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

<bold>Background: </bold>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.<bold>Methods: </bold>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.<bold>Results: </bold>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).<bold>Conclusions: </bold>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. [ABSTRACT FROM AUTHOR]