Direct Intra-Arterial Thrombectomy in Order to Revascularize Acute Ischemic Stroke Patients With Large Vessel Occlusion Efficiently in Chinese Tertiary Hospitals - DIRECT-MT

Jun 11, 2020
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Author/Summarized by Author:
Dharam J. Kumbhani, MD, SM, FACC
Summary Reviewer:
Deepak L. Bhatt, MD, MPH, MBA, FACC
Trial Sponsor:
National Health Commission of China and the Wu Jieping Medical Foundation
Date Published:
05/20/2020
Date Updated:
06/11/2020
Original Posted Date:
06/11/2020
References

Contribution To Literature:

The DIRECT-MT trial showed that among patients with acute ischemic stroke presenting within 4.5 hours of symptom onset due to proximal large arterial occlusion, the use of direct endovascular treatment was noninferior to endovascular treatment along with intravenous thrombolysis.

Description:

The goal of the trial was to compare the role of preprocedural thrombolytic therapy among patients with acute ischemic stroke with large-vessel occlusion who were scheduled to undergo endovascular thrombectomy.

Study Design

Patients with acute ischemic stroke presenting within 4.5 hours of symptom onset were randomized to endovascular thrombectomy along with intravenous alteplase (n = 329) or endovascular thrombectomy alone (n = 327). Alteplase was administered at a dose of 0.9 mg/kg (10% as bolus, 90% infused over 1 hour), with a maximum dose of 90 mg. A stent retriever was the primary device for thrombectomy; aspiration devices could be used as a secondary option if the initial reperfusion failed. Intra-arterial alteplase (maximum dose, 30 mg) or urokinase (maximum dose, 400,000 U) was accepted as rescue therapy in both groups, at the discretion of the treating physician.

  • Total screened: 1,586
  • Total number of enrollees: 656
  • Duration of follow-up: 90 days
  • Mean patient age: 69 years
  • Percentage female: 43%

Inclusion criteria:

  • Age ≥18 years
  • Acute ischemic stroke
  • Occlusion of the intracranial segment of the internal carotid artery (ICA) (both terminus and nonterminus occlusions) or of the first (M1) or proximal second (M2) segment of the middle cerebral artery (MCA), or both, as shown on computed tomographic angiography (CTA), that could be treated with intravenous alteplase within 4.5 hours after symptom onset
  • National Institutes of Health Stroke Scale (NIHSS) score ≥2

Exclusion criteria:

  • Disability before the stroke
  • Any contraindication to intravenous alteplase according to the American Heart Association (AHA)/American Stroke Association (ASA) guidelines

Other salient features/characteristics:

  • NIHSS score (median): 17
  • Median ASPECTS value: 9
  • Onset to tissue plasminogen activator (tPA): 135 minutes
  • Door-to-needle time: 45 minutes
  • Site of occlusion: ICA 31%, MCA-M1: 54%, M2 15%

Principal Findings:

The primary outcome, median modified Rankin scale score at 90 days for endovascular vs. endovascular + alteplase: 3 vs. 3 (hazard ratio 1.07, 95% confidence interval 0.81- 1.40; p for noninferiority = 0.04)

Secondary outcomes (for endovascular vs. endovascular + alteplase):

  • Median NIHSS at 5-7 days of discharge: 8 vs. 8
  • Expanded treatment in cerebral infarction (eTICI) score of 2b, 2c, or 3 on final angiogram: 79.4 vs. 84.5
  • Death: 17.7% vs. 18.8% (p = 0.71)
  • Symptomatic intracranial hemorrhage (ICH): 4.3% vs. 6.1% (p = 0.3)

Interpretation:

Among patients with acute ischemic stroke presenting within 4.5 hours of symptom onset due to proximal large arterial occlusion, the use of direct endovascular treatment was noninferior to endovascular treatment along with intravenous thrombolysis. Successful reperfusion prior to thrombectomy was low overall, but higher among patients also receiving alteplase; however, final eTICI scores were similar with the two strategies. As expected, bleeding complications, including symptomatic ICH were numerically higher with the combination strategy. These are interesting findings, and suggest that it may be possible to forgo concomitant thrombolytics for patients who are within the appropriate time period and with appropriate anatomy for endovascular treatment.

It is unclear if these findings can be generalized to Western populations, as well as in the setting of more contemporary devices, such as aspiration catheters, and more potent thrombolytics such as tenecteplase. In many ways, this discussion is analogous to the facilitated percutaneous coronary intervention discussion for patients with ST-segment elevation myocardial infarction. It is also unclear if the use of adjunctive thrombolytics could extend the window for treatment beyond 4.5 hours.

References:

Yang P, Zhang Y, Zhang L, et al., on behalf of the DIRECT-MT Investigators. Endovascular Thrombectomy With or Without Intravenous Alteplase in Acute Stroke. N Engl J Med 2020; 382:1981-93.

Clinical Topics: Cardiac Surgery, Dyslipidemia, Invasive Cardiovascular Angiography and Intervention, Prevention, Stable Ischemic Heart Disease, Vascular Medicine, Aortic Surgery, Cardiac Surgery and Arrhythmias, Cardiac Surgery and SIHD, Lipid Metabolism, Novel Agents, Interventions and Vascular Medicine, Chronic Angina

Keywords: Brain Ischemia, Coronary Occlusion, Endovascular Procedures, Fibrinolytic Agents, Intracranial Hemorrhage, Traumatic, Reperfusion, ST Elevation Myocardial Infarction, Stroke, Thrombectomy, Tissue Plasminogen Activator, Secondary Prevention, Urokinase-Type Plasminogen Activator, Vascular Diseases


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