Off-hour effect on time metrics and clinical outcomes in endovascular treatment for large vessel occlusion: A systematic review and meta-analysis

Background There is an ongoing debate on the off-hour effect on endovascular treatment (EVT) for acute large vessel occlusion (LVO). Aim This meta-analysis aimed to compare time metrics and clinical outcomes of acute LVO patients who presented/were treated during off-hour with those during working hours. Summary of review Structured searches on the PubMed, Embase, Web of Science, and Cochrane Library databases were conducted through 23 February 2021. The primary outcomes were onset to door (OTD), door to imaging, door to puncture (DTP), puncture to recanalization, procedural time, successful recanalization, symptomatic intracranial hemorrhage (SICH), mortality in hospital, good prognosis (90-day modified Rankin Scale (mRS) score 0-2), and 90-day mortality. The secondary outcomes were imaging to puncture (ITP), onset to puncture (OTP), onset to recanalization (OTR), door to recanalization (DTR) time, mRS 0-2 at discharge, and consecutive 90-day mRS score. The odds ratio (OR) and weighted mean difference (WMD) with 95% confidence interval (CI) of the outcomes were calculated using random-effect models. Heterogenicity and publication bias were analyzed. Subgroup and sensitivity analyses were conducted as appropriate. Nineteen studies published between 2014 and 2021 with a total of 14,185 patients were eligible for quantitative synthesis. Patients in the off-hour group were significantly younger than those in the on-hour group and with comparable stroke severity and intravenous thrombolysis rate. The off-hour group had longer OTD (WMD [95% CI], 12.83 [1.84-23.82] min), DTP (WMD [95% CI], 11.45 [5.93-16.97] min), ITP (WMD [95% CI], 10.39 [4.61-16.17] min), OTP (WMD [95% CI], 25.30 [13.11-37.50] min), OTR (WMD [95% CI], 25.16 [10.28-40.04] min), and DTR (WMD [95% CI], 18.02 [10.01-26.03] min) time. Significantly lower successful recanalization rate (OR [95% CI], 0.85 [0.76-0.95]; p = 0.004; I-2 = 0%) was detected in the off-hour group. No significant difference was noted regarding SICH and prognosis. But a trend toward lower OR of good prognosis was witnessed in the off-hour group (OR [95% CI], 0.92 [0.84-1.01]; p = 0.084; I-2 = 0%). Conclusions Patients who presented/were treated during off-hour were associated with excessive delays before the initiation of EVT, lower successful reperfusion rate, and a trend toward worse prognosis when compared with working hours. Optimizing the workflows of EVT during off-hour is needed.