- An increase in population-level influenza activity/influenza-like illness (ILI) is associated with increased hospitalizations for heart failure (HF).
Why this matters
- ILI presenting in a broad range of patients may increase risk for acute cardiovascular events and related hospitalizations, especially during peak influenza activity.
- Unweighted total 3541 and 4321 hospitalizations for MI and HF, respectively.
- Absolute 5% increase in monthly ILI activity associated with 24% increase in HF hospitalization rates in the same month (incidence rate ratio [IRR], 1.24; 95% CI, 1.11-1.38; P<.001>
- A 22% and 20% temporally associated increased HF risk was observed during severest influenza seasons 2010-2011 (IRR, 1.22; 95% CI, 1.01-1.49; P=.04) and 2012-2013 (IRR, 1.20; 95% CI, 1.02-1.40; P=.02), respectively.
- Overall influenza activity was not significantly associated with MI hospitalizations (IRR, 1.02; P=.72).
- HF hospitalization risk reduction noted with reduced ILI activity (IRR, 0.81; 95% CI, 0.72-0.90/absolute 5% decline in ILI), suggesting that it was 19% higher in months with elevated ILI activity vs baseline.
- Population-based surveillance study examining temporal ILI and MI, HF hospitalizations in community-dwelling adults, October 2010-September 2014.
- Funding: NIH.
- Individual-level ILI, MI/HF hospitalizations unknown.
- Other infections possibly linked to events.
- Inconsistent influenza severity data.
- Sampling bias.