Impact of invasive coronary function testing on management of ANOCA patients and secondary care resource utilisation: insights from a multicentre retrospective study in the UK.

BACKGROUND

Invasive coronary function testing (CFT) is indicated in patients with refractory angina with non-obstructed coronary arteries (ANOCA). Despite this, questions remain regarding patient selection for testing, safety and integration of CFT within clinical pathways and the impact that endotyping has on long term management of these patients. This study aims to investigate the safety of CFT in patients presenting with anginal chest pain, the prevalence of ANOCA endotypes in the tested population, and the impact of CFT on prescribed medical therapy and secondary care resource utilisation.

METHODS

A retrospective analysis of electronic case records of 159 consecutive patients who underwent complete invasive CFT at two UK centres between June 2022 and December 2024 was performed. All patients were tested for endothelium-independent coronary microvascular dysfunction (CMD) and coronary vasospasm (vasospastic angina (VSA)). 44 patients (27.6%) also underwent endothelial function assessment. The median length of follow-up was 9 months (IQR 4-16).

RESULTS

An ANOCA endotype was identified in 101 patients (63.5%) (CFT+ve). Of those, 24 (23.8%) were diagnosed with isolated CMD, 53 (52.4%) with isolated VSA and 24 (23.8%) with a mixed endotype. Five (3.1%) experienced intraprocedural adverse events. In 123 patients (77.3%), CFT led to a change in medical therapy. Re-hospitalisation for recurrent chest pain occurred in 21.7% of CFT+ve and 13.7% of CFT-ve patients, with the majority re-presenting within 6 months of CFT. VSA was linked to higher re-hospitalisation odds (OR 2.64 (1.10-6.33), p=0.03), and patients with VSA tended to re-present earlier than others (p=0.017). Higher antianginal therapy prescription and prior emergency presentations were also predictive of risk of re-presentation (OR 1.61, p=0.02 and OR 4.18, p=0.001, respectively).

CONCLUSIONS

CFT testing had low intraprocedural risk and influenced onward management. Hospitalisation for chest pain post CFT testing was common. Further refinement of clinical pathways, including early follow-up for medical optimisation, is suggested.