It’s well accepted that COVID-19 is largely a respiratory disease, with some of its most harmful effects taking place in the lungs. People with diabetes are at increased risk for severe disease if they get COVID-19 — not because their breathing tends to be impaired already, but because of factors that tend to reduce their immune system’s ability to fight off the infection, such as elevated blood glucose levels and obesity.
There’s emerging evidence, though, that COVID-19 can damage organs other than the lungs, including the heart and the brain. Since people with diabetes are at increased risk of heart disease, any long-term effects from the infection on heart health could be especially troubling.
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But according to two new studies, COVID-19 may be harming heart health indirectly — by reducing the screening and care available, or changing how people access care for cardiovascular problems.
Heart disease diagnosis procedures are down worldwide
The first study, published in the Journal of the American College of Cardiology, looked at rates of heart disease diagnosis around the world during the pandemic. Researchers looked at surveys submitted by 909 healthcare centers that provide cardiac diagnostic procedures in 108 countries. Overall, the volume of these procedures was down by 42% in March 2020 compared with March 2019, and down by 64% in April 2020 compared with March 2019.
The procedures that saw the biggest drop were cardiac stress tests, down by 78% at the lowest point, and transesophageal echocardiography, down by 76% at the lowest point. Coronary angiography — either internal or done by computed tomography (CT) scan — was also down by 55%.
Perhaps not surprisingly, the biggest drop in procedure volume was seen in poorer regions of the world, with an 84% drop seen in the Middle East and South Asia, an 82% drop in Latin America, and a 79% drop in Africa. But richer areas of the world — which account for a disproportionate number of overall cardiac screening procedures — also saw a large drop-off. Procedure volume fell by 68% in the United States and Canada, by 69% in Western Europe, and by 68% in Eastern Europe. Far East Asia saw the smallest drop of any region, with a 35% reduction in these procedures.
Needless to say, these drops in cardiac diagnosis procedures don’t mean that people suddenly had less need for them. Instead, the numbers reflect healthcare systems that changed their protocols to limit in-person visits, or a hesitance by potential patients to visit healthcare facilities and undergo these procedures. It remains to be seen what long-term effect these drops in diagnostic procedures have on heart health.
Spikes in heart disease deaths in the United States
Another study, also published in the Journal of the American College of Cardiology, found that there were spikes in deaths by certain cardiovascular causes in the spring of 2020 — around the same time that many areas of the country were seeing their first spikes in COVID-19, and many states had stay-at-home orders or similar restrictions.
The researchers looked at data from the National Center for Health Statistics on deaths caused by several different types of cardiovascular disease from January to June 2020. They compared these numbers with those from the previous year, looking for any patterns that emerged.
It became clear that there were spikes in deaths from two different causes during the spring: ischemic heart disease (reduced blood to the heart) and hypertensive diseases (high blood pressure). There were no significant differences between 2019 and 2020 in the rates of death from heart failure, cerebrovascular disease (such as stroke) or other types of heart and blood vessel diseases.
New York City, in particular, saw a huge increase in deaths from ischemic heart disease, with a rate 2.39 times as high as in 2019 during the study period. It also saw deaths from hypertensive diseases reach 2.64 times what they were in the same period of 2019. More modest but still significant increases were seen in New York State, New Jersey, Michigan and Illinois — but not in Massachusetts or Louisiana, indicating that even some states hit hard by the pandemic didn’t see an increase in cardiovascular disease deaths.
The mostly likely explanation for these death increases, according to the researchers, is that many people saw their regular healthcare interrupted during the pandemic, or put off urgent or emergency care. In an accompanying editorial, experts write that while excess deaths due to COVID-19 were excluded from the study — by not including anyone whose death certificate listed COVID-19 as a contributing cause — there may be people who developed COVID-19 but were never diagnosed with the disease, possibly leading to heart complications caused by the viral infection that made existing cardiovascular disease worse. It’s impossible to know how common this was, or whether it contributed to the spikes in death seen in the study.
One thing is clear, though. Either directly or indirectly, COVID-19 led to an increase in deaths from certain forms of cardiovascular disease — much larger in some areas of the country than in others — during the first half of 2020.
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