COVID-19 increases patients' risks for heart attack and stroke, suggests a study from Sweden that compared 86,742 individuals infected with SARS-CoV-2 in 2020 and 348,481 people without the virus.
In the week following a COVID-19 diagnosis, the risk of a first heart attack went up three- to eight-fold, and the risk of a first stroke due to a blood-vessel blockage rose three- to six-fold, the researchers found.
The risks then dropped steadily but remained elevated for at least four weeks, according to the report in The Lancet. The researchers did not include COVID-19 patients who had had heart attacks or strokes in the past, but for them, the risk of another heart attack or stroke is probably even higher, said coauthor Dr. Anne-Marie Fors Connolly of Umea University.
Flu vaccination linked with less severe COVID-19
Flu vaccination may lower the risk for severe illness from the coronavirus, including life-threatening sepsis infections and strokes, according to a report in PLoS One on Tuesday. The researchers studied nearly 75,000 COVID-19 patients, half of whom had received the most recently available flu shot.
They also found fewer patients who had flu shots had to be admitted to intensive care units or visited emergency departments, and fewer had dangerous blood clots in their legs, compared to patients who did not get flu shots.
Studies like this one, however, cannot prove that flu vaccines caused the better outcomes, or how they might have done so.
Stronger and larger studies would help "to validate these findings and determine if an increased emphasis on influenza vaccination will improve adverse outcomes in SARS-CoV-2-positive patients," the authors wrote.