Key Learning Points
What is already known
- Patients with ANOCA are often overlooked, experiencing delayed or mis-diagnosis and improper treatment.
- There is evidence of improved patient outcomes when a functional coronary angiography stratified treatment plan is utilized.
- A guarded prognosis is reported in some of these patients, with a risk of major adverse cardiac events (MACE) and on-going chest pain.
What this study adds
- This comprehensive cohort study of consecutive patients presenting with a chronic coronary syndrome with/without obstructive coronary artery disease provides a real-world perspective of their clinical journey in relation to pre/post-angiography assessments and outcomes.
- Pre-angiography clinical assessment of patients with ANOCA demonstrates they are indistinguishable from obstructive CAD in relation to angina symptoms and ischaemic markers but have fewer cardiovascular risk factors.
- Post-angiography, less than 1-in-4 patients with ANOCA are discharged with a cardiac diagnosis and only ∼1 in 20 underwent further invasive coronary physiology evaluation. At 12 months, symptoms and health status were similar between ANOCA and obstructive CAD patients, based on patient-reported outcomes. By 3 years, ∼1 in nine ANOCA and ∼1 in six obstructive CAD patients were admitted with acute coronary syndrome.
Introduction
Chronic coronary syndromes (CCS) traditionally constitute patients with obstructive coronary artery disease (i.e. CAD), due to significant atherosclerotic plaques impairing coronary blood flow in the supply/demand ischaemic paradigm. However, half of the patients undergoing elective invasive coronary angiography for a CCS presentation, do not have obstructive CAD (i.e. no stenoses ≥50%) to account for their symptoms and are frequently dismissed from cardiac care as having ‘non-cardiac pain’. Despite this ‘diagnostic label’, these patients may have ischaemic symptoms due to coronary vasomotor disorders (i.e. coronary artery spasm and/or coronary microvascular dysfunction), not readily diagnosed on routine diagnostic angiography. The notable 2024 European Society of Cardiology Chronic Coronary Syndrome Guidelines, have included these patients with non-obstructive CAD into the spectrum of CCS, using the terms ANOCA (Angina with Non-Obstructive Coronary Arteries) and INOCA (Ischaemia with Non-Obstructive Coronary Arteries) as working clinical diagnoses, which require further assessment of the underlying mechanisms responsible for the angina/ischaemia.
Classifying patients with a CCS presentation as obstructive CAD or ANOCA/INOCA based upon their angiographic findings, raises the question whether there are clinical differences between these groups. Abundant data demonstrate that a more extensive atherosclerotic burden on coronary angiography is associated with a greater risk of major adverse cardiovascular events (MACE), both in relation to the presence/absence of obstructive CAD and the number of coronary arteries involved. However, the clinical and diagnostic journey of patients with ANOCA/INOCA compared to the benchmark obstructive CAD has largely been inferred, as there is limited quantitative data. For example, ANOCA patients frequently have atypical chest pain and/or seldom have evidence of myocardial ischaemia, thereby justifying the label of ‘non-cardiac chest pain’. Thus, the aim of this study was to compare the journey of patients with ANOCA vs. obstructive CAD, particularly in relation to their (i) clinical presentation and (ii) diagnostic assessment, but also subsequent outcomes including (iii) 12-month patient-reported outcome measures (PROMs), and (iv) 3-year composite MACE.
