Maximal Admission Core Lesion Compatible With Favorable Outcome in Acute Stroke Patients Undergoing Endovascular Procedures.

BACKGROUND AND PURPOSE

Multiparametric imaging is meant to identify nonreversible lesions and predict on admission the minimum final infarct volume, a strong predictor of outcome. We aimed to confirm this hypothesis and define the maximal admission lesion volume compatible with favorable outcome (MALCOM).

METHODS

We studied patients with internal carotid artery/middle cerebral artery occlusion selected with multiparametric computed tomography/magnetic resonance imaging, who underwent endovascular procedures. Admission infarct core was measured on initial cerebral blood volume-computed tomography perfusion or diffusion weighted imaging-magnetic resonance imaging. We defined percentage of lesion growth (final lesion admission core/admission core) and MALCOM: cutoff admission core volume above which probability of modified Rankin Scale 0 to 2 is <10%.

RESULTS

Fifty-seven patients were studied (29 magnetic resonance imaging and 28 computed tomography perfusion). Mean core volume was 28±22 mL, and recanalization thrombolysis in cerebral ischemia 2b-3 was 77%. At 24 hours, mean infarct volume was 64±97 mL, and at 3 months modified Rankin Scale 0 to 2 was 45%. Median lesion growth was smaller in recanalizers (16.7% versus 198.3%; P<0.01). MALCOM was 39 mL. When recanalization was achieved, 64% of patients within MALCOM (<39 mL) achieved favorable outcome, whereas despite recanalization only 12% of patients beyond MALCOM (>39 mL) achieved modified Rankin Scale 0 to 2 (P=0.01). A regression model adjusted for age and recanalization showed that the only predictor of favorable outcome was having admission core lesion below MALCOM (OR: 9.3, 95% CI: 1.9-46.4; P<0.01). Analysis according to imaging modality showed that computed tomography-cerebral blood volume allowed larger MALCOM (42 mL) than magnetic resonance-diffusion weighted imaging (29 mL). In octogenarians, MALCOM (15 mL) was lower in younger patients (40 mL).

CONCLUSIONS

Admission lesion core is associated with final infarct volume and is a strong predictor of favorable outcome. MALCOM according to imaging modality and patient age could be set and used on admission to select candidates for endovascular procedures.