Research is beginning to reveal the lasting impact of covid-19 on cardiovascular health–even among so-called ‘mild’ cases. There is pressing need to ensure health systems are equipped to deal with an ensuing tide of disease.
Despite masks coming off in many countries, the covid-19 pandemic is far from over, especially in countries with low vaccination rates. But a new post-covid scenario is emerging around the globe—one where, contrary to expectation, the greatest burden may come from the non-hospitalised, so-called mild cases, as they start to experience legacy effects, including on the heart and circulation.
As its name suggests, the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which causes covid-19, is mostly known for its adverse effects on the lungs, especially in the acute phase. However, other vital organs and functions are also implicated—not least, the cardiovascular system.
A recent paper in Nature Medicine provides the first robust evidence of post-covid effects on the cardiovascular system. Unlike the flurry of preprint publications presenting incremental nuggets of knowledge on SARS-CoV-2, this significant study casts a floodlight on the lasting effects of covid-19.
More disease than expected
Of note, the study found that 12 months after a positive covid-19 test, significant numbers of patients are experiencing heightened risk of cardiovascular problems, including heart muscle inflammation, blood clots, stroke, myocardial infarction, and heart failure.
Senior author Professor Ziyad Al-Aly, a cardiologist and director of the Clinical Epidemiology Center and chief of research and development service at the Veterans Affairs St. Louis Health Care System in Missouri, was surprised by the findings. In particular, he and his colleagues did not expect such high incidence of cardiovascular risks and events 12 months after an initial ‘mild’ covid-19 infection.
The findings have important implications for healthcare systems around the world. "Even in patients mildly affected by covid, this could translate into millions of people requiring lifelong care for cardiovascular disease. We cannot underestimate the burden this will place on people as well as healthcare services,” Al-Aly says.
These data likely represent just a small fraction of a much bigger problem as the world continues to battle the pandemic. Instances of what is referred to as ‘long covid’ are likely to increase and worsen the already high chronic cardiovascular disease burden.
"Even in patients mildly affected by covid, this could translate into millions of people requiring lifelong care for cardiovascular disease"
“We already eat too much and our sedentary behaviours mean cardiovascular risk factors were significant even before covid,” Al-Aly says. “The pandemic will only amplify this further. We will have a tide of new cardiovascular disease burden on our hands, and, as of today, we are not totally equipped to deal with this.”
Not-so-mild risks
Al-Aly initially believed there might be post-covid, long-term cardiovascular implications only for high-risk categories such as smokers and those living with obesity, diabetes or kidney disease. “If someone had a heart problem such as an atrial fibrillation [which causes an irregular and often abnormally fast heart rate] that is predisposed to clotting, to start with, then it is more likely that they’ll experience blood clot.”
On the contrary, the study found an increased risk in all subgroups, irrespective of conventional cardiovascular risk factors. “It’s like being hit by a bus, in the sense that it doesn’t matter if you’re black or white, male or female—you’ll get an injury,” Al-Aly says.
Also, the finding that so-called mild, non-hospitalised covid-19 cases showed cardiovascular risk factors after infection came as a surprise. “This is important because it represents the vast majority of people who have had covid-19, because most do not need to be hospitalised,” Al-Aly says.
Overall, the study found that for every 100 people with covid-19, four experienced a cardiovascular event due to the virus, Al-Aly explains. Given global covid-19 cases exceed 540 million, the potential disease burden is significant.
Even [when the disease first emerged] covid was most often considered a respiratory disease, but when we see the outcomes now, we see this as a multi-system disease, or one with multi-system complications.
Drawing comparison with a contemporary control group that did not have covid-19, as well as a group from pre-covid times, people with a history of covid-19 were at increased risk of stroke, dysrhythmia [irregular rate of heart contraction], heart failure and deep vein thrombosis, among others.
The findings are beginning to emerge in clinical practice, says Amitava Banerjee, a professor of clinical data science and honorary consultant cardiologist at University College London Hospital who treats post-covid cardiovascular issues.
“As a practising cardiologist, I’ve been seeing patients who weren’t hospitalised for their covid but now complain of heart rhythm problems, of myocarditis, and other cardiac complications,” he says. Even [when the disease first emerged] covid was most often considered a respiratory disease, but when we see the outcomes now, we see this as a multi-system disease, or one with multi-system complications.
Banerjee says that non-hospitalised patients, representing the majority of individuals with long covid, can show normal heart scans earlier on, yet have functional impairments that affect their daily lives, such as an inability to go to work or care for their children. “Many are as affected as those who were hospitalised.”
Battling a care deficit
Perhaps unsurprisingly, the implications of covid-19 are potentially even more serious for people with pre-existing cardiovascular conditions. Worryingly, there is evidence that missed treatments have increased during the pandemic—whether a patient has contracted covid-19 or not.
Banerjee cites a study that shows how prescribing and dispensing of medications for cardiovascular disease have reduced in the UK throughout the pandemic, and how, irrespective of whether or not patients contracted covid-19, this has worsened outcomes. Similar patterns are believed to have emerged in many other countries.
Data on cardiovascular medications dispensed to 15.8 million individuals across England, Scotland and Wales showed nearly 400,000 fewer patients initiated antihypertensive treatment during 2020-2021 than in 2019.
On the projected rise in cardiovascular disease in a post-pandemic era, the study authors, led by Caroline Dale from University College London, conclude that “novel methods to identify and treat individuals who have missed treatment are urgently required to avoid large numbers of additional future cardiovascular disease events…”
Together, the evidence highlights the need to plan and prioritise services to accommodate the projected rising wave of cardiovascular health issues in the wake of the many millions of covid-19 infections in high-income as well as low- and middle-income countries (LMICs) alike.
Redressing the research imbalance
The World Heart Federation (WHF) is leading a 23-country study on covid-19 and cardiovascular disease in which 80% of the 5,000 participating patients are from Africa, Latin America and Southeast Asia.
“We want more insight into the risk factors for severe disease, clinical presentation and outcomes of various cardiovascular manifestations from low- to middle-income countries”
Professor Karen Sliwa, director of the Cape Heart Institute at the University of Cape Town, is one of the principal investigators. She hopes the study will redress the imbalance in covid-19 data that is predominately sourced from high-income countries.
“We want more insight into the risk factors for severe disease, clinical presentation and outcomes of various cardiovascular manifestations from low- to middle-income countries,” Sliwa says. “These data will assist us with future covid mutations and possibly new epidemics.”
In LMICs, many healthcare centres lack specialists, and there are often no intensive care units and very few ventilators, explains Sliwa. “Low- to middle-income countries have an increasing burden of obesity, poorly diagnosed and treated high blood pressure, and diabetes. This makes the population vulnerable to severe manifestations of covid-19 and other forms of influenza.”
The WHF will also extend the study to include a further 3,000 patients and investigate the long-term effects of covid-19 on cardiac function and mental health, says Sliwa.
Referring to the projected surge in cardiovascular risk factors and disease burden among people previously infected with covid-19 in LMICs, Sliwa says clinicians will need to be on the lookout for new-onset hypertension and manage cardiovascular precursors including obesity and diabetes. Improved access to diagnosis and affordable medication will be other key areas of focus.
Planning for a post-covid future
The pandemic continues to present a black hole of unknowns to researchers, clinicians and policymakers, but it is crucial to plan ahead to mitigate the predicted increase in cardiovascular disease.
Al-Aly uses the analogy of an earthquake to explain the pandemic scenario. “You wouldn’t be concerned about an earthquake only when the Earth is shaking—you’d have a lot of rebuilding and repair to do afterwards,” he says.
“Right now, we are still in the middle of the pandemic and the Earth is shaking, but at some point the pandemic will be in the rear-view mirror, and we will be left with the scars—the rubble and the mayhem left over.”
A national- and global-level cross-disciplinary strategy is required, he says. “Otherwise, there will be a surge in non-communicable diseases. We have spent the past 50 years doing a lot of work to improve the cardiovascular health of the population and the pandemic will certainly set us back by decades, if not more. It will erase decades of improvement in health and life expectancy in every country on Earth.”
Case study: India and the long-covid fallout
India recorded nearly 400,000 covid-19 cases per day in its second wave in April 2021. The healthcare system was crippled and the UK and European Union countries sent ventilators and oxygen concentrators to help ease the massive burden. Now, the country is “entering the endemic phase”, explains Professor Dorairaj Prabhakaran, director of the Centre for Control of Chronic Conditions at the Public Health Foundation of India. He believes India is gearing up to deal with an increase in cardiovascular disease. “I see many silver linings on the horizon right now. The government has a new plan called ‘Healthy India’ and cardiovascular disease is high on the list of conditions to tackle. It is prioritising cardiovascular risk factor screening—for example, for hypertension—and even the smallest districts have echocardiogram facilities. However, access to the poor and rural populations will continue to be an issue for some time.” Plus, Prabhakaran says, the primary healthcare system is being restructured with heart health in mind. Primary care centres and sub-centres will be re-designated as health and wellness centres that work across the continuum of care, connecting communities to the central health system. There will be facilities to address diet, tobacco use and physical activity, as well as rehabilitation after illness.