Discover the intriguing link between cardiac health and viral infections, hinting at the pivotal role of vaccinations like influenza and RSV in safeguarding against severe heart complications, igniting curiosity about their profound impact on cardiovascular protection.

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Inflammation binds heart disease and infection caused by viruses and bacteria. Inflammation can also lead to plaque rupture, thrombosis, and blocked arteries, causing heart attack and stroke. Avoidance of such complications supports the importance of vaccination in patients with cardiac disease.

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Threats of infection: Flu and RSV

The elderly and individuals with cardiac disease may be at increased risk for CHF, MI, and other cardiac complications, with CHF and MI occurring in as many as 22% of adult patients hospitalised with RSV. These patients also have a higher risk of acute coronary syndrome and arrhythmia. 

The inflammation that accompanies infection can contribute to atherosclerosis and lipid accumulation, and also to hypercoagulability, which can trigger acute coronary syndrome. In addition to these mechanisms, the danger of RSV infection may be rooted in elevated proinflammatory cytokines.

“This immune regulation,” they write, “may be relevant in cardiac disease, as patients with CHF have been shown to have decreased levels of interferon-ɣ, which recruits cytotoxic T-cells in response to viral pathogens.” 

The immune-inflammatory response likely plays a role in influenza and other infections.

The authors of a review published in Cardiology underscored this: “The mechanisms by which influenza increases the risk of CV events may be related to pro-inflammatory mediators, sympathetic stimulation and the activation of the coagulation cascade that may trigger rupture of vulnerable atherosclerotic plaques,” they wrote.[2] “Contributing factors may include the higher metabolic demand due to adrenergic surge and hyperdynamic CV response as well as potential compromise of oxygenation due to pulmonary infection.” 

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Vaccination guidelines

These patients should also stay current on a Tdap vaccine, which protects against diphtheria, tetanus, and pertussis.

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RSV

The CDC recommends RSV vaccination in elderly adults with chronic illnesses, such as heart disease.[4] The main exception is a severe allergic reaction to the vaccine. According to the CDC, the risk of severe RSV disease is higher if patients are living in a nursing home, have a chronic medical condition, or have a weakened immune system from illness (such as leukaemia or HIV infection) or from medications (such as cancer treatment or prior organ transplant surgery).

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Pneumococcal disease

Vaccination against pneumococcal disease may be particularly important in patients with chronic health conditions such as heart disease, liver disease, lung disease, diabetes mellitus, and substance use.

A subgroup analysis of a phase 3 study has examined the safety, tolerability, and immunogenicity of sequential administration of pneumococcal conjugate vaccine (PCV), either V114 (a 15-valent PCV containing serotypes 1, 3, 4, 5, 6A, 6B, 7F, 9V, 14, 18C, 19A, 19F, 22F, 23F, and 33F) or PCV13, followed in 6 months by a 23-valent pneumococcal polysaccharide vaccine, PPSV23.[5]

The investigators observed that stacking of these risk factors was associated with increased risk of pneumococcal disease, and the risk approached that seen in immunocompromised individuals. “Unlike immunocompromised individuals, most immunocompetent adults with medical conditions associated with an increased risk of pneumococcal disease respond well to vaccination,” the authors wrote.

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Myocarditis and COVID-19

Some attention has been given to the increased risk of myocarditis in patients immunised for COVID-19. According to key points published by the American College of Cardiology (ACC), myocarditis is a rare adverse effect following vaccination historically associated with hepatitis B, influenza, and smallpox.[6]

In 2021, the CDC reported a small association between the SARS-CoV-2 mRNA vaccines and cases of myocarditis and pericarditis of “approximately 12.6 cases per million second-dose mRNA vaccine among people aged between 12 and 39 years.” 

As for a mechanism, the science is unclear. It could be “related to mRNA sequence that encodes for the spike protein of SARS-CoV-2, or to the immune response that follows vaccination," noted the author writing for the ACC. "The propensity of young adults to develop myocarditis following the second dose of vaccine supports the hypothesis of the vaccine-associated maladaptive immune response, related to sex hormone differences, causing cardiac injury."

It’s worth mentioning that a single case of Takotsubo cardiomyopathy was observed following mRNA vaccination and vector-based vaccination, with no reports following the administration of inactivated vaccines.[7] 

Experts assert that the benefits of COVID-19 vaccination outweigh the “minor” risk of cardiac effects.

“Available data suggest that the risk of acute myocarditis associated with COVID-19 vaccination is very low, although more common in young male patients. Furthermore, vaccine-related myocarditis is self-limiting in most cases. These data should reassure physicians, patients, the general population, and media, as the benefit–risk assessment for SARS-CoV-2 mRNA vaccination shows a highly favourable balance for vaccination across all age and sex groups,” noted the ACC.

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Disclaimer: This story is contributed by Naveed Saleh and is a part of our Global Content Initiative, where we feature selected stories from our Global network which we believe would be most useful and informative to our doctor members.