Gadolinium-Enhanced Extracranial MRA Prior to Mechanical Thrombectomy Is Not Associated With an Improved Procedure Speed

Objectives: To assess whether performing a pre-intervention gadolinium-enhanced extracranial magnetic resonance angiogram (MRA) in addition to intracranial vascular imaging is associated with improved thrombectomy time metrics.Methods: Consecutive patients treated by MT at a large comprehensive stroke center between January 2012 and December 2017 who were screened using pre-intervention MRI were included. Patients characteristics and procedural data were collected. Univariate and multivariate analysis were performed to compare MT speed, efficacy, complications, and clinical outcomes between patients with and without pre-intervention gadolinium-enhanced extracranial MRA.Results: A total of 912 patients were treated within the study period, including 288 (31.6%) patients with and 624 (68.4%) patients without extracranial MRA. Multivariate analysis showed no significant difference between groups in groin puncture to clot contact time (RR = 0.93 [0.85–1.02], p = 0.14) or to recanalization time (RR = 0.92 [0.83–1.03], p = 0.15), rates of successful recanalization (defined as a mTICI 2b or 3, RR = 0.93 [0.62–1.42], p = 0.74), procedural complications (RR = 0.81 [0.51–1.27], p = 0.36), and good clinical outcome (defined by a mRS ≤ 2 at 3 months follow-up, RR = 1.05 [0.73–1.52], p = 0.79).Conclusion: Performing a pre-intervention gadolinium-enhanced extracranial MRA in addition to non-contrast intracranial MRA at stroke onset does not seem to be associated with a delay or shortening of procedure times

Neutrophil activation in patients treated with endovascular therapy is associated with unfavorable outcomes and mitigated by intravenous thrombolysis

International audienceBackground Accumulating evidence indicates that neutrophil activation (NA) contributes to microvascular thromboinflammation in acute ischemic stroke (AIS) due to a large vessel occlusion. Preclinical data have suggested that intravenous thrombolysis (IVT) before endovascular therapy (EVT) could dampen microvascular thromboinflammation. In this study we investigated the association between NA dynamics and stroke outcome, and the impact of IVT on NA in patients with AIS treated with EVT. Methods A single-center prospective study was carried out, including patients treated with EVT for whom three blood samples (before, within 1 hour, 24 hours post-EVT) were drawn to measure plasma myeloperoxidase (MPO) concentration as a marker of NA. Unfavorable outcome was defined as a modified Rankin score of 3–6 at 3 months. Results Between 2016 and 2020, 179 patients were included. The plasma MPO concentration peaked significantly 1 hour post-EVT (median increase 21.0 ng/mL (IQR −2.1–150)) and returned to pre-EVT baseline values 24 hours after EVT (median change from baseline −0.8 ng/mL (IQR −7.6–6.7)). This peak was strongly associated with unfavorable outcomes at 3 months (aOR 0.53 (95% CI 0.34 to 0.84), P=0.007). IVT before EVT abolished this 1 hour post-EVT MPO peak. Changes in plasma MPO concentration (baseline to 1 hour post-EVT) were associated with unfavorable outcomes only in patients not treated with IVT before EVT (aOR 0.54 (95% CI 0.33 to 0.88, P=0.013). However, we found no significant heterogeneity in the associations between changes in plasma MPO concentration and outcomes. Conclusions A peak in plasma MPO concentration occurs early after EVT and is associated with unfavorable outcomes. IVT abolished the post-EVT MPO peak and may modulate the association between NA and outcomes

Visual assessment of diffusion weighted imaging infarct volume lacks accuracy and reliability

International audiencePurpose The DAWN trial (Diffusion weighted imaging or CT perfusion Assessment with clinical mismatch in the triage of Wake-up and late presenting strokes undergoing Neurointervention with Trevo) has demonstrated the benefits of thrombectomy in patients with unknown or late onset strokes, using automated software (RAPID) for measurement of infarct volume. Because RAPID is not available in all centers, we aimed to assess the accuracy and repeatability of visual infarct volume estimation by clinicians and the consequences for thrombectomy decisions based on the DAWN criteria. Materials and methods 18 physicians, who routinely depend on MRI for acute stroke imaging, assessed 32 MR scans selected from a prospective databaseover two independent sessions. Raters were asked to visually estimate the diffusion weighted imaging (DWI) infarct volume for each case. Sensitivity, specificity, and accuracy of the estimated volumes were compared with the available RAPID measurements for various volume cut-off points. Thrombectomy decisions based on DAWN criteria with RAPID measurements and raters’ visual estimates were compared. Inter-rater and intra-rater agreement was measured using kappa statistics. Results The mean accuracy of raters was <90% for all volume cut-points. Inter-rater agreement was below substantial for each DWI infarct volume cut-off points. Intra-rater agreement was substantial for 55–83% of raters, depending on the selected cut-off points. Applying DAWN criteria with visual estimates instead of RAPID measurements led to 19% erroneous thrombectomy decisions, and showed a lack of reproducibility. Conclusion The visual assessment of DWI infarct volume lacks accuracy and repeatability, and could lead to a significant number of erroneous decisions when applying the DAWN criteria