High Sensitivity Troponin I and Myocardial Injury After Noncardiac Surgery in Cancer Patients: A Prospective Observational Cohort Study

Introduction: Myocardial injury after noncardiac surgery (MINS) is diagnosed when a postoperative troponin concentration exceeds the 99 th percentile upper reference limit for a presumed ischemic mechanism and is associated with increased perioperative mortality. Our goal was to investigate the prognostic characteristics of MINS in a wide oncologic surgical population using fourth generation (TnI) and fifth generation high-sensitivity (hsTnI) troponin-I assays. Methods: In this prospective cohort of adults who underwent noncardiac cancer surgery, waste blood was collected daily until postoperative day three for TnI and hsTnI. MINS was explored using peak postoperative elevation using three definitions: (1) MINS TnI = TnI (≥ 0.06 ng/mL), (2) MINS hsTnI = hsTnI (≥ 17 ng/L for females or ≥ 35 ng/L for males), or (3) MINS either = either TnI or hsTnI elevation. The association between each MINS definition and the endpoints (30-day mortality, observed to expected length of stay ratio [O:E LoS]) were quantified via logistic and log-linear regression. Results: The incidence of MINS TnI, MINS hsTnI , and MINS either were 4.6%, 9.3%, and 9.5% respectively. In univariable analysis, MINS hsTnI was associated with an increased risk of 30-day mortality with an odds ratio (OR) of 3.30 (95% confidence interval 1.07, 8.57; p=0.039). Similar results were found for MINS either but were not statistically significant for MINS TnI . Cardiotoxic chemotherapy had a 3-fold increased odds of 30-day mortality and a higher incidence of MINS hsTnI (12%) when compared to non-chemo patients (9%). Change in O:E LoS was statistically significantly higher (25%) in patients with MINS hsTnI . Conclusion: In a large oncology cohort, MINS was associated with increased odds of 30-day perioperative mortality. HsTnI assays may be better suited to screen for MINS. The relationship of cardiotoxic chemotherapy to MINS risk warrants further investigation.