“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
Presenter Disclosure Information Leah SwansonThe following relationships exist related to this presentation: No relationships to disclose
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 resuscitationLloyd-Jones D, Adams R, Carnethon M et al. Heart disease and stroke statistics-2009 update. Circulation 2009;119:e21-e181.
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
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 radicalsGeocadin RG, Koenig MA, Jia X et al. Management of brain injury after resuscitation from cardiac arrest. Neurol Clin. 2008;22:487-506.
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 normothermiaThe Hypothermia after Cardiac Arrest Study Group. Mild therapeutic hypothermia to improve the neurologic outcome after cardiacarrest. N Engl J Med. 2002;346:549-556.
HACA Study Group• Neurologic outcome• Pittsburgh cerebral performance category scale Cerebral Performance Category (CPC) CPC 1 Good cerebral performancePositive Outcomes CPC 2 Moderate cerebral disability CPC 3 Severe cerebral disabilityNegative Outcomes CPC 4 Coma or vegetative state CPC 5 Brain death
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
“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
“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
Methods Comparison HACA “Cool It”Cooling ActivationShivering PreventionProtocol 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
“Cool It” vs. HACA CoolingROSC toTarget Temp 800 720Arctic Sun to 700Target Temp 600 Time ( minutes)ROSC toArctic Sun 500 400 309 relative 300 hazard estimate 200 = 1.25 100 (for 1 hrdelay to TH) 0 HACA n=136 "Cool It" n=103
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
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