Influenza infection increases mortality risk in patients who had acute myocardial infarction or heart attack, according to a new study.
The study, presented at American Heart Association (AHA) Scientific Sessions 2018 in Chicago has found that influenza infection independently increased the mortality risk in those who had acute myocardial infarction (AMI) but was not a risk factor for the development of AMI.
The researchers conducted the study to determine whether influenza infection was an independent risk factor for the development of AMI. For the purpose, they analyzed data from the USA Nationwide Inpatient Sample database from 2012 to 2014.
A total of 2146 patients with influenza and AMI and 563,227 patients with AMI only were included in the study. The mean age of patients with influenza and AMI was 72.67 years and for those with AMI only the mean age was 68.82 years (P <.001).
- More women had both influenza and AMI vs AMI alone, 48.45% vs 41.67%, respectively (P <.001).
- The cost was higher and the hospital stay longer for patients with both influenza and AMI vs for patients with AMI alone ($98.24 USD and 8.8 days vs $81.88 USD vs 5.84 days, respectively; P<.001 for both).
- After adjusting for comorbidities, the adjusted odds ratio for patients with influenza having an AMI was 0.84 (95% CI, 0.80-0.89; P <.001). In patients with influenza-associated with mortality in AMI, the adjusted odds ratio was 1.34 (95% CI, 1.13-1.58; P <.001).
- Patients with influenza and AMI had increased length of hospital stay and in-hospital costs.
- Patients with influenza and AMI were more likely to be older in age and female.
- Influenza was not a risk factor for AMI developing but independently increased the risk for mortality in those in whom AMI developed.