Fatal heart attacks linked to COVID-19 declined in hospitals over the past two years, and vaccines played a key role, the Minneapolis Heart Institute Foundation reported Monday.
The finding builds the case for COVID-19 vaccination, albeit at a time of diminishing pandemic activity and risk in Minnesota. The state on Monday reported five COVID-19 deaths and 473 coronavirus infections but only a 2.9% positivity rate in COVID-19 testing, which remains below Minnesota's 5% caution level.
The Minneapolis-led research analyzed 586 heart attacks in COVID-19 patients in the U.S. and Canada and found a 25% reduction in deaths in hospitals from 2020 to 2021. Delayed addition of vaccine status to the research in 2021 resulted in the identification of only 22 heart attacks involving vaccinated patients and 171 involving unvaccinated patients.
None of the vaccinated patients died in the hospitals, though, which is significant when considering that 22% of the unvaccinated patients died, said Dr. Santiago Garcia, the lead Minneapolis researcher, who presented the findings on Monday at a scientific session of the American College of Cardiology in Washington, D.C.
"The ones that aren't vaccinated, they still have the nasty chest X-rays, they're short of breath, and that makes the management of the heart attack more complex," he said.
The research is based on 64 sites in the U.S. and Canada, which set up a registry to assess the impact of the pandemic on heart attack care and outcomes.
Vaccination was only part of the progress in 2021 when compared to 2020, when stay-at-home measures and COVID-19 fears led to people delaying medical care for preventable health problems.
While 77% of the heart attack patients with COVID-19 underwent catheterization to address blockages in blood vessels in 2020, that rate increased to 86% as caregivers were vaccinated and less concerned about being infected during the procedures, Garcia said. Caregivers also became more familiar with the characteristic blood clots in the course of COVID-19 that increased the risk of severe heart attacks.
The COVID-19 vaccine has lost effectiveness against a fast-spreading omicron variant of the coronavirus that caused the latest pandemic wave. A state update on Monday showed that fully vaccinated Minnesotans made up 37% of the 3,580 COVID-19 deaths in the second half of 2021 but 55% of the 1,049 deaths in the first two months of 2022.
Even the latest number demonstrates protection, though, when considering that fully vaccinated people make up 79% of Minnesota adults. The fully vaccinated population also includes more seniors at elevated risk of COVID-19 mortality along with people who haven't sought boosters and have little immunity left from their initial shots.
Only 49% of eligible Minnesotans 5 years and older are considered up to date with either recent initial COVID-19 vaccinations or scheduled booster doses. Dr. Gregory Poland, director of Mayo Clinic's Vaccine Research Group, urged people to receive recommended shots, noting that health problems occur at far higher rates from infections than vaccine side effects.
"I often say to people, 'Which risk do you want?' There is no risk-free option," he said.
COVID-19 hospitalizations in Minnesota nudged up slightly to 203 on Friday, but remain below the peak of 1,629 on Jan. 14. Health officials remain concerned that a BA.2 omicron subvariant could fuel a new pandemic wave, though, because the virus' presence is being found more frequently in Twin Cities wastewater.
The positivity rate of COVID-19 testing has been a stable indicator of pandemic severity for two years, but changes on Monday could disrupt its usefulness. The federal government no longer requires many labs to report negative COVID-19 test results, which could upset the calculations used to determine the positivity rate.
Wastewater sampling and hospitalizations will become more important measures if the positivity rate is no longer reliable, a Minnesota Department of Health spokesman said.