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Cardio Metabolic Health Congress – Official Blog

High Incidence of Acute Cardiovascular Events Among Hospitalized Influenza Patients

Combined with the toll of the prevailing COVID-19 pandemic, the flu season and the associated influx of illness are expected to place a significant burden on the public health system this fall and winter. The medical community is becoming increasingly burdened with the current upsurge in patient visits as well as the impending potential for adverse health consequences related to both diseases. High rates of cardiovascular events have been reported in adult patients hospitalized with influenza, per data from a recent study published in the Annals of Internal Medicine. 

Influenza and Acute Cardiovascular Events 

Coupled with the acute cardiovascular complications possible in COVID-19 illness, experts warn against a potential rise in cardiovascular events. In order to examine acute cardiovascular events and determine the risk factors for both acute heart failure and acute ischemic heart disease in adults hospitalized for influenza, researchers conducted a cross-sectional study of 80,621 adult patients (mean age of 69 years).

Data was obtained from the large, multi-center FluSurv-NET network and included patients from across 17 U.S. states with confirmed influenza during the 2010-2011 and 2017-2018 flu seasons. The research team utilized discharge codes to identify acute cardiovascular events; they also assessed exposure variables in their analysis including age, tobacco usage, chronic conditions, influenza vaccination, influenza antiviral medication, as well as influenza type and subtype.

Elevated Incidence of Acute CV Events

The study’s authors reported an 11.7% incidence of acute CV events in the cohort with acute heart failure and acute ischemic heart disease as the most common events occurring at 6.2% and 5.7%, respectively. Hypertensive crisis, cardiogenic shock, acute myocarditis, acute pericarditis, and cardiac tamponade were observed at lower rates, according to the team.

Patients who suffered acute CV events had a median length of hospital stay of 5 days, while for those with cardiogenic shock it was 9 days; 38.9% of cardiogenic shock patients died during the course of hospitalization.

Older age, extreme obesity, current tobacco use, atrial fibrillation, chronic heart failure, cardiomyopathy, coronary heart disease, diabetes mellitus, and chronic renal disease were all factors significantly associated with a higher risk of both acute heart failure and acute ischemic heart disease.

The study’s authors acknowledged their limitations, which included the sole enrollment of hospitalized patients with laboratory-confirmed influenza and a lack of available data on known risk factors for cardiovascular events – such as hypertension and hyperlipidemia. Furthermore, under-detection of influenza cases was likely as testing is primarily dependent on practitioner orders. Finally, acute cardiovascular events identified by ICD discharge codes could have been subject to misclassification bias, skewing the final results.

The population-based study revealed that nearly 12% of patients hospitalized with influenza experienced an acute cardiovascular event highlighting the current need for clinicians to ensure high rates of influenza vaccination. This is especially urgent among patients with underlying health conditions that already face a higher risk of adverse health outcomes related to both COVID-19 and the influenza virus.

“Increasing rates of influenza vaccination, especially among those with CV risk factors, is essential in preventing infection and potentially attenuating influenza-related CV complications and adverse outcomes,” noted the study authors. In the context of a global pandemic, the CDC urges wide-scale vaccination for all patients, however, cardiac patients in particular may benefit from the additional protection against acute CV events associated with influenza.

Novel Screening Method for Detection of Silent CAD

Cardiopulmonary diseases, such as coronary artery disease (CAD), remain as one of the major causes of death worldwide. Despite advancements in technology and research, currently recommended strategies for prevention and diagnosis have not been updated in recent years to better serve the needs of the population, which often lives unaware of the condition. New data reveals how strikingly common silent coronary artery disease is among the general population, with over 40% of healthy study participants experiencing subclinical coronary artery disease as well as a new technique that can be used to better diagnose such patients.

Updating Screening Methods

In an attempt to investigate potential novel screening methods for coronary artery disease, a team of researchers distributed a screening questionnaire developed to help identify those at risk for CAD to over 25,000 Swedish patients without cardiovascular issues. Participants also underwent coronary CT angiography (CCTA) to determine their heart health status. The study’s authors developed two prediction models: one relied on the assessment of risk factors and waist circumference measurements conducted by patients at home, and another more precise “clinical” model.

“The buildup of plaque does not cause symptoms in the early phases of atherosclerosis yet may lead to reduced blood flow to the heart and result in a heart attack,” lead study author Goran Bergström, MD, PhD, of Sahlgrenska Academy at Gothenburg University in Sweden said in statement. “We investigated whether a personalized screening strategy using data easily measured at home could predict which patients are at high risk of developing heart disease.”

Silent CAD Prediction Models

Both models appeared to readily identify people who would benefit from further cardiovascular screening. Silent coronary artery disease was common in the cohort with 42% of participants presenting with plaque in their coronary arteries. The researchers reported that approximately four in 10 people, aged between 50 and 64, had subclinical coronary artery disease and about one in 20 presented with serious CAD, with at least one coronary vessel with a minimum of 50% stenosis.

The home prediction model aptly identified at-risk patients; 30% of patients who scored the highest on the home questionnaire accounted for 67% of all patients with disseminated CAD detected using CCTA.

A higher prevalence of atherosclerosis was observed in men and in older patients, per Dr. Bergström. In addition, the researchers also reported the highest frequency of plaques detected in the proximal left anterior descending coronary artery, regardless of sex and severity of disease.

Bergström and colleagues’ study was the first ever to utilize the CCTA imaging technique in a large population sample; it also provides compelling evidence for the use of screening questionnaires prior to clinical visits to further assess patient risk for silent coronary artery disease. As atherosclerosis is widespread and can easily be predicted with a series of simple questions, the latest findings lay the foundation for the development of home-based screening strategies aimed at combating cardiovascular disease.

The use of CCTA technology only in those with high clinical risk profiles requires prospective validation, including the assurance that all prognostically significant non-obstructive CAD is detected so as to ensure that this at-risk group is not under-treated. Once the latest findings are validated prospectively, randomized clinical trials will be needed to determine if such an approach could be employed to improve outcomes and provide a more cost-effective solution over current medical care strategies.