Blood pressure reduction in hypertensive acute ischemic stroke patients does not affect cerebral blood flow
Bibliographic record
Abstract
The effect of blood pressure (BP) reduction on cerebral blood flow (CBF) in acute ischemic stroke is unknown. We measured regional CBF with perfusion-weighted MRI before and after BP treatment in a three-armed non-randomized prospective controlled trial. Treatment arm assignment was based on acute mean arterial pressure (MAP). Patients with (MAP) >120 mmHg ( n = 14) were treated with intravenous labetalol and sublingual (SL) nitroglycerin (labetalol group). Those with MAP 100–120 mmHg ( n = 17) were treated with SL nitroglycerin (0.3 mg) (‘NTG Group’) and those with baseline MAP<100 mmHg ( n = 18) were not treated with antihypertensive drugs (untreated group). Forty-nine patients (18 female, mean age 65.3 ± 12.9 years) were serially imaged. Labetalol reduced MAP by 12.5 (5.7–17.7) mmHg, p = 0.0002. MAP remained stable in the NTG (6.0 (0.4–16, p = 0.3) mmHg and untreated groups (−0.3 (−2.3–7.0, p = 0.2) mmHg. The volume of total hypoperfused tissue (CBF<18 ml/100 g/min) did not increase after labetalol (−1.1 ((−6.5)–(−0.2)) ml, p = 0.1), NTG (0 ((−1.5)–4.5) ml, p = 0.72), or no treatment 0.25 ((−10.1)–4.5) ml, p = 0.87). Antihypertensive therapy, based on presenting BP, in acute stroke patients was not associated with an increased volume of total hypoperfused tissue.
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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) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
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".