Effect of oral anti-coagulant on 12-month overall mortality rate in admitted elderly patient with newly diagnosed atrial fibrillation and atrial flutter

Background: Atrial fibrillation increases risk of ischemic stroke which leading to disability and mortality. However, benefit of early initiation of treatment for stroke prevention in elderly with newly diagnosed AF during hospitalization for non-cardiac reasons is questionable. Methods: We performed a retrospective cohort study in hospitalized patients from Siriraj hospital between 2003 to 2019. Participants with aged more than 75-year-old and newly diagnosed AF were included. Primary outcome was an overall mortality. Secondary outcomes were in-hospital mortality, non-fatal stroke, and bleeding event. Results: A total of 216 participants: 24 in the oral anticoagulant (OAC) group and 192 in the non-OAC group. Most oral anti-coagulant use was warfarin (91.7%). The mean age was 81.9 years in the OAC group and 82.9 in the non-OAC group. The mean CHA 2 DS 2 VASc score was 4.5 in the OAC group and 4.2 in the non-OAC group. The mean HAS-BLED score was 3.0 both groups. During index admission, there were 1 death in the OAC group and 83 deaths in the non-OAC group. Over the course of 1-year follow-up, there were 6 deaths in the OAC group and 107 in the non-OAC group. The HR was 0.33 (95% confident interval [CI], 0.15-0.75; p-value = 0.08). Non-CV death were 96.4% of all deaths. After an exclusion of in-hospital mortality, there were 5 deaths (21.7%) in the OAC group and 24 deaths (22%) in the non-OAC group. The hazard ratio was 0.93 (95% CI, 0.36-2.42; p-value = 0.879). There were 4 non-fatal strokes in the non-OAC group but none in the OAC group. There were 3 bleeding events in the OAC group and 4 bleeding events in the non-OAC group. The hazard ratio was 6.11 (95% CI, 1.37-27.32; p-value = 0.018). Conclusions: Non-CV death was the major cause of death during the hospitalization. Benefit of initiating OAC in patients with newly diagnosed AF during hospitalization may be limited by patients’ active conditions. However, stroke prevention after hospitalization should be considered.