Prognostic impact of respiratory infection status on 30-day mortality in older heart failure patients hospitalised for acute respiratory symptoms: a sub-analysis of the EVERY prospective cohort study

Background/Introduction Older adults with heart failure (HF) are highly vulnerable to respiratory viral infections. While influenza and COVID-19 were well investigated, the prognostic impact of other infections including respiratory syncytial virus (RSV) in this population was not scrutinised in previous prospective studies. Purpose We compared the 30-day mortality of RSV, COVID-19, influenza infection, and other infectious diseases with non-infectious diseases among older patients with HF hospitalised for acute respiratory symptoms. Methods This study was a predetermined sub-analysis of the EVERY study, a multicentre prospective cohort study. From the total cohort (N=3,067), we analysed 977 patients aged 50 years or older with a history of HF or new onset HF who were emergently hospitalised for acute respiratory symptoms. The primary outcome was 30-day all-cause mortality. Survival curves were estimated using the Kaplan-Meier method and compared across the five groups using the log-rank test. Multivariable logistic regression model was constructed to estimate adjusted odds ratios (aORs), adjusting for age, sex, Charlson Comorbidity Index and National Early Warning Score on admission. Results Among 977 patients were included (mean age 83 years, male 55.7%, etiology of heart failure: hypertensive heart disease 35.9%, atrial fibrillation 29.5%, ischemic cardiomyopathy 19.9%), the primary diagnoses were non-infectious diseases (n=321), COVID-19 (n=127), influenza (n=14), RSV (n=16), and other infections (n=499). The 30-day all-cause mortality was significantly higher in the RSV group (25.0%) compared to the non-infectious group (6.5%), COVID-19 group (11.8%), and influenza group (7.1%) (p value = 0.02). Kaplan-Meier curve demonstrated that mortality in the RSV group was significantly higher at the first week of admission (Figure 1). The multivariable model indicated that RSV infection was significantly associated with higher 30-day all-cause mortality (aOR 5.34; 95% CI 1.47–19.43; p=0.01) relative to non-infectious diseases. COVID-19 (aOR 1.59; p=0.21) and influenza (aOR 0.82; p=0.86) were not significantly associated with 30-day all-cause mortality (Table 1). Conclusion(s) Among older patients with HF, admission with RSV infection was significantly associated with 30-day all-cause mortality. Its risk was a five-fold compared to admission with non-infectious origins and the prognostic impact of RSV was higher than those of COVID-19 and influenza. In the management of older HF patients, the preventive measures against vaccine-preventable respiratory diseases, especially RSV, should be considered.