Stroke risk elevated first 3 days post–COVID-19 diagnosis

Older patients with COVID-19 may have an increased risk of being hospitalized for acute ischaemic stroke (AIS), particularly in the first 3 days following their COVID-19 diagnosis, according to a study presented at ISC 2022.

“Risk of AIS … was 10 times … as high during first 3 days after diagnosis of COVID-19 as during control periods,” said study lead author Dr Quanhe Yang from the Division for Heart Disease and Stroke Prevention at the US Centers for Disease Control and Prevention (CDC), Atlanta, Georgia, US.

The results were based on analysis of health records of 37,379 Medicare Fee-for-Service beneficiaries aged ≥65 years who were diagnosed with COVID-19 between April 2020 and February 2021 (median age at diagnosis 80.4 years, 56.7 percent female, 75.9 percent non-Hispanic White) and hospitalized for AIS between January 2019 and February 2021. Hospitalization for stroke 7 days before or 28 days after COVID-19 diagnosis served as the control period. Thirty-four percent of patients had a history of stroke. About 28 percent of patients died before the study ended.

When AIS on day of exposure (day 0) was included, the risk for AIS was greatest in the first 3 days (days 0–3) following COVID-19 diagnosis (incidence rate ratio [IRR], 10.3, 95 percent confidence interval [CI], 9.9–10.8). [ISC 2022, abstract TMP16]

The risk for AIS was still elevated up to 28 days following COVID-19 diagnosis, but to a lesser degree (IRR, 1.6, 95 percent CI, 1.4–1.8 [days 4–7], IRR, 1.4, 95 percent CI, 1.3–1.6 [days 8–14], and IRR, 1.1, 95 percent CI, 1.0–1.2 [days 15–28]).

However, the risk for AIS, while still higher than during the control period, declined when AIS on day of exposure (day 0) was excluded (IRR, 1.8, 95 percent CI, 1.6–2.0 for days 1–3 post–COVID-19 diagnosis).

Incidentally, the risk for AIS was also elevated in the 7 days prior to COVID-19 diagnosis (IRRs, 1.91 and 5.60 for days -7 to -1 and -7 to 0, respectively). 

Certain subgroups were identified as having a greater risk of AIS following COVID-19 diagnosis. For instance, the risk appeared greater among patients aged 65–74 years compared with those aged ≥85 years, as well as among patients with no prior history of stroke. However, the risk did not vary according to race and ethnicity or sex.

“Stroke following the diagnosis of COVID-19 is a possible complication of COVID-19 that patients and clinicians should be aware of,” Yang pointed out. “[The findings of this study] can inform diagnosis, treatment, and care of stroke among patients with COVID-19.”

Yang noted that inaccuracies regarding timing of SARS-CoV-2 exposure could not be ruled out, particularly during the early stages of the pandemic when diagnostic testing in the outpatient setting, type of tests, and turnaround time for results were inconsistent. In addition, the higher number of cases of AIS on day 0 and in the 7 days before COVID-19 diagnosis could have been attributed to COVID-19 screening being implemented in all hospitalized patients. 

Nonetheless, the findings highlight the importance of COVID-19 vaccination and other preventative measures to reduce both risk of infection and subsequent complications such as stroke, concluded Yang.

“This study did focus on older adults because that’s the data they had available because it was examining Medicare beneficiaries. But everyone is likely at risk for stroke after COVID,” said Professor Louise D. McCullough from The University of Texas Health Science Center at Houston, Texas, US, and chair of ISC 2022, who was not affiliated with the study.

“Any infection, we know is linked to stroke risk, probably because any infection will cause inflammation, and inflammation can cause clots or thrombus, which is the cause of stroke,” she said.