When COVID-19 was first seen in the United States, now more than a year ago, doctors considered it a respiratory ailment. But that didn't last long.
Researchers have linked the disease caused by the coronavirus directly to multiple heart-related issues. And it has contributed indirectly to deaths among people who had cardiac problems but delayed getting treatment.
Even as vaccines are being rolled out at varying levels across the country, doctors and scientists continue to learn more about COVID-19 and cardiovascular health, but here's what people with heart conditions should know now.
Conditions such as heart failure (where the heart does not pump blood effectively), coronary artery disease (blocked arteries) and cardiomyopathies (weakening, thinning and/or thickening of the heart muscle) lead to more severe cases of COVID-19, according to the "strongest and most consistent evidence" tracked by the Centers for Disease Control and Prevention.
People with obesity, Type 2 diabetes and a lung-related type of high blood pressure known as pulmonary hypertension are also considered at increased risk, according to the CDC. Systemic high blood pressure and cerebrovascular disease (which affects blood vessels in the brain, as in a stroke) might also put people at risk, the CDC says. Such data led the American Heart Association to issue a statement in January encouraging people with cardiovascular risk factors, heart disease or a history of heart attack or stroke to get vaccinated "as soon as possible."
The main concern for people with underlying heart conditions is COVID-19 could cause respiratory stress that would worsen those conditions, said Dr. Nisha Parikh, a clinical cardiologist and associate professor of medicine at the University of California at San Francisco. For example, it could strain the heart of someone who has had stents or bypass surgery. Or, if a lung infection hits someone with heart failure, "that can be really difficult to treat."
COVID-19 patients face longer-term issues, too.
The research isn't settled, but Parikh is seeing so-called long-haul patients with "a constellation of symptoms, and some of them are cardiac in nature" that linger after they are no longer infected with the virus. Those symptoms range from feeling lightheaded to heart palpitations and chest pain. "We've been looking into what could be causing that."
She noted that some research has found scarred hearts in COVID-19 patients. Excessive blood clotting is a serious concern, as is the effect of the virus on the inner lining of blood vessels.
So, people with underlying conditions need to be extra careful, Parikh said. That means following what's now time-honored advice.
"Wear the mask. Stay socially distant. And take the vaccine if offered," said Parikh, who has had her shots. "Because that will be the quickest way all of us can get through this safely."
Heart patients should continue taking their usual medications. ACE inhibitors and angiotensin receptor blockers, which are used to treat conditions such as high blood pressure and heart failure, were scrutinized at the start of the pandemic, but studies yielded good news. "They have no effect on COVID-19 disease severity in those with mild to moderate COVID-19, and a handful of studies suggest they might even be protective," Parikh said.
People having heart, stroke or other symptoms that might require emergency care shouldn't hesitate to get help, she said. "I think the chance of getting COVID-19 once you hit the hospital setting is pretty low because of all the safety measures." But delaying care – as many people did – might be deadly. Studies suggest the initial coronavirus surge brought increases in fatal heart attacks, possibly due to delayed care.
Parikh worries that might be happening again. "This is anecdotal, but I am a bit concerned that with the recent surge of COVID-19, people again might be avoiding the hospital."
People also need to take care of their mental health, she said. The pandemic has been "a huge psychological stress on all of us, our heart patients included, and I think that it's really important to recognize and acknowledge."
With social isolation, she said, "there is a lot of anxiety and sometimes depression, as well. And those are all risk factors for any heart condition getting worse – or if you're predisposed to a heart condition, for one to happen."
Staying connected digitally or finding ways to meet in-person safely can help, experts say.