Resumption of oral anticoagulation following traumatic injury and risk of stroke and bleeding in patients with atrial fibrillation: a nationwide cohort study

Aims We examined the risks of all-cause mortality, stroke, major bleeding, and recurrent traumatic injury associated with resumption of vitamin K antagonists (VKAs) and non-VKAs oral anticoagulants (NOACs) following traumatic injury in atrial fibrillation (AF) patients. Methods and results This was a Danish nationwide registry-based study (2005-16), including 4541 oral anticoagulant (OAC)-treated AF patients experiencing traumatic injury (defined as traumatic brain injury, hip fracture, or traumatic torso or abdominal injury). Within 90 days following discharge from traumatic injury, 60.6% resumed VKA (median age = 80, CHA(2)DS(2)-VASc = 4, HAS-BLED = 2), 16.7% resumed NOAC (median age = 81, CHA(2)DS(2)-VASc = 4, HAS-BLED = 2), and 22.7% did not resume OAC treatment (median age = 81, CHA(2)DS(2)-VASc= 4, HAS-BLED = 3). Switch from VKA to NOAC occurred among 9.5%. Since 2009, the trend in OAC resumption increased (P-value <0.0001), in particular with NOACs (P-value <0.0001). Follow-up started 90 days after discharge, and time-varying multiple Cox regression analyses were used for comparisons. Compared with non-resumption, VKA and NOAC resumption were associated with lower hazard [95% confidence interval (CI)] of all-cause mortality [hazard ratio (HR) 0.48 (0.42-0.53) and HR 0.55 (0.47-0.66), respectively] and ischaemic stroke [HR 0.56 (0.43-0.72) and HR 0.54 (0.35-0.82), respectively], increased major bleeding hazard [HR 1.30 (1.03 1.64) and HR 1.15 (0.81 1.63), respectively], and similar hazard of recurrent traumatic injury [HR 0.93 (0.73-1.18) and HR 0.87 (0.60-1.27), respectively]. Conclusion AF patients resuming VKA and NOAC treatment following traumatic injury have lower hazard of all-cause mortality and ischaemic stroke, increased hazard of major bleeding but without additional hazards of recurrent traumatic injury. Withholding OAC following a traumatic injury in AF patients may not be warranted.