Routine monitoring effective in detecting AF after ischemic stroke

The routine use of extended noninvasive cardiac-event monitoring after an acute stroke improves the detection of paroxysmal atrial fibrillation (PAF) and anticoagulation rates, according to a study published online July 30 in Stroke. This approach can help better prevent strokes and should be included in guidelines for investigating AF after ischemic stroke, according to the authors.

Researchers led by Peter Higgins, MRCP, of the University of Glasgow in Scotland, conducted a randomized controlled trial involving 100 patients who between May 2010 and September 2011 presented to two stroke centers with ischemic stroke symptoms within the past seven days. All the participants had a 12-lead electrocardiogram (ECG) showing sinus rhythm and no history of AF, atrial flutter or any irreversible condition incompatible with long-term anticoagulation.

“One in five patients with ischemic stroke or TIA will have a history of AF or is revealed to have AF on their initial 12-lead ECG, but further investigation is needed to detect culprit PAF and occult PAF, which confers future risk,” the authors wrote.

The researchers randomly assigned the participants to groups receiving either standard practice investigations (SP) to detect AF or SP and additional monitoring (SP-AM). They defined AM as seven days of noninvasive cardiac event monitoring by an accredited cardiac electrocardiology laboratory.

SP was considered to be strategies deemed appropriate by the treatment team that were consistent with current guidelines and nationwide practice.

The primary endpoint was the difference in the detection of AF between the two experimental groups, which was measured at 14 and 90 days.

“Within 14 days of stroke, sustained paroxysms of AF were detected in 18 percent of patients undergoing SP-AM versus 2 percent undergoing SP,” their analysis revealed. Additionally, SP-AM was able to detect paroxysms of any duration in 44 percent of participants in that group, while SP was only able to detect them in 4 percent of the other experimental group. These differences were also evident at 90 days.

They also found that anticoagulation was started more frequently in the SP-AM group compared with the SP group at both 14 and 90 days. Anticoagulation, the authors pointed out, can reduce AF risk better than antiplatelet therapy.

Ischemic stroke investigation guidelines recommend repeated 12-lead ECGs for all patients, Holter monitoring if an extended time period is warranted and extended ECG monitoring in cryptogenic stroke.

Based on their results and the findings of other studies, the authors recommended that guidelines be revised for this group of patients. Holter monitoring, they argued, is a less cost-effective and less effective AF detection method.

“Our trial provides randomized evidence for superior effectiveness of routine early and extended cardiac-event monitoring in all ischemic stroke patients with sinus rhythm, versus existing guideline-based practice,” they wrote. “Noninvasive cardiac-event monitoring should be routinely adopted as the standard of care in all stroke patients who appear to be in sinus rhythm.”