Laboratory-Confirmed Respiratory Infections as Predictors of Hospital Admission for Myocardial Infarction and Stroke: Time-Series Analysis of English Data for 2004-2015

Background. Acute respiratory infections are associated with increased risk of myocardial infarction (MI) and stroke; however, the role of different organisms is poorly characterized. Methods. Time-series analysis of English hospital admissions for MI and stroke (age-stratified: 45-64, 65-74, >= 75 years), laboratory-confirmed viral respiratory infections, and environmental data for 2004-2015. Weekly counts of admissions were modeled using multivariable Poisson regression with weekly counts of respiratory viruses (influenza, parainfluenza, rhinovirus, respiratory syncytial virus [RSV], adenovirus, or human metapneumovirus [HMPV]) investigated as predictors. We controlled for seasonality, long-term trends, and environmental factors. Results. Weekly hospital admissions in adults aged >= 45 years averaged 1347 (interquartile range [IQR], 1217-1541) for MI and 1175 (IQR, 1023-1395) for stroke. Respiratory infections ranged from 11 cases per week (IQR, 5-53) for influenza to 55 (IQR, 7-127) for rhinovirus. In the adjusted models, all viruses except parainfluenza were significantly associated with MI and ischemic stroke admissions in those aged >= 75. Among 65-to 74-year-olds, adenovirus, rhinovirus, and RSV were associated with MI but not ischemic stroke admissions. Respiratory infections were not associated with MI or ischemic stroke in people aged 45-64 years, nor with hemorrhagic stroke in any age group. An estimated 0.4%-5.7% of MI and ischemic stroke admissions may be attributable to respiratory infection. Conclusions. We identified small but strongly significant associations in the timing of respiratory infection (with HMPV, RSV, influenza, rhinovirus, and adenovirus) and MI or ischemic stroke hospitalizations in the elderly.