Overall, the risk of any heart complication over the course of one year was 63 percent higher in people who had gotten COVID compared with those in the contemporary control group. At the end of a year, there were 45 additional cardiovascular events—such as stroke or heart failure—per 1,000 people among those who tested positive for COVID. The comparison with historical data yielded similar results: the risk of cardiovascular problems in the group that had COVID was 58 percent higher than what was seen in the prepandemic control group.

When the researchers looked at people with mild COVID specifically, they found that this group had a 39 percent higher risk of developing heart problems, compared with the contemporary control group, or 28 additional cardiovascular problems per 1,000 people in 12 months.