Effect of definition and methods on estimates of prevalence of large vessel occlusion in acute ischemic stroke: a systematic review and meta-analysis

Abstract

IntroductionAccurate estimation of the incidence of large vessel occlusion (LVO) is critical for planning stroke systems of care and approximating workforce requirements. This systematic review aimed to estimate the prevalence of LVO among patients with acute ischemic stroke (AIS), with emphasis on definitions and methods used by different studies.MethodsA systematic literature review was performed to search for articles on the prevalence of LVO and AIS. All articles describing the frequency of LVO frequency among AIS patients were included. Studies without consecutive recruitment or confirmation of LVO with CT angiography or MR angiography were excluded. Heterogeneity of the studies was assessed; meta-regression was performed to estimate the effect of LVO definition and study methods on LVO prevalence.Results18 articles met the inclusion criteria: 5 studies presented population based estimates; 13 provided single hospital experiences (5 prospective, 8 retrospective). The AIS denominator (number of all AIS) from which LVO rates were generated was variable. Nine different definitions were used, based on occlusion site. Significant heterogeneity existed among the studies (I2=99%, P<0.001). The prevalence of LVO among patients with suspected AIS ranged from 13% to 52%. Overall prevalence was 30.0% (95% CI 25.0% to 35.0%). Pooled prevalence of LVO among suspected AIS patients was 21% (95% CI 19% to 30%). Based on meta-regression, the method of AIS denominator determination significantly influenced heterogeneity (P=0.018).ConclusionThe heterogeneity of LVO estimates was remarkably high. The method of AIS denominator determination was the most significant predictor of LVO estimates. Studies with a standardized LVO definition and methods of AIS estimation are necessary to estimate the true prevalence of LVO among patients with AIS.

Mechanical thrombectomy versus intravenous thrombolysis for distal large-vessel occlusion: a systematic review and meta-analysis of observational studies

“…Nevertheless, classifying the M 2 vessel is especially challenging due to its diverse branching patterns and highly heterogeneous angioarchitecture across patients. 31 In this meta-analysis, we did not include M 2 in our distal vessel definition. The nature of the M 2 occlusions could have been "proximal, large" M 2 that is similar to M 1 , rather than "distal, small" M 2 .…”

Mechanical Thrombectomy Access for All? Challenges in Increasing Endovascular Treatment for Acute Ischemic Stroke in the United States

“…LVOs account for approximately 30% of all patients with acute ischemic stroke 9 with studies showing prevalence ranging from 15% to 52%. 10 Yet approximately only 3.1% of acute ischemic stroke patients received MT in 2016. 11 This number increased to 8.4 % among patients treated at 176 endovascular centers in 2018.…”

Recanalization Therapy for Acute Ischemic Stroke with Large Vessel Occlusion: Where We Are and What Comes Next?

“…Acute ischemic stroke (AIS) persists as one of the leading causes of long-term disability and mortality both in the United States and globally despite significant advances in stroke care in the past three decades [1]. Large vessel occlusion (LVO) is determined as the underlying etiology in approximately 30-40% of ischemic strokes [2,3], contributing to 60% of post-stroke dependence and death at 90 days and 90% of post-stroke mortality at 6 months [4]. The first line standard of care for patients with AIS within 4.5 h of symptom onset remains intravenous thrombolysis [5,6].…”