Impact of Severe COVID-19 Infection on Coronary Microvascular Dysfunction in ANOCA Patients: A Cross-Sectional Study

Abstract

Background and aims
Millions of survivors from severe COVID-19 infection suffer from residual symptoms including anginal chest pain. The pathophysiological mechanisms, particularly the role of coronary microvascular dysfunction (CMD), however, remain elusive. We compared the incidence and endotypes of CMD in patients with angina without obstructive coronary artery disease (ANOCA) between those who had a history of severe COVID-19 infection (COVID group, defined as COVID patients needing supplemental oxygen therapy with SpO2 < 90% on room air), versus those who didn’t (Control group).

Methods
This multicentre, prospective cohort study enrolled 117 ANOCA patients (COVID group n=59, Control group n=58). All participants underwent exercise stress testing and invasive coronary physiology assessment to measure coronary flow reserve (CFR), and the index of microvascular resistance (IMR). CMD was defined as CFR<2.0 or IMR≥25. Patients also completed the modified Seattle Angina Questionnaire (SAQ-7) after invasive functional assessment.

Results
CMD was diagnosed in 42 patients (35.9%): 47.5% in the COVID group and 24.1% in the Control group (p=0.015). The prevalence of structural CMD was significantly higher in the COVID group (28.8% vs. 5.2%, p<0.001). The median IMR was significantly higher in the COVID versus the Control group (20.00 [15.00, 42.00] vs. 17.00 [12.00, 21.00], p=0.002) while no significant differences were observed in CFR and FFR. The SAQ-7 summary scores (54.44 vs. 59.44, p=0.003) and physical limitation and quality-of-life domain scores were all significantly lower in the COVID group.

Conclusions
The incidence of CMD, particularly structural CMD, was higher in ANOCA patients with a history of severe COVID-19 infection, suggesting a link between persistent angina and CMD in this population.