Abstract 117: Mild Induced Hypothermia and Emergency Percutaneous Coronary Intervention After Out-of-Hospital Cardiac Arrest Complicating ST-Elevation Myocardial Infarction: Long-Term Survival and Neurological Outcome
Background: Therapeutic hypothermia has been integrated into international resuscitation guidelines to improve survival after out-of-hospital cardiac arrest (OHCA). Data on long-term results are limited, especially in patients with acute ST-elevation myocardial infarction (STEMI) complicated by OHCA.
Methods: Clinical and procedural data of 48 patients who underwent percutaneous coronary intervention (PCI) for STEMI after witnessed OHCA were analysed: 24/48 patients were treated with mild induced hypothermia (MTH) and their results were compared to 24 historical controls without cooling. MTH was performed using an intravascular cooling system (CoolGard®, therapeutic temperature 34°C maintained for 24h, followed by controlled rewarming of 0.2°C/h up to 37°C). Neurological recovery was assessed using the Cerebral Performance Category score at 30-days and 1-year follow up (CPC1: complete recovery; CPC2: moderate neurological disability; CPC3: severe neurological disability; CPC4: comatose).
Results: Time delay until arrival of emergency medical service was short in both groups (6±2min in the MTH-group vs. 7±2minutes in controls, p=0.171). Initial rhythm was ventricular fibrillation in 75% of the MTH-group and in 66.7% of the controls (p=0.752). There were no differences in baseline characteristics regarding age, gender, pH, lactate and creatinine on admission, as well as in angiographic findings and procedural data. Successful PCI was performed in both groups with the same frequency (79% vs. 75%, p=1.00). 30-days mortality was 33.3% in both groups (8/24 vs. 8/24, p=1.00). 1-year mortality was 37.5% (9/24) vs. 50% (12/24), p=0.561. Good neurological outcome (CPC status ≤2) was significantly more frequent in 30-days survivors of the MTH-group (n=12/16, 75%) than in survivors of the control group (n=4/16, 25%, p<0.02). Patients who survived the first year in CPC ≤2 more frequently had received MTH (74% vs. 35%, p<0.02) and successful PCI (100 vs. 62.1%, p<0.002).
Conclusions: Mild induced hypothermia does not seem to influence 30-day mortality after out-of-hospital cardiac arrest due to STEMI. However, survivors more often present a favourable neurological outcome, which is associated with improved long-term survival.
- © 2011 by American Heart Association, Inc.