Automatic detection of paroxysmal atrial fibrillation in patients with ischaemic stroke: better than routine diagnostic workup?

BACKGROUND AND PURPOSE: Prolonged electrocardiogram (ECG) monitoring after ischaemic stroke increases the diagnostic yield of paroxysmal atrial fibrillation (pAF). In order to facilitate the additional workload involved in ECG analysis due to prolonged monitoring times, we investigated the effectiveness of pAF detection with an automated software algorithm (SA) in comparison to the routine staff-based analysis (RA) during standard stroke-unit care. Therefore, patients with acute ischaemic stroke or transitory ischaemic attack presenting with sinus rhythmus on the admission ECG and no history of atrial fibrillation were prospectively included. METHODS: A 24-h Holter ECG assessment was performed using either RA based on a computer-aided evaluation and subsequent review by a cardiologist or a commercially available automated SA. In the case of discordant results concerning the occurrence of pAF between the two methods, the data underwent an independent external rating. RESULTS: Of 809 prospectively enrolled patients, 580 patients fulfilled the inclusion criteria. pAF was ultimately diagnosed in 3.3% of the cohort (19 patients). SA and RA correctly diagnosed pAF in 17 patients resulting in a comparable diagnostic effectiveness of the analysis methods (sensitivity: SA 89.5% vs. RA 89.5%; specificity: SA 99.3% vs. RA 99.1%; κ, 0.686; P < 0.001; 95% confidence interval, 0.525-0.847). RA revealed clinically relevant ECG abnormalities in an additional seven patients. CONCLUSIONS: Although it should not completely replace RA, SA-based evaluation of Holter ECG reaches a high diagnostic effectiveness for the detection of pAF and can be used for a rapid and resource-saving analysis of ECG data to deal with prolonged monitoring times.

Clinical predictors to identify paroxysmal atrial fibrillation after ischaemic stroke.

BACKGROUND AND PURPOSE: Detection of paroxysmal atrial fibrillation (pAF) after an ischaemic cerebrovascular event is of imminent interest, because oral anticoagulation as a highly effective secondary preventive treatment is available. Whereas permanent atrial fibrillation (AF) can be detected during routine electrocardiogram (ECG), longer detection duration will detect more pAF but might be resource consuming. The current study tried to identify clinical predictors for pAF detected during long-term Holter ECG and clinical follow-up. METHODS: Patients with acute ischaemic stroke were prospectively investigated with an intensified algorithm to detect pAF (7-day Holter ECG, follow-up investigations after 90 days and 1 year). RESULTS: Two hundred and eighty-one patients were included, 44 of whom had to be excluded since they presented with permanent AF and another 13 patients had to be excluded due to other causes leaving 224 patients (mean age 68.5 years, 58.5% male). Twenty-nine (12.9%) patients could be identified to have pAF during prolonged Holter monitoring, an additional 13 (5.8%) after follow-up investigations. Multivariate analysis identified advanced age [odds ratio (OR) 1.05, 95% confidence interval (CI) 1.01-1.08] as well as clinical symptoms >24 h (OR 5.17, 95% CI 1.73-15.48) and a history of coronary artery disease (OR 3.14, 95% CI 1.35-7.28) to be predictive for the detection of pAF. CONCLUSIONS: In acute stroke patients with advanced age, history of coronary artery disease and clinical symptoms >24 h, a prolonged Holter ECG monitoring and follow-up is warranted to identify pAF. This could increase the detection rate of patients requiring anticoagulation and may be able to reduce the risk of recurrent stroke in the case of successful anticoagulation of these patients.