Predictors of Intracranial Hemorrhage Volume Expansion in Patients Receiving Factor Xa Inhibitors in ANNEXA‐4: Time and Severity Matter Most
Bibliographic record
Abstract
Background Andexanet alfa, a specific reversal agent for factor Xa inhibitors, resulted in effective hemostasis in 79% of patients with intracranial bleeding in the ANNEXA‐4 (Andexanet Alfa, a Novel Antidote to the Anticoagulation Effects of Factor Xa Inhibitors) trial (NCT02329327). However, little is known about predictors associated with hematoma expansion in patients with factor Xa inhibitor–associated intracranial hemorrhage (ICrH) receiving andexanet alfa. Methods The ANNEXA‐4 trial was a prospective, single‐arm, open‐label study of andexanet alfa in patients with acute major bleeding within 18 hours after taking a factor Xa inhibitor. Hematoma volumes at baseline and 12 hours after andexanet alfa treatment were measured using a computerized‐assisted volumetric method. Univariable and multivariable logistic regression analyses of clinical and nonclinical parameters were performed to identify factors predictive of different volumes of hematoma expansion. To this end, an ICrH Expansion Scale was developed. Results Overall, 305 ANNEXA‐4 study patients with baseline and follow‐up imaging were included, 15.7% of whom showed evidence of any ICrH expansion ≥6‐mL. Patients with ≥6‐mL ICrH expansion had a significantly ( P< 0.05) higher proportion of ICrH with multiple compartment involvement (36% versus 14.3%); shorter times from symptom onset to baseline computed tomography (median, 1.6 hours [interquartile range (IQR), 1.2–4.3 hours] versus 3.7 hours [IQR, 1.6–7.0 hours]); lower Glasgow Coma Scale scores (14 [IQR, 12–15] versus 15 [IQR, 14–15]); higher systolic blood pressure 15 minutes before andexanet alfa bolus (mean, 151.6 mm Hg [SD, 24.1 mm Hg] versus 143.3 mm Hg [SD, 22.3 mm Hg]); and larger median baseline ICrH volumes (29.3 mL [IQR, 13.3–50.8 mL] versus 8.6 mL [IQR, 2.1–22.4 mL]). Multivariable analysis confirmed shorter symptom onset‐to‐computed tomography time and larger ICrH volume as independent predictors of ≥6‐mL growth and ICrH Expansion Scale change. Lower Glasgow Coma Scale showed a trend ( P = 0.06) as an independent predictor of ≥6‐mL growth but was an independent predictor of ICrH Expansion Scale change. Conclusion Shorter time from symptom onset to computed tomography, larger hematoma volumes, and lower Glasgow Coma Scale score at presentation increased the risk of ICrH expansion in patients with factor Xa inhibitor–associated ICrH treated with andexanet alfa.
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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 | 0.002 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| 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 | 0.000 | 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".