Association Between Prompt Defibrillation and Epinephrine Treatment With Long-Term Survival After In-Hospital Cardiac Arrest

Abstract

Background: Prior studies have reported higher in-hospital survival with prompt defibrillation and epinephrine treatment in patients with in-hospital cardiac arrest (IHCA). Whether this survival benefit persists after discharge is unknown.

Methods: We linked data from a national IHCA registry with Medicare files and identified 36 961 patients ≥65 years of age with an IHCA at 517 hospitals between 2000 and 2011. Patients with IHCA caused by pulseless ventricular tachycardia or ventricular fibrillation were stratified by prompt (≤2 minutes) versus delayed (>2 minutes) defibrillation, whereas patients with IHCA caused by asystole or pulseless electric activity were stratified by prompt (≤5 minutes) versus delayed (>5 minutes) epinephrine treatment. The association between prompt treatment and long-term survival for each rhythm type was assessed with multivariable hierarchical modified Poisson regression models.

Results: Of 8119 patients with an IHCA caused by ventricular tachycardia or ventricular fibrillation, the rate of 1-year survival was higher in those treated with prompt defibrillation than with delayed defibrillation (25.7% [1466 of 5714] versus 15.5% [373 of 2405]; adjusted relative risk [RR], 1.49; 95% confidence interval [CI] 1.32-1.69; P<0.0001). This survival advantage persisted at 3 years (19.1% versus 11.0%; adjusted RR, 1.45; 95% CI, 1.23-1.69; P<0.0001) and at 5 years (14.7% versus 7.9%; adjusted RR, 1.50; 95% CI, 1.22-1.83; P<0.0001). Of 28 842 patients with an IHCA caused by asystole/pulseless electric activity, the rate of 1-year survival with prompt epinephrine treatment was higher than with delayed treatment (5.4% [1341 of 24 885] versus 4.3% [168 of 3957]; adjusted RR, 1.20; 95% CI, 1.02-1.41; P=0.02), but this survival benefit was no longer present at 3 years (3.5% versus 2.9%; adjusted RR, 1.17; 95% CI, 0.95-1.45; P=0.15) and at 5 years (2.3% versus 1.9%; adjusted RR, 1.18; 95% CI, 0.88-1.58; P=0.27).

Conclusions: Prompt defibrillation for IHCA caused by ventricular tachycardia or ventricular fibrillation was associated with higher rates of long-term survival throughout 5 years of follow-up, whereas prompt epinephrine treatment for asystole/pulseless electric activity was associated with greater survival at 1 year but not at 3 or 5 years. By quantifying the greater survival associated with timely defibrillation and epinephrine administration, these findings provide important insights into the durability of survival benefits for 2 process-of-care measures in current resuscitation guidelines.

Keywords: electric countershock; heart arrest; survival.

Figure 1. Study Cohort

Figure 2. Survival curves for patients with pulseless VT or VF arrests, according to promptness of defibrillation

Survival curves during the first year are depicted in the inset figure. (p-values obtained using log-rank test)

Figure 3. Survival curves for patients with asystole or PEA arrests, according to promptness of epinephrine administration

Survival curves during the first year are depicted in the inset figure. (p-values obtained using log-rank test)