COVID-19 is an independent risk factor for acute myocardial infarction (AMI) and ischemic stroke, according to a new analysis of more than 84,000 patients.
The study, published in The Lancet, included every patient diagnosed with COVID-19 in all of Sweden through September 2020. While 57% of patients were women, the median patient age was 48 years old. More than 348,000 control patients were also included in the analysis.
"To the best of our knowledge, our study ... is the largest study done on the association between COVID-19 and acute cardiovascular events," wrote lead author Ioannis Katsoularis, MD, of Umeå University in Sweden, and colleagues.
While previous studies confirmed that COVID-19 is a “probable” risk factor for AMI, Katsoularis et al. set out to reach a clearer conclusion.
Overall, the team found,186 first AMIs and 36 deaths occurred during the study period. The median age of patients who had an acute MI during the study period was 73 years old, and 59% were men.
“When day 0 was excluded from the first risk period, compared with the control period, the risk of AMI following COVID-19 was significantly increased in the first and second weeks, but also during the pre-exposure period,” the authors explained.
In addition, a patient's risk of an AMI after being diagnosed with COVID-19 increased in the first and second weeks following COVID-19.
The authors found that the risk of AMI in the third and fourth weeks did not substantially increase vs. the control period. However, they did report a significant link between acute MI and COVID-19 in the month before COVID-19.
Looking at stroke data, the team found that there were 254 ischemic stroke events during the study period. The median age of those patients was 79 years old, and 53% were men.
“With day 0 excluded from the risk period, the risk of ischemic stroke was significantly increased in the first 2 weeks (by approximately three times) and in the last 2 weeks (by approximately two times) following COVID-19 compared with the control period,” the authors wrote. “The risk of ischemic stroke was also significantly increased in the short period before COVID-19. When day 0 was included in the risk period, the risk of ischemic stroke was increased by approximately six times in the first week following COVID-19, by approximately three times in the second week following COVID-19, and by approximately two times in the third and fourth weeks following COVID-19, all compared with the control period.”
The team did note that their study included certain limitations, including the fact that some patients may have not reported minor cardiovascular events in the earliest stages of the COVID-19 pandemic. Also, some patients may have been too ill to undergo a complete evaluation. Even with those things in mind, however, the team was able to include a large amount of data while reaching its conclusions.
"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," the authors concluded.
Read the full study here.