Abstract P64: The First Documented Cardiac Arrest Rhythm in Patients with Heart Failure
Background: Heart failure (HF) patients have abnormal cellular anatomy and myocardial mechanics that may impact the initial heart rhythm and subsequent outcomes in cardiac arrest (CA).
Hypothesis: Patients with pre-existing HF are less likely to have ventricular fibrillation/pulseless ventricular tachycardia (VF/pVT) as the first documented heart rhythm in CA and have poorer survival than patients without prior HF.
Purpose: Identify the first documented rhythm in hospitalized patients with and without a history of HF who experience a CA.
Methods: We evaluated 60,389 consecutive, adult, index, pulseless CA events from 426 hospitals participating in the National Registry of Cardiopulmonary Resuscitation from 1/1/2000 through 11/30/2005. The primary endpoint was the first documented CA rhythm. Secondary endpoints were the % of patients treated with defibrillation, return of spontaneous circulation (ROSC), and survival to discharge. Chi square and the Student t-test were used for comparison of descriptive variables. We estimated propensity scores using a non-parsimonious, logistic regression model to determine secondary outcomes.
Results: Thirty three percent of patients had a pre-existing diagnosis of HF. More HF patients were female (42.8 vs. 41.5%, p= .002) and had a history of prior arrest (8.2 vs. 7.0%, p= .00001). HF patients were more likely to have VF/pVT (27.3 vs. 22.4%) and less likely to have asystole (36.2 vs. 39.7%) (p= .00001) than patients without HF. There was no difference in ROSC (58.5 vs. 54%, p= .09) (95% CI 1.041, 0.99 – 1.09), survival to discharge (17.9 vs. 17.1%, p= .39) (95% CI 1.027, 0.96 – 1.09), and good neurological outcomes (82.2 vs. 83.7%, p= .07) between the groups. In patients with acute myocardial infarction as a precipitating cause of the CA, HF patients were less likely to have VF/pVT (29.8 vs. 39.1%) and more likely to have asystole (33.6 vs. 24.9%) (p= .000001). Females were less likely to survive a VF/pVT arrest than males in both HF (24.9 vs. 29.1%) and no HF (20.3 vs. 23.9%) (p= .000001) categories.
Conclusion: HF patients are more likely to have VF/pVT as a presenting rhythm in CA than non-HF patients but overall survival and neurological outcomes are no different than hospitalized arrest patients without HF.