Some science shows that contracting Covid-19 may lead to an increased risk of cardiovascular conditions. Photo / 123RF
Survivors of the disease are at increased risk of lingering impacts on both heart and brain health, follow-up studies suggest.
There have been dire predictions about the longer-term impacts of the Covid-19 pandemic and perhaps
one of the more concerning is that we are set to experience a “cardiovascular aftershock”.
Already there is some science to show that contracting the virus may lead to an increased risk of cardiovascular conditions. A study published in Nature Medicine suggests that problems might persist for at least a year, and even those with relatively mild symptoms can be affected.
Researchers used national healthcare databases from the US Department of Veterans Affairs to build a cohort of nearly 154,000 people who caught Covid-19 early on. The veteran population tends to be older, white, and male, but researchers found increased risk in every subgroup they looked at, regardless of age, ethnicity or gender. A wide range of cardiovascular conditions was involved, including abnormal heart rhythms, heart muscle inflammation, blood clots, strokes, heart failure and heart attack, and the risks increased with the severity of the infection.
We already knew that there was a connection between heart attacks and the flu. The risk of a heart attack is six times greater in the week following an influenza infection than at any point in the year prior or following. Flu stresses the body and makes the heart work harder. It increases inflammation and the chance that blood clots will form and blood pressure will rise. All of that is another good reason to have an annual flu jab.
With Covid-19, scientists are beginning to suspect there may be more happening. Researchers at the University of Queensland have found cardiac tissue damage, associated with DNA damage and repair, in Covid patients, but this wasn’t seen in tissue taken from the hearts of influenza patients. Although the study involved samples from a small number of people – all of whom had died – the researchers believe it has shown categorically that Covid-19 is not “just like the flu”.
In New Zealand, thanks to lockdowns and border controls, we had far lower numbers of people infected with earlier variants of Covid-19 than most other countries, and we still can’t say what the long-term impact of the pandemic will be on the nation’s cardiovascular health.
“It’s all a bit of an unknown at the moment,” says Heart Foundation medical director and cardiologist Gerry Devlin, “but we are seeing patients coming to our clinics who have cardiovascular symptoms post-Covid, things like chest discomfort, ongoing breathlessness and palpitations.”
Rather than assuming that these are effects of long Covid and hopefully temporary, it is important to get checked by a doctor in case the symptoms are actually signalling an underlying condition such as ischaemic heart disease (plaque build-up in the arteries causing them to narrow and stiffen) or heart disease caused by chronic high blood pressure. As Devlin puts it: “All the usual suspects.”
Given the potential for an increased risk of cardiovascular disease from contracting Covid, we need to do more to manage the risks we can control, Devlin believes.
“We talk a lot about cardiovascular risk assessment and we’re very good at that in New Zealand,” he says. “We lead the world, in lots of ways. But we’re not as good at managing cardiac risks. That means managing people’s high blood pressure, diabetes and cholesterol, and counselling around tobacco cessation.”
The heart isn’t the only organ to be affected by Covid-19 infection. Further research drawing on data from those US veterans, again published in Nature Medicine, found they were at increased risk of a wide range of neurological complications in the first year after infection. These include stroke, memory problems, mental health conditions, joint pain, hearing problems, migraines and dizziness.
The virus has been associated with changes in brain structure, and scientists at King’s College London found that an extreme immune response to it can increase the death rate of neurons and affect regeneration in the hippocampus region of the brain, which is crucial for learning and memory.
This may explain the brain fog some sufferers experience.