Abstract 17541: Impact of Therapeutic Hypothermia on Hemodynamics and Prognosis of Acute Coronary Syndrome After Resuscitation From Out-of-hospital Cardiac Arrest

Abstract

Backgrounds: Although therapeutic hypothermia is recommended for neurologically unconscious patients after resuscitation from cardiac arrest, few data exist regarding clinical management during therapeutic hypothermia in acute coronary syndrome (ACS), requiring emergent coronary intervention. Therefore, we analyzed the impact of hypothermia on hemodynamics and prognosis of unconscious ACS patients. Methods and Results: We investigated consecutive 21 ACS patients (16 men, mean age 62.8±9.1) who were unconscious and induced hypothermia after resuscitation from out-of-hospital cardiac arrest between April 2009 to March 2014. Invasive hemodynamic monitoring with a pulmonary artery catheter was used during hypothermia with the target body temperature 34°C. ACS was diagnosed with emergent coronary angiography before or during cooling in all cases, and 18 patients had underwent emergent percutaneous coronary intervention. Average required time for the target body temperature from cardiac arrest were 6.8±2.6 hours. During hypothermia, mean blood pressure and cardiac index decreased significantly from 91.3 to 72.7 mmHg and 2.5 to 1.5 l/min/m2, respectively (p<0.05), except for 5 patients with percutaneous cardiopulmonary support (PCPS). Under these conditions, 14 patients had hypokalemia and required potassium replacement and 7 patients had anemia and required a transfusion of red cell concentrates. Therapeutic hypothermia was discontinued early in 8 patients (fatal arrhythmia or circulatory instability in 5 patients, death in 3 patients with PCPS). Average length of stay in our hospital was 26.9 days (1-75 days). Importantly, 8 patients had a good functional outcome as defined by a cerebral performance category scale (CPC) 1-2, 7 patients had CPC 4 at the time of discharge, although there were still 6 death cases. Interestingly, of 8 patients with hypothermia early discontinued, 6 patients (75%) had a good functional outcome (CPC 1-2). Shorter time until return of spontaneous circulation was the most significant factor for a good neurological outcome. Conclusions: These results demonstrate that with hypothermia the outcome of ACS was favorable as far as maintaining hemodynamic state, probably due to less occurrence of fatal arrhythmias.