Adverse prognosis of incidentally detected ambulatory atrial fibrillation: A cohort study


Screening for atrial fibrillation and the impact on stroke and thromboembolism: the harder one looks, the more we find

Atrial fibrillation is the commonest heart rhythm condition (all of us have a 1 in 4 lifetime risk of developing atrial fibrillation) often remains undetected and usually is diagnosed incidentally. Nonetheless, asymptomatic irregular heart beat increases the risk of stroke, myocardial infarction and premature death, reasons enough to screen for atrial fibrillation, as current research suggests.

An incidental meeting of two men from opposite sides of the world, epidemiologist Carlos Martinez (Frankfurt, Germany), and cardiologist Ben Freedman, (Sydney, Australia), at the 2012 European Society of Cardiology (ESC), sparked the idea of investigating outcomes of asymptomatic atrial fibrillation. The challenge was to identify a group of patients first diagnosed with atrial fibrillation who (previously or currently) noticed none of the typical symptoms: palpitations, dizziness, fainting or shortness of breath. "We wanted to find out if incidentally discovered atrial fibrillation has the same bad outcomes as when atrial fibrillation is discovered because a patient complains of symptoms," Freedman explained.

The researchers identified 5,555 people in whom atrial fibrillation was discovered incidentally in general practice in the absence of symptoms. Then they compared them with almost 25,000 people who served as a healthy age-matched control of the same age (average age 71) and gender. The results revealed that asymptomatic atrial fibrillation was associated with twice the risk of stroke and premature death. The latter occurred in almost 12% of the afflicted within three years compared to only 6% in people without abnormal heart beats. There was also a small increase in the risk of a heart attack. Only half of the afflicted received oral anticoagulants, i.e. warfarin, which almost completely reversed their formerly increased risk of stroke, and partially reversed their elevated risk of premature death. Patients who were placed on aspirin, however, weren´t that fortunate as their (substantial) risk did not change. "If atrial fibrillation is found, our study suggests it should be treated with oral anticoagulants, but not aspirin," the authors pointed out.

Screening is justified

In a recent publication in Thrombosis and Haemostasis1, the authors demonstrated that a single screen for atrial fibrillation using either pulse or ECG in people over the age of 65 is likely to detect 1.4% of the afflicted who had been still unaware of their condition." Because we have shown that this diagnosis is far from benign, and that the outcome can be favorably influenced by anticoagulant treatment, it may be worth running screening programs to detect atrial fibrillation in this age group," Freedman said.

In another paper, they showed that atrial fibrillation could easily and accurately be detected by a simple inexpensive ECG using a novel hand-held device attached to an iPhone2. The ECG device is built into a case that fits onto the iPhone with a diagnosis available within 30 seconds. "Given such easy ways to detect atrial fibrillation," he added "and our demonstration of the poor outcomes that can be substantially modified by treatment, our results would make a reasonable case to screen for this abnormal heart rhythm in the population, as well as in the clinic....These findings could influence national guidelines about screening for atrial fibrillation."

Facts to remember

Atrial fibrillation has a poor prognosis for increased stroke and thromboembolism, even when it is picked up incidentally in patients without symptoms. However, screening for atrial fibrillation and subsequent treatment with anticoagulants  but not aspirin  can significantly reduce the elevated risk of stroke and premature death. These are strong arguments for screening as recommended in guidelines. Yet it seems to be particularly important to carry out a targeted population screening for people 65 and older. The goal is to reduce the burden of stroke and premature death associated with this common, yet often asymptomatic and undetected arrhythmia.
Werner Zwick, M.A.

1 Martinez C, Katholing A, Freedman SB: Opens external link in new windowAdverse prognosis of incidentally detected ambulatory atrial fibrillation. A cohort study. Thromb Haemost 2014 112 2: 276-286
2  Lowres N, Neubeck L, Salkeld G, et al. Opens external link in new windowFeasibility and cost-effectiveness of stroke prevention through community screening for atrial fibrillation using iPhone ECG in pharmacies. The SEARCH-AF study. Thromb Haemost 2014; 111: 1007-1199

PR contact:
Stefanie Engelfried
public relations

Schattauer GmbH
Verlag für Medizin und Naturwissenschaften
Hölderlinstrasse 3
70174 Stuttgart
Tel: 0711-22987-20
Fax: 0711-22987-85
E-Mail: Öffnet ein Fenster zum Versenden der E-Mailstefanie.engelfried(at)