On the third anniversary of the WHO’s declaration of a global pandemic, we explore the relationship between high blood pressure and the risk of serious illness and death from Covid-19.

By Amy Synnott

If you suspected your blood pressure went up during the pandemic, you might be correct. Average blood pressure readings increased as the coronavirus spread, according to a 2022 observational study published in the journal, Circulation.¹ And the resulting hypertension epidemic could have a huge impact on the number of strokes, heart failure, and heart attacks we see in the future, the researchers note. ²

According to a 2020 study published in the European Respiratory Journal, hypertension is the most common comorbidity seen among hospitalized patients with Covid 19. Of perhaps even greater concern: Those suffering from hypertension have a significantly higher risk of severe cases of Covid, resulting in hospitalization and even death.³  

Analyzing data from 1590 hospitalized patients from 575 hospitals in mainland China, researchers in this study found those who suffered from severe cases were 32.7% more likely to suffer from hypertension (versus 12.6% in non-severe cases). They were also more likely to have other conditions strongly associated with vascular dysfunction, including cardiovascular diseases (33.9% versus 15.3%), cerebrovascular diseases (50.0% versus 15.3%), diabetes (34.6% versus 14.3%), chronic obstructive pulmonary disease, aka COPD (62.5% versus 15.3%), and chronic kidney diseases (38.1% versus 15.7%). ⁴ 

While hypertension accounted for a little over one third of the severe cases in this study, it’s worth noting that high blood pressure is closely linked to the development — and progression of —virtually all of those other comorbidities: cardiovascular disease, cerebrovascular disease (which affects blood flow in the brain), diabetes, COPD (a condition involving constriction of the airways and difficulty breathing), and chronic kidney disease, according to a 2022 report from the American Heart Association published in Circulation.⁵ 

In a 2021 review in Frontiers of Physiology that explored the relationship between hypertension and Covid 19,  researchers wrote, “It’s still unclear whether high blood pressure is a risk factor for acquiring COVID-19, or whether controlled blood pressure among patients with hypertension is or is not less of a risk factor.”⁶      

How Hypertension Increases the Risk of Severe Covid Outcomes  

Cardiovascular health impacts Covid-19 outcomes in several ways, says Ray Townsend, M.D., the Director of Hypertension at the University of Pennsylvania School of Medicine.  Individuals with high blood pressure have an increased risk of blood clots, and the coronavirus increases that risk. “Patients with Covid tend to form clots in the arterial circulation [the flow of blood in the vessels that supply the heart muscle], ” he says. “This can lead to stroke, heart attack, and peripheral vascular disease.”  

Townsend says venous clots — blockages in peripheral veins that supply blood flow to the legs and feet known as deep vein thrombosis — are also common in Covid patients. “This can cause a pulmonary embolism, where a blood clot travels to, and blocks, lung circulation.” 

A 2022 study published in the Journal of the American Medical Association found the risk of blood clots was higher among hospitalized Covid 19 patients than those hospitalized for influenza.⁷ Analyzing the outcomes of over 90,000 patients, the researchers at Perelman School of Medicine at the University of Pennsylvania found the risk of developing venous thromboembolism was 5.3%  in patients diagnosed with the flu.  

Among those hospitalized for Covid, the risk of deep vein thrombosis was 9.5% before vaccine availability and 10.9 percent after COVID-19 vaccines became available. The risk of arterial thromboembolism, a blood clot that travels from one part of the body to the brain (stroke) or heart (heart attack), was 14.4 percent in patients hospitalized with the flu compared with 15.8 percent in those with Covid before vaccine availability and 16.3 percent during vaccine availability. 

“Although COVID-19 is primarily considered a respiratory illness, some evidence suggests the virus may also induce excessive blood clotting, or hypercoagulability, in the body,” the researchers wrote.  

Covid Increases Cardiovascular Complications

Not only does hypertension increase risk of serious illness from Covid infection, the disease itself can negatively affect cardiovascular health for months after the acute phase has ended, according to a 2022 study published in the journal, Nature Medicine. ⁸ 

Using medical databases from the US Department of Veterans Affairs, the researchers show that individuals who have recovered from COVID-19 are at increased risk cerebrovascular disorders, dysrhythmias (abnormal heart rhythms), heart disease, pericarditis (swelling or irritation of the membrane around the heart), myocarditis (inflammation — often caused by a viral infection — of the middle layer of heart wall), heart failure and thromboembolic disease (the aforementioned syndrome involving a blood clot that travels from one part of the body to another, blocking arteries and predisposing one to heart attack or stroke).  

These cardiovascular risks were seen even in those who avoided hospitalization (though they increased depending on their care setting during the acute phase, i.e., non-hospitalized, hospitalized and admitted to intensive care). “Our results provide evidence that the risk and one-year burden of cardiovascular disease in survivors of acute COVID-19 are substantial,” the researchers wrote.  

The Cartesian Study

In May 2020, the Artery Society in Europe announced the launch of a multicenter research project to explore the medium- and long-term consequences of COVID-19 on the cardiovascular system. The researchers are using ATCOR’s SphygmoCor® XCEL technology to analyze central hemodynamic patient data.

In the ongoing study, patients recently diagnosed with COVID-19 infection will be evaluated three to six months post diagnosis and again one year after diagnosis. Evaluation will include assessment of carotid-femoral PWV and central blood pressure waveform analysis as well as indicators of carotid geometry and stiffness, endothelial function, 24-hour central blood pressure, and small artery remodeling. Both a five- and 10-year clinical follow-up is planned to determine the risk of cardiovascular events associated with central hemodynamics and arterial stiffness among survivors of coronavirus.[5]

The Importance of Pulse Wave Analysis

The vascular implications of COVID-19—and its ongoing presence in our lives—highlight the need for sophisticated diagnostic techniques that go way the insights offered by standard peripheral blood pressure measurements. Combined with a traditional brachial cuff, ATCOR’s SphygmoCor® arterial waveform analysis offers both clinicians and researchers vital insights into their patients’ subclinical vascular health—including but not limited to arterial stiffness, pulse wave reflections, and central aortic blood pressure. As we continue to adjust to “the new normal with Covid,” the widespread adoption of this gold standard technology in decentralized trials and clinical practices can help stem the impact of Covid 19 on the hypertension epidemic. 

SOURCES:  

Laffin LJ, Kaufman HW, Chen Z, Niles JK, Arellano AR, Bare LA, Hazen SL. Rise in Blood Pressure Observed Among US Adults During the COVID-19 Pandemic. Circulation. 2022 Jan 18;145(3):235-237. doi: 10.1161/CIRCULATIONAHA.121.057075. Epub 2021 Dec 6. PMID: 34865499; PMCID: PMC8763044. 

Comorbidity and its impact on 1590 patients with Covid-19 in China: A Nationwide Analysis 

Wei-jie Guan,  et al. European Respiratory Journal Jan 2020, 2000547; DOI: 10.1183/13993003.00547-2020 

Tsao, Connie W et al. “Heart Disease and Stroke Statistics-2022 Update: A Report From the American Heart Association.” Circulation vol. 145,8 (2022): e153-e639. doi:10.1161/CIR.0000000000001052 

Lo Re V 3rd,et al.Association of COVID-19 vs Influenza With Risk of Arterial and Venous Thrombotic Events Among Hospitalized Patients. JAMA. 2022 Aug 16;328(7):637-651. doi: 10.1001/jama.2022.13072. PMID: 35972486; PMCID: PMC9382447. 

REVIEW article, Front. Physiol., 03 May 2021, Sec. Vascular Physiology, https://doi.org/10.3389/fphys.2021.665064 

Xie, Yan et al. “Long-term cardiovascular outcomes of COVID-19.” Nature medicine vol. 28,3 (2022): 583-590. doi:10.1038/s41591-022-01689-3 

McEniery CM, Cockcroft JR, Roman MJ, Franklin SS, Wilkinson IB. Central blood pressure: current evidence and clinical importance. Eur Heart J. 2014 Jul;35(26):1719-25. doi: 10.1093/eurheartj/eht565. Epub 2014 Jan 23. PMID: 24459197; PMCID: PMC4155427.