Dexmedetomidine use and short-term all-cause mortality in ICU patients with ischemic stroke and atrial fibrillation: a propensity-matched analysis from MIMIC-IV.

Introduction Preclinical studies have demonstrated that dexmedetomidine (DEX), a sedative widely used in intensive care units (ICUs), exerts neuroprotective effects. However, its potential protective role and underlying mechanisms in ischemic stroke patients with atrial fibrillation (AF) remain unclear. The study's objective was to assess the connection between the early administration of DEX and short-term mortality from all causes in patients with ischemic stroke and AF. Methods From the MIMIC-IV database, patients with ischemic stroke and AF were identified, including those who were administered DEX and those who were not. The primary endpoint was 7-day all-cause mortality, and the secondary endpoint was 90-day all-cause mortality. Propensity score matching (PSM) was utilized to ensure baseline covariates were balanced. Cox proportional hazards models and Kaplan-Meier survival curves and were utilized to evaluate the association between dexmedetomidine (DEX) use and mortality, with subgroup analyses conducted to ensure the findings' robustness. Results In total, 1,355 patients with ischemic stroke and AF participated, with 253 (18.7%) receiving DEX. After PSM, 208 pairs were matched. In the fully adjusted model, dexmedetomidine (DEX) administration was significantly associated with lower all-cause mortality compared with the control group at both 7 days (before PSM, HR=0.36, 95%CI: 0.19-0.68, P=0.002; after PSM, HR=0.26, 95%CI: 0.12-0.54, P<0.001) and 90 days (before PSM, HR=0.84, 95%CI: 0.66-1.07, P=0.162; after PSM, HR=0.72, 95%CI: 0.53- 0.97, P=0.031). The subgroup analyses revealed that DEX's protective effect was stronger in patients aged 70 and above, females, those with hypertension, and those without heart failure or chronic kidney disease. Kaplan-Meier survival curves consistently illustrated that DEX users had greater survival probabilities both before and after matching. Conclusion In patients with ischemic stroke complicated by AF, DEX administration is connected to decreased mortality, underlining the possible importance of DEX in ICU settings.