ASSERT study demonstrates effectiveness of implantable device monitoring in predicting stroke


Results of a new trial demonstrated that pacemaker patients without history of atrial tachycardia (AT) or atrial fibrillation (AF) who have device-detected arrhythmias are approximately 2.5 times more likely to have a stroke than patients who do not have device-detected arrhythmias.

Data of the trial were presented by Jeff S Healey, principal investigator for the arrhythmias program at the Population Health Research Institute of McMaster University and Hamilton Health Sciences in Hamilton, Canada, at the American Heart Association Scientific Sessions 2010 in Chicago, USA.

ASSERT (Asymptomatic af and stroke evaluation in pacemaker patients and the AF reduction atrial pacing trial) is a St Jude Medical sponsored trial conducted by the Population Health Research Institute of McMaster University and Hamilton Health Sciences.

“These results are significant because they demonstrate that even brief, asymptomatic AF episodes can cause a stroke, and that the proportion of strokes that are associated with atrial arrhythmias is much higher than previously thought,” said Healey. “This trial shows that by using the information already available in implantable pacemakers and defibrillators, physicians can identify patients at risk for stroke, earlier than would otherwise be the case, even before they experience arrhythmia symptoms.”

ASSERT studied 2,580 pacemaker patients over the age of 65 with hypertension and no history of AF. The trial was a cohort study designed to determine whether the detection of arrhythmias using pacemaker-based diagnostics predicts an increased risk of stroke in elderly, hypertensive patients without any history of AF. Atrial fibrillation had previously been linked to an increased risk of stroke but it was not clear that brief, often asymptomatic AF episodes are associated with an increased risk for stroke as well.