Introduction of an embolus detection guided TIA service at the HAGA Teaching Hospitals, The Netherlands

Background: Current protocols for treatment of patients with recent carotid artery TIA or minor stroke stress the importance of rapid diagnosis and treatment of symptomatic carotid artery stenosis to prevent stroke recurrence. ABCD2 scores are used as predictors of stroke recurrence in this patient group but these factors cannot predict individual stroke risk. TCD embolus detection however can determine individual stroke risk. Therefore this study provides data of clinical implementation of a new embolus detection system (EDS) which has been developed for automatic detection of micro-embolic signals (MES) in TIA and minor Stroke patients.

Methods: Patients with a recent carotid artery TIA or minor Stroke went through an EDS guided protocol. It included a prompt start of anti-thrombotic drugs by the (in-)house physician in every patient, an early (within 24–48 hrs of admittance) 30 minutes examination of the middle cerebral arteries to detect MES. Patients exhibiting positive embolization were subjected to a rapid (max. 48 hrs) diagnostic work-up and treatment. In case of negative embolization the work-up was done at a regular time interval (1–2 weeks).

Results: 12% of the patients were MES positive. MES showed both low intensity and short duration. MES were associated with ulcerative high grade carotid artery stenosis (1 out of 3 patients with carotid artery stenosis over 50% showed MES). MES were clinically associated with amaurosis or speech disturbances rather than pure motor or sensory events. The decision making component of the EDS validated against human experts showed a better than 88% overall agreement in discriminating MES and artifacts. Rapid diagnostic work-up was performed in all patients with positive embolization. Carotid angioplasty or surgery was performed within 1.6 days in patients with a recent TIA, high grade carotid artery stenosis and positive embolization. In patients with a high grade stenosis and negative embolization the time interval between the duplex scanning and carotid surgery or angioplasty was 15 days. Stroke recurrence rate at 3 month was zero in both patient groups with or without cerebral embolization.

Conclusion: The EDS can be used as a reliable screening tool for patients with recent TIA or minor stroke. Implementation of EDS guided TIA and Stroke services might positively influence the outcome of these patients by rapid identification and subsequent treatment of patients with a high risk of stroke recurrence.