# 6624
Each year during the winter months we see an increase in the rate of heart attacks and coronary related deaths.
During the middle-to-late 1990’s a study looked at more than 250,000 AMI’s (acute myocardial infarctions) and found that the rate of heart attacks in the winter ran 53% higher than during the summer.
Spencer FA, Goldberg RJ, Becker RC, Gore JM.
Over the years this spike in `winter mortality’ has been blamed on a variety of factors.
Colder temperatures, increased respiratory infections (including influenza & Pneumonia), over indulgence in food and alcohol, diminished activity levels, forgetting to take prescription medicines, and holiday stress.
While cold weather combined with strenuous physical activity (like clearing snow from sidewalks) have often been blamed for this spike, even in balmy Southern California, studies have shown a 33% increase in heart attacks over the holidays.
When Throughout the Year Is Coronary Death Most Likely to Occur?
A 12-Year Population-Based Analysis of More Than 220 000 Cases
Robert A. Kloner, MD, PhD; W. Kenneth Poole, PhD; Rebecca L. Perritt, MS
Increasingly, inflammation is being seen as a contributor to Cardiovascular disease (CVD), and studies (like this one from the NIH) to `to determine whether a common anti-inflammatory drug can reduce heart attacks, strokes, and deaths’ are underway around the world.
One of the hallmarks of an infection is the body’s inflammatory response, which has led some researchers to suppose that some infections might increase one’s risk of having a heart attack.
Which brings us to a new study appearing in the Journal of Infectious Diseases that suggest Influenza - and other acute respiratory infections - can act as a trigger for heart attacks.
Influenza Infection and Risk of Acute Myocardial Infarction in England and Wales: A CALIBER Self-Controlled Case Series Study
Charlotte Warren-Gash, Andrew C. Hayward1, Harry Hemingway2, Spiros Denaxas2, Sara L. Thomas3, Adam D. Timmis5, Heather Whitaker6 and Liam Smeeth4
ABSTRACT (Excerpt)
Results. Of 22 024 patients with acute coronary syndrome, 11 208 met the criterion of having had their first AMI at the age of ≥40 years, and 3927 had also consulted for acute respiratory infection. AMI risks were significantly raised during days 1–3 after acute respiratory infection (incidence ratio, 4.19 [95% confidence interval, 3.18–5.53], with the effect tapering over time. The effect was greatest in those aged ≥80 years (P = .023). Infections occurring when influenza was circulating and those coded as influenza-like illness were associated with consistently higher incidence ratios for AMI (P = .012).
Conclusions. Influenza and other acute respiratory infections can act as a trigger for AMI. This effect may be stronger for influenza than for other infections.
In the same issue of J Infect Disease is an editorial called Increasing Evidence That Influenza Is a Trigger for Cardiovascular Disease.
Although both articles are behind a pay wall, CIDRAP NEWS has a brief summary of the study’s findings:
A couple of years ago we saw a study in the CMAJ: Flu Vaccinations Reduce Heart Attack Risk that found that those over the age of 40 who get a seasonal flu vaccine each year may reduce their risk of a heart attack by as much as 19%.
Almost immediately questions were raised over the way this study was conducted (see Vaccine/Heart Attack Study Questioned), and so the results are in dispute.
But today’s study adds to growing evidence that influenza may be a significant contributor to the number of heart attacks each year.
While more study will be needed to confirm this link, it does add another good reason to get that flu shot every year. Particularly for those of us over the age of 40, who are at greater risk of cardiovascular disease.
