Underutilization of Ambulatory ECG Monitoring After Stroke and TIA

Study Questions:

How often do patients with recent stroke or transient ischemic attack (TIA) undergo 24-hour electrocardiograms (ECGs), as recommended by a variety of stroke-related guidelines?

Methods:

Data from the Ontario Stroke Registry, spanning years from 2003 to 2013, were analyzed. Patients with a first acute ischemic stroke or TIA in sinus rhythm and without known atrial fibrillation were identified. The primary outcome was the proportion of patients who received at least 24-hour Holter monitoring within 30 days after stroke/TIA. Secondary analyses assessed total duration of ECG monitoring completed within 90 days after stroke/TIA, temporal trends in monitoring use, and use of Holter monitoring relative to echocardiography.

Results:

Among 17,398 consecutive eligible patients (mean age 68.8 years), 30.6% had at least 24 hours of Holter monitoring within 30 days after stroke/TIA. Less than 1% of patients received monitoring beyond 48 hours. Stroke/TIA patients were nearly twice as likely to receive an echocardiogram as a Holter monitor within 90 days (odds ratio, 1.8; 95% confidence interval, 1.67–2.01).

Conclusions:

The authors concluded that less than one third of patients received 24-hour Holter monitoring, which may lead to an overdiagnosis of strokes as cryptogenic, and an underdiagnosis of atrial fibrillation.

Perspective:

Holter ECG monitoring detects paroxysmal AF in about 5% of stroke patients. Not surprisingly, clinical trials demonstrated longer monitoring results in greater rates of AF detection, with up to 30% of patients identified as having AF. This has great implications because anticoagulant therapy is usually not prescribed after stroke unless the patient has AF. Antiplatelet, but not anticoagulant, therapy is usually prescribed after stroke/TIA in patients with cryptogenic stroke. What remains unclear is whether there is an AF burden threshold, which is necessary for the post-stroke/TIA patient to derive benefit from anticoagulant therapy. Nonetheless, these findings underscore the need to improve compliance with guideline recommendations for post-stroke patients. Future guidelines are virtually certain to recommend extended ECG monitoring with either an external or implantable loop monitor.

Keywords: Anticoagulants, Arrhythmias, Cardiac, Atrial Fibrillation, Echocardiography, Electrocardiography, Electrocardiography, Ambulatory, Ischemic Attack, Transient, Secondary Prevention, Stroke, Vascular Diseases


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