Abstract 61: Reperfusion Beyond 4.5 Hours Reduces Infarct Growth And Improves Clinical Outcome
Bibliographic record
Abstract
Background and purpose: The ECASS 3 study demonstrated efficacy of intravenous thrombolysis up to 4.5h after stroke onset. It has been hypothesized that some patients have tissue at risk and an acceptably low hemorrhage risk beyond 4.5h. Imaging based selection may help identify these patients for late reperfusion therapies. No randomized data have shown efficacy of tPA or reperfusion later than 4.5h after onset. We analysed the Echoplanar Imaging Thrombolytic Evaluation Trial (EPITHET) data to assess the effect of treatment and reperfusion on attenuation of infarct growth in the 4.5 to 6 hour time window. Methods: Patients were randomized to placebo or tissue plasminogen activator (tPA) between 4.5-6h from stroke onset (without using imaging selection criteria). Pre-treatment DWI and day 90 T2-weighted lesion volumes (average of manually outlined lesions by 2 independent raters) were compared to assess the influence of tPA and reperfusion on absolute and relative infarct growth. Day 3 volume was used when day 90 data was missing. The effect of tPA on reperfusion was also assessed. Good clinical outcome was defined as a National Institute of Health Stroke Scale (NIHSS) at day 90 0-1 or improvement ≥ 8 from baseline. Good functional outcome was defined as modified Rankin Scale (mRS) 0-2. Results: Of 69 patients treated 4.5-6hrs hours after stroke onset, infarct growth could be assessed in 63. The median relative growth was significantly lower in the tPA group compared to placebo (0.94 vs 1.68, p=0.025). There was a nonsignificant trend towards lower absolute growth (-0.17mL vs 9.56mL, p=0.069). Reperfusion markedly reduced relative (0.80 vs 1.89, p<0.001) and absolute infarct growth (-2.49mL vs 39.50mL, p<0.001). Reperfusion was more likely in the tPA group (57.7 vs 25.0% p=0.026) and was associated with better clinical and functional outcomes (86.4% vs 28.1% p<0.001 and 72.7 vs 34.4% p=0.012). Conclusion: Thrombolysis after 4.5 hours reduced infarct growth and increased the rate of reperfusion. The strong positive effect of reperfusion on clinical and functional outcomes in this later time window is evidence of persisting salvageable ischemic penumbra. This supports continuing efforts to extend the treatment window for reperfusion therapies.
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 | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.001 | 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) | 0.012 | 0.002 |
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".