Addressing the science and research behind Coronavirus (COVID-19) and Heart Disease

Watch our video interview with Professor Bob Graham about coronavirus (COVID-19), the science and how that impacts those with cardiovascular disease and pre-existing heart conditions.

30 March 2020
Update 25 Nov 2021: Information from this article was accurate at the time of publishing and reflected the rules/advice announced by governing bodies at that time.

Video transcript

Hi, I'm Professor Bob Graham at the Victor Chang Cardiac Research Institute and I'm also a Cardiologist at St Vincent's Hospital here in Sydney. A lot has happened since I last did these videos and I really want to thank you for sending in all your questions. I hope that you found the previous video helpful.

Today I'd like to address some of the scientific issues related to COVID-19 and heart disease because I'm sure a lot of you have a lot more questions, and while I can't answer all of them specifically and only in general terms, I hope that you find them helpful. Research is really important if we're going to address COVID-19. We are, in a sense, at war, and we can't withdraw all the troops. I think it's important that we continue to do research, to try and find new ways to tackle this horrible pandemic.

Broadly speaking, what research is currently being conducted into coronavirus (COVID-19) and cardiovascular disease?

Let me address that in a number of ways. We now know that a small percentage of people who contract very severe coronavirus (COVID-19) can get severe heart issues as a result. Although in most cases, the problem is in the lungs and the heart suffers secondarily.

However, there are some areas where heart conditions and COVID intersect directly.

Some of you may have heard that there are tablets that we use, drugs that we use to treat autoimmune diseases have been suggested will be helpful in coronavirus (COVID-19) treatment. That's still unproven. It's all anecdotal and we need to do proper trials. One of the problems is one of the drugs that's been recommended can cause an irregularity of the heart. In fact, it can cause a heart to stop. So you've got to be very careful before you start taking treatments like this before they're proven. So please be careful. If you have heard about these treatments and you want to try them, please don't do that unless you first consult your GP or your Cardiologist - particularly if you've got underlying heart disease.

How important is medical research?

It's absolutely critical if we're going to make advances. One of the advances we're trying to work on is understanding what happens to those people who have very severe respiratory distress syndrome or severe disease. And we know that when you get to a point where you've got very bad lung disease, you've only got about a 50% chance of surviving. We also know that in those people they get marked activation of their immune cells and it starts to attack not only the virus, but also normal cells in the heart and in the lungs.

What we're trying to do is to use a stem cell approach to dampen down that hyperimmune response. And anecdotally, we've had now three patients who have all done very well. So we're optimistic but it is still very early days and we need to get these protocols in and start to look at this sort of stem cell treatment in a very sophisticated and proper trialled way, so that we know the results at the end really mean something and we're not doing more harm than good. That's the way that clinical trials work.

Why do experts keep referring to SARS?

SARS stands for Severe Acute Respiratory distress and you've probably heard about that. That was an epidemic that happened a few years ago. This is a different virus, although it's very related to SARS and in fact, it's called SARS-CoV-2. So it's a cousin of SARS. It causes a different disease, not as severe as SARS, which kills many people very quickly. SARS is quite a 'stupid virus', as once it's killed people it's got nowhere to go, and so it dies.

COVID-19 is what I call a 'Cinderella virus'. It kills a few people, but is very infectious. And it also is really nasty because it can be spread before people know they have symptoms. So in a sense, it is a virus that has worked out the best way to keep going and to infect as many people as possible. Although, it's not as severe in terms of the ability to go on and cause bad disease or death, like SARS, it's certainly severe enough. So that's the difference between SARS and coronavirus or COVID-19.

Are the mortality rates for coronavirus (COVID-19) higher than we expected or initially thought?

I think the jury's still out. Mortality rates, of course, depend upon how many people have a disease and die versus how many people have a disease and don't die. Now we know fairly accurately how many people have the disease and die. What we don't know is how many people have the disease and don't die. And what we really need, and this is where research is so important, we need to have a blood test so we can test very quickly whether or not somebody has had COVID-19. We will then know accurately how many people had the disease and then we can determine what the death rate is. What we do know, however, is that people who are elderly, those who've got co-morbidities such as heart disease or diabetes, or who are immunosuppressed, they do worse and they have a much higher death rate than healthy people.

What about coronavirus (COVID-19) and young people?

Fortunately, we know that the very young seem to do very well and only have mild disease. And there are very, very few deaths in people who are young. But still, don't forget that most people are between 30 and 50 so the majority of people who get this disease will be in that age range. And we know that 80% will do well, 14% will have fairly severe disease and 6% will have a very, very severe disease that will require intensive care treatment. So we've got a lot of people being affected. We are going to need a lot of treatment and a lot of ICU beds. And what we want to try and do is 'flatten the curve'. And that is to slow down the infection, hopefully, stop it altogether, so that medical treatments and hospitals can keep up with the demand.

If we have too much demand too quickly, what's called a surge, then we won't be able to treat some people because we won't have enough ventilators and ICU beds. So it's very, very important that you practice social distancing, wash your hands, do all the things we can to reduce the amount of infection. And to put that into some numerical terms, there's a value that's used in epidemiology called the R0. So that's the amount of, in a sense, the amount of infectivity. So the common flu has an R0 of about 1.3. And what that means is that if you have the common flu, you will infect on average 1.3 other people. And each one of those 1.3 people will infect another 1.3 people. And if you do that 10 times, you will have one person who started with a common flu will have infected 14 people.

What is the RO for Coronavirus COVID-19?

People have suggested the R0 is 2.2, after ten times, rather than having 14 people, you now have infected 300 people. So you can see how the ability of this virus to spread is potentially really a problem. If on the other hand, the R0 is 3 rather than 2.2 or 1.4, I think most of you will be surprised to learn that after 10 occurrences like that, you will now not have infected 14 people; you will not have infected 300 people; you will have infected 40,000 people! And some people say the R0 for coronavirus is three. I think most people think it's lower than that fortunately.

What we've got to try and do by social distancing is get that R0 to less than one, so that we're not passing it on. So I can't stress how important it is to practice social distancing, wash your hands, self-isolation if you've got the disease, and keep yourself as healthy as you can.

Thank you very much again for all your support and for your interesting questions.

** Professor Bob Graham was the inaugural Executive Director of the Victor Chang Cardiac Research Institute for 26 years.

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