Viral and bacterial infections can trigger life-threatening inflammation and hypercoagulability in patients with cardiac disease.
The CDC recommends vaccinating patients with heart disorders and other chronic diseases for RSV, influenza, COVID-19, and pneumococcus, following age-appropriate guidelines.
The risk of adverse effects of vaccines in patients with cardiac disease is relatively small and outweighed by their benefits.
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.
Threats of infection: Flu and RSV
Cardiac disease is linked to influenza and RSV infection. Research has demonstrated that cardiac complications following influenza infection are decreased in patients who are vaccinated, according to the authors of a review published in the Journal of the American College of Cardiology.
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 hospitalized 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.
As the review authors explain, RSV infection has been associated with elevated levels of proinflammatory cytokines in the lungs, including interleukin 6 (IL-6), IL-1β, and tumor necrosis factor alpha, mediated via type I interferon signaling.
“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. “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.”
The American Heart Association (AHA) stresses the importance of vaccination for cardiac patients, noting that those who are 60 years or older should engage in shared decision-making with their physicians about vaccinations for COVID-19, flu, and pneumococcal disease.
These patients should also stay current on a Tdap vaccine, which protects against diphtheria, tetanus, and pertussis.
The CDC recommends RSV vaccination in elderly adults with chronic illnesses, such as heart disease. The main exception is 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 leukemia or HIV infection) or from medications (such as cancer treatment or prior organ transplant surgery).
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.
By virtue of the clinical sequelae of these conditions, as well as the effects of treatment, these patients may have accumulated “stacked comorbidities” leading to impaired immune function and greater susceptibility to infection.
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.
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.
Myocarditis and COVID-19
Some attention has been given to the increased risk of myocarditis in patients immunized 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.
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.”
The vast majority of patients with acute myocarditis associated with COVID-19 vaccination experienced resolution of symptoms at follow-up, with electrocardiogram/echocardiography and laboratory testing returning to normal.
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 by 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.
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 favorable balance for vaccination across all age and sex groups,” noted the ACC.
What this means for you
Cardiologists should encourage their patients to stay current on their vaccinations, as the cardiac risks are minimal. Vaccination against influenza and RSV, especially, can reduce the risk of CHF, MI, and other cardiac complications.
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