Rating Risk of Cardiac Events after RSV in Older Adults

The risk of a cardiac event, including heart failure or acute coronary syndrome, was found to be higher in older adults hospitalized for respiratory syncytial virus (RSV) infection than the reported risk with influenza, in a recent literature review and meta-analysis.¹

"While the cardiac impacts of other respiratory viral pathogens, such as influenza, are well described, the connection between RSV and acute or subacute cardiac disease is less recognized," point out lead author Jehidys Motiel, PhD, P95 Clinical and Epidemiology Services, Leuven, Belgium, and colleagues.

"Understanding the relationship between RSV disease and cardiac events is crucial for a comprehensive assessment of the burden of RSV disease in adult and for determining the potential clinical and economic benefits of RSV vaccination for this population," they assert.

Montiel and colleagues suggest several mechanisms which might underlie adverse cardiovascular sequelae from RSV infection, particularly if associated with pre-existing disease, including chronic inflammation, disruption of endothelial function, hypercoagulability and immune dysregulation.

The review and meta-analysis was funded by Pfizer, which manufactures one of 3 RSV vaccines approved for older adults and those with increased risk factors. Twenty-eight studies met inclusion criteria, with the analysis focusing on 25 which assessed patients hospitalized for RSV. Each of the studies reported absolute risk of cardiac events, and 16 provided either the relative risk, or sufficient data to calculate risk relative to other infections.The studies were conducted in several countries, with participants ranging in age from 64.1 to 79.5 years and with 49.9 to 67.5% females.

The investigators found a "substantial" absolute risk of any cardiac event following RSV infection among older, hospitalized patients, estimated at 19.2% (95% CI 15.1-24.2). They noted that in this, and other measures, there was considerable variability across studies.They attributed the range of estimates to the different outcomes within this broad category, and to differences in sample size (from 19 to 6,428 subjects).

Heart failure was the most reported cardiac event following RSV infection, with an estimated absolute risk of 15.7% (14.8-16.5). Motiel and colleagues found data suggesting that the risk was higher for patients with pre-existing disease, ranging from 23.4 to 66.7%. Of 2 studies assessing acute coronary syndrome (ACS), the larger (n=3,564) estimated risk at 5.4% (3.1-9.5); while the other, which stratified results for sample sizes ranging from 2 to 47 participants, did not find increased risk for ACS.

The investigators note that their calculation of risk for ACS in patients with RSV infection relative to influenza did not reach statistical significance (RR 1.2, 0.9-1.5), but that the elevated RR point estimate suggests a possible increased risk. They did find greater risk of any cardiac event following RSV than influenza (relative risk [RR] 1.2, 1.1-1.4), as well as for heart failure (RR 1.3, 1.1-1.6).

"Although relative risk estimates were not adjusted for differences in baseline risk, the risk of cardiac events after RSV appears comparable to the risk after influenza and possibly higher," the investigators observe."Given that influenza is a well-known risk factor for cardiac conditions, this result suggests comparable morbidity for the two pathogens."

Reference

1. Montiel J, Williams E, Robles-Rodríguez WG, et al. The risk of cardiac disease events after respiratory syncytial virus disease: a systematic literature review and meta-analysis. Eur Respir Rev. 2026; 35:250160. doi:10.1183/16000617.0160-2025.