Endovascular thrombectomy with or without systemic thrombolysis?

Abstract

Objectives: Current recommendations advocate that pretreatment with intravenous thrombolysis (IVT) should first be offered to all eligible patients with emergent large vessel occlusion (ELVO) before an endovascular thrombectomy (ET) procedure. However, there are observational data that question the safety and efficacy of IVT pretreatment in patients with ELVO.

Methods: We performed a meta-analysis of the included subgroups from ET randomized controlled trials (RCTs) to evaluate the comparative efficacy between direct ET without IVT pretreatment and bridging therapy (IVT and ET) in patients with ELVO.

Results: We included a total of seven RCTs, including 1764 patients with ELVO (52.8% men). Patients receiving bridging therapy (IVT followed by ET) had lower rates (p = 0.041) of 90-day death/severe dependency (modified Rankin Scale-score of 5-6; 19.0%, 95% CI: 14.1-25.1%) compared with patients receiving only ET (31.0%, 95% CI: 21.2-42.9%). Moreover, patients receiving IVT and ET had a nonsignificant (p = 0.389) trend towards higher 90-day functional independence rates (51.4%, 95% CI: 42.5-60.1%) compared with patients undergoing only ET (41.7%, 95% CI: 24.1-61.7%). Finally, shift-analysis uncovered a nonsignificant trend towards functional improvement at 90 days for bridging therapy over ET (cOR = 1.28, 95% CI: 0.91-1.89; p = 0.155). It should be noted that patients included in the present meta-analysis were not randomized to receive IVT, and thus the two groups (bridging therapy versus ET monotherapy) may differ in terms of baseline characteristics and, in particular, in terms of onset to groin puncture time and thus the risk of confounding bias cannot be ruled out.

Conclusion: Despite the limitations and the risk of confounding bias, our findings contradict the recent notion regarding potential equality between ET and bridging therapy in ELVO patients and suggest that IVT and ET are complementary therapies that should be pursued in a parallel and noncompeting fashion.

Keywords: acute ischemic stroke; emergent large vessel occlusion; intravenous thrombolysis; mechanical thrombectomy; meta-analysis.

Figure 1.

Flow chart presenting the selection procedure of eligible studies. ELVO, emergent large vessel occlusion; ET, endovascular thrombectomy; IA, intra-arterial; IVT: intravenous thrombolysis.

Figure 2.

Risk of bias (a) summary that reviews authors’ judgments about each risk of bias item for each included study and (b) graph that reviews authors’ judgments about each risk of bias item presented as percentages across all included studies.

Figure 3.

Subgroup analyses of the percentages of patients with death or severe dependency (three-month mRS-scores of 5–6) stratified by pretreatment with IVT. All patients were randomized in the ET group of the included seven randomized controlled clinical trials. ET, endovascular thrombectomy; IVT, intravenous thrombolysis;

Figure 4.

Subgroup analyses of the percentages of patients with functional independence (3-month mRS-scores of 0–2) stratified by pretreatment with IVT. All patients were randomized in the ET group of the included seven randomized controlled clinical trials. ET, endovascular thrombectomy; IVT, intravenous thrombolysis;

Figure 5.

Distribution of mRS scores at 90 days in patients randomized in the ET group of the included seven randomized controlled clinical trials, stratified by pretreatment with IVT. ET, endovascular thrombectomy; IVT, intravenous thrombolysis.