Background Invasive coronary function testing (CFT) has recently gained Class I recommendation in the ESC guidelines in patients with intractable anginal symptoms and unobstructed coronary arteries (ANOCA).1 Despite this, questions remain regarding safety and integration of CFT within clinical pathways and the impact that endotyping has on long term management of these patients with stratified medical therapy. Little is known about the impact of either a positive or a negative diagnosis on healthcare resources utilisation. Purpose To investigate the rate of diagnosis of specific ANOCA endotypes in patients presenting with anginal chest pain and to assess the impact of CFT on prescribed medical therapy and secondary care resource utilisation in this patient population. Methods A retrospective analysis of electronic care records of 255 patients who underwent CFT at two NIHR-BHF CMD Workstream registered UK centres between June 2022 and December 2024 has been performed. All patients had bolus and/or continuous thermodilution testing for endothelium-independent CMD (e-iCMD), and, of those, 163 (63.9%) had coronary vasospasm (VSA) provocation. In addition, 47 (18.4%) had endothelium-dependent CMD (e-dCMD) testing via novel continuous thermodilution method.2 The median length of follow up was 13 months (IQR 6–21). Results Overall, an endotype of ANOCA was identified in 136 (53.5%) of patients (ANOCA+ve). Isolated e-iCMD was found in 55 patients (21.6%). Isolated VSA was diagnosed in 55 patients (33.7% of tested), and isolated e-dCMD was diagnosed in 2 patients (4.3% of tested). A mixed endotype was diagnosed in 24 patients (14.7% of tested) (figure 1). Five (2%) intraprocedural adverse events were reported (four episodes of arrhythmia requiring cardioversion, one ad-hoc percutaneous coronary intervention due to dissection). In 179 patients (70.2%), CFT resulted in a change in medical therapy prescription. Following CFT, 66.4% of confirmed ANOCA -ve and 11.7% of ANOCA+ve patients were discharged from cardiology follow up. Of the 103 patients who had outpatient follow up since procedure (64%), 41 (39.8%) were discharged after first attendance (figure 2). 19.1% of ANOCA+ve patients and 18.5% of ANOCA-ve patients re-attended acute secondary healthcare services with chest pain. Of the ANOCA-ve re-attenders, 66.7% did not have VSA provocation as part of CFT. One episode (0.7%) of MACE (myocardial infarction) in ANOCA +ve group during study follow up was identified. Conclusions In this real-world study, CFT testing had low intraprocedural risk and confirmed ANOCA endotype in a majority of patients with anginal symptoms. Substantial changes to management of both ANOCA+ve and -ve patients were instigated as a result of testing, but clinical pathways need further refinement. Mixed endotypes are common and thus complete CFT testing should include e-iCMD, e-dCMD and VSA provocation to ensure correct endotype classification and targeted medical therapy. References Vrints C, Andreotti F, Koskinas KC, et al. 2024 ESC guidelines for the management of chronic coronary syndromes. Eur Heart J. 2024;45:3415–3537. Ibrahim A, Fawaz S, Sajjad U, et al. Coronary endothelial function: a novel acetylcholine infusion protocol with continuous thermodilution. J Am Coll Cardiol Intv. 2025 Feb;18(4):539–541.
Abramik et al. (Wed,) studied this question.
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