Abstract 10103: Improvement in Survival With Favorable Neurological Outcome in Elderly Japanese Patients With Out-of-Hospital Cardiac Arrest: A Nationwide Observational Cohort Study

Abstract

Introduction: Although older age is associated with worse prognosis after cardiac arrest, little is known about the improvement in survival of very elderly patients with out-of hospital cardiac arrest (OHCA). Hypothesis: We aimed to evaluate the survival trends and predictors of favorable prognosis in this population. Method: We analyzed the records of 607,147 OHCA events obtained from a prospectively collected nationwide Utstein-style Japanese database from 2008 to 2012. The end-point was 1-month survival with favorable neurological outcome (Cerebral Performance Category Scale, category 1 or 2; CPC 1-2). Results: In total, 334,730 OHCA patients aged ≥75 years were eligible for analyses. The overall 1-month CPC 1-2 rate was 0.88% (2,933/334,730). OHCA aged 75-84 years had better 1-month CPC 1-2 rate than those ≥85years (1.18% [2,067/174,781] vs 0.54% [866/159,949], p <0.0001). The 1-month CPC 1-2 rate improved in OHCA aged ≥75 years (0.73% [433/59,595] in 2008 to 0.96% [708/73,487] in 2012, p for trend <0.001), even in only OHCA aged ≥85 years (0.42% [115/27,163] in 2008 to 0.65% [241/36,860] in 2012, p for trend <0.0001). Multivariate logistic regression analysis indicated that bystander-witnessed arrest (adjusted odds ratio [aOR] 5.7, 95% confidential interval [CI] 5.2–6.3, p <0.0001) and initial shockable rhythm (aOR 10.6, 95% CI 9.8–11.5, p <0.0001) were significantly associated with 1-month CPC 1-2 rates of OHCA aged ≥75 years. OHCA with bystander witness and initial shockable rhythm had a higher 1-month CPC 1-2 rate than the others (11.14% [1,061/9,520] vs 0.58% [1,872/325,210], p <0.0001, aOR 19.1, 95% CI 17.6–20.7, p <0.0001). The 1-month CPC 1-2 rate of OHCA with initial unshockable rhythm also improved 0.42% (239/56,927) in 2008 to 0.60% (420/70,583) in 2012 (p for trend <0.001); however, in OHCA without bystander witness, the 1-month CPC 1-2 rate did not improve between 2008 (0.19% [71/36,736]) and 2012 (0.28% [125/45,224]) (p for trend = 0.080). Conclusion: Data drawn from a large subset of elderly patients in Japanese registry suggest that rate of 1-month CPC 1-2 from OHCA have significantly improved during the study period; however, the OHCA outcome differed by bystander-witness and first documented rhythm.