Cleaner air from pandemic lockdowns might be tied to fewer heart attacks

A new study suggests that when air pollution was low during stay-at-home lockdowns at the start of the COVID-19 pandemic, fewer ST-elevation myocardial infarctions (STEMI) occurred.

Researchers looked at the link between air pollution and STEMI in 29 states from Jan. 1, 2019 to Apr. 30, 2020, which included the COVID-19 lockdown period from roughly Mar. 11-30, 2019. There was little road traffic and almost no air travel taking place during the lockdown period, which resulted in a significant decrease in exhaust emissions and air pollution.

On days when air pollution was lower, the number of STEMIs was also lower.

These findings were presented at the American Heart Association (AHA) 2021 Scientific Sessions by Sidney Aung, a fourth-year medical student at the University of California San Francisco, and colleagues.

“The pandemic-related shutdown was ‘a unique opportunity’ to investigate how a short period of cleaner air might be associated with fewer severe heart attacks”, senior author Gregory M. Marcus, MD, professor and associate chief of cardiology for research, University of California San Francisco, told Medscape in an email.

However, because this was an observational study, the researchers acknowledged that it cannot prove cause and effect and that other unknown factors could explain the decrease in MI.

Nonetheless, “these data suggest that a reduction in particulate matter with the shutdown may be at least partly responsible for the drop in heart attacks,” Marcus said.

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