Adopting the new anticoagulants: all aboard or all in good time?

At last there is now more than 1 oral anticoagulant (OAC) available for stroke prevention in atrial fibrillation. Though more choice is a good thing, it does mandate knowing which drug is the most appropriate in a given clinical situation. Three novel OACs--dabigatran, rivaroxaban, and apixaban--are approved for use in atrial fibrillation in Canada. They have each been evaluated in large, randomized controlled trials where they have been shown to be noninferior, or in some cases superior, to warfarin (Coumadin). Prescription coverage for these drugs is increasingly available through third party and government drug plans. The major enhancements of the novel OACs relate to their rapid, consistent anticoagulant effect at fixed dosing and the lack of need for monitoring of anticoagulant effect. Nonetheless, their use is not foolproof and practitioners must be familiar with their limitations. On balance, we favour the use of novel OACs over warfarin in patients who are anticoagulant-naive, given their increased ease of use. However, we advocate switching from warfarin only if international normalized ratio control has been poor or if frequent monitoring is problematic.

New England Medical Center Posterior Circulation registry.

Among 407 New England Medical Center Posterior Circulation registry patients, 59% had strokes without transient ischemic attacks (TIAs), 24% had TIAs then strokes, and 16% had only TIAs. Embolism was the commonest stroke mechanism (40% of patients including 24% cardiac origin, 14% intraarterial, 2% cardiac and arterial sources). In 32% large artery occlusive lesions caused hemodynamic brain ischemia. Infarcts most often included the distal posterior circulation territory (rostral brainstem, superior cerebellum and occipital and temporal lobes); the proximal (medulla and posterior inferior cerebellum) and middle (pons and anterior inferior cerebellum) territories were equally involved. Severe occlusive lesions (>50% stenosis) involved more than one large artery in 148 patients; 134 had one artery site involved unilaterally or bilaterally. The commonest occlusive sites were: extracranial vertebral artery (52 patients, 15 bilateral) intracranial vertebral artery (40 patients, 12 bilateral), basilar artery (46 patients). Intraarterial embolism was the commonest mechanism of brain infarction in patients with vertebral artery occlusive disease. Thirty-day mortality was 3.6%. Embolic mechanism, distal territory location, and basilar artery occlusive disease carried the poorest prognosis. The best outcome was in patients who had multiple arterial occlusive sites; they had position-sensitive TIAs during months to years.

North American clinical experience with the EKOS MicroLysUS infusion catheter for the treatment of embolic stroke.

BACKGROUND AND PURPOSE: We present early experience with the EKOS MicroLysUS infusion catheter for acute embolic stroke treatment in North America. This study was designed to demonstrate the safety of the device and to determine if sonography accelerates thrombolysis and improves clinical outcomes. METHODS: Fourteen patients aged 40-77 years with anterior- or posterior-circulation occlusion presented with cerebral ischemia 3-6 or 4-13 hours after symptom onset, respectively. Patients were treated with the catheter and simultaneous intraarterial thrombolysis. Procedural and clinical information, including time to lysis, degree of recanalization, National Institute of Health Stroke Scale (NIHSS) score, and modified Rankin Scale (mRS) score was recorded before treatment and afterward (immediately and at 24 hours, 1 week, 1 month, and 3 months). RESULTS: Ten patients presented with acute anterior-circulation emboli; four patients, with posterior-circulation emboli (NIHSS score, 9-23 [mean. 18.2] and 11-27 [mean, 18.75], respectively). Three deaths occurred at 24 hours: two from hemorrhage and one from cerebral swelling. Deaths also occurred at 1 week and 1 month after treatment. Thrombolysis in Myocardial Ischemia grade 2-3 flow was achieved in eight patients in the first hour. Average time to recanalization was 46 minutes. Mean NIHSS scores in eight of nine survivors at 90 days were 5 in the anterior-circulation group and 3 in the posterior-circulation group; mean mRS scores at 90 days were 2 and 3, respectively. No catheter-related adverse events occurred. CONCLUSION: Use of the EKOS MicroLysUS infusion catheter is feasible in the treatment of acute ischemic stroke. Further studies to evaluate its efficacy are warranted.