CT-angiography source images indicate less fatal outcome despite coma of patients in the Basilar Artery International Cooperation Study.

Background Coma is associated with poor outcome in patients with basilar artery occlusion. Aims We sought to assess whether the posterior circulation Acute Stroke Prognosis Early CT Score and the Pons-Midbrain Index applied to CT angiography source images predict the outcome of comatose patients in the Basilar Artery International Cooperation Study. Methods Basilar Artery International Cooperation Study was a prospective, observational registry of patients with acute basilar artery occlusion with 48 recruiting centers worldwide. We applied posterior circulation Acute Stroke Prognosis Early CT Score and Pons-Midbrain Index to CT angiography source images of Basilar Artery International Cooperation Study patients who presented with coma. We calculated adjusted risk ratios to assess the association of dichotomized posterior circulation Acute Stroke Prognosis Early CT Score (≥8 vs. <8) and Pons-Midbrain Index (<3 vs. ≥3) with mortality and favourable outcome (modified Rankin Scale score 0-3) at one month. Results Of 619 patients in the Basilar Artery International Cooperation Study registry, CT angiography source images were available for review in 158 patients. Among these, 78 patients (49%) presented with coma. Compared to non-comatose patients, comatose patients were more likely to die (risk ratios 2.34; CI 95% 1.56-3.52) and less likely to have a favourable outcome (risk ratios 0.44; CI 95% 0.24-0.80). Among comatose patients, a Pons-Midbrain Index < 3 was related to reduced mortality (adjusted RR 0.66; 95% CI 0.46-0.96), but not to favourable outcome (adjusted RR 1.19; 95% CI 0.39-3.62). Posterior circulation Acute Stroke Prognosis Early CT Score dichotomized at ≥ 8 vs. <8 was not significantly associated with death (adjusted RR 0.70; 95% CI 0.46-1.05). Conclusion In comatose patients with basilar artery occlusion, the extent of brainstem ischemia appears to be related to mortality but not to favourable outcome.

Collateral flow predicts outcome after basilar artery occlusion: The posterior circulation collateral score.

BACKGROUND AND AIM: Our aim was to assess the prognostic value of a semiquantitative computed tomography angiography-based grading system, for the prediction of outcome in patients with acute basilar artery occlusion, based on the presence of potential collateral pathways on computed tomography angiography: the posterior circulation collateral score (PC-CS). METHODS: One hundred forty-nine patients with acute basilar artery occlusion from the Basilar Artery International Cooperation Study were included. We related poor outcome at one month, defined as a modified Rankin scale score of 4 or 5, or death to collateral flow with Poisson regression. We used a 10 points grading system to quantify the potential for collateral flow in the posterior communicating arteries and the cerebellar arteries. Additionally, the relation between the presence and size of posterior communicating arteries and outcome was analyzed. RESULTS: Thirty-six patients had poor (PC-CS: 0-3), 59 patients intermediate (PC-CS: 4-5), and 54 patients good (PC-CS: 6-10) collaterals. Multivariable analyses showed a statistically significant lower risk of poor outcome in patients with a good PC-CS than in patients with a poor PC-CS (risk ratio (RR): 0.74, 95% confidence interval (CI): 0.58-0.96), but not for patients with an intermediate PC-CS compared with patients with a poor PC-CS (RR: 0.95, 95% CI: 0.78-1.15). Multivariable analyses showed a statistically significant lower risk of poor outcome for the presence of at least one posterior communicating artery and for larger caliber of posterior communicating arteries (RR: 0.79, 95% CI: 0.66-0.95 and 0.76, 95% CI: 0.61-0.96, respectively). CONCLUSIONS: The PC-CS predicted poor outcome at one month. In a separate analysis, both the absence and smaller caliber of posterior communicating arteries predicted poor outcome.

Clot length predicts recanalisation but not outcome after basilar artery occlusion.

INTRODUCTION: The aim of our study was to evaluate the effect of clot length on both recanalisation and outcome in acute basilar artery occlusion (BAO). PATIENTS AND METHODS: One hundred forty-nine patients with an acute basilar artery occlusion from the Basilar Artery International Cooperation Study (BASICS) were included. Clot length was assessed on computed tomographic angiography. Thrombus length was divided in tertiles and was related to recanalisation and outcome at 1 month, with Poisson regression. Modified Rankin scale scores of 4 or 5, or death were considered poor outcomes. Additionally, clot length was analysed as a continuous variable. RESULTS: Forty-nine patients (33%) had a short (4-11 mm), 50 (34%) an intermediate (12-22 mm), and 50 (34%) a long clot (≥23 mm). Multivariable analyses showed a significantly lower probability of recanalisation but no statistically significant difference in poor outcome for patients with a long clot compared with patients with a short clot (RR 0.64, 95% CI: 0.42-0.98 and RR 1.10, 95% CI: 0.88-1.37, respectively). No statistically significant differences were found for patients with an intermediate clot length compared with patients with a short clot length (RR 0.97, 95% CI: 0.75-1.25 and RR 1.11, 95% CI: 0.88-1.40, respectively). Analyses of clot length as a continuous variable showed a 10% reduction in chance of recanalisation and a 2% increase in risk of poor outcome with every centimeter increase in clot length (RR 0.90, 95% CI: 0.78-1.04 and RR 1.02, 95% CI: 0.98-1.05, respectively). CONCLUSIONS: Clot length predicted recanalisation but not outcome at 1 month in patients with a BAO. We found 2% more poor outcome and 10% less recanalisation with every centimeter increase in clot length.