| HMCAS-D (n = 831) | HMCAS-P (n = 788) | p Value | |
| TOAST subgroups (ICD-10 category) | |||
| Large vessel disease (I63.0 + I63.3) (n (%)) | 328 (41.3) | 319 (46.2) | 0.06 |
| Cardiac embolism (I63.4) (n (%)) | 332 (41.8) | 266 (38.3) | 0.2 |
| Small vessel disease (lacunar, I63.5) (n (%)) | 9 (1.1) | 6 (0.9) | 0.7 |
| Clinical course | |||
| NIHSS score at 2 h (median (IQR)) | 13 (8–18) | 17 (12–20) | <0.001 |
| NIHSS score at 24 h (median (IQR)) | 11 (4–17) | 17 (12–21) | <0.001 |
| NIHSS score at day 7 (median (IQR)) | 8 (2–15) | 15 (9–24) | <0.001 |
| Neurological improvement ⩾4 points NIHSS at 2 h (n (%)) | 274 (35.1) | 123 (17.1) | <0.001 |
| Dramatic neurological improvement at 2 h (n (%)) | 114 (14.6) | 34 (4.7) | <0.001 |
| TACI syndrome (approximate definition) (n (%)) | 397 (47.7) | 411 (52.2) | 0.08 |
| Presence of infarct on follow-up CT scan (n (%)) | 740 (89.1) | 754 (95.7) | <0.001 |
| Outcomes | |||
| mRS at day 90 (median (IQR)) | 3 (1–5) | 4 (3–6) | <0.001 |
| Independence (mRS 0–2 at day 90) (n (%)) | 296 (41.5) | 134 (19.0) | <0.001 |
| Mortality (n (%)) | 111 (15.3) | 214 (30.2) | <0.001 |
| SICH, SITS-MOST definition (%) | 1.8 | 0.6 | 0.06 |
| SICH, RCT definition (%) | 8.5 | 12.3 | 0.02 |
HMCAS-D, hyperdense middle cerebral artery sign, disappearance; HMCAS-P, hyperdense middle cerebral artery sign, persistence; mRS, median Rankin Scale score; NIHSS, National Institute of Health Stroke Scale; SICH, symptomatic intracerebral haemorrhage; ICD, International Classification of Diseases; RCT randomised controlled trial; SITS-MOST, Safe Implementation of Thrombolysis in Stroke-Monitoring Study; TACI, total anterior circulation infarct.