I tell all my patients, “You don’t want to get COVID”. This is especially true if you have heart disease.
Soon after the pandemic started, it became clear that people with heart problems were more likely to end up in hospital and get severe disease. So what is the risk, and why is the disease worse?
Most people think of COVID as a flu-like illness predominantly causing breathing problems. In severe cases, hospital admission and oxygen are required, and if the condition gets worse intensive care support with ventilation may be needed. But the data from Europe shows that the people who die from COVID often die due to cardiac complications.
People with a history of cardiovascular disease, such as a previous heart attack or heart failure, are at particularly high risk. The chance of developing severe COVID or dying is about three times higher than for people without heart disease. The more surprising finding is that people who only have risk factors for heart disease, such as high blood pressure and diabetes, are also vulnerable to severe infection with a risk approximately twice that of normal.
How is the heart affected?
Our knowledge about the effects of COVID on the heart has evolved since the beginning of the pandemic. Initially, it was thought the virus could infect the heart muscle directly and cause a condition called myocarditis, but it is now believed that this is a rare complication. The current view is that damage to the heart is secondary to complications of severe infection.
If you catch COVID, your body produces chemicals called cytokines. These are a necessary part of inflammation. They help switch on the immune system and activate cells in the blood to help fight the infection. In most people, they do their job, and the infection settles. But, in some cases, there is a massive overproduction of cytokines which causes damage to many organs. This is called a “cytokine storm”. These are the people who go on to get severe COVID.
The process is complicated. The high level of cytokines affects the circulation and damages blood vessels, causing small blood clots. Cytokines also directly affect the heart muscle, and the heart contractions become weaker. This is when things start to go downhill.
When somebody has COVID, they usually present with infection in the chest. This means that less oxygen can get into the blood. The heart muscle struggles to work without enough oxygen. At the same time, the cytokines are released, impeding the heart muscle function, which causes the blood pressure to drop, and less blood is pumped through the lungs. This means even less oxygen gets into the blood, and a vicious cycle starts where the oxygen level gets progressively lower, and the heart gets weaker. On top of all of this, there is a high risk of blood clots forming, which can further decrease the oxygen supply. Eventually, the system fails.
People without heart disease have a much greater reserve, and they can cope with a low blood oxygen, but if the heart is already damaged, it is much harder to keep the systems going.
Extra oxygen and ventilation can support the patient through the acute infection, and gradually the cytokine production decreases. In addition, lying patients face down (proning) helps to improve oxygen supply to the blood.
What can I do to keep safe?
- Make sure you are vaccinated. A booster vaccine will likely become available either later this year or early next year. Get the booster as soon as you can.
- Continue to take standard precautions. Wear a mask indoors when around other people.
- Ensure people around you are vaccinated.
What if I get COVID?
- Keep taking your cardiac medication. It is essential you continue your blood pressure tablets. Early in the pandemic, there were concerns that the ACE inhibitors (Accupril, quinapril, lisinopril. ..in fact, any drug that ends ..pril) might make the disease worse, but that is no longer thought to be the case.
- Keep taking your blood thinners. There is a high incidence of blood clots in patients with COVID. If you get COVID, you may even be asked to increase your anticoagulant dose, especially if you are on prophylactic treatment (e.g. 10mg of rivaroxaban).
Unfortunately, heart problems can occur after you have recovered from COVID. Long COVID, which occurs after the acute infection, can cause several heart problems. I will cover these in another post.
If you have concerns about the COVID risks and heart problems, feel free to share them here.