Does COVID-19 affect the heart? A cardiologist writes
The first COVID-19 patient who died in Kerala was a 69-year-old man from Chullickal, Kochi. He was my patient, suffering from severe heart disease. He sustained a major heart attack and underwent bypass surgery in 2014. Since then I have been following up with him meticulously.
The patient was very prompt in taking medicines and carrying out my precautionary instructions regarding diet, exercise and other lifestyle modifications. Even though he had a poorly pumping heart, he was doing his daily activities and taking care of his business in Dubai fairly well without many complaints. He travelled frequently to Dubai and this March when he returned from Dubai, he didn’t know that he was infected with coronavirus. On reaching Kochi airport, he was febrile and very weak, and subsequently taken to Cooperative Medical College for intensive care. Despite all emergency measures, his heart condition deteriorated and he succumbed a week later.
COVID-19, the disease caused by the new coronavirus SARS-CoV-2, has made hundreds of thousands sick and continues to kill large numbers of people worldwide. Primarily considered life-threatening for its effects on the respiratory tract and lungs, new studies find that COVID-19 can also cause heart injury in people with or without prior heart issues. Prior heart disease is a risk factor for higher mortality in these patients. Injury to the heart muscles can also happen to people who are free of any prior heart ailments.
There are several reasons that viruses, like the flu or SARS-CoV-2, can become deadly. Three common reasons are coinfection with another microbe; respiratory failure when the respiratory tract and lungs are weakened by the infection; and a ‘cytokine storm’ caused by an overwhelming immune system response to the disease.
Cytokines are proteins that regulate a wide range of biological functions, one of them being inflammation and repair. The inflammatory response of cytokines can lead to heart damage via the mechanism of heart failure. When heart failure occurs, the heart muscles are not in a position to pump adequate blood to meet the requirements of the different organs of the body, thereby causing multi organ failure and subsequent death. The inflammation of the heart muscle is called myocarditis.
Studies on hospitalised COVID-19 patients from China, US and Europe show that severe heart failure following acute myocarditis was identified as a complication in 45-55% of patients who died and in 3% who recovered. In all the patients who died, a marker for heart muscle damage called ‘Troponin’ was significantly elevated. It has to be emphasised that patients with myocarditis who underwent coronary angiography showed normal coronary arteries confirming that the disease process is inflammation and not heart attack.
Surprisingly, it is found that SARS-CoV-2 is somehow more virulent toward the heart than other viruses and the heart injury can occur in any several ways. First, the subset of people with COVID-19 having no prior underlying heart disease who develop fulminant myocarditis as mentioned earlier. The second subset is people with pre-existing heart disease like my patient mentioned at the beginning. They are at a greater risk for severe cardiovascular and respiratory complications from COVID-19. The heart pumping function can deteriorate substantially and patients develop severe shortness of breath, which subsequently causes death.
Dr George Thayil
The third subset of people is those with previously undiagnosed heart disease that may be presenting with previously silent cardiac symptoms unmasked by the viral infection. In people with existing heart vessel blockages, infection, fever and inflammation can destabilise previously asymptomatic fatty depositions (plaque) inside the heart vessels. Fever and inflammation also render the blood more prone to clotting while also interfering with the body’s ability to dissolve clots.
The fourth subset may experience heart damage that mimics heart attack injury even if their arteries lack the fatty, calcified flow-limiting blockages known to cause classic heart attacks. This can occur when the heart is deprived of oxygen, which may be caused by a mismatch between oxygen supply and oxygen demand. Fever and inflammation accelerate heart rate and increase metabolic demands on many organs, including the heart. That stress is compounded if the lungs are infected and incapable of exchanging oxygen and carbon dioxide optimally.
A survey of major hospitals across the world showed that the number of severe heart attacks being treated had dropped by 40-60% since the novel coronavirus took hold in March. The scenario in Kerala is also not different, that is, new heart attacks in people without COVID-19 infection. The cardiologists are now worried about a second wave of deaths caused indirectly by COVID-19; patients may be afraid to go to hospitals that they are dying at home or waiting so long to seek care that they are going to suffer massive damage to their heart or brains.
The whole medical community is discussing this, asking where are all the heart patients? But there are also other factors that could account for this, like the positive outcome of the pandemic shutdown including decrease in air pollution, fewer heavy restaurant meals, less stress levels especially with less or no traffic, happiness and peace in the family, regular intake of medicines, no alcohol-no smoking, sufficient sleep, etc. Nature and the environment have become more living friendly. These positive aspects tremendously impact the mental and physical health of human beings.
Even if you aren’t directly affected by COVID-19, the pandemic has been a significant stressor on everyone’s lives. Indeed, there could be long-term consequences to the stress, anxiety and fear that has overwhelmed the globe for months. As per the American Epidemiological Society, coronavirus is going to be with us for 2-3 more years. Post-traumatic stress disorder that occurs after witnessing a traumatic event, such as a natural catastrophe, a serious accident, terrorist attack or a physical assault, can also happen in this scenario.
How will the COVID-19 outbreak end? How will this story wrap up? Pandemics end when the virus doesn’t have enough susceptible people to infect. The catastrophic 1918 Spanish flu pandemic is thought to have infected 500 million people worldwide, many of them soldiers living in close quarters fighting in World War I. Once the war ended and people dispersed, the spread slowed as people had less contact. But the flu was ultimately halted in part because those who survived it had immunity and the virus didn’t hop as easily as it did at the beginning.
Another possibility is that SARS-Cov-2 will mutate in a potentially beneficial way, making it more difficult for the virus to infect people. But because the virus has established itself in human populations, a vaccine is the only way to eradicate it. And simultaneously we have to adopt new behavioural discipline and social ethics to contain this virus.
Dr George Thayil, MD, FACC, FRCP, is Senior Consultant Cardiologist at Lourdes Hospital, Kochi.