Time for Stroke Thrombectomy…

Jason Kendall Southmead Hospital

North Bristol NHS TrustSeptember 2016

• Technology• Evidence• Clinical cases• Referral guideline

Thrombectomy for acute ischaemic stroke

• Technology• Evidence• Clinical cases• Referral guideline

Thrombectomy for acute ischaemic stroke

“Do I need a thrombectomy…?”

The technology… how does it work?

Proximal occlusion… Recanalisation

What is the evidence?

• Thrombectomy plus usual care (thrombolysis) vs usual care alone • CTA confirmation of proximal arterial occlusion in anterior cerebral circulation

+ESCAPESWIFT-PRIMEREVASCATEXTEND-IA

All published in NEJM, 2015

TRIAL AGE NIHSS TIME RADIOLOGYMR CLEAN No age limit > 2 < 6 hrs No exclusion

ESCAPE No age limit “disabling stroke” < 12 hrs ASPECTS > 6Moderate to good collaterals on CTA

SWIFT - PRIME 18-80 “moderate to severe deficit” < 6 hrs ASPECTS > 6Target mismatch penumbra

REVASCAT 18-85 > 6 < 8 hrs ASPECTS > 7

EXTEND – IA No age limit Not specified < 6 hrs Evidence of salvageable tissue on CT perfusion; Ischaemic Core < 70 mls

TRIALS inclusion criteria

What is the evidence?

TRIAL AGE NIHSS TIME RADIOLOGYMR CLEAN No age limit > 2 < 6 hrs No exclusion

ESCAPE No age limit “disabling stroke” < 12 hrs ASPECTS > 6Moderate to good collaterals on CTA

SWIFT - PRIME 18-80 “moderate to severe deficit” < 6 hrs ASPECTS > 6Target mismatch penumbra

REVASCAT 18-85 > 6 < 8 hrs ASPECTS > 7

EXTEND – IA No age limit Not specified < 6 hrs Evidence of salvageable tissue on CT perfusion; Ischaemic Core < 70 mls

TRIALS inclusion criteria

What is the evidence?

TRIAL AGE NIHSS TIME RADIOLOGYMR CLEAN No age limit > 2 < 6 hrs No exclusion

ESCAPE No age limit “disabling stroke” < 12 hrs ASPECTS > 6Moderate to good collaterals on CTA

SWIFT - PRIME 18-80 “moderate to severe deficit” < 6 hrs ASPECTS > 6Target mismatch penumbra

REVASCAT 18-85 > 6 < 8 hrs ASPECTS > 7

EXTEND – IA No age limit Not specified < 6 hrs Evidence of salvageable tissue on CT perfusion; Ischaemic Core < 70 mls

TRIALS inclusion criteria

What is the evidence?

TRIAL AGE NIHSS TIME RADIOLOGYMR CLEAN No age limit > 2 < 6 hrs No exclusion

ESCAPE No age limit “disabling stroke” < 12 hrs ASPECTS > 6Moderate to good collaterals on CTA

SWIFT - PRIME 18-80 “moderate to severe deficit” < 6 hrs ASPECTS > 6Target mismatch penumbra

REVASCAT 18-85 > 6 < 8 hrs ASPECTS > 7

EXTEND – IA No age limit Not specified < 6 hrs Evidence of salvageable tissue on CT perfusion; Ischaemic Core < 70 mls

TRIALS inclusion criteria

What is the evidence?

TRIAL AGE NIHSS TIME RADIOLOGYMR CLEAN No age limit > 2 < 6 hrs No exclusion

ESCAPE No age limit “disabling stroke” < 12 hrs ASPECTS > 6Moderate to good collaterals on CTA

SWIFT - PRIME 18-80 “moderate to severe deficit” < 6 hrs ASPECTS > 6Target mismatch penumbra

REVASCAT 18-85 > 6 < 8 hrs ASPECTS > 7

EXTEND – IA No age limit Not specified < 6 hrs Evidence of salvageable tissue on CT perfusion; Ischaemic Core < 70 mls

TRIALS inclusion criteria

What is the evidence?

TRIAL AGE NIHSS IV t-PA Efficacy outcome (mRS 90 days)MR CLEAN(N=500)

66 17 89% OR 1.67 favourable mRS shift

ESCAPE(N=316)

71 17 73% Median mRS 2 vs 4 Functional independence 53% vs 29%

SWIFT – PRIME(N=196)

66 17 100% Median mRS 2 vs 3 Functional independence 60% vs 35%

REVASCAT(N=206)

66 17 78% OR 1.7 for favourable mRS shift

EXTEND – IA(N=70)

70 17 100% Median mRS 3 vs 1

TRIALS outcome

No safety concerns in any trial

What is the evidence?

TRIAL AGE NIHSS IV t-PA Efficacy outcome (mRS 90 days)MR CLEAN(N=500)

66 17 89% OR 1.67 favourable mRS shift

ESCAPE(N=316)

71 17 73% Median mRS 2 vs 4 Functional independence 53% vs 29%

SWIFT – PRIME(N=196)

66 17 100% Median mRS 2 vs 3 Functional independence 60% vs 35%

REVASCAT(N=206)

66 17 78% OR 1.7 for favourable mRS shift

EXTEND – IA(N=70)

70 17 100% Median mRS 3 vs 1

TRIALS outcome

No safety concerns in any trial

What is the evidence?

TRIAL AGE NIHSS IV t-PA Efficacy outcome (mRS 90 days)MR CLEAN(N=500)

66 17 89% OR 1.67 favourable mRS shift

ESCAPE(N=316)

71 17 73% Median mRS 2 vs 4 Functional independence 53% vs 29%

SWIFT – PRIME(N=196)

66 17 100% Median mRS 2 vs 3 Functional independence 60% vs 35%

REVASCAT(N=206)

66 17 78% OR 1.7 for favourable mRS shift

EXTEND – IA(N=70)

70 17 100% Median mRS 3 vs 1

TRIALS outcome

No safety concerns in any trial

What is the evidence?

TRIAL AGE NIHSS IV t-PA Efficacy outcome (mRS 90 days)MR CLEAN(N=500)

66 17 89% OR 1.67 favourable mRS shift

ESCAPE(N=316)

71 17 73% Median mRS 2 vs 4 Functional independence 53% vs 29%

SWIFT – PRIME(N=196)

66 17 100% Median mRS 2 vs 3 Functional independence 60% vs 35%

REVASCAT(N=206)

66 17 78% OR 1.7 for favourable mRS shift

EXTEND – IA(N=70)

70 17 100% Median mRS 3 vs 1

TRIALS outcome

No safety concerns in any trial

What is the evidence?

TRIAL AGE NIHSS IV t-PA Efficacy outcome (mRS 90 days)MR CLEAN(N=500)

66 17 89% OR 1.67 favourable mRS shift

ESCAPE(N=316)

71 17 73% Median mRS 2 vs 4 Functional independence 53% vs 29%

SWIFT – PRIME(N=196)

66 17 100% Median mRS 2 vs 3 Functional independence 60% vs 35%

REVASCAT(N=206)

66 17 78% OR 1.7 for favourable mRS shift

EXTEND – IA(N=70)

70 17 100% Median mRS 3 vs 1

TRIALS outcome

No safety concerns in any trial

What is the evidence?

TRIAL AGE NIHSS IV t-PA Efficacy outcome (mRS 90 days)MR CLEAN(N=500)

66 17 89% OR 1.67 favourable mRS shift

ESCAPE(N=316)

71 17 73% Median mRS 2 vs 4 Functional independence 53% vs 29%

SWIFT – PRIME(N=196)

66 17 100% Median mRS 2 vs 3 Functional independence 60% vs 35%

REVASCAT(N=206)

66 17 78% OR 1.7 for favourable mRS shift

EXTEND – IA(N=70)

70 17 100% Median mRS 3 vs 1

TRIALS outcome

No safety concerns in any trial

What is the evidence?

What is the evidence?

TRIALS outcome: pooled data (n=1287)

OR = 2.49 for reduced disability at 90 days

OR = 2.71 for functional independence (mRS = 0-2) at 90 days

NNT = 2.6 for reduced mRS by 1 point at 90 days

Effect consistent across wide range of age and stroke severity

Mean time to thrombolysis = 100 mins Mean time to thrombectomy = 285 mins The Lancet, April 2016

TRIALS key message• Thrombectomy (in addition to standard care) is effective

and safe

Translation into clinical practice• Who?• When? • Where?

Trial inclusion criteria and logistics…

Case 1• 40 year old male• Awoke at 0845am with RSW and speech

problems• Last seen well before bed at midnight • Wife called ambulance and taken to ED• Dysphasia with RSW• NIHSS 17

Case 1: CT on arrival 09:24

Case 1: CTA

Case 1 angio

RecanalisationMCA occlusion

Case 1 outcome• 24 hours NIHSS = 8 (17 at presentation)

• Home with ESD (after 2 weeks)• Walking• Moderate dysphasia

Case 1 Discussion pointsHow much damage is acceptable on CTH before procedure

futile?MR CLEAN vs ESCAPE, SWIFT PRIME, REVASCAT

How important is the onset time?REVASCAT (<8hrs), ESCAPE (<12hrs) vs others (<6 hrs)

Would CTP have been useful?SWIFT PRIME, ESCAPE, EXTEND-IA

Case 2• 90 year old female, previously living independently• Admitted with PE and new AF• Started rivaroxaban

• Dense left upper limb weakness and facial weakness whilst inpatient

• NIHSS 5

Case 2: CT 60 minutes from symptom onset

Case 2 CTA

…Discrepancy betweenNIHSS and proximal MCA

occlusion

Right MCA occlusion

Collateral flow from anterior cerebral artery…

Collateral flow from anterior cerebral artery…

Collateral flow from anterior cerebral artery…

Collateral flow from anterior cerebral artery…

Initial contrast image… …several seconds later

Recanalisation (120 mins post onset)Stent across thrombus

Case 2: outcome

• NIHSS 2 at 24 hrs, neurologically independent

• Discharged to residential home

Case 2 discussion pointsIs any age too old?

Inclusion criteria varied across trials16% > 80 years old in MR CLEAN

Is any NIHSS too low?Inclusion criteria varied across trialsOutcome for “minor stroke”?

Importance of CT angiography

Case 3• 79 year old female• Background hypertension• Presented one hour after symptom onset to

DGH• NIHSS 18• Dense right sided weakness and dysphasia

Case 3: initial CT at DGH

Case 3• CTA confirmed proximal MCA occlusion• Thrombolysis and transfer• Transfer from DGH to SMD took 2 hours• On arrival dypshasia and weakness improving• NIHSS 10• Taken straight to angio suite for intervention

Case 3 Angio

Recanalisation post iv tPAContinued to improve, discharged functionally independent NIHSS = 4

Case 3 discussion points• Right decisions with right information early

CT and CTA at referring centre? Repeat imaging if situation substantially changes during transfer

• How to achieve rapid transfer?Robust referral pathwayTreat inter-hospital transfer as 999 call Consider helicopter transfer

ED referral criteria for thrombectomy

Who? No upper age limitDemonstration of major vessel occlusion on CT angiogramNIHSS = 4 or higherTime from onset to intervention within 6 hours

When / Where? Monday – Friday, 8am – 4pm, Southmead Hospital

Action: (1) Commence IV thrombolysis (if no contra-indication)(2) Call stroke physician at Southmead to arrange transfer(3) Arrange transfer to Southmead ED

Conclusions

• Thrombectomy is effective and safe• CT and CTA essential for patient selection• Longer time window for thrombectomy compared

with thrombolysis• Urgent referral and rapid transfer

Time for Stroke Thrombectomy…

Jason Kendall Southmead Hospital

North Bristol NHS TrustSeptember 2016

Basilar artery occlusion

Basil Fawlty…?

Before… …after

National (IQR) NBT (IQR)

Onset to puncture (min) 211.5 (178.5-292.5) 168.5 (150-185)

Onset to end of procedure (min) 294.5 (234.5-360.5) 275 (216-285)

Puncture to deployment (min) 22 (15-31.5) 32 (20-35)

Puncture to end of procedure (min) 61.5 (41-85) 45 (31-108)

Clock start to puncture (min) 131.5 (89-181) 88.5 (65-92)

Clock start to deployment (min) 167.5 (111-208.5) 120 (112-124)

Clock start to end of procedure (min) 201.5 (152.5-254) 200 (120-200)

NBT experience30 cases from January – August 2016

SSNAP data:

National (IQR) NBT (IQR)

Onset to puncture (min) 211.5 (178.5-292.5) 168.5 (150-185)

Onset to end of procedure (min) 294.5 (234.5-360.5) 275 (216-285)

Puncture to deployment (min) 22 (15-31.5) 32 (20-35)

Puncture to end of procedure (min) 61.5 (41-85) 45 (31-108)

Clock start to puncture (min) 131.5 (89-181) 88.5 (65-92)

Clock start to deployment (min) 167.5 (111-208.5) 120 (112-124)

Clock start to end of procedure (min) 201.5 (152.5-254) 200 (120-200)

NBT experience30 cases from January – August 2016

SSNAP data: