Objectives Rationale for IV-tPA in acute ischemic stroke The - - PDF document

1 tPA: Where are we now? What is new? New 30 Minute Door to Needle Target

• Dr. Kelvin Ng Kuan Huei MBBS MRCP

McMaster University / Hamilton Heath Sciences Stroke Program

Disclosures

None to declare

Objectives

• Rationale for IV-tPA in acute ischemic

stroke

• The expanding role for IV-tPA in acute

ischemic stroke

• Aiming for the 30 minute door to needle

target

2

Time is Brain

• For every minute delay in

treating an ischemic stroke, 1·9 million brain cells die, 13·8 billion synapses, and 12 km of axonal fibers are lost

• Each hour in which treatment

does not occur, the brain loses as many neurons as it does in almost 3.6 years of normal aging

Rationale for IV-tPA

• Two major zones of injury in

ischemic stroke

• The ischemic core
• The penumbra

(salvageable)

• The penumbra may remain

viable for several hours due to collateral flow

3

Rationale for IV-tPA

• Improves disability predominantly
• IV tPA – 11% absolute benefit compared to placebo

(NNT = 9)

• Every 15 minutes of expedited start to IV-tPA results in a

4% relative increased likelihood of independence

• In Ontario, the proportion of patients treated with

IV-tPA is ~ 12% (20-30% are estimated to be eligible)

• At HHS in 2015, 23% of all ischemic strokes received IV-

tPA

The expanding role for IV-tPA in acute ischemic stroke

• The age of patients
• The severity of the

stroke

• The extended time

window

4

tPA for ischemic stroke is effective irrespective of age with no obvious heterogenous treatment effect No evidence that age modified proportional hazards of alteplase

Aiming for the 30 minute door to needle target

Canadian Stroke Best Practice Recommendations: Hyperacute Stroke Care Guidelines, Update 2015

5 Working Together

• Seamless integration across

interprofessional teams

• Patients, paramedics, emergency

departments, stroke teams, radiology and neurointerventionalist

• Parallel processes
• Expedited CT imaging including CTA

Time is Brain: A Case Study

Time Event

5.30am 70 year old man found by wife in bathroom following collapse with left hemiplegia 7.00am EMS activated and patient assessed 7.32am Patient brought into ER 7.39am Non-contrast CT head performed. CTA aborted as patient was agitated and unable to remain still for scan due to neck pain. 8.35am CTA head performed. Decision made not for tPA and for EVT 8.45am Cerebral angiogram and EVT initiated with anaesthetist support Time Event Processes

5.30am 70 year old man found by wife in bathroom following collapse with left hemiplegia Early identification of stroke symptoms. FAST campaign EMS 7.00am EMS activated and patient assessed EMS communication Paramedic on-scene management (recognize and mobilise) Direct transport protocols and pre-alert to ER and stroke team. 7.32am Patient brought into ER Assessment by ER team for stability and expedited imaging 7.39am Non-contrast CT head performed. CTA aborted as patient was agitated and unable to remain still for scan due to neck pain. Assessment by radiology and stroke physician and EVT team informed. Transfer back to ER for monitored light sedation and C-spine assessment 8.35am CTA head performed. Decision made not for tPA and for EVT Simultaneous assessment by radiology, stroke and EVT physician 8.45am Cerebral angiogram and EVT initiated with anaesthetist support Patient transferred from CT straight to endovascular suite Neuro Stepdown team informed of new admission.

6

Objectives

• Rationale for IV-tPA in acute ischemic

stroke

• The expanding role for IV-tPA in acute

ischemic stroke

• Aiming for the 30 minute door to needle

target