Background: Therapeutic hypothermia (TH) is associated with improved neurologic outcomes in comatose survivors of out-of-hospital cardiac arrest (OHCA). There are currently limited data on the outcomes of patients presenting with resuscitated OHCA in the setting of acute myocardial infarction. The aim of this study was to assess the outcomes of comatose survivors of OHCA complicating acute myocardial infarction treated with primary percutaneous coronary intervention (PCI) and TH.
Methods: A retrospective cohort analysis was performed on all consecutive patients referred for primary PCI and TH between August 2008 and December 2013 in a single center. The primary endpoint was survival to hospital discharge with sufficient neurologic recovery (defined as Cerebral Performance Category score <2).
Results: Among 886 consecutive patients referred for primary PCI, 24 were comatose survivors of OHCA complicating acute myocardial infarction. All these patients underwent primary PCI followed by TH. Median patient age was 59 (IQR 35-87) years and 11 (45.8%) patients had anterior ST-elevation myocardial infarction. Median OHCA-to-balloon time was 120 min (IQR 75-340) while median OHCA-to-TH initiation time was 250 min (IQR 180-310). Survival with sufficient neurologic recovery to enable discharge home was reached in 16 (66.7%) patients. Time between initiation of cardiopulmonary resuscitation (CPR) to return of spontaneous circulation (ROSC) <20 min was associated with a lower occurrence of death and poor neurologic outcome compared to CPR-to-ROSC time ≥20 min (15.4 vs 54.5%, p=0.05). The occurrence of major bleeding was 8.3%, while no stent thrombosis was reported.
Conclusions: TH in conjunction with primary PCI is feasible and associated with acceptable outcome in the majority of comatose survivors of OHCA complicating acute myocardial infarction, especially if CPR-to-ROSC time was <20 min. Randomized studies are needed to better assess the superiority of TH and primary PCI vs primary PCI alone in this complex subset of OHCA patients.