A031 Non-ACS Diagnosis in Suspected Acute Coronary Syndrome and Regional Variations - An ANZACS-QI Study

Abstract

Rate of invasive coronary angiography (ICA) has risen over past two decades. Many non-coronary and non-cardiac conditions can mimic acute coronary syndrome (ACS), with less than 30% of chest pain presentations being ACS. There is a potential for inappropriate and unnecessary procedural risks. This study reviews New Zealand regional variation in non-ACS diagnosis in patients suspected of ACS. Consecutive patients ≥18y presenting with their first suspected ACS and underwent coronary angiography in 2015-2019 were identified from the ANZACS-QI registry. Two cohorts were compared: 1) suspected STEMI and 2) suspected NSTEACS. Patient demographics, investigations and discharge diagnosis were obtained from the registry. 30,317 patients were identified. 6059 (20%) suspected STEMI among which the rate of false-positive diagnosis across all district health boards (DHB) was <12% and appears independent of patient volume. In comparison, a wider variation exists for suspected NSTEACS, up to 27.3%, and demonstrates a general trend of higher non-ACS diagnosis in higher volume centres. The non-ACS condition most likely to raise suspicion for ACS on presentation and undergo ICA includes stress cardiomyopathy (11.9%), arrhythmia (10.4%), stable angina (9.3%) and myocarditis (7.9%). Low rates of false-positive diagnosis for patients presenting with suspected STEMI across the nation. Comparatively, non-ACS diagnoses rate is higher particularly in higher volume centres for suspected NSTEACS. However, ICA appears to be appropriately performed as diagnostic tools for common non-ACS conditions that can mimic potentially life-threatening ACS.