Acute Cardiac Events in Hospitalized Older Adults With Respiratory Syncytial Virus Infection

IMPORTANCE Respiratory syncytial virus (RSV) infection can cause severe respiratory illness in older adults. Less is known about the cardiac complications of RSV disease compared with those of influenza and SARS-CoV-2 infection. OBJECTIVE To describe the prevalence and severity of acute cardiac events during hospitalizations among adults aged 50 years or older with RSV infection. DESIGN, SETTING, AND PARTICIPANTS This cross-sectional study analyzed surveillance data from the RSV Hospitalization Surveillance Network, which conducts detailed medical record abstraction among hospitalized patients with RSV infection detected through clinician-directed laboratory testing. Cases of RSV infection in adults aged 50 years or older within 12 states over 5 RSV seasons (annually from 2014-2015 through 2017-2018 and 2022-2023) were examined to estimate the weighted period prevalence and 95% CIs of acute cardiac events. EXPOSURES Acute cardiac events, identified by International Classification of Diseases, 9th Revision, Clinical Modification or International Statistical Classification of Diseases, Tenth Revision, Clinical Modification discharge codes, and discharge summary review. MAIN OUTCOMES AND MEASURES Severe disease outcomes, including intensive care unit (ICU) admission, receipt of invasive mechanical ventilation, or in-hospital death. Adjusted risk ratios (ARR) were calculated to compare severe outcomes among patients with and without acute cardiac events. RESULTS The study included 6248 hospitalized adults (median [IQR] age, 72.7 [63.0-82.3] years; 59.6% female; 56.4% with underlying cardiovascular disease) with laboratory-confirmed RSV infection. The weighted estimated prevalence of experiencing a cardiac event was 22.4% (95% CI, 21.0%-23.7%). The weighted estimated prevalence was 15.8% (95% CI, 14.6%-17.0%) for acute heart failure, 7.5% (95% CI, 6.8%-8.3%) for acute ischemic heart disease, 1.3% (95% CI, 1.0%-1.7%) for hypertensive crisis, 1.1% (95% CI, 0.8%-1.4%) for ventricular tachycardia, and 0.6% (95% CI, 0.4%-0.8%) for cardiogenic shock. Adults with underlying cardiovascular disease had a greater risk of experiencing an acute cardiac event relative to those who did not (33.0% vs 8.5%; ARR, 3.51; 95% CI, 2.85-4.32). Among all hospitalized adults with RSV infection, 18.6% required ICU admission and 4.9% died during hospitalization. Compared with patients without an acute cardiac event, those who experienced an acute cardiac event had a greater risk of ICU admission (25.8% vs 16.5%; ARR, 1.54; 95% CI, 1.23-1.93) and in-hospital death (8.1% vs 4.0%; ARR, 1.77; 95% CI, 1.36-2.31). CONCLUSIONS AND RELEVANCE In this cross-sectional study over 5 RSV seasons, nearly one-quarter of hospitalized adults aged 50 years or older with RSV infection experienced an acute cardiac event (most frequently acute heart failure), including 1 in 12 adults (8.5%) with no documented underlying cardiovascular disease. The risk of severe outcomes was nearly twice as high in patients with acute cardiac events compared with patients who did not experience an acute cardiac event. These findings clarify the baseline epidemiology of potential cardiac complications of RSV infection prior to RSV vaccine availability.