52 The introduction of a coronary microvascular testing service, a DGH experience

Introduction Coronary microvascular dysfunction (CMD) is associated with an increase in both morbidity and mortality. It is an under recognised and under treated cause of ischaemic heart disease. Invasive coronary angiography provides a means of definitively testing both the macro and micro circulation for flow limiting coronary artery disease, CMD and vasospasm. A CMD testing service was introduced in our centre in 2023. Methods A 1 year retrospective review of consecutively tested patients. Following diagnostic angiography with fractional flow reserve (FFR) both endothelial independent (adenosine) and dependent (acetylcholine) function was tested. Bolus or continuous infusion thermodilution techniques were used. Bolus coronary flow reserve (CFR) or absolute CFR, index of microcirculatory resistance (IMR) and acetylcholine flow reserve (AChFR) were reported. Epicardial vasospasm provocation testing was undertaken with bolus intracoronary acetylcholine. Results 26 procedures, 62% female, aged 62+/-12. Median number of diagnostic tests prior to CMD testing was 2 IQR2, health care encounters 4 IQR6 with a time to diagnosis of 14 IQR41 months. 35% of cases were diagnosed with epicardial vasospasm, 31% mixed vasospasm and CMD, 19% normal and 15% had CMD only. 81% of cases had management altered following testing. Testing results are presented in table 1. Conclusions A large proportion of symptomatic patients tested had a diagnosis made with subsequent changes to their management. To reduce delay to diagnosis our Rapid Access Chest Pain Clinic (RACPC) pathway has been altered to facilitate earlier CMD referral. In patients presenting with angina additional CMD testing should be considered when unobstructed coronary arteries are found at angiography. Conflict of Interest None