Abstract 324: Use of Troponin Testing After Non-cardiac Surgery in Ontario

Background: Myocardial infarction after non-cardiac surgery is common and associated with worse patient outcomes. In 2017, the Canadian Cardiovascular Society (CCS) published guidelines endorsing postoperative cardiac troponin surveillance in higher-risk patients having non-cardiac surgery. The objective of this study was to evaluate the proportion of non-cardiac surgery patients recommended for post-operative troponin testing and use of troponin testing in accordance with this guideline. Methods: We conducted a retrospective observational study of patients aged 40-105 years having moderate to high risk non-cardiac surgery in Ontario, Canada from January 1, 2010 to December 31, 2017. Classes of surgeries included orthopedics, gynecology, general, urology, vascular, and thoracic. Recommendations for troponin testing was determined by CCS criteria. Troponin testing within 2 days of the surgery was ascertained using the Ontario Laboratory Information System. Results: There were 268,269 patients in the cohort recommended for troponin testing during the study period. Mean age was 66.7 ± 11.9 years, 58.2% were female, and 12.3% underwent urgent surgery. According to CCS guidelines, 72.4% of elective surgery patients and 81.2% of urgent surgery patients would be recommended for post-operative troponin screening. The observed testing rate was 10.5% for elective patients and 26.4% for urgent surgery patients. Observed rates of testing for CCS recommended patients varied significantly by surgery: 5.5% for hysterectomies to 64.0% for open abdominal aortic aneurism repair (see Figure). Conclusions: Based on the current CCS guidelines, the majority of patients undergoing moderate to high-risk surgery should receive troponin testing. However, testing rates in Ontario were substantially lower with significant variations based on the type of surgery. The implication for routine troponin testing recommendation is substantial given the low utilization of troponin testing.