Effect of alteplase on the development of symptomatic infarct swelling by change in HAS between baseline and follow-up
| Baseline HAS | Changes in HAS at follow-up | Alteplase n/N* | Control n/N* | Effect of alteplase on development of infarct swelling, OR (95% CI) | P value for interaction |
| Presence (n=673) | Persistent (n=324) | 28/152 | 18/172 | 1.93 (1.02 to 3.66) | 0.62; d.f.=1 |
| Disappeared (n=349) | 9/198 | 5/151 | 1.39 (0.46 to 4.24) | ||
| Subtotal | 37/350 | 23/323 | 1.54 (0.89 to 2.66) | ||
| Absence (n=2057) | Newly developed (n=196) | 8/90 | 5/106 | 1.97 (0.62 to 6.25) | 0.98; d.f.=1 |
| None (n=1861) | 21/957 | 10/904 | 2.01 (0.94 to 4.28) | ||
| Subtotal | 29/1047 | 15/1010 | 1.89 (1.01 to 3.55) | ||
| Total | NA | 66/1397 | 38/1333 | 1.69 (1.13 to 2.54) | 0.96; d.f.=3 |
*N or n=number of patients in each subgroup of morphological changes in HAS presence, n/N: n=number of patients with infarct swelling.
d.f., degree of freedom; HAS, hyperdense artery sign; NA, not applicable.