The Impact of COVID-19 Infection on the Prevalence of Coronary Microvascular Dysfunction in Lithuanian Patients with Angina

Introduction The global COVID-19 pandemic has impacted healthcare systems and patient outcomes, with evidence suggesting long-term cardiovascular complications in individuals who have recovered from the infection. One such complication is coronary microvascular dysfunction (CMD), a condition characterized by impaired coronary microcirculation and resulting in persistent angina and ischemic symptoms despite the absence of obstructive coronary artery disease. CMD's prevalence may be exacerbated by the systemic inflammation and endothelial dysfunction associated with COVID-19. Although long COVID is known to cause a range of symptoms, CMD's specific role in those manifestations remains poorly understood. Aim To investigate the prevalence of CMD in patients with a history of COVID-19 infection who are currently experiencing symptoms of angina. Methods A total of 117 patients presenting with angina symptoms, were divided into two groups based on their COVID-19 history. The first group of 59 patients with a previous positive test for COVID-19 (COVID group), while the second group comprised 58 patients with no documented history of COVID-19 (control group). Clinical and demographic data were collected to ensure comparability between groups. To evaluate the prevalence of CMD, participants underwent comprehensive invasive coronary physiological assessments. These included the measurement of coronary flow reserve (CFR) and the index of microvascular resistance (IMR), which are considered gold-standard methods for diagnosing CMD. CMD was defined according to the guidelines of the ESC, ACC/AHA, and EAPCI as either a CFR < 2.0 or an IMR ≥ 25. Results Between June 2023 and June 2024, 117 patients with angina symptoms were divided into two groups: 59 patients in the COVID-19 group and 58 in the control group. The mean age of the participants was 65.95 ± 11.43 years, and both groups were similar in terms of demographic characteristics, clinical histories, and baseline laboratory results. In the COVID-19 group, 3 patients (5.1%) had recovered from the infection within the past 6 months, 17 patients (28.8%) had recovered between 6 and 12 months earlier, and 39 patients (66.1%) had recovered more than a year before enrolment. The median duration of COVID-19 symptoms was 14 days (IQR 9-18) The prevalence of CMD was significantly higher in the COVID-19 group, with 28 patients (47.5%) in the COVID-19 group meeting the criteria for CMD, versus 14 patients (24.1%) in the control group (p = 0.015). Conclusions Patients with angina and a history of COVID-19 had a significantly higher CMD prevalence compared to those without a history of COVID-19. These findings indicate a potential association between long COVID and CMD, which could explain the persistence of angina symptoms and signs of ischemia in this population. Further studies are warranted to explore the underlying mechanisms and therapeutic strategies to address CMD in post-COVID-19 patients.