10-Day Holter-ECG Monitoring Following Ischemic Stroke Leads to Increased AFib Detection Rates

A randomized controlled trial on older patients found that 10 days of Holter monitoring undertaken 0, 3 and 6 months after ischemic stroke from any apparent cause detected atrial fibrillation (AFib) in 3 times as many patients as 24 hours of nearly immediate Holter monitoring.

German investigators randomized 398 stroke patients aged 60 years and above between the 2 monitoring regimens. The study population had a mean age of 73 years (± a standard deviation of 7 years) and 40.2% of its members were female. All patients presented with sinus rhythm at admission, had no history of AF and were randomized within 7 days of their initial strokes.

After 6 months, AFib lasting 30 seconds or more had been detected in 13.5% (27 patients) of the intensified and enhanced monitoring group and 4.5% (9 patients) of the control group (absolute difference [AD], 9.0 %; 95% confidence interval [CI], 3.5% to 14.6 %; p=0.002). The number of patients needed to screen with the enhanced monitoring to find an additional case of AF was 11.

No additional cases of AFib were detected over the next 6 months in the enhanced monitoring group, but regular care detected 4 more cases in the control group, making the final rate of AFib detection 13.5% in the enhanced monitoring group and 6.6% in the control group (AD, 6.9%; 95% CI, 1.0% to 12.8%; p=0.018).

Investigators also collected data on stroke recurrence after 12 months, data that suggested the enhanced monitoring might reduce recurrence but failed to rise near the level of statistical significance. The all-stroke recurrence rate was 2.5% in the enhanced monitoring group and 4.5% in the control group (p=0.28), while the rate of transient ischemic attack was 1.5% in the enhanced monitoring group and 2.5% in the control group (p=0.48).

“Repeated 10-day Holter-ECG monitoring initiated early after ischemic stroke was superior to standard of care for the detection of atrial fibrillation within 6 months in stroke patients aged 60 years and above,” the investigators wrote in an abstract they presented at the International Stroke Conference in Los Angeles.

Rolf Wachter, MD, a study co-author from the University of Gotting, said in a press conference after the presentation that the results of the trial, which was funded by monitor-maker Boehringer Ingelheim, that enhanced monitoring should be considered for all patients who would benefit from an early AF diagnosis.

Current guidelines from the American Heart Association and American Stroke Association already recommend about 30 days of rhythm monitoring within 6 months of acute ischemic stroke or transient ischemic attack with no apparent cause, but they recommend only 24 hours in cases where doctors believe they can identify the cause of the event.

The investigators noted several limitations to the trial. It was too small to evaluate whether the increased number of AFib diagnoses led to a significant reduction in stroke recurrence, and it’s unclear whether its findings in a patient population comprised mostly of northwestern Europeans would hold among other ethnic groups.

Wachter also noted another potential limitation in his press conference: cost. The additional Holter monitoring would be expensive, and there’s little chance of it becoming common unless insurers agree to pay for it.