Incidence of acute ischemic stroke after COVID-19 or influenza among older adults, findings from PCORnet and HealthVerity, 2022

BackgroundAlthough COVID-19 is a known risk factor for thrombotic conditions including embolism, stroke, and myocardial infarction, stroke incidence after implementation of thromboprophylaxis during COVID-19 hospitalization in 2021 and how incidence may differ from influenza is unknown. MethodsPCORnet and HealthVerity (HV) data assets were used to identify patients aged [&ge;]65 years with no prior stroke and COVID-19 or influenza during January 1-December 31, 2022, and AIS from 3 days before to 28 days after COVID-19 or influenza diagnosis. Overall demographic information (age [for HV], sex, race/ethnicity), underlying conditions, level of care, outcomes, and incidence were described and compared between those with early (-3 to 7 days from diagnosis date) and late (8 to 28 days) AIS. ResultsAmong 245,352 (PC) and 639,396 (HV) patients aged [&ge;]65 years with COVID-19, the incidence of ischemic stroke in the 3 days prior to 7 days after diagnosis of COVID-19 (PC: 962/100,000 and HV: 447/100,000) and influenza (PC: 589/100,000 and HV: 387/100,000) was significantly higher than in the 8 to 28 days after diagnosis (COVID PC: 81/100,000 and HV: 141/100,000)(influenza PC:75/100,000 and HV: 15/100,000)(all P<0.01). ConclusionsContinued risk for AIS with acute COVID-19 and influenza underscore the importance of monitoring and prevention measures for older adults.