Efficacy and safety of endovascular thrombectomy in mild ischemic stroke: results from a retrospective study and meta-analysis of previous trials

Abstract

Background Mechanical thrombectomy has been proven as a standard care for moderate to severe ischemic stroke with anterior large vessel occlusion (LVO); however, whether it is equally effective in mild ischemic stroke (MIS) is controversial. Methods In this retrospective study, a total of 177 Chinese patients presenting with MIS (NIHSS ≤8) and LVO between January 2014 and September 2017 from seven comprehensive stroke centers were identified. Odds of good outcome with endovascular thrombectomy versus medical treatment were obtained by logistic regression analysis and propensity-score matching method, and a meta-analysis pooled results from six studies ( n = 733). Results Good outcome (mRS: 0–1) was 58.2% (46/79) in the thrombectomy and 46.9% (46/98) in the medical group, which showed no statistical significance before adjustment ( P = 0.13; OR = 1.57, 95% CI: 0.86 to 2.86). The adjusted ORs of thrombectomy versus medical group were 3.23 (95% CI, 1.35 to 7.73; P = 0.008) by multivariable logistic analysis, 2.78 (1.12 to 6.89; P = 0.02) by propensity score matching analysis, and 3.20 (1.22 to 8.37; P = 0.01) by propensity score matching analysis with additional adjustments, respectively. Thrombectomy treatment did not result in excessive mortality or symptomatic intracranial hemorrhage after adjustments. The meta-analysis did not confirm the associations between good outcome and endovascular treatment. Conclusions The current study indicates that endovascular thrombectomy is associated with good functional outcome in MIS patients with LVO, and without additional risk of symptomatic intracranial hemorrhage and mortality. Although the meta-analysis failed to demonstrate its superiority compared to medical treatment, randomized clinical trials are needed. Electronic supplementary material The online version of this article (10.1186/s12883-019-1372-9) contains supplementary material, which is available to authorized users.

More expansive horizons: a review of endovascular therapy for patients with low NIHSS scores

“…Three investigations (30%) observed significantly higher rates of sICH in patients receiving EVT (11.8 vs 0%, p=0.03), 4 (5.8% vs 0%; p=0.02), 8 (10% vs 2%; p=0.02). 12 However, the increased sICH risk observed by Shang et al was not significant after adjusting for confounders. 12 Three studies (30%) observed increased EVT asymptomatic intracranial hemorrhage (35% vs 10%, p=0.04), 10 (22% vs 3%, p=0.002), 3 (16.5% vs 6.1%, p=0.008) 11 but not sICH.…”

“…12 However, the increased sICH risk observed by Shang et al was not significant after adjusting for confounders. 12 Three studies (30%) observed increased EVT asymptomatic intracranial hemorrhage (35% vs 10%, p=0.04), 10 (22% vs 3%, p=0.002), 3 (16.5% vs 6.1%, p=0.008) 11 but not sICH. 3 10 11 Four investigations (40%) did not detect any difference in hemorrhagic complications between EVT and BMM.…”

“…We identified 10 manuscripts comparing EVT with BMM in patients with LVO-AIS and a low NIHSS score (table 2), six (60%) of which had low NIHSS defined as NIHSS score ≤5. [3][4][5][6][7][8][9][10][11][12] Additionally, four meta-analyses were identified (two, NIHSS score ≤5; two, NIHSS score ≤8). 3 12 18 19 To compare EVT with BMM in mild strokes, the functional benefits of recanalization must be weighed against the added risk of the EVT procedure.…”

“…6 In patients with an NIHSS score ≤8, Shang et al found that EVT resulted in a significantly higher likelihood of excellent outcome (OR=3.2, p=0.008); however, the metaanalysis they performed failed to confirm these associations. 12 Six manuscripts with original patient data failed to detect EVT clinical benefit in patients with a low NIHSS score. 3 4 8-11 Urra et al published the first retrospective study of low NIHSS EVT versus BMM in 2014.…”

“…2 3 The efficacy of EVT in patients with AIS-LVO and a low NIHSS score continues to be widely debated, with the literature comprising retrospective investigations that demonstrate conflicting results. [3][4][5][6][7][8][9][10][11][12] Variability in outcomes in patients with AIS and a low NIHSS score highlights the limitations of the NIHSS as a screening tool for treatment eligibility. 13 While the NIHSS is predictive of overall AIS outcome, not all low NIHSS scores are equivalent with regard to clinical outcome.…”