Influenza and Cardiovascular Disease: Does Swine-Origin, 2009 H1N1 Flu Virus Represent a Risk Factor, an Acute Trigger, or Both?

[tetano]

Semin Thromb Hemost 2010; 36(1): 049-058
DOI: 10.1055/s-0030-1248724

? Thieme Medical Publishers


Influenza and Cardiovascular Disease: Does Swine-Origin, 2009 H1N1 Flu Virus Represent a Risk Factor, an Acute Trigger, or Both?

Giuseppe Lippi1,3, Massimo Franchini2,3, Emmanuel J. Favaloro4
1 U.O. Diagnostica Ematochimica, Azienda Ospedaliero-Universitaria di Parma, Parma, Italy
2 Servizio di Immunoematologia e Medicina Trasfusionale, Azienda Ospedaliero-Universitaria di Parma, Parma, Italy
3 Dipartimento di Patologia e Medicina di Laboratorio, Azienda Ospedaliero-Universitaria di Parma, Parma, Italy
4 Department of Haematology, Institute of Clinical Pathology and Medical Research (ICPMR), Westmead Hospital, Westmead, Australia
ABSTRACT

Influenza infection has become an important focus of both public and medical attention because of high-level perceived clinical and public health effects, enormously amplified by the current and ongoing 2009 H1N1 flu pandemic, sustained by the swine-origin influenza A (H1N1) virus (S-OIV). The current transmission of this virus among humans appears much higher than that traditionally observed with seasonal influenza, raising several outbreaks of febrile respiratory infection ranging in severity from self-limited to severe, even life-threatening disease. Reliable biological and clinical evidence support a significant association between influenza infection and cardiovascular disorders, so that S-IOV might also be regarded as a potential multifaceted bioweapon able to affect the function of the cardiovascular system through a kaleidoscope of humoral, biological, and biochemical mechanisms. In acute coronary ischemic episodes, on one hand, it seems reasonable to consider any acute influenza virus infection as a precipitating factor that is the final event propelling predisposed individuals (e.g., those with preexisting coronary artery disease) over a threshold that precipitates the development of infarction in synergy with other well-known triggers. On the other hand, influenza virus-induced endothelial dysfunction, modification of lipoprotein metabolism, atherosclerotic plaque outgrowth, and inflammation additionally support the role of influenza infection as a strong cardiovascular risk factor. Comprehensive information regarding the 2009 H1N1 infection remains limited, so that it seems unreasonable to draw definitive conclusions. Nevertheless, current recorded mortality data would lead us to conclude that this new virus might represent a sinister threat to humankind, with cardiovascular mortality risk highlighting an additional crucial role for increasing further the alert against this threat. It also seems reasonable to support calls for vaccination against these viruses, both the seasonal and the new S-OIV, because this might represent a feasible strategy for short- and long-term prevention of virus-associated cardiovascular disease.

https://www.thieme-connect.com/DOI/DOI10.1055/s-0030-1248724

 

[Vibrant62]

Re: Influenza and Cardiovascular Disease: Does Swine-Origin, 2009 H1N1 Flu Virus Represent a Risk Factor, an Acute Trigger, or Both?

These are very strong conclusions - see highlights.


Reliable biological and clinical evidence support a significant association between influenza infection and cardiovascular disorders, so that S-IOV might also be regarded as a potential multifaceted bioweapon able to affect the function of the cardiovascular system through a kaleidoscope of humoral, biological, and biochemical mechanisms.

In acute coronary ischemic episodes, on one hand, it seems reasonable to consider any acute influenza virus infection as a precipitating factor that is the final event propelling predisposed individuals (e.g., those with preexisting coronary artery disease) over a threshold that precipitates the development of infarction in synergy with other well-known triggers. On the other hand, influenza virus-induced endothelial dysfunction, modification of lipoprotein metabolism, atherosclerotic plaque outgrowth, and inflammation additionally support the role of influenza infection as a strong cardiovascular risk factor. Comprehensive information regarding the 2009 H1N1 infection remains limited, so that it seems unreasonable to draw definitive conclusions. Nevertheless,

current recorded mortality data would lead us to conclude that this new virus might represent a sinister threat to humankind, with cardiovascular mortality risk highlighting an additional crucial role for increasing further the alert against this threat. It also seems reasonable to support calls for vaccination against these viruses, both the seasonal and the new S-OIV, because this might represent a feasible strategy for short- and long-term prevention of virus-associated cardiovascular disease.

https://www.thieme-connect.com/DOI/D...s-0030-1248724

 

[tetano]

Re: Influenza and Cardiovascular Disease: Does Swine-Origin, 2009 H1N1 Flu Virus Represent a Risk Factor, an Acute Trigger, or Both?

The Lancet Infectious Diseases, Volume 9, Issue 10, Pages 601 - 610, October 2009

doi:10.1016/S1473-3099(09)70233-6Cite or Link Using DOI

Influenza as a trigger for acute myocardial infarction or death from cardiovascular disease: a systematic review
Original Text
Dr Charlotte Warren-Gash MBChB a Corresponding AuthorEmail Address, Prof Liam Smeeth MRCGP b, Andrew C Hayward FIBiol a


Summary
Cardiac complications of influenza infection, such as myocarditis, are well recognised, but the role of influenza as a trigger of acute myocardial infarction is less clear. We did a systematic review of the evidence that influenza (including influenza-like illness and acute respiratory infection) triggers acute myocardial infarction or cardiovascular death. We examined the effectiveness of influenza vaccines at protecting against cardiac events and did a meta-analysis of data from randomised controlled trials. 42 publications describing 39 studies were identified. Many observational studies in different settings with a range of methods reported consistent associations between influenza and acute myocardial infarction. There was weaker evidence of an association with cardiovascular death. Two small randomised trials assessed the protection provided by influenza vaccine against cardiac events in people with existing cardiovascular disease. Whereas one trial found that influenza vaccination gave significant protection against cardiovascular death, the other trial was inconclusive. A pooled estimate from a random-effects model suggests a protective, though non-significant, effect (relative risk 0?51, 95% CI 0?15?1?76). We believe influenza vaccination should be encouraged wherever indicated, especially in people with existing cardiovascular disease, among whom there is often suboptimum vaccine uptake. Further evidence is needed on the effectiveness of influenza vaccines to reduce the risk of cardiac events in people without established vascular disease.

 

[tetano]

Re: Influenza and Cardiovascular Disease: Does Swine-Origin, 2009 H1N1 Flu Virus Represent a Risk Factor, an Acute Trigger, or Both?

Influenza may account for a rise in heart attack deaths during flu season, say British researchers.

They add that while a flu vaccine can prevent these deaths, fewer than half of the most vulnerable heart patients in Britain actually receive a vaccine every year.

"We believe influenza vaccination should be encouraged wherever indicated, especially in those people with existing cardiovascular disease," write Dr Charlotte Warren-Gash of University College London and colleagues the journal Lancet Infectious Diseases.

"Further evidence is needed on the effectiveness of influenza vaccines to reduce the risk of cardiac events in people without established vascular disease."
Increased risk

Warren-Gash and colleagues reviewed 39 studies conducted between 1932 and 2008 on the potential links between flu and heart deaths.

The large populations studies showed a rise in deaths due to heart disease or heart attacks when influenza viruses were circulating, they found.

Seasonal influenza kills about 250,000 to 500,000 people a year, a figure that experts came up with by carefully monitoring confirmed flu deaths in a small area, counting excess deaths during influenza season over large populations, and consolidating both calculations.

Warren-Gash's team found the proportion of excess influenza deaths that were due to heart disease ranged from 35% to 50%.

Four out of eight studies showed people who were vaccinated from seasonal influenza were less likely to have a heart attack they found.

But in Britain, only 47% of people with risk factors such as chronic heart disease, asthma or diabetes received a flu shot last year.

http://www.abc.net.au/science/articles/2009/09/22/2692963.htm

 

[Vibrant62]

Re: Influenza and Cardiovascular Disease: Does Swine-Origin, 2009 H1N1 Flu Virus Represent a Risk Factor, an Acute Trigger, or Both?

For clarity for thread readers.

This latter Lancet 2009 study applies to the effects of seasonal influenza on MI risks and CV mortality, whereas the first appears to highlight a disproportionate effect of A/H1N1 or Swine Flu on CV risk markers that is over and above the known/ recognised/ anticipated effects of seasonal influenza.

 

[Shannon Bennett]

Re: Influenza and Cardiovascular Disease: Does Swine-Origin, 2009 H1N1 Flu Virus Represent a Risk Factor, an Acute Trigger, or Both?

Absolutely fascinating.

 

[sharon sanders]

Re: Influenza and Cardiovascular Disease: Does Swine-Origin, 2009 H1N1 Flu Virus Represent a Risk Factor, an Acute Trigger, or Both?

Absolutely fascinating.

I agree.