One in 10 hospitalized RSV patients has a concurrent acute CV event

In a large cross-sectional study evaluating individuals hospitalized for respiratory syncytial virus (RSV), influenza, and COVID-19, one in 10 patients hospitalized for RSV had a concurrent acute cardiovascular (CV) event, and the odds of cardiac events were substantially higher in RSV vs COVID-19 hospitalizations.

In the RSV subset, 234 (10.9 percent) had an acute CV event, which were mostly cardiac events (n=220). The most frequent events were dysrhythmias (n=99), followed by heart failure (HF; n=66) and ischaemic heart disease (IHD; n=61) episodes. The most common dysrhythmia was atrial fibrillation or flutter (n=60).

Pre-existing cardiac history was associated with a higher odds of an acute CV event among RSV hospitalizations (adjusted odds ratio [aOR], 2.53). [JAMA Network Open 2025;8:e2511764]

Compared with the boosted COVID-19 subgroup, the RSV subset had a higher odds of any CV event (aOR, 1.31) and individual CV events such as any dysrhythmia (aOR, 1.52), HF (aOR, 1.75), and other cardiac events, including cardiac arrest, non-ischaemic cardiomyopathy, cardiogenic shock, myocarditis, and pericarditis (aOR, 1.63).

Similarly, the RSV subgroup had a higher odds of any CV event, dysrhythmia, HF, and other cardiac events (aORs, 1.58, 1.59, 2.92, and 2.40, respectively) than unboosted COVID-19 patients.

The odds of a CV event were not significantly different between the RSV and influenza subsets, except in contemporaneous hospitalizations after the pandemic (2023–2024), where the odds of HF were markedly higher in RSV vs vaccine-breakthrough influenza hospitalizations (aOR, 2.09). “This finding likely reflects the impact of influenza vaccination in mitigating severe disease during the rebound in seasonal influenza that occurred after the pandemic,” the investigators explained.

The odds of intensive care unit admission during RSV hospitalization increased with the presence of any CV event* (aOR, 2.36), any cardiac event** (aOR, 2.54), any major adverse CV or cerebrovascular event (aOR, 3.15), any IHD episode (aOR, 4.90), and any HF (aOR, 2.52).

Those with pre-existing cardiac history a vaccine priority

“Cardiac manifestations of RSV are hypothesized to arise directly from myocardial injury or indirectly via a post-inflammatory response and increased CV strain attributed to pulmonary disease,” the researchers explained.

To better contextualize the burden of acute cardiac events in RSV compared with other vaccine-preventable respiratory viral infections (RVIs), the researchers conducted a population-based study prior to the RSV vaccination rollout. After excluding coinfections, the study included 32,960 Singaporean adults (mean age 66.58 years, 51.7 percent women) who were hospitalized for RSV (n=2,148), influenza (n=14,389), or COVID-19 (n=16,423).

As the study predated the availability of RSV vaccination in Singapore, all patients hospitalized for RSV were unvaccinated against RSV. Participants hospitalized for influenza were stratified into vaccinated or unvaccinated subgroups, while those hospitalized for COVID-19 were stratified into boosted (≥3 vaccine doses) or unboosted (<3 vaccine doses) subgroups.

Evaluating the role of vaccination in mitigating the risk of CV events tied to vaccine-preventable RVIs remains crucial, considering the availability of RSV vaccines for older adults and the existing vaccine skepticism during the COVID-19 endemicity, they said.

“Individuals with a pre-existing cardiac history remain at higher risk of acute cardiac events during RSV hospitalization and should be prioritized for vaccination,” the investigators said.  “[They] might also benefit from more intensive clinical evaluation and monitoring for cardiac events during RSV hospitalization in light of greater risk.”