Irregular heartbeat described as `modifiable` risk factor for stroke
Washington: Atrial fibrillation patients can reduce their risk of stroke by rhythm control treatments and by the use of antithrombotic therapies, according to experts.
These therapies have been improved in the past few years by the introduction of new anticoagulant drugs, such that AF - like high blood pressure or smoking - may now be considered a “modifiable” risk factor for stroke, whose treatment can reduce the degree of risk.
Speaking on behalf of the European Society of Cardiology (ESC), Professor Freek Verheugt, from the Onze Lieve Vrouwe Gasthuis in Amsterdam said: “All individuals with irregular heart beat should see a doctor, who can diagnose whether this heart rhythm disorder is likely to lead to stroke. If so, blood thinning medication can reduce the risk of stroke by up to 70percent.”
The latest ESC Clinical Practice Guidelines on Cardiovascular Disease Prevention, which were revised this year, describe stroke as the “second major cardiovascular disease” (after coronary heart disease) and, like CHD, with enormous scope for prevention.
Indeed, more than 50 percent of the reductions seen in heart disease mortality over recent decades relate to changes in risk factors. In addition, the treatments prescribed to lower blood pressure, for example, also reduce the risk of stroke, such that stroke prevention is still the most evident effect of antihypertensive treatment.
The overall theme of this year’s World Stroke Day on 29th October is “One in Six”, referring to the facts that one in six people will have a stroke at some point in their lifetime, and that a stroke will be the cause of someone’s death every six seconds.
These, says the World Stroke Organization, are everyday people leading everyday lives, but around 85 percent of them will have risk factors that, if identified, are preventable.
The Interstroke study, which was reported in 2010 following an analysis of stroke data from 22 countries, indicates that just ten risk factors are associated with 90 percent of total stroke risk. The highest attributable effect of individual risk factors was 35 percent from hypertension, 26.5 percent for waist-to-hip ratio, and 19 percent for current smoking.
The ESC emphasises that most of these risks for stroke are also the same major risks for coronary heart disease - high blood pressure, smoking, obesity, lack of exercise and excessive alcohol consumption.
In addition, AF, this common disorder of heart rhythm, is also clearly associated with an increased risk of stroke. Indeed, the very latest ESC guidelines on AF, published in August, state: “Diagnosing AF before the first complications occur is a recognized priority for the prevention of strokes”, and that “even short episodes of ‘silent’ AF convey an increased risk for stroke”.
While the guidelines advise that the evidence in favour of aspirin in stroke prevention is “weak”, they add that a new range of anticoagulant drugs are “broadly preferable” for stroke prevention in AF, but, because experience remains limited, they are recommended within the context of “strict adherence to approved indications”.
The guidelines state that these novel anticoagulants “offer efficacy, safety, and convenience” compared with previous therapies.
Professor Verheugt emphasises that stroke is not an inevitable consequence of ageing and that, by identifying and modifying risk factors, there are substantial opportunities to reduce stroke risk - through lifestyle interventions and the control of high blood pressure and AF.