Continuous ECG useful for AF screening long after stroke

Use of a 7-day Holter monitoring for poststroke atrial fibrillation (AF) screening in a primary care setting appears to increase the number of AF cases, markedly improving the detection rate compared with pulse palpation and 12-lead electrocardiogram (ECG), according to a study.

The study included 366 AF-free patients who had an ischaemic stroke over 1 year before enrolment and were aged >49 years at stroke onset. The mean age was 70 years, and 65.6 percent of the population were men. The median time from last stroke was 3.9 years, and the median CHA₂DS₂-VASc score was 4. None of them had mitral valve stenosis or a mechanical heart valve.

All patients were screened for AF using pulse palpation, 12-lead ECG, and 7-day Holter monitoring in a primary care setting. AF was detected in 122 patients (33 percent) via pulse palpation, three patients (0.82 percent) via the 12-lead ECG, and 17 patients (4.6 percent) via 7-day Holter monitoring.

The number needed to screen to detect a single case of AF with 7-day Holter monitoring was 22 patients. Using this diagnostic approach as reference standard, pulse palpation missed nine of 17 patients with AF while the 12-lead ECG missed 14. They achieved a sensitivity of 47 percent (95 percent confidence interval [CI], 23–72) and 18 percent (95 percent CI, 4–43), respectively, for detecting AF.

Logistic regression analysis showed that older patients were more likely to be diagnosed with AF (odds ratio, 1.1, 95 percent confidence interval, 1.02–1.15). On the other hand, high levels (≥400 pg/mL) of NT-proBNP were not associated with AF.

The findings indicate that additional continuous ECG methods should be considered for poststroke AF screening, especially given the low sensitivities of pulse palpation and 12-lead ECG, according to researchers.