The Belgian registry on coronary function testing (BELmicro registry): study population and prevalence of coronary vascular dysfunction

Abstract Background Coronary function tests (CFT) play a pivotal role in the diagnosis of coronary vascular dysfunction and in providing patients with tailored therapy. Aims To describe baseline characteristics and prevalence of coronary microvascular dysfunction (CMD) and coronary vasospasm in a real-world population of patients undergoing CFT. Methods The Belgian registry on coronary function testing (BELmicro registry) is a prospective, observational registry that includes 14 centers in Belgium. All patients undergoing clinically indicated CFT were included. Baseline characteristics, CFT data, and clinical outcomes were collected. Results Between October 2021 and September 2023, 449 patients were enrolled. The mean age was 65 ± 10 years, and 47.4% of patients were male. Fifty-nine percent of patients had hypertension, 18.7% diabetes, 69.5% hypercholesterolemia, and 40.1% smoking habit. On coronary angiography, the presence of coronary stenosis ≥ 50% was detected in 20.3% of patients. A microvascular physiology assessment was performed in 95.5% of patients, a vasoreactivity test in 28.5%, and both in 24.0%. CMD was diagnosed in 23.6% of patients. Definite epicardial vasospasm was diagnosed in 27.3% of patients, and microvascular spasm in 14.1%. The rates of severe complications were 0.7% for the microvascular physiology assessment and 0% for the vasoreactivity test. Conclusion Participants in the BELmicro registry represent a real-world population of patients, characterized by a high burden of cardiovascular risk factors. Both CMD and coronary vasospasm were frequent. CFT in daily clinical practice was feasible with a low rate of complications.Visual summaryScatter plot of measurements