COVID causing heart damage

Despite the fact that Covid is a respiratory disease that spreads - chiefly - through the air and causes lung infections, the repercussions of the disease are felt throughout the body, including in the heart. A new study out this week looking at patients admitted to hospital with covid has found that half of them had evidence of heart damage caused by the disease. British Heart Foundation cardiologist Marc Dweck led the study...

Marc - We know from other viral infections that viruses and other bugs can cause problems with heart function. And we know with COVID-19 that people who have preexisting heart disease are more likely to get COVID infections, and have more serious disease.

Chris - And does that mean then that COVID causes heart problems? Or is it just that we're seeing an over representation of people with heart problems who then succumb to COVID?

Marc - Yeah, that's an excellent question. I think it's a mixture of both. We did a study of more than 1200 patients from 69 countries across the world. And now, these were people with severe COVID-19 infection who had been admitted to the hospital. And when we looked at the scans of their heart that they had done, we found that half of the scans showed some form of abnormality in how the heart was pumping. Now, often this was mild. However, in one in seven patients, the heart damage was severe, meaning that the heart was struggling to effectively pump enough blood around the body. We then did another analysis where we excluded all the patients who have any form of history of heart disease. And when we looked at those people, just under half of them had some form of heart damage, and one in eight had severe heart damage, but they didn't have any damage registered before. And so our assumption is that that damage was new and related to the virus.

Chris - How do you think the virus is actually damaging the heart? What's it doing?

Marc - Yeah, this is the next question we really need to answer. And I think that is very important. There are several different hypotheses. One is that the virus is directly affecting the heart muscle, causing inflammation in the heart muscle that impairs its ability to pump. Another explanation is that people who have a very serious illness, develop a stress response in their heart muscle, where again, the heart fails to pump properly. The interesting thing about that is if you treat the other conditions that they have, then the heart goes back to normal. And finally people with COVID-19 are more likely to develop blood clots, and this can cause problems in the lungs and in the heart that can lead to impairment in how the heart pumps. So we really need to understand what the exact mechanism of the damage is. A; so that we can give people the right treatment, but B; so that we can understand what the longterm consequences of this heart damage is. Are people going to be left with heart failure in the future?

Chris - If as many as a half had signs of this happening, the half of the patients that you studied, is it actually very serious, the impact on the heart? Or is it one of those things, if it is reversible, it is going to recover that a person may not even know this has happened, and they just feel a bit out of sorts for a while, and then things get better and they think, phew, glad that's gone away?

Marc - Yeah. I think that's really important to understand. I mean, this study didn't address that question. It was in a very specific group of patients that were very sick with COVID-19 in hospital. The truth is we don't know how common it is for the heart to be involved in milder cases. Most people who have COVID-19 don't need a hospital, and we don't know how often their heart is involved. I suspect. And again, this is a guess, that in the milder forms of the disease, the heart isn't really involved. But what our study has shown is that if you have a very severe form of the illness and you're in hospital, then the heart can reasonably commonly, become involved. And we, as doctors should be thinking about that, because actually it's an opportunity. We have very good treatments that treat heart problems. And so there's an opportunity if we can pick these patients up, to get them better and out of hospital, back to a normal life.

Chris - To what extent do you think that COVID might just be bringing forward the inevitable for these patients that you've picked up with heart problems? I.E. given a little bit longer, they would have got to that point anyway, and it's just accelerated the pace.

Marc - Well, I think time will tell, I think, as we understand what actually causes the damage, we'll understand that better. I personally think that this is a response to the infection, that will largely get better as we treat the infection. So I don't think it's inevitable that these patients would have developed heart problems in any case. I think it is directly due to the virus, whether that's the virus affecting the muscle directly, or just the stress of having a really severe illness affecting the heart.

Chris - There's a group of people who are now dubbing themselves the long haulers. People who've had coronavirus infection, it's been documented and they've got through the worst of it, but it just seems to be going on forever. There are people who say, I used to run marathons. Now I struggle to run up the stairs. Do you think that in a proportion of these people and they're both young and old, that actually heart failure may be a sort of hidden element to this?

Marc - I think that's possible. I think this is an area that is often difficult to understand. Some people feel extremely tired following a viral illness or indeed a pneumonia. And it can just be a response to that very serious infection that a patient has had. In a small proportion, it is certainly possible that tiredness, and in particular if that's accompanied by symptoms like breathlessness or ankle swelling, that that may be due to problems with the heart. And I think the heart should be looked at.