People with serious heart problems have been getting the wrong message about avoiding the hospital during the COVID-19 pandemic, and they are at greater risk of dying as a result, doctors say.

People experiencing signs of possible heart attack like chest pain and shortness of breath should contact their doctor, call 911 or go to the emergency room — even in the middle of the pandemic. Signs of a heart attack vary, though uncomfortable pressure in the center of the chest that lasts more than a few minutes is most common.

But several studies, including one led by researchers at the Minneapolis Heart Institute Foundation, have shown interventions for heart attacks have quickly declined during the pandemic. In Paris, researchers found that cardiac arrests outside of hospitals grew drastically in March and April, and the proportion of those patients admitted to the hospital alive dropped by almost half.

A Star Tribune analysis of death records in Minnesota dating back to 2015 shows the total number of deaths in the state is about 20% higher than normal since early March. About 80% of the excess deaths were caused by people contracting COVID-19, the records showed.

Dr. Santiago Garcia, an interventional cardiologist at the Minneapolis Heart Institute and corresponding author of the paper that included the Minnesota data on declining heart interventions, said researchers believe patients are either afraid of getting COVID-19 if they go to the hospital or are misunderstanding directives from state and federal officials about avoiding health care that can be delayed.

And since shortness of breath can be a symptom of both a heart attack and COVID-19, some patients with heart problems may be self-isolating at home hoping the virus will pass — not realizing that the heart attack they're having may be damaging their heart by depriving it of oxygenated blood.

"If in doubt, please come to the emergency department," Garcia said. "We want to see patients who have shortness of breath and chest pain. ... We need to do tests to decide whether you have COVID or a heart attack, because the treatment is very different."

In March and April, the Minneapolis Heart Institute at Abbott Northwestern Hospital in south Minneapolis saw declines of at least 27% in patients who came to the hospital with serious attacks and patients getting angioplasties to reopen clogged arteries on the heart, compared with the first two months of 2020.

Minnesota went under a state of emergency on March 13. Six days later, Gov. Tim Walz ordered health care providers in the state to postpone elective surgeries and procedures, saying the greatest risk posed by the pandemic would be overwhelming the health care system. Elective procedures were allowed to resume May 11.

As of Sunday, the state had tallied 24,850 confirmed cases of COVID-19 in Minnesota since the first was diagnosed March 5. More than 18,000 of them have had enough time pass without symptoms that they no longer need to remain in isolation.

Health officials say 1,040 people in Minnesota have died from COVID-19, including 848 people in long-term care or assisted-living facilities. The rate of death has been consistent in Minnesota in recent weeks, with a seven-day average of between 19 and 25 deaths per day since April 26.

On Sunday, 11 of 14 newly reported deaths occurred in long-term care or assisted living facilities and included two patients who were at least 100 years old when they died. COVID-19 is more dangerous for older residents and those living in group settings, and for people with lung disease, serious heart conditions, cancer, severe obesity and diabetes, and kidney patients on dialysis.

As of Sunday, 257 people with COVID-19 were in intensive care in Minnesota. There haven't been fewer than 200 people in intensive care for COVID-19 since May 13.

But as larger numbers of people go to the hospital for COVID-19, people with other problems are not doing so — and not just in Minnesota.

The decline in heart-attack care was still apparent when the Minnesota data were pooled with the results from eight other heart-care centers around the country, including Massachusetts General Hospital in Boston and major heart-care centers in Illinois, Iowa, Michigan, New York, Ohio and Washington.

A preliminary version of the article published in the Journal of the American College of Cardiology reported a 38% decline in patients going to the emergency room for serious heart attack care in March at the nine hospitals, compared with monthly averages for the previous 14 months.

In March 2019, the nine hospitals treated 208 serious heart attack patients; a year later that dropped to 138, the paper shows. Last year, no month dipped below 181 cases. The researchers said their results agreed with a similar paper in Spain, which documented a 40% decline in angioplasty procedures under pandemic conditions there.

The U.S. paper did not attempt to show whether trends in heart-attack care have led to increased deaths in Minnesota. But in France, researchers with the long-running Paris Sudden Death Expertise Center found that fewer patients were arriving at the hospital alive after cardiac arrest.

Heart attack and cardiac arrest are different but related events. Heart attack means cardiac muscle tissue is being damaged by a lack of oxygen because of poor blood flow through the arteries on the exterior surface of the heart. Such tissue damage can lead to dangerous irregular heart beats called arrhythmias, or it can cause the heart to suddenly stop beating, which is cardiac arrest.

The sudden-death research center in France looked at trends among 6.8 million inhabitants of the greater Paris area and found that while the overall number of cardiac arrests outside the hospital had grown, the proportion of those patients who were admitted to the hospital alive dropped significantly during the Paris lockdown.

Only 12.8% of people with out-of-hospital cardiac arrest in the study area were admitted to the hospital alive from March 16 to April 26, compared with a historical average of 22.8% over the previous eight years, the report in the Lancet Public Health journal says.

About a third of the excess cases of out-of-hospital cardiac arrest had a suspected or confirmed case of COVID-19.

"Although these findings might be partly related to direct COVID-19 deaths, indirect effects through lockdown, behavior changes, and pandemic related health system issues (overwhelming of EMS and postponement of consultations and scheduled nonurgent procedures) are probable," the study authors concluded.

In particular, people who go into cardiac arrest at home may not have access to public automated external defibrillators needed to restart the heart. And they're less likely to get cardiopulmonary resuscitation, even though the center has found survival rates are almost eight times higher when a bystander administers CPR.

If the trends in avoiding hospital care continue, Garcia said he's concerned about unraveling the progress that has been made in educating the public on the signs of heart attack.

"We've been telling patients for two decades, if you are having chest pain, come to the emergency department, call 911, let us know. And all of a sudden the message that came out was exactly the opposite — stay home," Garcia said. "And now we are seeing the consequences of that."

Staff writers Glenn Howatt and MaryJo Webster contributed to this report.

Joe Carlson • 612-673-4779