Mechanical thrombectomy for anterior circulation stroke: 5-year experience in a statewide service with differences in pretreatment time metrics across two hospitals sites.

Kabra, Ruchi; Phillips, Timothy J; Saw, Jacqui-Lyn; Phatouros, Constantine C; Singh, Tejinder P; Hankey, Graeme J; Blacker, David; Ghia, Darshan; Prentice, David; McAuliffe, William

OBJECTIVE To audit our institutional mechanical thrombectomy (MT) outcomes for acute anterior circulation stroke and examine the influence of workflow time metrics on patient outcomes. METHODS A database of 100 MT cases was maintained throughout May 2010-February 2015 as part of a statewide service provided across two tertiary hospitals (H1 and H2). Patient demographics, stroke and procedural details, blinded angiographic outcomes, and 90-day modified Rankin Scale (mRS) scores were recorded. The following time points in stroke treatment were recorded: stroke onset, hospital presentation, CT imaging, arteriotomy, and recanalization. Statistical analysis of outcomes, predictors of outcome, and differences between the hospitals was carried out. RESULTS Thrombolysis in Cerebral Infarction (TICI) 2b/3 reperfusion was 79%. Forty-nine per cent of patients had good clinical outcomes (mRS 0-2). In a subgroup analysis of 76 patients with premorbid mRS 0-1 and first CT performed ≤4.5 h after stroke onset, 60% had good clinical outcomes. Patient and disease characteristics were matched between the two hospitals. H1 had shorter times between hospital presentation and CT (32 vs 55 min, p=0.01), CT and arteriotomy (33 vs 69 min, p=0.00), and stroke onset and recanalization (198 vs 260 min, p=0.00). These time metrics independently predicted good clinical outcome. Median days spent at home in the first 90 days was greater at H1 (61 vs 8, p=0.04) than at H2. A greater proportion of patients treated at H1 were independent (mRS 0-2) at 90 days (54% vs 42%); however, this was not statistically significant (p=0.22). CONCLUSIONS Outcomes similar to randomized controlled trials are attainable in 'real-world' settings. Workflow time metrics were independent predictors of clinical outcome, and differed between the two hospitals owing to site-specific organizational differences.