Flu may increase heart attack risk, study suggests

By Dr Deepu

"Cardiovascular events triggered by influenza are potentially preventable by vaccination," the researchers wrote.

       The study used confirmed cases of flu, analyzing 364 heart attacks from mid-2008 through mid-2015 among Ontario residents age 35 or older who were registered with the province’s publicly funded health insurance program.
The investigators found that the heart attack rate was 20.0 admissions per week during the seven days after diagnosis of the flu, versus 3.3 per week during the 52 weeks before and 51 weeks after that seven-day window.
The  above results were based on study involving 148,307 cases of  patients who were tested for influenza. Among all of those tests, 19,729 turned up positive for the flu. And among those cases, there were 332 patients who had at least one heart attack in the year before or after their flu specimen was tested. (The study authors tallied 364 hospitalizations for acute myocardial infarction overall, meaning that some unlucky folks had two or more heart attacks during the two-year observation period.)

Twenty of those heart attacks occurred within one week of a positive flu test. That, of course, was a rate of 20 heart attacks per week.
The other 344 heart attacks happened some other time in the two-year observation period. That worked out to 3.3 heart attacks per week.
That means the risk of a heart attack was six times greater in the first week after flu testing than at other times when the flu was much less likely to be a factor.

The researchers redid their analysis by splitting up that danger week into two parts. They found that heart attack risk was 6.3 times greater during the first three days after a flu test and 5.8 times greater in days four through seven.

About one-quarter of the patients in the study were 65 years old, and the rest were older. When the researchers examined those two groups separately, the link between flu infection and heart attack risk held up only for the older group.

There was no sign of an increased heart attack risk in the rest of the first month after getting a flu test.

The data in the study came from Ontario, Canada, where residents have public health insurance and universal access to medical care. Information on influenza test results came from the Flu and Other Respiratory Viruses Research Cohort, and heart attack hospitalizations were tracked by the Discharge Abstract Database of the Canadian Institute for Health Information.

The researchers, led by Dr. Jeffrey C. Kwong of the University of Toronto, acknowledged that they couldn't do their analysis based on the date when patients were actually infected with the influenza virus, or when they first began having symptoms, because that information was not available. However, in cases where patients get a flu test, they have typically been sick for only one or two days first.

Also, not all flu cases are severe enough to prompt patients to go and get tested. That means the results of this study may not apply to people with milder illnesses, they added.

The researchers did notice that when flu test results came back positive for certain other kinds of respiratory infections instead of for influenza, there was still an increased (though smaller) short-term risk for heart attacks. That suggests that it's not the flu itself that's the problem — it's the biological impact of a respiratory infection.

For instance, an infection can create conditions that make blood clots more likely to form and cause blood vessels to constrict. Infections also cause inflammation and can reduce blood pressure. All of these are risk factors for a heart attack, Kwong and his colleagues wrote.

The study results suggest that people who want to avoid a heart attack should be sure to get a flu shot — and that doctors and public health officials should encourage them to do so.

Study: Acetaminophen No Better Than Placebo In Fighting Flu Symptoms

By Dr Deepu

Study: Acetaminophen No Better Than Placebo In Fighting Flu Symptoms .The New York Times (12/9, Bakalar) reports “a randomized trial has found that” acetaminophen “is no more effective than a placebo, with no discernible effect at all on reducing fever or other flu symptoms.” The study was performed by researchers at Medical Research Institute of New Zealand, and is published in Respirology.

It was a randomized, double-blind, placebo-controlled trial of adults aged 18–65 years with influenza-like illness and positive influenza rapid antigen test. Treatments were given with 1 g paracetamol four times a day, or matching placebo, for 5 days. Pernasal swabs were taken for influenza quantitative RT-PCR at Baseline and Days 1, 2 and 5. Temperature and symptom scores were recorded for 5–14 days or time of resolution respectively. The primary outcome variable was area under the curve (AUC) for quantitative PCR log₁₀ viral load from Baseline to Day 5.

They studied  80 participants were randomized: There were 22 and 24 participants who were influenza PCR-positive in placebo and in paracetamol groups respectively. In all participants there were no differences in symptom scores, temperature, time to resolution of illness and health status, with no interaction between randomized treatment and whether influenza was detected by PCR.they therefore concluded that the regular paracetamol had no effect on viral shedding, temperature or clinical symptoms in patients with PCR-confirmed influenza. There remains an insufficient evidence base for paracetamol use in influenza infection.

Fauci Optimistic About The Development Of A Universal Flu Vaccine Within Next 5 To 10 Years

By Dr Deepu

In a 1,500-word article, NBC News (10/20) reports on its website on this year’s flu vaccine, the market environment, and the push for vaccination. The piece also reports on the “holy grail for flu: A universal vaccine,” which is currently being pursued at the National Institutes of Health. National Institute of Allergy and Infectious Diseases Director Dr. Anthony Fauci “said he’s optimistic a universal vaccine is five to 10 years away.” In an interview, Fauci said, “I think that we are making extraordinary progress and we can sort of see that light at the end of the tunnel.” He added, “If we can successfully induce a response against that stem part of that protein, we’re going to be very close to developing a universal flu vaccine.” In the meantime, public health researchers “emphasized the best thing the public can do to avoid spread of the flu is to wash hands, cover coughs and sneezes…and get vaccinated.”