Abstract 235: Hypothermia Does Not Ameliorate Post-Cardiac Arrest Myocardial Dysfunction
Background: Post-cardiac arrest myocardial dysfunction (PAMD) may contribute to mortality after cardiac arrest. The degree of PAMD in out-of-hospital cardiac arrest patients treated with hypothermia is unknown.
Hypothesis: We hypothesized that in patients with known ejection fraction (EF) prior to cardiac arrest (Pre), EF would be decreased during the immediate post-cardiac arrest period (Post) and that hypothermia would mitigate this change.
Methods: Retrospective review of patients treated between 1/1/2005 and 12/31/2009 with Pre-EF and Post-EF within 24 hours of cardiac arrest. EF was measured using transthoracic echocardiogram, transesophageal echocardiogram, and ventriculogram during catheterization. Demographic data, inotropic support and temperature during echocardiogram, EF, and presence of global hypokinesis were recorded. Three month post-cardiac arrest EF was determined in a subset of subjects. Pre-EF versus Post-EF and change in EF for hypothermia were compared using Fisher's exact and Wilcoxon rank sum tests.
Results: Of 144 eligible subjects, 36 had Pre-EF available [median 30 (IQR 15, 125) weeks prior to arrest]. Mean age was 61 (SD 15) years, 17 (42%) male, and 15 (42%) with VF/VT as the primary rhythm of arrest. The majority (N=27, 75%) were comatose on arrival and 25/27 (93%) received hypothermia therapy. Median (IQR) Pre-EF was 55–60% (35–40%, 60–65%) and decreased to Post-EF of 45–50% (20–25%, 60–65%). Pre-EF and Post-EF did not differ in 23 (64%) subjects. Average EF decrease was 9.2±11% (Range 0–40%). Subjects with temperature <34°C during the echocardiogram (N=13, 36%) experienced an EF decrease of 8.5±9.4%, similar to normothermic subjects (9.6±12%; p=0.87). Subjects with temperature <34°C during the echocardiogram were not more likely to be on vasopressors (7/13, 54%) than normothermic subjects (11/23, 48%, p=0.9) Global hypokinesis was reported in both Pre (N=13, 36%) and Post (N=10, 28%) echocardiograms (p=ns). In 5 subjects, 3 month post-arrest EF was measured. The EF recovered to baseline in 4/5 subjects with a median of 35–40%.
Conclusion: PAMD was detected in 36% of subjects after cardiac arrest. In this cohort, EF decrease and vasopressor requirement did not differ between hypothermic and normothermic subjects.
- © 2010 by American Heart Association, Inc.