BACKGROUND: There have been few studies of the outcome in elderly patients who have suffered in-hospital cardiac arrest (IHCA) and the association between cardiac arrest characteristics and survival.

AIM: The aim of this large observational study was to investigate the survival and neurological outcome in the elderly after IHCA, and to identify which factors were associated with survival.

METHODS: We investigated elderly IHCA patients (≥70years of age) who were registered in the Swedish Cardiopulmonary Resuscitation Registry 2007-2015. For descriptive purposes, the patients were grouped according to age (70-79, 80-89, and ≥90years). Predictors of 30-day survival were identified using multivariable analysis.

RESULTS: Altogether, 11,396 patients were included in the study. Thirty-day survival was 28% for patients aged 70-79 years, 20% for patients aged 80-89 years, and 14% for patients aged ≥90years. Factors associated with higher survival were: patients with an initially shockable rhythm, IHCA at an ECG-monitored location, IHCA was witnessed, IHCA during daytime (8 a.m.-8 p.m.), and an etiology of arrhythmia. A lower survival was associated with a history of heart failure, respiratory insufficiency, renal dysfunction and with an etiology of acute pulmonary oedema. Patients over 90 years of age with VF/VT as initial rhythm had a 41% survival rate. We found a trend indicating a less aggressive care with increasing age during cardiac arrest (fewer intubations, and less use of adrenalin and anti-arrhythmic drugs) but there was no association between age and delay in starting cardiopulmonary resuscitation (CPR). In survivors, there was no significant association between age and a favourable neurological outcome (CPC score: 1-2) (92%, 93%, and 88% in the three age groups, respectively).

CONCLUSIONS: Increasing age among the elderly is associated with a lower 30-day survival after IHCA. Less aggressive treatment and a worse risk profile might contribute to these findings. Relatively high survival rates among certain subgroups suggest that discussions about advanced directives should be individualized. Most survivors have good neurological outcome, even patients over 90 years of age.