and (3) the probable proportion of MINS cases that would go undetected without troponin monitoring because of a lack of an ischemic symptom.

RESULTS: Three hundred and sixty-seven orthopaedic patients (11.9%) had MINS. MINS was associated independently with 30-day mortality including among those who had had orthopaedic surgery. Orthopaedic patients without and with MINS had a 30-day mortality rate of 1.0% and 9.8%, respectively (odds ratio [OR], 11.28; 95% confidence interval [CI], 6.72 to 18.92). The 30-day mortality rate was increased for patients with MINS who had an ischemic feature (i.e., symptoms, or evidence of ischemia on electrocardiography or imaging) (OR, 18.25; 95% CI, 10.06 to 33.10) and for those who did not have an ischemic feature (OR, 7.35; 95% CI, 3.37 to 16.01). The proportion of orthopaedic patients with MINS who were asymptomatic and in whom the myocardial injury would have probably gone undetected without TnT monitoring was 81.3% (95% CI, 76.3% to 85.4%).

CONCLUSIONS: One in 8 orthopaedic patients in our study had MINS, and MINS was associated with a higher mortality rate regardless of symptoms. Troponin levels should be measured after surgery in at-risk patients because most MINS cases (>80%) are asymptomatic and would go undetected without routine measurements.

METHODS: We conducted a model-based cost-consequence analysis to compare the impact of routine troponin T monitoring versus standard care (troponin T measurement triggered by ischemic symptoms) on the incidence of MINS detection. Model inputs were based on Canadian patients enrolled in the Vascular Events in Noncardiac Surgery Patients Cohort Evaluation (VISION) study, which enrolled patients aged 45 years or older undergoing inpatient noncardiac surgery. We conducted probability analyses with 10 000 iterations and extensive sensitivity analyses.

RESULTS: The data were based on 6021 patients (48% men, mean age 65 [standard deviation 12] yr). The 30-day mortality rate for MINS was 9.6%. We determined the incremental cost to avoid missing a MINS event as $1632 (2015 Canadian dollars). The cost-effectiveness of troponin monitoring was higher in patient subgroups at higher risk for MINS, e.g., those aged 65 years or more, or with a history of atherosclerosis or diabetes ($1309).

METHODS: The authors randomized 10,010 patients with or at risk of atherosclerosis and scheduled for noncardiac surgery in a 1:1:1:1 ratio to clonidine/aspirin, clonidine/aspirin placebo, clonidine placebo/aspirin, or clonidine placebo/aspirin placebo. Patients started taking aspirin or placebo just before surgery; those not previously taking aspirin continued daily for 30 days, and those taking aspirin previously continued for 7 days. Patients were also randomly assigned to receive clonidine or placebo just before surgery, with the study drug continued for 72 h.

RESULTS: Neither aspirin nor clonidine had a significant effect on the primary 1-yr outcome, a composite of death or nonfatal myocardial infarction, with a 1-yr hazard ratio for aspirin of 1.00 (95% CI, 0.89 to 1.12; P = 0.948; 586 patients [11.8%] vs. 589 patients [11.8%]) and a hazard ratio for clonidine of 1.07 (95% CI, 0.96 to 1.20; P = 0.218; 608 patients [12.1%] vs. 567 patients [11.3%]), with effect on death or nonfatal infarction. Reduction in death and nonfatal myocardial infarction from aspirin in patients who previously had percutaneous coronary intervention at 30 days persisted at 1 yr. Specifically, the hazard ratio was 0.58 (95% CI, 0.35 to 0.95) in those with previous percutaneous coronary intervention and 1.03 (95% CI, 0.91to 1.16) in those without (interaction P = 0.033). There was no significant effect of either drug on death, cardiovascular complications, cancer, or chronic incisional pain at 1 yr (all P > 0.1).

Objective: To determine the association between perioperative hsTnT measurements and 30-day mortality and potential diagnostic criteria for MINS (ie, myocardial injury due to ischemia associated with 30-day mortality).

Design, Setting, and Participants: Prospective cohort study of patients aged 45 years or older who underwent inpatient noncardiac surgery and had a postoperative hsTnT measurement. Starting in October 2008, participants were recruited at 23 centers in 13 countries; follow-up finished in December 2013.

Exposures: Patients had hsTnT measurements 6 to 12 hours after surgery and daily for 3 days; 40.4% had a preoperative hsTnT measurement.

Main Outcomes and Measures: A modified Mazumdar approach (an iterative process) was used to determine if there were hsTnT thresholds associated with risk of death and had an adjusted hazard ratio (HR) of 3.0 or higher and a risk of 30-day mortality of 3% or higher. To determine potential diagnostic criteria for MINS, regression analyses ascertained if postoperative hsTnT elevations required an ischemic feature (eg, ischemic symptom or electrocardiography finding) to be associated with 30-day mortality.

Results: Among 21 842 participants, the mean age was 63.1 (SD, 10.7) years and 49.1% were female. Death within 30 days after surgery occurred in 266 patients (1.2%; 95% CI, 1.1%-1.4%). Multivariable analysis demonstrated that compared with the reference group (peak hsTnT <5 ng/L), peak postoperative hsTnT levels of 20 to less than 65 ng/L, 65 to less than 1000 ng/L, and 1000 ng/L or higher had 30-day mortality rates of 3.0% (123/4049; 95% CI, 2.6%-3.6%), 9.1% (102/1118; 95% CI, 7.6%-11.0%), and 29.6% (16/54; 95% CI, 19.1%-42.8%), with corresponding adjusted HRs of 23.63 (95% CI, 10.32-54.09), 70.34 (95% CI, 30.60-161.71), and 227.01 (95% CI, 87.35-589.92), respectively. An absolute hsTnT change of 5 ng/L or higher was associated with an increased risk of 30-day mortality (adjusted HR, 4.69; 95% CI, 3.52-6.25). An elevated postoperative hsTnT (ie, 20 to <65 ng/L with an absolute change ≥5 ng/L or hsTnT ≥65 ng/L) without an ischemic feature was associated with 30-day mortality (adjusted HR, 3.20; 95% CI, 2.37-4.32). Among the 3904 patients (17.9%; 95% CI, 17.4%-18.4%) with MINS, 3633 (93.1%; 95% CI, 92.2%-93.8%) did not experience an ischemic symptom.

METHODS: Analysis of patients discharged after inpatient noncardiac surgery in a large international prospective cohort study across 28 centers from 2007-2013 of patients aged ≥45 years followed to one year after surgery. We estimated 1) the cumulative post-discharge incidence of death and other outcomes up to a year after surgery and 2) the adjusted time-varying associations between post-discharge death and pre-discharge complications including myocardial injury after noncardiac surgery, major bleeding, sepsis, infection without sepsis, stroke, congestive heart failure, clinically important atrial fibrillation or flutter, amputation, venous thromboembolism, and acute kidney injury managed with dialysis.

RESULTS: Among 38,898 patients discharged after surgery, the cumulative one-year incidence was 5.8% (95% CI, 5.5-6.0%) for all-cause death and 24.7% (24.2-25.1%) for all-cause hospital readmission. Pre-discharge complications were associated with 33.7% (27.2-40.2%) of deaths up to 30 days after discharge and 15.0% (12.0-17.9%) up to one year. Most of the association with death was due to myocardial injury after noncardiac surgery (15.6% [9.3-21.9%) of deaths within 30 days, 6.4% [4.1-8.7%] within one year), major bleeding (15.0% [8.3-21.7%] within 30 days, 4.7% [2.2-7.2%] within one year), and sepsis (5.4% [2.2-8.6%] within 30 days, 2.1% [1.0-3.1%] within one year).

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.