LAUSR

Background: 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 Method: 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 Results: 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%) Conclusion: 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