Long-term survival and residual hazard after in-hospital cardiac arrest

SummaryAimThe purpose of this study was to determine long-term survival after in-hospital cardiac arrests and to explore if and when the excess mortality risk imposed by the index event reaches that of an age and sex matched general population.MethodA retrospective analysis of data from 1571 in-hospital cardiac arrests between the calendar years 1997 and 2002 inclusive was performed. Two hundred and fifty-nine people survived until hospital discharge, 220 of which were residents in England and included in the study. Kaplan–Meier curves were constructed for the survivors and an age and sex matched comparator population, and survival compared with a one-sample log rank test. Smoothed hazard curves were constructed for the two populations. Differences in outcome from year of index event were also sought.Results16.5% of patients survived to hospital discharge. Patients continue to experience a mortality rate greater than that of the comparator population during the first 200 days, with overall 70 deaths versus 18.7 as predicted from life tables (p < 0.0001). The hazard is greatest after resuscitation and falls thereafter until about 2 years where it is not very different to that of the comparator population and then subsequently rises. No evidence was found of a difference in the first year survival between patients resuscitated in different calendar years (p > 0.3 for all tests).ConclusionThe residual risk to an individual cardiac arrest survivor's life is greatest during the first year of survival, but declines progressively during the first 2 years after the event, subsequently approaching the risk experienced by the general population.