Risk of Recurrent Stroke in Patients with Symptomatic Mild (20-49% NASCET) Carotid Artery Stenosis.

OBJECTIVE: The objective of this study was to evaluate the risk of recurrent ischaemic stroke in patients with ultrasound assessed symptomatic mild carotid artery stenosis (20-49% NASCET) treated solely with modern medical treatment. METHOD: This was a retrospective, observational register cohort study. Three groups of patients were recruited from a database of all carotid Doppler ultrasound examinations performed in the Gothenburg region between 2004 and 2009. Patients with symptomatic mild carotid artery stenosis (n = 162) were compared with patients with asymptomatic carotid artery stenosis (n = 301) of equal degree and a group of patients with surgically (CEA) treated symptomatic moderate or severe carotid artery stenosis (n = 220). Kaplan-Meier estimates and Cox proportional hazard models were used to compare the primary outcome (ipsilateral ischaemic stroke) between groups. RESULTS: After a 3 year follow up, the cumulative incidence of recurrent ipsilateral stroke in patients with symptomatic mild carotid artery stenosis was 7.4%. Patients with symptomatic mild carotid artery stenosis had a substantially increased risk of recurrent ipsilateral stroke compared with asymptomatic patients with equal degree of stenosis (HR 5.5. 95% CI 1.8-17.1; p = .003) as also compared with patients with CEA treated symptomatic moderate or severe stenosis (HR 7.8. 95% CI 1.62-37.8; p = .011). CONCLUSIONS: The present study on patients with symptomatic mild carotid artery stenosis, as determined by Doppler ultrasound, shows that there is still a substantial risk of recurrent stroke in this group.

Transcranial Doppler microembolic signals and serum marker evidence of brain injury during transcatheter aortic valve implantation.

BACKGROUND: Recent studies have shown that transcatheter aortic valve implantation (TAVI) is associated with new foci of restricted diffusion on cerebral magnetic resonance imaging suggestive of cerebral microembolism. The aim of the present investigation was to quantify the cerebral embolic load and to evaluate during which phase of the TAVI procedure microembolism occurs. We also evaluated the association between the cerebral embolic load and post-procedural release of S100B, a serological marker of cerebral injury. METHODS: In 21 patients, we described the extent and intra-procedural distribution of microemboli during the TAVI procedure using the transcranial Doppler technique. S100B, a marker of astroglial injury, was measured for 24 h after the procedure, and the area under the curve (AUC(24h) ) relating S100B to time was calculated. RESULTS: During the TAVI procedure, a mean of 282 ± 169 emboli was detected, 37% occurred during manipulation of the aortic arch/root/valve by guide wires and catheters, 22% occurred immediately after balloon dilatation of the native valve and 41% occurred during frame expansion of the valve prosthesis. S100B increased in all patients with a peak at 1 h after the procedure and returned to baseline after 4 h. There was a positive correlation between the total amount of cerebral microemboli and the AUC(24h) for S100B (r = 0.68, P < 0.001). None of the patients developed neurological impairment. CONCLUSION: TAVI is associated with a substantial amount of cerebral microemboli. The microembolic load correlates to the degree of post-procedural release of a marker of cerebral injury.