COVID-19 Increases the Risk of New Myocardial Infarction in Patients with Old Myocardial Infarction: A Retrospective Observational Study.

Background: We aimed to investigate the incidence of new acute myocardial infarction (AMI), in patients with Coronavirus disease (COVID-19) who had old MI. We hypothesized that COVID-19 increases the rate of repeated AMI in this population regardless of age and gender. Methods: A retrospective analysis was conducted for adult patients admitted with COVID-19 and developed thromboembolic event (TEE) in 2020. Patients were categorized based on the history of old MI, new MI, age, and gender. Results: Among 16,903 patients with COVID-19 who were admitted, 210 (1.2%) developed TEE (89% were males, 55% were <55 years old, and 80.5% had an old MI). COVID-19 was severe in 32% of cases. AMI occurred in 160 patients (42.5% STEMI and 57.5% NSTEMI). In patients with prior MI, 92.5% developed another AMI. NSTEMI was higher in patients with severe COVID-19 than STEMI (33% vs 21%). Patients with severe COVID-19 had higher mortality (39.4% vs 5.6%), fewer rates of prior MI (74% vs 83%), hypertension (40% vs 60%), and STEMI (31.8% vs 46.5%) than mild COVID-19 patients. On multivariable analysis, COVID-19 severity was an independent predictor of mortality (OR10; 95%CI 1.62-67.19) after adjustment for age, gender, diabetes mellitus, C-reactive protein, serum Ferritin, Procalcitonin, and Fibrinogen values, and prior or new MI. Conclusions: Patients with old MI could develop a new AMI in 80% of COVID-19. However, the mortality was higher in patients without a history of MI due to the severity of COVID-19. Attention should be given to patients who possess thrombotic risk factors in pandemics.