Clinical profile and long-term outcomes of chest pain patients with coronary microvascular dysfunction from the emergency department - results from the Yale-CMD registry.

OBJECTIVE

To investigate the long-term prognosis of coronary microvascular dysfunction (CMD) in emergency department (ED) patients with chest pain for major adverse cardiac events (MACE) due to all-cause mortality, myocardial infarction (MI), heart failure (HF), or stroke.

METHODS

A prospective cohort of ED patients evaluated by hybrid cardiac positron emission tomography with attenuation computed tomography within 24 h of arrival. Patients were classified as: (1) Controls - coronary flow reserve (CFR) ≥2 without perfusion defect or coronary calcification; (2) CMD: CFR <2 without defect or calcification; or (3) CAD/CALC - established or new coronary artery disease (CAD) or calcification (CALC). We conducted annual follow-ups for MACE and all-cause healthcare utilization (hospitalizations and ED visits). We adjusted incidence rates (aIR) and hazard ratio (aHR) for demographics, comorbidities, and medications.

RESULTS

Between 2014 and 2020, 189 patients were enrolled: 95 (50 %) Controls, 34 (18 %) with CMD, and 60 (32 %) with CAD/CALC. Median follow-up time was 50 months (38-92), and a total of 187 unique MACE were recorded in 44 patients. CMD patients had 4× higher MACE risk than controls (aIR 3.8; 95 % CI: 2.1-6.6). CAD/CALC patients had similarly higher risk than controls (aIR: 4.5; 95 % CI: 2.6-7.8). CMD patients had 4× higher risk for time to first MACE than controls (aHR: 3.6; 95 % CI: 1.2-10.7) and higher healthcare utilization per 100 person-months (aIR: 124; 95 % CI: 119-130). Using Seattle Angina Questionnaire, CMD patients showed worse angina frequency than controls (difference: -16.4, 95 % CI: -29.5 to -3.4).

CONCLUSIONS

Patients with contemporary phenotypes of ischemia (CMD and CAD/CALC) had higher adverse events than controls, positing ED encounters as an opportunity for early identification and treatment.