Abstract W P60: Blood Pressure Reduction In Acute Ischemic Stroke Does Not Affect Ischemic Core Tissue Perfusion
Bibliographic record
Abstract
Introduction: Blood pressure (BP) reduction in acute ischemic stroke patients can potentially decrease cerebral blood flow (CBF) in ischemic tissue due to disrupted autoregulation, particularly in the ischemic core. We tested this hypothesis using a 3 group non-randomized controlled study of serial CBF measurements in ischemic stroke patients. Methods: Patients with acute ischemic stroke ≤72h of symptom onset were recruited. Groups were assigned according to baseline mean arterial blood pressure (MAP): patients with MAP >120mmHg were treated with intravenous labetalol and sublingual (SL) nitroglycerin and those with MAP 100-120 mmHg were treated with SL nitroglycerin. The BP reduction target was 10% of the baseline MAP. Patients with MAP<100 mmHg formed the control group. Patients underwent MR perfusion-weighted imaging (PWI) and diffusion-weighted imaging (DWI) before and after BP reduction. Blinded planimetric assessment was done to determine PWI deficits and DWI lesion volumes in the ischemic core region. Results: A total of 48 patients with mean±SD age of 65.4±13.2 years were enrolled at 23.4±15.3h after symptom onset. The mean time difference between perfusion scans was 25.6±9.5 min.Median(IQR) DWI volume was 11.1 (96.8) ml. Mean MAP was 126±7.5 mmHg in the MAP>120 group(n=13), 109.9±4.9 mmHg in the MAP 100-120 group (n=16), and 89.9±6.2 mmHg in the controls (n=19). Mean BP reduction in the treated patients was 11.9±6.7 mmHg (95% CI 15.6-3; p=0.04). Baseline mean relative CBF (rCBF) in ischemic core tissue was 1.1±0.47 in the MAP >120 group, 0.87±0.35 in the MAP 100-120 group and 0.78±0.32 in controls. The mean change in rCBF following BP reduction did not differ between the MAP >120 group (0.03±0.17), MAP 100-120 group (0.06±0.17) and controls (0.08±0.25) (p=0.28). Similarly, there was no difference in the mean relative cerebral blood volume (p=0.3) and relative mean transit time (p=0.58) before and after BP reduction. In patients treated with SL nitroglycerin (n=17), there was no improvement in mean lesional rCBF (0.04±0.17 vs.-0.02±0.18, p=0.25). Conclusion: Modest BP reduction does not lead to an immediate decrease in CBF, within the ischemic core. Acute antihypertensive therapy may be less directly harmful than has been postulated.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.002 | 0.001 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.005 | 0.001 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".