Assessment of Risk Factors for Coronary Artery Restenosis and Patient Survival During the COVID-19 Pandemic

<b>Background</b>: In-stent restenosis of coronary arteries is a significant problem in interventional cardiology. Inflammatory processes in the arterial intima play a key role among the well-known risk factors for restenosis. The COVID-19 pandemic has contributed to the development of inflammation and the activation of the coagulation system. The aim of this study was to assess the risk factors for coronary artery restenosis and patient survival during the COVID-19 pandemic. <b>Materials and Methods</b>: We performed a cross-sectional study on a targeted sample of patients with coronary artery disease who underwent repeat myocardial revascularization (931 patients). The main study group, consisting of patients with coronary artery stent restenosis, included 420 patients (38.5% had previous COVID-19). The control group included 511 patients without stent restenosis (20.9% had COVID-19). <b>Results</b>: The results of multiple logistic regression analysis showed that the odds ratio (OR) for COVID-19 was 2.29 (95% CI 2.78-3.19) (<i>p</i> < 0.001), and the OR for C-reactive protein (CRP) was 1.08 (95% CI 1.002-1.013). The average hospital survival time for subjects with prior COVID-19 (N = 269) was 9.53 ± 0.106 days (95% CI 9.32-9.74), while for those without COVID-19 (N = 662), it was 9.89 ± 0.032 days (95% CI 9.83-9.96) (<i>p</i> < 0.001). The one-year survival time was 316.7 ± 6.982 days (95% CI 303.0-330.4) for the COVID-19 group and 340.14 ± 3.243 days (95% CI 333.8-346.5) for the non-COVID-19 group (<i>p</i> < 0.001). <b>Conclusions</b>: The main risk factors for in-stent restenosis were COVID-19 and elevated CRP levels. The average survival time in the group with prior COVID-19 was statistically significantly lower than in patients without COVID-19, both during the hospital stay and within one year after repeated revascularization.