Some studies suggest that the risk of cardiovascular problems, such as a heart attack or stroke, remains high even many months after a SARS-CoV-2 infection clears up. Researchers are starting to pin down the frequency of these issues and what is causing the damage.

In December 2020, a week before cardiologist Stuart Katz was scheduled to receive his first COVID-19 vaccine, he came down with a fever. He spent the next two weeks wracked with a cough, body aches and chills. After months of helping others to weather the pandemic, Katz, who works at New York University, was having his own first-hand experience of COVID-19.

On Christmas Day, Katz’s acute illness finally subsided. But many symptoms lingered, including some related to the organ he’s built his career around: the heart. Walking up two flights of stairs would leave him breathless, with his heart racing at 120 beats per minute. Over the next several months, he began to feel better, and he’s now back to his normal routine of walking and cycling. But reports about COVID-19’s effects on the cardiovascular system have made him concerned about his long-term health. “I say to myself, ‘Well, is it really over?’” Katz says.