A study published in the Journal of the Neurological Sciences has found that Mobile Cardiac Outpatient Telemetry (MCOT) supports the detection of a high rate of occult paroxysmal atrial fibrillation (PAF) in cryptogenic stroke and transient ischaemic attack (TIA) patients.
Daniel J Miller, Department of Neurology, Henry Ford Hospital, Detroit, USA, and colleagues performed a retrospective analysis on patients evaluated by MCOT (CardioNet) monitoring within six months of a cryptogenic stroke or TIA. The researchers performed multivariate analysis with survival regression methods using baseline characteristics to determine predictive risk factors for detection of paroxysmal atrial fibrillation. Kaplan–Meier estimates were computed for 21-day PAF rates.
Miller et al analised 156 records and found that PAF occurred in 27 (17.3%) patients during MCOT monitoring of up to 30days. The authors found that the rate of PAF detection significantly increased from 3.9% in the initial 48hours, to 9.2% at 7days, 15.1% at 14days, and 19.5% by 21days (p<0.05).
The researchers also found that female gender, premature atrial complex on ECG, increased left atrial diameter, reduced left ventricular ejection fraction and greater stroke severity were independent predictors of PAF detection on multivariate analysis with strongest correlation seen for premature atrial complex on ECG (HR 13.7, p=0.001).
Miller, senior author of the study, commented: “This study highlights the importance of a standardised approach to the evaluation for potential arrhythmias in patients with cryptogenic stroke or TIA. Screening with a minimum of 21 days of outpatient telemetry monitoring with automated arrhythmia detection software should be considered a routine part of the stroke evaluation in these patients. Identification and treatment of atrial fibrillation in these patients will likely reduce the risk of future stroke.”
Miller et al concluded: “Length of monitoring is strongly associated with detection of PAF, with an optimal monitoring period of at least 21days. Of the predictors of PAF detection, the presence of premature atrial complexes on ECG held the strongest correlation with PAF.”
This recent clinical trial supports the results from a previous study, “Atrial fibrillation detected by mobile cardiac outpatient telemetry in cryptogenic tia or stroke”, authored by AH Tayal et al, Allegheny General Hospital, Comprehensive Stroke Center, Pittsburgh, USA, and published in the 18 November 2008 issue of Neurology which concluded that the MCOTdetected a high rate of atrial fibrillation in patients that have experienced a TIA or stroke.