Prospective Multicenter Study of Changes in MTT after Aneurysmal SAH and Relationship to Delayed Cerebral Ischemia in Patients with Good- and Poor-Grade Admission Status

BACKGROUND AND PURPOSE: Patients with aneurysmal SAH and good clinical status at admission are considered at a lower risk for delayed cerebral ischemia. Prolonged MTT may be associated with an increased risk. It is unclear whether this is dependent on clinical status. Our purpose was to determine whether increased MTT within 3 days of aneurysmal SAH compared with baseline is associated with a higher risk of delayed cerebral ischemia in patients with good (World Federation of Neurosurgical Societies I–III) versus poor (World Federation of Neurosurgical Societies IV–V) admission status.

MATERIALS AND METHODS: This prolonged MTT was a multicenter, prospective cohort investigation of 87 patients with aneurysmal SAH. MTT was measured at admission before aneurysm treatment (MTT1) and following repair (MTT2) within 3 days of admission; MTT_diff was calculated as the difference between MTT2 and MTT1. Changes in MTT across time were assessed with repeated measures analyses. Risk of delayed cerebral ischemia or death was determined with multivariate logistic regression analysis.

RESULTS: In patients with a good grade (n = 49), MTT was prolonged in patients who developed delayed cerebral ischemia, with MTT_diff significantly greater (0.82 ± 1.5) compared with those who did not develop delayed cerebral ischemia (−0.14 ± 0.98) (P = .03). Prolonged MTT was associated with a significantly higher risk of delayed cerebral ischemia or death (OR = 3.1; 95% CI, 1.3–7.4; P = .014) on multivariate analysis. In patients with poor grades (n = 38), MTT_diff was not greater in patients who developed delayed cerebral ischemia; MTT1 was significantly prolonged compared with patients with a good grade.

CONCLUSIONS: Patients in good clinical condition following aneurysmal SAH but with increasing MTT in the first few days after aneurysmal SAH are at high risk of delayed cerebral ischemia and warrant close clinical monitoring.