1. Thrombectomy in Acute Stroke
Christopher J. White, MD, MSCAI
Prof and Chairman of Medicine
Ochsner Medical Center

2. Disclosures: Stroke Intervention
Christopher J. White MD
Research: None.
Speakers: Nada.
Stock: Zero.
Consultant: Nothing.

3. Ischemic Stroke Therapy
PATIENT SELECTION
IV Thrombolysis
≤ 4.5 hrs from onset.
Widely available.
Restricted population.
No bleed on CT.
SBP < 185 mmHg
DBP < 110 mmHg
Low bleeding risk.
Mechanical Thrombectomy
≤ 6 hrs from onset.
ASPECTS > 6.
Large vessel occlusion.
Disabling strokes (NIHSS > 5).
MCA occlusion.
Speech impaired.
Vision impaired.

4. NINDS Trial 10x 624 pts randomized within 3 hrs.
National Institute of Neurological Disorders and Stroke rt-PA Study Group M2
BASELINE
624 pts randomized within 3 hrs.
Placebo
Rt-PA 0.9 mg/kg (max 90 mg) over 1 hr.
Neurological assessment
TPA increased full recovery rate 21% to 34% (32% relative) at 3 months (OR=1.7 (95%CI ) p= 0.008).
Mortality not different between groups.
IC bleed rt-PA 6.4% vs 0.6% (p < 0.001).
IV-tPA
10x
NEJM 1995;333:

5. EARLY TRIALS: Mechanical Thrombectomy
The initial trials did not demonstrate conclusive benefit for endovascular therapy, although there were promising signals.
There seemed to be a balance between early and effective mechanical reperfusion with the risk of intracranial hemorrhage (ICH) that was related to reperfusion of nonviable brain.
MERCI
MR RESCUE
SYNTHESIS EXP
IMS-III

6. Interventional Management of Stroke
IMS-III: Early Trials
Interventional Management of Stroke
No benefit for MT ± IV-TPA vs. IV-TPA in moderate to severe acute ischemic stroke.
However, there were significant weaknesses.
CTA was not required, which allowed the inclusion of patients who did not have intracranial large-vessel occlusion.
First generation MT devices used.
Merci Retriever

7. PARADIGM SHIFT MR CLEAN ESCAPE EXTEND IA SWIFT PRIME REVASCAT
Between December 2014 and April 2015, 5 RCTS provided compelling evidence that mechanical thrombectomy (MT) improves outcomes after acute ischemic stroke.
MT significantly improved clinical outcome in patients with proximal intracranial occlusion of the anterior circulation compared with IV t-PA.
MR CLEAN
ESCAPE
EXTEND IA
SWIFT PRIME
REVASCAT

8. EVOLUTION OF STROKE Rx
The major differences between these positive endovascular trials and past trials were:
CTA to select patients with LVO.
Select viable brain (penumbra).
Stent retrievers for thrombectomy.
Papanagiotou P. and White C. J Am Coll Cardiol Intv. 2016; 9(4):307–17.

9. Strategy: Early Treatment
Time to Rx
Reperfusion Flow
(A) Relationship between onset to intra-arterial therapy/reperfusion and NNT in patients undergoing EVT among second- and third-generation endovascular trials. The NNT to have good outcome decreases with rapid treatment times. (B) Relationship between good reperfusion (TICI 2b) score and NNT among second- and third-generation trials. IA = intra-arterial; IMS = Interventional Management of Stroke; MR CLEAN = Multicenter Randomized Clinical Trial of Endovascular Treatment for Acute Ischemic Stroke in the Netherlands; MR RESCUE = Mechanical Retrieval and Recanalization of Stroke Clots Using Embolectomy; NNT = number needed to treat; TICI = Thrombolysis In Cerebral Infarction; other abbreviations as in Figure 4.
Khandelwal P, et al. J Am Coll Cardiol 2016;67:2631–44.

10. Strategy: Effective Reperfusion
Good Reperfusion
Good Neurologic Outcomes
NNT
(A) Relationship between onset to intra-arterial therapy/reperfusion and NNT in patients undergoing EVT among second- and third-generation endovascular trials. The NNT to have good outcome decreases with rapid treatment times. (B) Relationship between good reperfusion (TICI 2b) score and NNT among second- and third-generation trials. IA = intra-arterial; IMS = Interventional Management of Stroke; MR CLEAN = Multicenter Randomized Clinical Trial of Endovascular Treatment for Acute Ischemic Stroke in the Netherlands; MR RESCUE = Mechanical Retrieval and Recanalization of Stroke Clots Using Embolectomy; NNT = number needed to treat; TICI = Thrombolysis In Cerebral Infarction; other abbreviations as in Figure 4.
Khandelwal P, et al. J Am Coll Cardiol 2016;67:2631–44.

11. META-ANALYSIS
Pooled estimates for achieving modified Rankin Scale (mRS) 0-2 outcomes with Endovascular Recanalization Therapy vs. Control.
Pooling all RCT’s (SWIFT PRIME [Solitaire with the Intention for Thrombectomy as Primary Endovascular Treatment], ESCAPE [Endovascular Treatment for Small Core and Anterior Circulation Proximal Occlusion With Emphasis on Minimizing CT to Recanalization Times], EXTEND-IA [Extending the Time for Thrombolysis in Emergency Neurological Deficits—Intra-Arterial], REVASCAT [Randomized Trial of Revascularization with Solitaire FR Device versus Best Medical Therapy in the Treatment of Acute Stroke Due to Anterior Circulation LVO Presenting within Eight Hours of Symptom Onset]), adjusted for age, sex, baseline stroke severity, site of occlusion, intravenous alteplase treatment, carotid occlusion, Alberta Stroke Program CT Score, and time from onset to treatment to randomization. Reprinted with permission from Campbell et al. (31). ASPECTS = Alberta Stroke Program Early CT Score; CI = confidence interval; ICA = internal carotid artery; MCA = middle cerebral artery; NIHSS = National Institute of Health Stroke Scale.
Hong KS, et al. J Stroke Sep; 17(3): 268–281

12. OPTIMAL MANAGEMENT OF ACUTE ISCHEMIC STROKE
SUMMARY
OPTIMAL MANAGEMENT OF ACUTE ISCHEMIC STROKE
Onset to Rx ≤ 6hrs
Shorter times to reperfusion.
Improved patient selection.
Better thrombectomy devices.
Aspects ≥ 6
NIHSS ≥ 5
Large Vessel Occlusion
Stent Retrievers
Khandelwal P, et al. J Am Coll Cardiol 2016;67:2631–44.