An increased risk for ischemic stroke in the short-term period following COVID-19 infection

Abstract

Abstract Background The association disclosed between COVID-19 infection and ischemic stroke (IS) raises concern. The exact risk periods, which were not consistent between studies, require further investigation. Methods We linked between two national databases: the national COVID-19 database and the Israeli National Stroke Registry. The self-controlled case series method was used to estimate the association between COVID-19 infection and a first IS. The study population included all Israeli residents who had both a first IS event and a first COVID-19 diagnosis during 2020. The date of the PCR test served to define the day of exposure, and the 28 days following it were categorized into three risk periods: days 1-7, 8-14, and 15-28. A relative incidence (RI) with a 95% confidence interval (95% CI) was calculated based on the incidence rate of events in a post-exposure period, compared to the incidence rate in a control period. Results From 01-January-2020 to 31-December-2020, 308,015 Israelis aged 18+ were diagnosed with COVID-19 and 9,535 were diagnosed with a first IS. Linking between the two databases, 555 persons had both diagnoses during 2020. The mean age of the study population was 71.5±13.7, 55.1% were males, 77.8% had hypertension, 73.7% had hyperlipidemia, 51.9% had diabetes, 28.5% had ischemic heart disease and 25.6% had atrial fibrillation. Comparing between the risk period and the control period, we found a very similar distribution of the cardiovascular risk factors. The risk for an acute IS was 3.3-fold higher in the first week following COVID-19 diagnosis, compared with a control period (RI = 3.3; 95% CI 2.3-4.6). The RI among males (RI = 4.5; 95% CI 2.9-6.8) was 2.2-fold higher compared to females. The increased risk did not last beyond the first week following exposure. Conclusions Physicians should be aware of the elevated risk for IS among patients experiencing COVID-19, particularly among men with high burden of cardiovascular risk factors. Key messages • Risk for an ischemic stroke is elevated in COVID-19 patients upon infection. • This finding was particularly evident in men with cardiovascular risk factors.