Cancer is not associated with higher short or long-term mortality after successful resuscitation from out-of-hospital cardiac arrest when adjusting for prognostic factors

Abstract

Objective: As the prevalence of malignancies in the general population increases, the odds of an out-of-hospital cardiac arrest (OHCA) patient having a history of cancer likewise increases, and the impact on post-cardiac arrest care and mortality is not well known. We aimed to investigate 30-day and 1-year mortality after successful resuscitation in patients with cancer prior to OHCA compared with OHCA patients without a previous cancer diagnosis. Methods: A cohort of 993 consecutive OHCA patients with successful resuscitation during 2007–2011 was included. Vital status was obtained from the Danish Civil Register, and cancer diagnoses from the Danish National Patient Register dating back to 1994. Primary endpoints were 30-day, 1-year and long-term mortality (no cancer: mean 811 days; cancer: mean 406 days), analysed by Cox regression. Functional status assessed by cerebral performance category at discharge and use of post-resuscitation care were secondary endpoints. Results: A total of 119 patients (12%) were diagnosed with cancer prior to OHCA. Mortality was higher in patients with cancer (30-day 69% vs. 58%, P=0.01); however, after adjustment for prognostic factors cancer was no longer associated with higher mortality (hazard ratio (HR)30 days 0.98, 95% confidence interval (CI) 0.76–1.27, P=0.88; HR1 year 0.99, 95% CI 0.78–1.27, P=0.96 HRend of follow-up 0.95, 95% CI 0.75–1.20, P=0.67). Favourable cerebral performance category scores in patients alive at discharge did not differ (cerebral performance category 1 or 2 n=310 (84%) vs. n=31 (84%), P=1). Conclusion: Cancer prior to OHCA was not associated with higher mortality in patients successfully resuscitated from OHCA when adjusting for confounders. Cancer prior to OHCA should be used with caution when performing prognostication after OHCA.