 |
| GPs alerted to influenza cardiac risk |
23-Aug-2007 |
|
|
|
By Bianca Nogrady
GPs are urged to be alert for cardiac symptoms in high-risk patients with influenza, as Australia struggles through its worst flu season in several years.
Experts warned the infection could trigger acute coronary syndrome in patients with existing heart disease, and urged doctors to take preventive action.
Speaking at the Australian Doctor/HealthEd GP Summit on Diabetes, Obesity and Heart Disease, Associate Professor Ian Wilcox, clinical associate professor at the University of Sydney, said the inflammatory response provoked by influenza was the likely catalyst for MI, sudden cardiac death or unstable angina in patients with existing disease.
“Inflammation is a trigger to plaque rupture because inflammation softens the atherosclerotic plaque,” Professor Wilcox told Australian Doctor after the summit.
“The ones that are most prone to rupture are the soft, lipid-rich plaques, whereas chronic high-grade narrowing may well be rupture resistant because it’s quite sclerotic and has got a lot of collagen and reinforcing tissue in the surface.”
Professor Wilcox suggested doctors should have a high index of suspicion when chest pain occurred with flu infection in high-risk patients, such as those with type 2 diabetes and high cholesterol, and those who smoked, particularly if the pain presented as dull discomfort that did not change with breathing.
Associate Professor Derek Chew, head of cardiology at Adelaide’s Flinders Medical Centre, agreed there was an association between influenza and MI in high-risk patients, but said the mechanism could be more to do with the increased stress of illness than inflammation.
The National Centre for Immunisation Research and Surveillance is conducting a pilot clinical trial of influenza vaccination for prevention of acute coronary syndrome and strokes.
But Professor Chew said a previous study into the effect of vaccination on the risk of MI in high-risk patients found no benefit.
Professor Raina MacIntyre, an epidemiologist with the National Centre for Immunisation Research and Surveillance, said it was recommended patients with chronic heart disease should be vaccinated against influenza, but there was not enough evidence to justify vaccinating an entire family to protect high-risk family members.
She said the more severe the influenza, the greater the number of heart attacks that were likely to result.
In general for prevention, Professor Wilcox said exercise was a clear-cut way to reduce inflammation, but aspirin and statins should also be considered for high-risk patients. “Statins reduce the inflammatory response, so statins help to make plaques less likely to rupture,” he said.
Professor Wilcox suggested that if doctors were considering introducing statins based on a patient’s risk profile, the flu season could tip the balance in favour of therapy.
|
Submit your feedback here: