The Utility of Therapeutic Hypothermia for Post-Cardiac Arrest Syndrome Patients With an Initial Non-Shockable Rhythm
Background—Therapeutic hypothermia (TH) attenuates reperfusion injury in comatose survivors of cardiac arrest. The utility of TH in patients with non-shockable initial rhythms has not been widely accepted. We sought to determine whether TH improved neurologic outcome and survival in post-arrest patients with non-shockable rhythms.
Methods and Results—We identified 519 patients after in- and out-of-hospital cardiac arrest with non-shockable initial rhythms from the Penn Alliance for Therapeutic Hypothermia (PATH) registry between 2000-2013. Propensity score matching was used. Patient and arrest characteristics used to estimate the propensity to receive TH were age, sex, location of arrest, witnessed arrest, and duration of arrest. To determine the association between TH and outcomes, we created two multivariable logistic models controlling for confounders. Of 201 propensity score matched pairs, mean age was 63±17 years; 51% were male; and 60% had an initial rhythm of pulseless electrical activity. Survival to hospital discharge was greater in patients who received TH (17.6% vs. 28.9%; p<0.01), as was discharge CPC of 1-2 (13.7% vs 21.4%; p= 0.04). In adjusted analyses, patients who received TH were more likely to survive (OR 2.8, 95% CI: 1.6-4.7) and have better neurologic outcome (OR 3.5, 95% CI: 1.8-6.6) than those that did not receive TH.
Conclusions—Using propensity score matching, we found patients with non-shockable initial rhythms treated with TH had better survival and neurologic outcome at hospital discharge than those who did not receive TH. Our findings further support the use of TH in patients with initial non-shockable arrest rhythms.
- Received March 3, 2015.
- Revision received August 25, 2015.
- Accepted September 10, 2015.