Risk of Acute Myocardial Infarction and Ischaemic Stroke Following COVID-19 in Sweden: A Self-Controlled Case Series and Matched Cohort Study
The Lancet (08/14/21) Vol. 398, No. 10300, P. 599 DOI: 10.1016/S0140-6736(21)00896-5
Katsoularis, Ioannis; Fonseca-Rodríguez, Osvaldo; Farrington, Paddy; et al.
COVID-19 is an independent risk factor for acute myocardial infarction (MI) and ischemic stroke, according to new research out of Sweden. The study is believed to be the largest one conducted thus far on the association between COVID-19 and acute cardiovascular events. The study used two methods to assess whether there was an association between COVID-19 and acute MI and ischemic stroke. The self-controlled case series (SCCS), which included 86,742 patients diagnosed with COVID-19 between Feb. 1 and Sept. 14, 2020, compared incidence rate ratios (IRRs) for first acute MI or ischemic stroke following COVID-19 compared with a control period. The matched cohort study, which included 348,481 matched control patients, was used to determine the odds of acute MI or ischemic stroke in the first 2 weeks after COVID-19 onset compared with individuals who had not been diagnosed with COVID-19. In the SCCS, when the day of exposure was excluded from the risk period, the IRR for acute MI was 2.89 in the first week, 2.53 in the second week, and 1.60 in weeks 3 and 4 following COVID-19. When the day of exposure was included, the IRR was 8.44 in the first week, 2.56 for the second week, and 1.62 for weeks 3 and 4 following COVID-19. For ischemic stroke, when day of exposure was excluded, the IRRs were 2.97 in the first week, 2.80 in the second week, and 2.10 in weeks 3 and 4 following COVID-19. When including the day of exposure, the IRRs were 6.18 for the first week, 2.85 for the second week, and 2.14 for weeks 3 and 4 following COVID-19. In the matched cohort analysis excluding the day of exposure, the odds ratio (OR) for acute MI was 3.41 and 3.63 for stroke in the 2 weeks following COVID-19. The OR for acute MI when the day of exposure was included was 6.61 and 6.74 for ischemic stroke in the 2 weeks following COVID-19. "Our results indicate that acute cardiovascular complications might represent an essential clinical manifestation of COVID-19 and the long-term effects might be a challenge for the future," conclude the researchers.