Transcranial Doppler ultrasound to evaluate the risk of hyperperfusion after endovascular stroke thrombectomy.

BACKGROUND AND PURPOSE: Hemorrhagic transformation (HT) has been reported in up to 50% of acute ischemic stroke (AIS) patients with a large vessel occlusion (LVO) treated with endovascular thrombectomy (EVT). HT may be driven by postrecanalization hyperperfusion injury and is independently associated with worse functional outcomes. Strategies to identify patients at risk for HT may assist in developing preventive therapies. METHODS: We prospectively included adult AIS patients with an anterior circulation LVO achieving successful recanalization after EVT. Consenting participants received transcranial Doppler ultrasound (TCD) within 18 hours of procedure completion. We compared flow velocities according to the presence of HT on the computed tomography scan performed within the first 24±12 hours from the end of EVT. We also evaluated the association of flow velocities with systemic blood pressure (BP) readings at the time of insonation. RESULTS: A total of 48 patients consented to participate in the study. Six (12%) were excluded due to the absence of temporal windows. HT was detected in 20 participants (48%). Those with HT had higher peak systolic velocities on the middle cerebral arteries compared to those without HT for both the symptomatic (107±42 vs. 82±25 cm/second, p = .024) and asymptomatic (97±21 vs. 81±25 cm/second, p = .040) sides. No correlation of flow velocities on either the symptomatic or asymptomatic side and BP measurements at the time of insonation was detected. CONCLUSION: TCD can identify patients at risk of HT following successful EVT. TCD could serve as an inexpensive ancillary test to guide participant selection for clinical trials targeting postprocedural reperfusion injury.

Association Between Low-Dose Rivaroxaban With or Without Aspirin and Ischemic Stroke Subtypes: A Secondary Analysis of the COMPASS Trial.

Importance: The COMPASS (Cardiovascular Outcomes for People Using Anticoagulation Strategies) randomized clinical trial was stopped early owing to the efficacy of low-dose rivaroxaban plus aspirin in preventing major cardiovascular events. The main reason for early trial termination was the effect of combination therapy on reducing ischemic strokes. Objective: To analyze the association between low-dose rivaroxaban with or without aspirin and different ischemic stroke subtypes. Design, Setting, and Participants: This is a secondary analysis of a multicenter, double-blind, randomized, placebo-controlled study that was performed in 33 countries from March 12, 2013, to May 10, 2016. Patients with stable atherosclerotic vascular disease were eligible, and a total of 27 395 participants were randomized and followed up to February 6, 2017. All first ischemic strokes and uncertain strokes that occurred by this date were adjudicated using TOAST (Trial of Org 10172 in Acute Stroke Treatment) criteria. The analysis of ischemic stroke subtypes was evaluated using an intention-to-treat principle. Statistical analysis was performed from March 12, 2013, to February 6, 2017. Interventions: Participants received rivaroxaban (2.5 mg twice a day) plus aspirin (100 mg once a day), rivaroxaban (5 mg twice a day), or aspirin (100 mg once a day). Main Outcomes and Measures: Risk of ischemic stroke subtypes during follow-up. Results: A total of 291 patients (66 women; mean [SD] age, 69.4 [8.5] years; 43 [14.8%] had a previous nonlacunar stroke) experienced an ischemic stroke. During the study, 49 patients (16.8%) received a diagnosis of atrial fibrillation. Applying TOAST criteria, 59 strokes (20.3%) were cardioembolic, 54 strokes (18.6%) were secondary to greater than 50% stenosis of the ipsilateral internal carotid artery, 42 strokes (14.4%) had a negative evaluation that met criteria for embolic stroke of undetermined source, and 21 strokes (7.2%) were secondary to small vessel disease. There were significantly fewer cardioembolic strokes (hazard ratio [HR], 0.40 [95% CI, 0.20-0.78]; P = .005) and embolic strokes of undetermined source (HR, 0.30 [95% CI, 0.12-0.74]; P = .006) in the combination therapy group compared with the aspirin-only group. A trend for reduction in strokes secondary to small vessel disease (HR, 0.36 [95% CI, 0.12-1.14]; P = .07) was not statistically significant. No significant difference was observed between the 2 groups in strokes secondary to greater than 50% carotid artery stenosis (HR, 0.85 [95% CI, 0.45-1.60]; P = .61). Rivaroxaban, 5 mg, twice daily showed a trend for reducing cardioembolic strokes compared with aspirin (HR, 0.57 [95% CI, 0.31-1.03]; P = .06) but was not associated with reducing other stroke subtypes. Conclusions and Relevance: For patients with systemic atherosclerosis, low-dose rivaroxaban plus aspirin was associated with large, significant reductions in cardioembolic strokes and embolic strokes of undetermined source. However, these results of exploratory analysis need to be independently confirmed before influencing clinical practice. Trial Registration: ClinicalTrials.gov identifier: NCT01776424.

Stroke Outcomes in the COMPASS Trial.

BACKGROUND: Strokes were significantly reduced by the combination of rivaroxaban plus aspirin in comparison with aspirin in the COMPASS trial (Cardiovascular Outcomes for People Using Anticoagulation Strategies). We present detailed analyses of stroke by type, predictors, and antithrombotic effects in key subgroups. METHODS: Participants had stable coronary artery or peripheral artery disease and were randomly assigned to receive aspirin 100 mg once daily (n=9126), rivaroxaban 5 mg twice daily (n=9117), or rivaroxaban 2.5 mg twice daily plus aspirin (n=9152). Patients who required anticoagulation or had a stroke within 1 month, previous lacunar stroke, or intracerebral hemorrhage were excluded. RESULTS: During a mean follow-up of 23 months, fewer patients had strokes in the rivaroxaban plus aspirin group than in the aspirin group (83 [0.9% per year] versus 142 [1.6% per year]; hazard ratio [HR], 0.58; 95% CI, 0.44-0.76; P<0.0001). Ischemic/uncertain strokes were reduced by nearly half (68 [0.7% per year] versus 132 [1.4% per year]; HR, 0.51; 95% CI, 0.38-0.68; P<0.0001) by the combination in comparison with aspirin. No significant difference was noted in the occurrence of stroke in the rivaroxaban alone group in comparison with aspirin: annualized rate of 0.7% (HR, 0.82; 95% CI, 0.65-1.05). The occurrence of fatal and disabling stroke (modified Rankin Scale, 3-6) was decreased by the combination (32 [0.3% per year] versus 55 [0.6% per year]; HR, 0.58; 95% CI, 0.37-0.89; P=0.01). Independent predictors of stroke were prior stroke, hypertension, systolic blood pressure at baseline, age, diabetes mellitus, and Asian ethnicity. Prior stroke was the strongest predictor of incident stroke (HR, 3.63; 95% CI, 2.65-4.97; P<0.0001) and was associated with a 3.4% per year rate of stroke recurrence on aspirin. The effect of the combination in comparison with aspirin was consistent across subgroups with high stroke risk, including those with prior stroke. CONCLUSIONS: Low-dose rivaroxaban plus aspirin is an important new antithrombotic option for primary and secondary stroke prevention in patients with clinical atherosclerosis. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov . Unique identifier: NCT01776424.