1. “Cool It”: Therapeutic Hypothermia for
Recovery of Neurologic Function in
High Risk Patients Following Cardiac Arrest
Leah A. Swanson, Kalie M. Edelstein, William M. Parham,
Jon S. Hokanson, Richard F. Shronts, Barbara T. Unger, Wendy B. George,
Ivan J. Chavez, Timothy D. Henry, Michael R. Mooney
Minneapolis Heart Institute Foundation
Abbott Northwestern Hospital
March 29, 2009

2. Presenter Disclosure Information
Leah Swanson
The following relationships exist related to this presentation:
No relationships to disclose

3. Cardiac Arrest
• Out-of-hospital cardiac arrest (OOHCA)
• 295,000 people annually in the US
• 7.9% median survival rate
• Anoxic encephalopathy and neurologic deficits
• Therapeutic hypothermia (TH) clinical trials
• ILCOR recommendation for TH after resuscitation
Lloyd-Jones D, Adams R, Carnethon M et al. Heart disease and stroke statistics-2009 update. Circulation 2009;119:e21-e181.

4. Hypothermia History
• 1950s - cardiac and neurologic surgeries
• Late 1950s - after cardiac arrest
 uncertain benefits
 difficulties with implementation
• 1990s - studies in animal models
 histological benefits
 functional benefits
• 2002 - randomized clinical trials of TH

5. Mechanisms
hypothermia ischemia
lower glutamate excitotoxicity
metabolic rate release
inflammatory
cascades
less oxygen calcium shifts
consumption cell death
blood brain barrier
reperfusion mitochondrial disruption & cerebral
dysfunction edema
oxygen-free radicals
Geocadin RG, Koenig MA, Jia X et al. Management of brain injury after resuscitation from cardiac arrest. Neurol Clin. 2008;22:487-506.

6. HACA Study Group
• Randomized trial 2002 -hypothermia vs normothermia
• Methods
 Inclusion - OOHCA due to VF
 Exclusion – cardiogenic shock
3351
• Hypothermia group assessed
 32 C - 34 C 3246 30 275
ineligible not included enrolled
 cooled for 24 hrs
 rewarming over 8 hrs 137 138
hypothermia normothermia
The Hypothermia after Cardiac Arrest Study Group. Mild therapeutic hypothermia to improve the neurologic outcome after cardiac
arrest. N Engl J Med. 2002;346:549-556.

7. HACA Study Group
• Neurologic outcome
• Pittsburgh cerebral performance category scale
Cerebral Performance Category (CPC)
CPC 1 Good cerebral performance
Positive Outcomes
CPC 2 Moderate cerebral disability
CPC 3 Severe cerebral disability
Negative Outcomes
CPC 4 Coma or vegetative state
CPC 5 Brain death

8. HACA Study Outcomes
Survival and Neurologic Outcome at Discharge
Hypothermia Normothermia
Survival 87/137 (64%) 69/138 (50%)
Favorable neurologic
64/134 (47%) 42/135 (31%)
outcome

9. “Cool It” Methods
Level 1 Heart Attack Program – STEMI transfers
“Cool It” Program - regional TH system - Feb 2006
Inclusion Exclusion
 non-traumatic OOHCA  comatose before arrest
 ROSC within 60 min  DNR
 unresponsive  active bleeding
 cardiogenic shock
 all ages

10. “Cool It” Methods
• Transfer patients
 standardized protocols
 ice during transfer
• STEMI – immediate
angiography and PCI
• Arctic Sun® TH device
• Target temperature 33 C for 24 hrs
• Rewarming at 0.5 C/hr
• Cerebral function at discharge

12. “Cool It” Patient Demographics
• 103 patients (Feb 2006-Oct 2008)
• 78 male, 25 female
Asystole
• Average age 62 years PEA
• 76% transferred Vtach Vfib
• 50% “Cool It” & STEMI
• 40% cardiogenic shock

13. “Cool It” Outcomes
HACA Non-HACA
criteria P
All Patients criteria
(PEA, asystole, Value
(VT & VF) shock)
Total
103 52 51
Number
Survival at
58 (56%) 38 (73%) 20 (39%) 0.0007
Discharge

14. “Cool It” vs. HACA Survivors
"Cool It" 70%
n =58 8.6%
23.8%
HACA 60%
n=84
50%
% of Survivors
40%
30%
20%
10%
0%
CPC 1 CPC 2 CPC 3 CPC 4
Neurologic Outcome at Discharge

15. Methods Comparison
HACA “Cool It”
Cooling Activation
Shivering Prevention
Protocol Cooling Activation
Protocol
Shivering Prevention
• no prehospital cooling • target temp – as soon as
••
•
emergency
Pancuronium
mattress cooling device •• possible in the field,
field, referring
Atracurium
• ice packs
department hospital, in transfer
• referring hospital, or in
•• target temp
IV bolus every two
randomization •• Infusion - – early
education TOF
transfer
• ice packs after 4 hrs • Arctic Sun® cooling device
hrs monitoring& initiation
recognition

16. “Cool It” vs. HACA Cooling
ROSC to
Target Temp
800 720
Arctic Sun to 700
Target Temp
600
Time ( minutes)
ROSC to
Arctic Sun
500
400 309
relative
300
hazard
estimate 200
= 1.25 100
(for 1 hr
delay to TH) 0
HACA n=136 "Cool It" n=103

17. Summary
• “Cool It” protocol applied TH to high risk
patients
 cardiogenic shock
 PEA & asystole
• “Cool It” TH enhanced survival in HACA
criteria patients
• “Cool It” TH preserved neurologic and
functional status in a broader patient
population
• “Cool It” survivors discharged with
higher neurologic outcomes
• “Cool It” patients cooled to target
temperature in less time

18. Conclusions
• OOHCA is a significant health issue
• TH is a markedly underutilized treatment
• “Cool It” TH program
 high survival rate
 high quality of life and cognitive and functional abilities
• “Cool It” TH - early & organized treatment
 standardized protocols
 outstate education
 rapid & early initiation of TH
 multidisciplinary team
 data collection and feedback
• TH can effectively be applied to a higher risk patient population
than previously examined
• Neuroprotective adjunct to regional STEMI programs

19. Thank You!