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April 6, 2022 – Deaths among hospitalized patients who had both COVID-19 and the most severe type of heart attack were 25% lower in 2021 than in 2020, and no deaths occurred among patients who had been vaccinated against COVID-19, according to data presented at the American College of Cardiology’s 71st Annual Scientific Session. The study is based on an analysis of data from the world’s largest registry of patients confirmed to have both COVID-19 and a type of heart attack known as a STEMI.
“We observed a reduction in in-hospital mortality, our primary endpoint, from 33% in 2020 to 23% in 2021—a 25% decline after adjusting for age, sex, race, diabetes or other factors that could have played a role,” said Santiago Garcia, MD, director of the structural heart program at the Christ Hospital in Cincinnati and the study’s principal investigator. “We also saw a decline in our secondary endpoint—a composite of death, stroke or a repeat heart attack—from 35% in 2020 to 25% in 2021.”
Most heart attacks are caused by a blood clot in an artery to the heart that’s been narrowed by a buildup of fatty deposits or plaque. In a STEMI, the most severe type of heart attack, an artery to the heart is completely blocked, causing the death of some heart tissue.
Patients with COVID-19 are at elevated risk for a heart attack during the first two weeks after they become infected with the virus, Garcia said. This elevated risk is thought to occur because COVID-19 increases the risk for blood clots.
The North American COVID-19 STEMI (NACMI) registry was established in 2020 to capture information about treatment and outcomes for hospitalized patients who were confirmed to have both COVID-19 and a STEMI, he said. Sixty-four medical centers and health systems from across the U.S. and Canada contributed anonymized data for patients treated at their institutions. In April 2021, Garcia and his colleagues reported that in 2020, 33% of North American patients with both COVID-19 and a STEMI died in the hospital.
For the current study, the researchers compared patients with both COVID-19 and a STEMI who were treated in 2020, before vaccines against COVID-19 became available, and those treated in 2021, after the first COVID-19 vaccines received emergency use authorization from the U.S. Food and Drug Administration.
The research team analyzed data from 586 patients, of whom 227 were treated in 2020 and 359 in 2021. About 75% of patients were over the age of 55 and over 70% were male. Roughly 70% had high blood pressure, while about 45% had diabetes. Patients’ average body mass index was about 28, indicating that they were overweight. In 2020, 61% of patients were non-white, compared with 42% in 2021.
In 2021, 83 patients out of 359 (23%) died in the hospital, compared with 75 out of 227 (33%) in 2020. Of the 359 patients treated in 2021, 90 (25%) died or had a stroke or repeat heart attack, compared with 80 of the 227 patients (35%) treated in 2020. The risk of in-hospital death was 70% higher for patients who had abnormal chest X-ray findings in their lungs (known as pulmonary infiltrates) and for those whose heart had low blood pressure or completely stopped pumping blood (cardiogenic shock). Patients aged 66 or older and those with diabetes were also more likely to die in the hospital.
Vaccination data was available for 193 (54%) of the patients treated in 2021. Of these, 22 patients (11%) had been vaccinated, and none of these patients died while in the hospital. By contrast, 37 of the 171 unvaccinated patients (22%) died in the hospital—an in-hospital death rate considerably above the expected rate of about 4%-6% for patients who have had a STEMI, Garcia said.
“In 2020, before vaccines were available for COVID-19, we saw significantly more patients presenting to the hospital with shortness of breath as their primary symptom, rather than with the more typical heart-attack symptom of chest pain,” Garcia said. “Having shortness of breath, having an abnormal chest X-ray and needing to be on a ventilator were all factors that increased patients’ risk of dying. Yes, they had had a severe type of heart attack, but they did not necessarily die from the heart attack—they died from severe COVID-19. In 2021, however, the availability of vaccines significantly reduced hospitalizations and deaths due to COVID-19 infection, including among patients who had a STEMI.”
When Garcia and his colleagues looked specifically at outcomes by COVID-19 vaccination status in the subgroup of patients treated in 2021, they found that vaccinated patients were far less likely to experience severe respiratory illness.
“We saw zero deaths in the hospital among vaccinated patients, while the death rate for unvaccinated patients remained high,” Garcia said. “These findings provide additional support for the value of COVID-19 vaccination in older adults.”
Limitations of the study include that it is observational and retrospective, Garcia said. In addition, data on vaccination status was available for roughly half of the patients in the registry. Finally, the study did not capture information about variants of the SARS-CoV-2 virus, including the omicron variant, which was first reported in the U.S. in 2021.
The NACMI registry is a collaboration among three interventional cardiology professional organizations: the Society for Cardiovascular Angiography and Interventions, the American College of Cardiology Interventional Council, and the Canadian Association of Interventional Cardiology. The Minneapolis Heart Institute Foundation is the data coordinating center for the study.
This study was simultaneously published online in the Journal of the American College of Cardiology at the time of presentation. The study was funded by grants from Medtronic, Inc., Abbott Vascular and an American College of Cardiology Quality Initiative Grant.
For more information: www.acc.org
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