Influenza-Associated Hospitalizations and Risk for Subsequent Heart Failure Hospital Admissions: A 20-Year Territory-Wide Registry Study in Hong Kong.

Chair, Sek Ying; Cheng, Ho Yu; Choi, Kai Chow; Fung, Erik Y M G; Siow, Elaine K C; Cao, Xi

Little is known about the risk of hospitalization for cardiovascular disease after influenza infection in younger adults. This Hong Kong territory-wide study using clinical registry data between 1997 and 2017 examined the association between influenza-associated hospitalizations and the risk of subsequent hospitalization for heart failure (HHF) in 3 age groups: 18-44, 45-65, and >65 years. The exposure was defined as any infection with influenza virus as a primary principal diagnosis for hospitalization, whereas the non-exposed control comprised hospitalizations for elective orthopedic surgery. Logistic regression was used to determine the risk for HHF within 12 months of hospital discharge comparing the exposed versus non-exposed groups. Results showed that influenza-associated hospitalization in the preceding 12 months was associated with increased risks for subsequent HHF in all age groups (all P <0.001). Of note, the 18-44 age group was found to have the highest elevated risk for HHF (adjusted odds ratio = 14.90, 95% confidence interval: 4.48, 49.58). In view of the relatively small number of subsequent HHF episodes in this age group, future studies are needed to confirm the elevated risk in this group and explore the role of age in the relationship between influenza-associated hospitalization and subsequent HHF.