With almost a million elective surgeries in Australia, cardiac complications leading to death still remain a significant contributor to post-operative mortality in elective non-cardiac surgery [1]. Therefore, appropriate screening, investigations, and perioperative management of cardiovascular disease are required, with guidelines most notably from the American College of Cardiology (ACC)/American Heart Association (AHA) [2]. Current guidelines recommend appropriate risk stratification using risk score calculators based on history and examination, with further recommendations including investigations, medical therapy, perioperative care, and further long-term therapy [3]. We conducted an audit of cardiac investigations that have been ordered pre-operatively in the preadmission clinic for patients undergoing non-cardiac elective surgery, to compare it to current published guidelines and determine whether there was an avoidable delay to operation.

 

This was a retrospective audit of non-cardiac surgery cases that attended preadmission clinic throughout 2023 at Maroondah Hospital, part of Eastern Health in metropolitan Victoria, Australia. Eastern Health Human Research and Ethics Committee approval was obtained, 22nd March 2024 (QA24-029-106550). Data was collected via electronic medical records and included ASA grading, cardiac risk factors, cardiac investigations ordered (excluding ECG) and their results, and whether these investigations led to a delay in surgery.

 

A total of 1693 patients attended preadmission clinic, with 161 (9.5%) patients having cardiac investigations ordered. Of those, only 42 patients (26%) had positive results, and of those 28 were followed-up by cardiology. There were 105 patients with a proposed surgery date, 45 (43%) of whom had surgery delayed due to cardiac investigations, and 27 were delayed with a negative test result (p value = 0.0075). Furthermore, for patients who were delayed with a negative test result,14 patients (52%) did not require cardiac investigations when applying ACC/AHA guidelines (p value = <0.0001).

 

Compared to a similar audit conducted at the same institution in 2007, there has been a noteworthy reduction in percentage of tests conducted, dropping from 19% to 9.5%. However, the percentage of positive investigations has remained relatively similar at, 23% compared to 26%. Both audits agree with global literature that over-investigation is common but can potentially be avoided by following local or international guidelines for ordering cardiac tests. Moving forward, we plan to re-audit after implementing such guidelines, with the objective of further reducing unnecessary cardiac investigations that may lead to delays in surgery.

 

1.     Yao Y, Dharmalingam A, Tang C, Bell H, Dj McKeown A, McGee M, et al. Cardiac risk assessment with the Revised Cardiac Risk Index index before elective non-cardiac surgery: A retrospective audit from an Australian tertiary hospital. Anaesthesia and Intensive Care. 2021;49(6):448-54.

2.     Fleisher LA, Fleischmann KE, Auerbach AD, Barnason SA, Beckman JA, Bozkurt B, et al. 2014 ACC/AHA Guideline on Perioperative Cardiovascular Evaluation and Management of Patients Undergoing Noncardiac Surgery. Circulation. 2014;130(24):e278-e333.

3.     3. Pannell LMK, Reyes EM, Underwood SR. Cardiac risk assessment before non-cardiac surgery. European Heart Journal - Cardiovascular Imaging. 2013;14(4):316-22.