Flu, Some Upper Respiratory Infections Up Heart Attacks
Increased incidence of acute myocardial infarction in first 7 days after positive respiratory viral diagnosis
(HealthDay News) -- Certain respiratory infections, especially influenza, are associated with an increased risk of acute myocardial infarction during the first 7 days after respiratory specimen collection, according to a study published in the New England Journal of Medicine.
Jeffrey C. Kwong, MD, from the Institute for Clinical Evaluative Sciences in Toronto, and colleagues used a self-controlled case-series design to examine the correlation between laboratory-confirmed influenza infection and hospitalization for acute myocardial infarction. High-specificity laboratory methods were used to confirm influenza infection in respiratory specimens, and hospitalization for acute myocardial infarction was ascertained from administrative data.
The researchers identified 364 hospitalizations for acute myocardial infarction that occurred within one year before and one year after a positive influenza test. Twenty of these occurred during the risk interval (first 7 days after respiratory specimen collection) and 344 occurred during the control interval (one year before and one year after the risk interval). The incidence ratio was 6.05 for admission for acute myocardial infarction during the risk interval versus the control interval. After day 7 there was no increased incidence. The incidence ratios were 10.11, 5.17, 3.51, and 2.77 for acute myocardial infarction within 7 days of detection of influenza B, influenza A, respiratory syncytial virus, and other viruses, respectively.
"We found a significant association between respiratory infections, especially influenza, and acute myocardial infarction," the authors write.