Late in the COVID-19 pandemic, mortality rates were elevated for Medicare beneficiaries with cardiovascular risk factors or established cardiovascular disease compared with the prepandemic period. Hospital visit rates were also lower and use of outpatient visits were higher during this period, according to study results. 

“Patients with cardiovascular disease are very vulnerable to both the acute and long-term effects of COVID — on their bodies and on the health system that cares for them,” study researcher Karen Joynt Maddox, MD, MPH, told Medscape Medical News.

Despite the first waves of COVID causing immense morbidity and mortality and healthcare avoidance for older adults, little is known about what happened on a population level as the pandemic dragged on, said Joynt Maddox, who is a cardiologist at WashU Medicine in St Louis, Missouri. 

“Did people return to their pre-COVID habits in seeking care?” she said. “Did COVID cause higher mortality, or was there a ‘healthy survivor’ effect as many had predicted, where peaks in mortality would be offset later by lower mortality rates? There were just a lot of remaining unknowns about the downstream consequences of the pandemic.”

Significant Mortality Spike 

These unknowns led Joynt Maddox, Rishi K. Wadhera, MD, MPP, MPhil, of Harvard Medical School in Boston, and colleagues to conduct the study. Their analysis involved all Medicare fee-for-service and Medicare Advantage beneficiaries with cardiovascular risk factors or established cardiovascular disease from January 2018 to December 2022. Risk factors included hypertension, diabetes, and hyperlipidemia. Cardiovascular disease included coronary heart disease, heart failure, atrial fibrillation, and stroke.

In all, the study featured about 51.4 million beneficiaries in the prepandemic period (ie, January 2018 to December 2019) and about 55.2 million beneficiaries in the late pandemic period (ie, January 2021 to July 2022). 

Data showed that hospital visit rates dropped in the late pandemic period compared with the prepandemic period (adjusted incidence rate ratio [aIRR], 0.918; 95% CI, 0.915-0.922). These declines were apparent for rural and urban beneficiaries, across all levels of social vulnerability, and in both fee-for-service and Medicare Advantage beneficiaries, the researchers wrote. 

Conversely, use of outpatient visits during the late pandemic period rose (aIRR, 1.141; 95% CI, 1.134-1.149). Increases were higher on average among urban communities and Medicare Advantage beneficiaries.

The researchers also found that all-cause mortality was elevated during the late pandemic period (aIRR, 1.248; 95% CI, 1.240-1.257), and that these mortality surges tracked with national COVID-19 mortality. The greatest increase in all-cause mortality was observed among beneficiaries in the most socially vulnerable communities (aIRR, 1.116; 95% CI, 1.106-1.124) and those covered by Medicare Advantage (aIRR, 1.342; 95% CI, 1.329-1.356).

For Clyde W. Yancy, MD, MSc, chief of the Division of Cardiology at Northwestern University Feinberg School of Medicine in Chicago, the 25% rise in mortality represents the most worrisome issue. 

“With more than 1 million aggregate deaths due to COVID-19, this calculus may simply reflect the overall burden of mortality during the pandemic,” Yancy told Medscape Medical News. “Yet if any of this risk was attributable to structural challenges accessing healthcare, we are forewarned to anticipate this yet again.”

Likely Responsible Factors 

Although Joynt Maddox noted that she and fellow researchers do not know the exact reason behind these patterns, she believes there are at least three contributing factors: biology, behavior, and system strain. 

“The mortality that we see in the data matches up with COVID spikes more broadly; that tells me that the virus is triggering cardiovascular events in addition to causing respiratory problems,” Joynt Maddox said. “We kind of knew that from flu, but this raises lots of interesting questions about the impact of viruses on inflammation and cardiovascular disease.”

Regarding behavior, she said some people avoided healthcare in the early days of COVID, and emergency department and hospital utilization didn’t fully rebound, which could have had negative consequences.

“Finally, there have been real changes to the healthcare system,” Joynt Maddox said. “Hospitals have closed; nursing homes have closed; and primary care continues to be under immense strain. 

“It’s impossible to say which of these drove the results (probably all did), but it does suggest a few places where we need a deeper dive.”

Joynt Maddox has received research support from the National Heart, Lung, and Blood Institute, National Institute of Nursing Research, National Institute on Aging, and National Center for Advancing Translational Sciences; has served as an Associate Editor for JAMA; has served on the Health Policy Advisory Council for the Centene Corporation (St Louis, Missouri); and has received research funding from Humana. Yancy reported no relevant financial relationships. 

Brian Ellis is a freelance writer and editor who lives in Southwest Virginia.