Alberta Stroke Program Early CT Score applied to CT angiography source images is a strong predictor of futile recanalization in acute ischemic stroke.

INTRODUCTION: Reliable predictors of poor clinical outcome despite successful revascularization might help select patients with acute ischemic stroke for thrombectomy. We sought to determine whether baseline Alberta Stroke Program Early CT Score (ASPECTS) applied to CT angiography source images (CTA-SI) is useful in predicting futile recanalization. METHODS: Data are from the FUN-TPA study registry (ClinicalTrials.gov; NCT02164357) including patients with acute ischemic stroke due to proximal arterial occlusion in anterior circulation, undergoing reperfusion therapies. Baseline non-contrast CT and CTA-SI-ASPECTS, time-lapse to image acquisition, occurrence, and timing of recanalization were recorded. Outcome measures were NIHSS at 24 h, symptomatic intracranial hemorrhage, modified Rankin scale score, and mortality at 90 days. Futile recanalization was defined when successful recanalization was associated with poor functional outcome (death or disability). RESULTS: Included were 110 patients, baseline NIHSS 17 (IQR 12; 20), treated with intravenous thrombolysis (IVT; 45 %), primary mechanical thrombectomy (MT; 16 %), or combined IVT + MT (39 %). Recanalization rate was 71 %, median delay of 287 min (225; 357). Recanalization was futile in 28 % of cases. In an adjusted model, baseline CTA-SI-ASPECTS was inversely related to the odds of futile recanalization (OR 0.5; 95 % CI 0.3-0.7), whereas NCCT-ASPECTS was not (OR 0.8; 95 % CI 0.5-1.2). A score ≤5 in CTA-SI-ASPECTS was the best cut-off to predict futile recanalization (sensitivity 35 %; specificity 97 %; positive predictive value 86 %; negative predictive value 77 %). CONCLUSIONS: CTA-SI-ASPECTS strongly predicts futile recanalization and could be a valuable tool for treatment decisions regarding the indication of revascularization therapies.

Good Clinical and Radiological Correlation from Standard Perfusion Computed Tomography Accurately Identifies Salvageable Tissue in Ischemic Stroke.

INTRODUCTION: It has been debated whether the penumbral pattern, as identified using multimodal imaging, is a specific marker of tissue viability in ischemic stroke. We assessed whether perfusion computed tomography (PCT) accurately identifies salvageable tissue and helps predict postreperfusion outcomes. METHODS: A retrospective study of patients with anterior circulation stroke undergoing reperfusion therapies who had a PCT before treatment and an assessment of vessel recanalization post treatment was conducted. Tissue at risk was considered as that with reduced cerebral blood flow, whereas the infarct core was the region of reduced cerebral blood volume, the mismatch region being salvageable tissue. The volume of hypodensity in slices corresponding to perfusion acquisition cage in 24-hour computed tomography (partial lesion volume [PLV]) was measured. Outcome variables were the amount of preserved tissue, that is, the difference between volumes of tissue at risk and PLV expressed as a percentage, and the modified Rankin Scale (mRS) score at 3 months. RESULTS: Patients (n = 34) meeting the inclusion criteria were included. Vessel recanalization was associated with a larger amount of tissue at risk preserved from definite lesion (89% [interquartile range {IQR}: 76-94] versus 46% [IQR: 23-86], P < .005). The amount of preserved tissue correlated with clinical outcome at 24 hours: for each 10% of preserved tissue, the National Institutes of Health Stroke Scale score improved by 3 points (95% confidence interval [CI]: -4.9 to -.8, P = .007) and was the only predictor of independency (mRS score 0-2) following adjustment for covariates (odds ratio 1.15, 95% CI: 1.04-1.28, P = .005). CONCLUSIONS: PCT provides accurate markers of viability of tissue in acute ischemic stroke and could help predict the degree of improvement following reperfusion.

Mechanical thrombectomy in patients with medical contraindications for intravenous thrombolysis: a prospective observational study.

BACKGROUND AND PURPOSE: The present study was conducted with the objective of evaluating the safety of primary mechanical thrombectomy (MT) in patients with large vessel occlusion (LVO) stroke and comorbidities that preclude treatment with IV thrombolysis (IVT), compared with patients who received standard IVT treatment followed by MT. Secondary objectives were to analyse the recanalization rate and outcomes. METHODS: A prospective observational multicenter study (FUN-TPA) that recruited patients treated within 4.5 hours of symptom onset was performed. Treatments were IVT followed by MT if occlusion persisted, or primary MT when IVT was contraindicated. Outcome measures were procedural complications, symptomatic intracranial hemorrhage (SICH), recanalization rate, National Institutes of Health Stroke Scale (NIHSS) score at 7 days, modified Rankin Scale (mRS) score and mortality at 90 days. RESULTS: Of 131 patients, 21 (16%) had medical contraindications for IVT and were treated primarily with MT whereas 110 (84%) underwent IVT, followed by MT in 53 cases (40%). The recanalization rate and procedural complications were similar in the two groups. There were no SICHs after primary MT vs 3 (6%) after IVT+MT. Nine patients (43%) in the primary MT group achieved independence (mRS 0-2) compared with 36 (68%) in the IVT+MT group (p=0.046). Mortality rates in the two groups were 14% (n=3) vs 4% (n=2) (p=0.13). Adjusted ORs for independence in patients receiving standard IVT+MT vs MT in patients with medical contraindications for IVT were 2.8 (95% CI 0.99 to 7.98) and 0.24 (95% CI 0.04 to 1.52) for mortality. CONCLUSIONS: MT is safe in patients with potential comorbidity-derived risks that preclude IVT. MT should be offered, aiming for prompt recanalization, to patients with LVO stroke unsuitable for IVT. TRIAL REGISTRATION NUMBER: NCT02164357; Results.

Mechanical thrombectomy for basilar artery thrombosis: a comparison of outcomes with anterior circulation occlusions.

BACKGROUND AND PURPOSE: The benefits of mechanical thrombectomy (MT) in basilar artery occlusions (BAO) have not been explored in recent clinical trials. We compared outcomes and procedural complications of MT in BAO with anterior circulation occlusions. METHODS: Data from the Madrid Stroke Network multicenter prospective registry were analyzed, including baseline characteristics, procedure times, procedural complications, symptomatic intracranial hemorrhage (SICH), modified Rankin Scale (mRS), and mortality at 3 months. RESULTS: Of 479 patients treated with MT, 52 (11%) had BAO. The onset to reperfusion time lapse was longer in patients with BAO (median (IQR) 385 min (320-540) vs 315 min (240-415), p<0.001), as was the duration of the procedures (100 min (40-130) vs 60 min (39-90), p=0.006). Moreover, the recanalization rate was lower (75% vs 84%, p=0.01). A trend toward more procedural complications was observed in patients with BAO (32% vs 21%, p=0.075). The frequency of SICH was 2% vs 5% (p=0.25). At 3 months, patients with BAO had a lower rate of independence (mRS 0-2) (40% vs 58%, p=0.016) and higher mortality (33% vs 12%, p<0.001). The rate of futile recanalization was 50% in BAO versus 35% in anterior circulation occlusions (p=0.05). Age and duration of the procedure were significant predictors of futile recanalization in BAO. CONCLUSIONS: MT is more laborious and shows more procedural complications in BAO than in anterior circulation strokes. The likelihood of futile recanalization is higher in BAO and is associated with greater age and longer procedure duration. A refinement of endovascular procedures for BAO might help optimize the results.