Long-term prognosis following resuscitation from out-of-hospital cardiac arrest: role of aetiology and presenting arrest rhythm.

OBJECTIVE: Little is known about long-term prognosis following resuscitation from out-of-hospital cardiac arrest, especially as it relates to the presenting rhythm or arrest aetiology. We investigated long-term survival among those discharged alive following resuscitation according to presenting rhythm and arrest aetiology.
METHODS: We conducted a cohort investigation of all non-traumatic adult out-of-hospital cardiac arrest patients resuscitated and discharged alive from hospital between January 1, 2001 and December 31, 2009 in a large metropolitan emergency medical service system. Information about demographics, circumstances, presenting arrest rhythm and aetiology was collected using the dispatch, EMS, and hospital records. Long-term vital status was ascertained using state death records and the Social Security Death Index through 31st December 2010. We used Kaplan Meier to evaluate survival.
RESULTS: During the study period, a total of 1001/5958 (17%) persons were resuscitated and discharged alive, of whom 313/1001 (31%) presented with a non-shockable rhythm and 210/1001 (21%) had a non-cardiac aetiology. Overall median survival was 9.8 years with 64% surviving >5 years. Five-year survival was 43% for non-shockable rhythms compared to 73% for shockable rhythms, and 45% for non-cardiac aetiology compared to 69% for cardiac aetiology (p<0.001 respectively).
CONCLUSION: Cardiac arrest due to non-shockable rhythm or non-cardiac aetiology comprises a substantial proportion of those who survive to hospital discharge. Although long-term survival in these groups is less than their shockable or cardiac aetiology counterparts, nearly half are alive 5 years following discharge. The findings support efforts to improve resuscitation care for those with non-shockable rhythms or non-cardiac cause.