Cardiologists should encourage their patients to get their annual flu shots as a means of reducing their cardiovascular morbidity and mortality, according to a new review. "We wrote this review to empower cardiologists and physicians in general to understand a bit more about the nuances of flu shots and the developing COVID vaccines in order to advocate for our patients," said Dr. Jacob A. Udell of Women's College Hospital and the University of Toronto, in Canada. "We are in a unique position to ensure our patients, who are at high risk for contracting both flu and COVID, that they should certainly be getting a flu shot this year, and the right flu shot for them, and no longer miss the chance to further protect themselves," he told Reuters Health by email. Seasonal influenza has been associated with increased cardiovascular events, including myocardial infarct-associated deaths and hospitalizations, Dr. Udell and colleagues note in the Journal of the American College of Cardiology. Influenza and other serious infections can destabilize patients with pre-existing cardiovascular disease through increased metabolic demand, they add, and hypoxemia complications can further exacerbate underlying cardiovascular disease. Influenza virus can also precipitate acute cardiovascular events by stimulating a potent acute inflammatory response, which is known to trigger acute plaque rupture and global myocardial depression. COVID-19 appears to increase cardiovascular morbidity and mortality through similar mechanisms, as well as through increased thrombogenicity. Numerous studies have suggested that influenza vaccination can prevent adverse cardiovascular outcomes. But despite international guidelines recommending routine vaccination for patients with cardiovascular disease, uptake is lacking and is often not a top priority, even at the time of a cardiovascular hospitalization. Particularly for older populations, which have a greater risk for and higher prevalence of cardiovascular disease, the newer high-dose vaccine appears to afford greater protection against influenza. Several cardiovascular outcome trials are underway to examine the possibility of reducing cardiovascular morbidity and mortality using both the standard- and high-dose influenza vaccines in patients with varying cardiovascular disease (CVD) phenotypes. To reduce the hundreds of thousands of preventable deaths from both influenza and COVID-19, though, additional research is needed to identify effective strategies for preventing and managing both infections, the authors say. "If one comes down with flu-like symptoms this fall/winter, we can't initially tell the difference between flu and COVID-19," Dr. Udell said. "The influenza vaccine is key to protecting us from flu-like illness similar in size and scope to COVID-19. One less acute respiratory infectious illness with morbidity and mortality when we are in the midst of a COVID-19 pandemic to need to worry about." Dr. Peder Langeland Myhre of the University of Oslo, in Norway, who recently reviewed cardiovascular hospitalizations, influenza activity, and COVID-19 measures, told Reuters Health by email, "The most important point is for clinicians and researchers in cardiovascular care to utilize the wealth of experience from influenza vaccination when facing COVID-19, as there are many similarities: CVD is an important risk factor in infection with both viruses; both may cause exacerbation of established CVD and unmask previously undiagnosed CVD in at-risk patients." "Physicians should be encouraged to influenza vaccinate all patients with established CVD and other high-risk groups, such as patients with diabetes," said Dr. Myhre, who was not involved in the review. "This is particularly important during the pandemic, both to reduce the burden on healthcare systems and to optimize the health situation to be best prepared for a potential COVID-19 infection." —Will Boggs, MD Source
