Univariate comparison of high-volume centers performing intra-arterial stroke therapies with lower volume centers
| Variable | High-volume center (N=280) N (%) | Lower volume center (N=162) N (%) | p Value |
| Demographics | |||
| Age (mean±SD) | 65±15 | 67±14 | 0.09 |
| Women | 133 (48) | 91 (56) | 0.09 |
| Hypertension | 206 (74) | 125 (77) | 0.49 |
| Atrial fibrillation | 102 (43) | 54 (33) | 0.47 |
| Diabetes mellitus | 65 (23) | 41 (25) | 0.64 |
| Mean±SD NIHSS | 17±5 | 18±6 | 0.53 |
| Location of thrombus | |||
| M1 MCA | 194 (69) | 114 (70) | 0.91 |
| M2 MCA | 32 (11) | 22 (14) | 0.34 |
| Carotid terminus | 49 (18) | 29 (18) | 0.89 |
| Tandem occlusion | 35 (13) | 12 (7) | 0.11 |
| Clinical variables | |||
| Intravenous t-PA administered | 134 (48) | 61 (38) | 0.04 |
| Outside hospital transfer | 180 (64) | 50 (31) | 0.0001 |
| Successful reperfusion | 212 (76) | 92 (57) | 0.001 |
| Good clinical outcome (N=390) | 109/236 (46) | 49/154 (32) | 0.009 |
| Symptomatic hemorrhage | 21 (8) | 12 (7) | 0.65 |
| Asymptomatic hemorrhage | 82 (29) | 57 (35) | 0.12 |
| Median (IQR) infarct volume (cm3) (N=352 patients) | 41 (20–106) | 57 (27–140) | 0.03 |
| Timings for each step | |||
| Mean±SD time from symptom onset to CT acquisition (min) | 317±174 | 194±135 | 0.19 |
| Mean±SD CT acquisition to groin puncture (min) | 89±64 | 153±82 | 0.002 |
| Mean±SD groin puncture to guide catheter run (min) | 12±7 | 28±27 | 0.001 |
| Mean±SD first injection to microcatheter placement (min) | 20±16 | 32±28 | 0.001 |
| Mean±SD total procedure time (min) | 92±47 | 125±62 | 0.003 |
MCA, middle cerebral artery; NIHSS, NIH Stroke Scale; t-PA, tissue plasminogen activator.