RESEARCH has shown that seasonal influenza is associated with a significant excess burden of mortality and hospitalisations among patients with heart failure, highlighting the need for enhanced preventative measures in this vulnerable population.
This study sought to quantify the annual excess morbidity and mortality associated with seasonal influenza in Danish patients with heart failure from 2010 to 2018. Influenza is known to exacerbate health conditions in patients with heart failure, but population-level data on its broader impact has been limited. By estimating the number of deaths and hospitalisations attributable to influenza activity, this research provides crucial insights into the scale of the problem.
Using nationwide data, the study analysed weekly deaths and hospitalisations among an annual average of 70,570 heart failure patients. Influenza circulation was measured by the proportion of influenza-positive samples tested at Danish hospitals (mean: 25,180 samples per year). These data were incorporated into a time series linear regression model, adjusted for temperature, seasonality, and long-term trends. The analysis estimated that influenza activity contributed to an annual excess of 250 all-cause deaths (95% CI: 144–489), representing 2.6% of all deaths in heart failure patients. This included 115 cardiovascular deaths (95% CI: 62–244), or 2.9% of all cardiovascular-related deaths. Additionally, influenza activity was associated with 251 excess hospitalisations for influenza or pneumonia (95% CI: 107–533), accounting for 5.0% of such admissions.
These findings underscore the significant impact of seasonal influenza on heart failure patients, both in terms of mortality and hospitalisations. The results support the prioritisation of influenza vaccination and prompt antiviral treatments in this high-risk group. Furthermore, public health strategies aimed at reducing influenza circulation may substantially benefit patients with heart failure. Future research should explore the cost-effectiveness of targeted interventions and further investigate the underlying mechanisms linking influenza to cardiovascular complications. In clinical practice, these results serve as a compelling reminder for clinicians to remain vigilant in managing influenza risk in heart failure patients, especially during peak seasons.
Katrina Thornber, EMJ
Reference
Modin D et al. Excess mortality and hospitalizations associated with seasonal influenza in patients with heart failure. JACC. 2024;84(25):2460-7.
