Association between Advance Directives and Invasive Life Support Use at End of Life: A Retrospective Cohort Study

CONTEXT: Invasive life support is commonly administered at the end of life. However, decisions made in emergency situations often differ from the preferences of patients and their families. OBJECTIVES: We investigated whether explicitly documented advance directives (ADs) were associated with the use of invasive life support, including endotracheal intubation and chest compressions. METHODS: We conducted a single-centre retrospective cohort study by analysing data from all patients who died in our cardiac care unit (CCU) between January 2015 and July 2025. After excluding those who died intraoperatively, of noncardiac causes, or within two hours of admission, 139 patients were included in the final analysis. RESULTS: Fifty-five patients (39.6%) had an AD. Patients with an AD had significantly lower odds of receiving endotracheal intubation and chest compressions (P < 0.001). Older age and a history of heart failure were also independently associated with reduced use of endotracheal intubation (P < 0.001 and P = 0.003, respectively). Among the 71 patients who died at night time, 40 (56.3%) received endotracheal intubation, compared with 25 of 68 (36.8%) who died during the daytime (P = 0.008). CONCLUSIONS: Explicitly documented ADs were independently associated with reduced use of invasive life support. Night time death was an independent risk factor for receiving endotracheal intubation, revealing a systemic tendency towards default aggressive resuscitation. Therefore, implementing systematic and specific procedures for recording and accessing ADs is crucial to ensure that end-of-life medical interventions in the cardiac care unit align with the wishes of patients and their families.