Troponin testing after non-cardiac surgery in Ontario: an observational study

Background — In 2017, the Canadian Cardiovascular Society (CCS) published guidelines recommending post-operative troponin surveillance in higher-risk patients having major non-cardiac surgery. The objective of this study was to evaluate the proportion of major non-cardiac surgery patients that would meet recommendations for troponin testing and to assess the rates of troponin testing prior to guideline adoption.

Methods — We conducted a retrospective observational study of patients aged 40-105 undergoing a subset of major non-cardiac surgeries that included orthopedics, gynecology, general, urology, vascular, and thoracic surgeries in Ontario, Canada from January 1, 2010 to December 31, 2017. The primary outcomes were the proportion of patients recommended for testing based on the guidelines and rates of troponin testing within 2 days of surgery.

Results — We identified 257,704 patients who underwent non-cardiac surgery. Mean age was 66.4±11.9 years and 12.4% underwent urgent surgery. Applying the CCS guidelines, 71.2% of elective surgery patients and 81.0% of urgent surgery patients would have met recommendations for post-operative troponin screening while 10.8% and 27.1% received post-operative troponin testing respectively. Most elective surgery patients met recommendations for testing based on the age criterion (54.9%), followed by diabetes (24.6%) and high-risk surgery (22.7%) criterions. Troponin testing varied substantially by types of surgery: highest for open abdominal aortic aneurisms and lowest for hysterectomies.

Conclusions — Based on the CCS guidelines, most patients undergoing the subset of surgeries assessed would have met recommendations for routine troponin testing. In contrast, routine troponin testing prior to guideline adoption was done infrequently in Ontario, with substantial variations based on the surgery type.