Complications from COVID-19 can make the most dangerous kinds of heart attacks even more deadly, according to a new study.
The finding has special implications for African American and Hispanic residents, as well as diabetics, since those three groups are at greater risk of having severe heart attacks and contracting COVID-19.
In a first-of-its-kind effort, a group of North American heart hospitals examined nearly 600 patients and found a surprisingly high death rate among COVID-19 patients with the most severe heart attacks, caused by complete blockage of an artery supplying oxygen to the heart muscle.
"These patients are at very high risk," said interventional cardiologist Dr. Santiago Garcia, primary investigator at the Minneapolis Heart Institute Foundation, where the data are being analyzed. "Mortality for heart attack patients ... should be in single digits. We're seeing mortality here that is 32%."
The findings, announced at a medical conference this month, were the public's first glimpse of results from the ongoing project known as NACMI, an international consortium compiling data from COVID-19 patients who have a so-called "STEMI" heart attack involving a completely blocked blood vessel.
The study examined 594 STEMI patients treated at 64 hospitals during the pandemic in Canada and the U.S. through Oct. 4 and found those with confirmed cases of COVID died in the hospital at almost triple the rate as those who tested negative for the viral illness.
About 20% of all heart attacks are thought to be STEMI.
The study also documented an increased risk of in-hospital strokes among COVID-positive heart-attack patients.
Scientists widely believe COVID makes heart attacks and strokes more likely, and more dangerous, by causing changes in the heart, lungs and blood. The NACMI research can't prove COVID triggers heart attacks and strokes — only that mortality rose when both were present.
But doctors say the correlation is noteworthy.
"Those are stunning numbers," said Dr. Mladen Vidovich, an interventional cardiologist and associate journal editor in Chicago who was not involved in the research. He said the death rate in the COVID group was similar to what was seen among heart-attack patients 50 years ago.
The risks are especially significant for African American and Hispanic patients, who tested positive for COVID more often than white and Asian patients in the first release of NACMI data. Organizers will be adding patients in Mexico and South America and tracking long-term outcomes.
Cardiologists say the early results underscore the long-standing recommendation that people feeling heart-attack signs should go to the hospital — even with hospitalizations for COVID-19 on the rise.
In Minnesota, 500 people have been admitted to the hospital for COVID-19 in the past week, including 106 cases sent to intensive care, the Minnesota Department of Health reported.
On Sunday, the Health Department added 1,684 new cases to the state's tally, which now stands at 133,802. The deaths of 2,335 Minnesotans have been attributed to COVID since March, including 21 fatalities reported Sunday. Those who died included 12 residents of long-term care. One person was under 35 and the rest were 50 or older.
In Minnesota, white residents make up 80% of the population and 79% of the deaths from COVID-19.
But looking at the spread of the disease, African American and Hispanic populations have borne a disproportionate impact. Minnesota's Hispanic community represents 5% of the population and 14% of COVID cases. Black residents make up 6% of the population and 14% of the cases.
Most people having heart attacks today don't have COVID-19. But heightened risks from the one-two combo of heart attacks and COVID-19 are particularly important for Black and Hispanic residents, who were clearly overrepresented in the heart-attack-with-COVID cohort.
"We think that it's a real signal that we are seeing, that patients from many minority groups seem to have more severe forms of COVID-19," Garcia said. "The next question is, why? And diabetes may be the answer to that, obesity may be the answer to that. But yes, we need to understand that."
A heart attack happens when blood vessels that supply oxygen and nutrients to keep the muscle beating get clogged. A complete block — known as ST-segment Elevation Myocardial Infarction, or STEMI — starves and kills heart tissue quickly, the same way that a stroke kills brain tissue.
The preferred way to treat patients with total blockages is to quickly inflate a medical balloon inside the clogged artery to reopen it and usually leave behind a metal tube called a stent to keep it open. Sometimes patients get clot-busting drugs called thrombolytics, which carry their own risks.
More knowledge of virus
In China, medical authorities early in the pandemic recommended drugs instead of balloons, to limit health care workers' exposure to the virus. Mortality quickly began to rise, researchers found.
As personal protective equipment became more available and knowledge about the virus increased, American medical associations adopted guidelines recommending patients still get treated with balloons and stents, not drugs.
"That was recommended based on no data. So we are providing, essentially for the first time, feasibility data from the U.S. and Canada saying, 'Yes, we can do this the same way we've been doing it in non-COVID patients,' " Garcia said.
The NACMI data showed 79% of the COVID-positive patients made it to the special room in the hospital for balloon interventions, and 71% received a balloon procedure. COVID patients were treated in an average of 80 minutes, compared to 78 minutes for non-COVID patients.
But even with optimal treatment in the hospital, STEMI patients are at much greater risk of death if they get COVID.
"If you have chest pain or shortness of breath, come to the hospital," said Dr. Tim Henry, a longtime cardiology researcher in Minneapolis who now works at the Christ Hospital in Cincinnati. "It's safe to come, and we can treat you."
Staff writer Kim Hyatt contributed to this report.
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