Rapid Assessment of Blood Pressure Variability and Outcome After Successful Thrombectomy

Background and Purpose: High blood pressure (BP) variability after endovascular stroke therapy is associated with poor outcome. Conventional BP variability measures require long recordings, limiting their utility as a risk assessment tool to guide clinical decision-making. Here, we performed rapid assessment of BP variability by spectral analysis and evaluated its association with early clinical improvement and long-term functional outcomes. Methods: We conducted a prospective study of 146 patients with anterior circulation ischemic stroke who underwent successful endovascular stroke therapy. Spectral analysis of 5-minute recordings of beat-to-beat BP was used to quantify BP variability. Outcomes included initial clinical response and modified Rankin Scale at 90 days. Results: Increased BP variability at high frequencies was independently associated with poor functional outcome at 90 days (adjusted odds ratio [aOR], 1.85 [95% CI, 1.07–3.25], P =0.03; low-/high-frequency ratio aOR, 0.67 [95% CI, 0.46–0.92], P =0.02) and reduced likelihood of an early neurological recovery (aOR, 0.62 [95% CI, 0.44–0.91], P =0.01 and aOR, 1.37 [95% CI, 1.03–1.87], P =0.04, respectively). Conclusions: High-frequency BP oscillations after successful reperfusion may be harmful and associate with a decreased likelihood of neurological recovery and favorable functional outcomes. Rapid assessment of BP variability throughout the postreperfusion period is feasible and may allow for a more personalized BP management.

Utilization and Availability of Advanced Imaging in Patients With Acute Ischemic Stroke

Background: Recent clinical trials have established the efficacy of endovascular stroke therapy and intravenous thrombolysis using advanced imaging, particularly computed tomography perfusion (CTP). The availability and utilization of CTP for patients and hospitals that treat acute ischemic stroke (AIS), however, is uncertain. Methods: We performed a retrospective cross-sectional analysis using 2 complementary Medicare datasets, full sample Texas and 5% national fee-for-service data from 2014 to 2017. AIS cases were identified using International Classification of Diseases , Ninth Revision and International Classification of Diseases , Tenth Revision coding criteria. Imaging utilization performed in the initial evaluation of patients with AIS was derived using Current Procedural Terminology codes from professional claims. Primary outcomes were utilization of imaging in AIS cases and the change in utilization over time. Hospitals were defined as imaging modality–performing if they submitted at least 1 claim for that modality per calendar year. The National Medicare dataset was used to validate state-level findings, and a local hospital-level cohort was used to validate the claims-based approach. Results: Among 50 797 AIS cases in the Texas Medicare fee-for-service cohort, 64% were evaluated with noncontrast head CT, 17% with CT angiography, 3% with CTP, and 33% with magnetic resonance imaging. CTP utilization was greater in patients treated with endovascular stroke therapy (17%) and intravenous thrombolysis (9%). CT angiography (4%/y) and CTP (1%/y) utilization increased over the study period. These findings were validated in the National dataset. Among hospitals in the Texas cohort, 100% were noncontrast head CT–performing, 77% CT angiography–performing, and 14% CTP-performing in 2017. Most AIS cases (69%) were evaluated at non-CTP–performing hospitals. CTP-performing hospitals were clustered in urban areas, whereas large regions of the state lacked immediate access. Conclusions: In state-wide and national Medicare fee-for-service cohorts, CTP utilization in patients with AIS was low, and most patients were evaluated at non-CTP–performing hospitals. These findings support the need for alternative means of screening for AIS recanalization therapies.

Stroke Imaging Selection Modality and Endovascular Therapy Outcomes in the Early and Extended Time Windows

Background and Purpose: Advanced imaging has been increasingly used for patient selection in endovascular stroke therapy. The impact of imaging selection modality on endovascular stroke therapy clinical outcomes in extended time window remains to be defined. We aimed to study this relationship and compare it to that noted in early-treated patients. Methods: Patients from a prospective multicentric registry (n=2008) with occlusions involving the intracranial internal carotid or the M1- or M2-segments of the middle cerebral arteries, premorbid modified Rankin Scale score 0 to 2 and time to treatment 0 to 24 hours were categorized according to treatment times within the early (0–6 hour) or extended (6–24 hour) window as well as imaging modality with noncontrast computed tomography (NCCT)±CT angiography (CTA) or NCCT±CTA and CT perfusion (CTP). The association between imaging modality and 90-day modified Rankin Scale, analyzed in ordinal (modified Rankin Scale shift) and dichotomized (functional independence, modified Rankin Scale score 0–2) manner, was evaluated and compared within and across the extended and early windows. Results: In the early window, 332 patients were selected with NCCT±CTA alone while 373 also underwent CTP. After adjusting for identifiable confounders, there were no significant differences in terms of 90-day functional disability (ordinal shift: adjusted odd ratio [aOR], 0.936 [95% CI, 0.709–1.238], P =0.644) or independence (aOR, 1.178 [95% CI, 0.833–1.666], P =0.355) across the CTP and NCCT±CTA groups. In the extended window, 67 patients were selected with NCCT±CTA alone while 180 also underwent CTP. No significant differences in 90-day functional disability (aOR, 0.983 [95% CI, 0.81–1.662], P =0.949) or independence (aOR, 0.640 [95% CI, 0.318–1.289], P =0.212) were seen across the CTP and NCCT±CTA groups. There was no interaction between the treatment time window (0–6 versus 6–24 hours) and CT selection modality (CTP versus NCCT±CTA) in terms of functional disability at 90 days ( P =0.45). Conclusions: CTP acquisition was not associated with better outcomes in patients treated in the early or extended time windows. While confirmatory data is needed, our data suggests that extended window endovascular stroke therapy may remain beneficial even in the absence of advanced imaging.