Female gender increases stroke risk in AF patients aged over 75 years by 20%

August 27, 2012

Female gender increases the risk of stroke in patients with atrial fibrillation (AF) aged >75 years by 20%, according to a study presented today at the ESC Congress 2012. The findings were presented by Anders Mikkelsen, from Denmark.

The results suggest that female gender should not be included as an independent /thromboembolism (TE) risk factor in guidelines or schemes used in treatment of with .

The increased risk of stroke and TE in patients with atrial fibrillation depends on additional risk factors, and female sex has been suggested as one such risk factor. The 2010 ESC Guidelines for the management of atrial fibrillation consider female gender a minor risk factor for stroke/TE, and recommend oral anticoagulants for <65 years with one additional minor risk factor, and females 65-74 with no additional . Oral anticoagulants can effectively lower the risk of stroke/TE for patients with atrial fibrillation, but also increase the risk of bleeding disorders and should therefore be given only to patients at high risk of stroke/TE.

The aim of the study was to investigate the association between female gender and stroke/TE in a large nationwide cohort. Previous studies on this subject have delivered diverging results. Some studies have found an increased risk with female gender, while others have not. The novelty of the current study is that the risk of stroke/TE associated with female gender was investigated in a very large population and in a range of age intervals.

The large study population was assembled by linking patients in national Danish registers, using the personal registration number given to all Danish citizens. The researchers identified patients with nonvalvular atrial fibrillation between 1997-2008 who were not treated with oral anticoagulants and subdivided the population into three age intervals: <65, 65-74, and ≥75 years. The specific were chosen because they are used as cut-off points in atrial fibrillation risk stratification schemes (e.g. CHA2DS2-VASc) and in current guidelines.

The study included 87,202 nonvalvular atrial fibrillation patients, of whom 44,744 (51.3%) were female.

Female gender did not increase the risk of stroke in patients aged <75 years. The relative ratio associated with female gender was 0.89 (95% confidence interval: 0.70-1.13) for patients aged <65 and 0.91 (0.79-1.05) for patients aged 65-74 years.

For patients aged >75 years, female gender was associated with a 1.20 (1.12-1.28) increased risk of stroke after 1 year of follow up. The 1.20 corresponds to a 20% increased risk in this age group.

"Our study showed that female sex was only associated with an increased risk of stroke for AF patients aged ≥75 years," said Mr Mikkelsen. "This suggests that female sex should not be included as an independent stroke/TE risk factor in guidelines or in risk stratification schemes used in treatment of patients with atrial fibrillation. Female patients >75 years of age qualify for anticoagulation therapy regardless of gender because age ≥75 years is an independent risk factor for stroke/TE."

He added: "Our findings could have an impact on current guidelines used in the treatment of atrial fibrillation; however more research is needed to confirm our results."

Explore further: Rheumatoid arthritis linked to irregular heart rhythm

Related Stories

Rheumatoid arthritis linked to irregular heart rhythm

March 8, 2012
People with rheumatoid arthritis are at a greater risk of irregular heart rhythm (known as atrial fibrillation) and stroke compared with the general population, finds a study published in the British Medical Journal today.

BUSM: Severe sepsis, new-onset AF associated with increased risk of hospital stroke, death

November 13, 2011
A recent study led by researchers at Boston University School of Medicine (BUSM) shows an increased risk of stroke and mortality among patients diagnosed with severe sepsis and new-onset atrial fibrillation (AF) during hospitalization.

Women with irregular heart rhythm carry a higher risk of stroke than men

May 31, 2012
Women with irregular heart rhythm (known as atrial fibrillation) have a moderately increased risk of stroke compared with men, suggesting that female sex should be considered when making decisions about anti-clotting treatment, ...

Innovations in anticoagulation for stroke prevention

June 13, 2012
New scientific findings in anticoagulation for stroke prevention are paving the way for updates to the European Society of Cardiology (ESC) Guidelines for the management of atrial fibrillation.

Atrial arrhythmias detected by pacemakers increase risk of stroke

January 11, 2012
An irregular heartbeat that you don't even feel but can be picked up by a pacemaker is associated with a significantly increased risk of stroke, says a new McMaster University study.

Recommended for you

Could aggressive blood pressure treatments lead to kidney damage?

July 18, 2017
Aggressive combination treatments for high blood pressure that are intended to protect the kidneys may actually be damaging the organs, new research from the University of Virginia School of Medicine suggests.

Quantifying effectiveness of treatment for irregular heartbeat

July 17, 2017
In a small proof-of-concept study, researchers at Johns Hopkins report a complex mathematical method to measure electrical communications within the heart can successfully predict the effectiveness of catheter ablation, the ...

Concerns over side effects of statins stopping stroke survivors taking medication

July 17, 2017
Negative media coverage of the side effects associated with taking statins, and patients' own experiences of taking the drugs, are among the reasons cited by stroke survivors and their carers for stopping taking potentially ...

Study discovers anticoagulant drugs are being prescribed against safety advice

July 17, 2017
A study by researchers at the University of Birmingham has shown that GPs are prescribing anticoagulants to patients with an irregular heartbeat against official safety advice.

Protein may protect against heart attack

July 14, 2017
DDK3 could be used as a new therapy to stop the build-up of fatty material inside the arteries

Heart study finds faulty link between biomarkers and clinical outcomes

July 14, 2017
Surrogate endpoints (biomarkers), which are routinely used in clinical research to test new drugs, should not be trusted as the ultimate measure to approve new health interventions in cardiovascular medicine, according to ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.