Early reperfusion and clinical outcomes in patients with M2 occlusion: pooled analysis of the PROACT II, IMS, and IMS II studies

Object. The role of endovascular therapy in patients with acute ischemic stroke and a solitary M-2 occlusion remains unclear. Through a pooled analysis of 3 interventional stroke trials, the authors sought to analyze the impact of successful early reperfusion of M-2 occlusions on patient outcome. Methods. Patients with a solitary M-2 occlusion were identified from the Prolyse in Acute Cerebral Thromboembolism (PROACT) II, Interventional Management of Stroke (IMS), and IMS II trial databases and were divided into 2 groups: successful reperfusion (thrombolysis in cerebral infarction [TICI] 2-3) at 2 hours and failed reperfusion (TICI 0-1) at 2 hours. Baseline characteristics and clinical outcomes were compared. Results. Sixty-three patients, 40 from PROACT II and 23 from IMS and IMS II, were identified. Successful early angiographic reperfusion (TICI 2-3) was observed in 31 patients (49.2%). No statistically significant difference in the rates of intracerebral hemorrhage (60.9% vs 47.6%,p = 0.55) or mortality (19.4% vs 15.6%, p = 0.75) was observed. However, there was a trend toward higher incidence of symptomatic hemorrhage in the TICI 2-3 group (17.4% vs 0%, p = 0.11). There was also a trend toward higher baseline glucose levels in this group (151.5 mg/dl vs 129.6 mg/dl, p = 0.09). Despite these differences, the rate of functional independence (modified Rankin Scale Score 0-2) at 3 months was similar (TICI 2-3, 58.1% vs TICI 0-1, 53.1%; p = 0.80). Conclusions. A positive correlation between successful early reperfusion and clinical outcome could not be demonstrated for patients with M-2 occlusion. Irrespective of reperfusion status, such patients have better outcomes than those with more proximal occlusions, with more than 50% achieving functional independence at 3 months.