Anticoagulation Challenges in Hematogeriatrics: Effectiveness and Safety of Direct Oral Anticoagulants Vs Vitamin k Antagonist in Elderly with Atrial Fibrillation

BACKGROUND Direct oral anticoagulants (DOAC) are increasingly used in patients with Non Valvular Atrial Fibrillation (NVAF) for stroke prevention. However, Follow-Up (FU) and dosing these agents in the elderly can be challenging due to different factors, such as chronic kidney disease, frailty, falls, multifactorial anemia and concomitant polypharmacy. These factors in elderly patients predisposes to both thromboembolic and bleeding events once atrial fibrillation occurs. Therefore, balancing risks and benefits of antithrombotic strategies in older populations is crucial. Despite recent increases in DOAC use in NVAF, there are still limited data regarding DOACs effectiveness and safety in frail elderly patients. AIM To assess the effectiveness and safety according to DOAC or Vitamin K Antagonist (VKA) in a cohort of elderly patients with NVAF. METHODS From April 2016 to April 2019, we consecutively included NVAF elderly patients (≥80 years-old) treated with DOAC or VKA in a prospective multicenter registry. Demographic, laboratory, frailty risk stratification and antithrombotic therapy data were collected. Patients had a minimum FU of 6 months. VKA patients had a standard FU through digital international normalized ratio (INR) control and the efficacy of therapy was determined by the time in therapeutic range (TTR) values from the preceding 6 months of treatment using Rosendaal's method. FU in DOAC patients was performed through structured and integral assessment following the Tromboc@t Working Group recommendations for management in patients receiving DOAC (Olivera et al, Med Clin 2018). Key practical management aspects are listed in the flow chart (Figure 1). Clinical Frailty Scale (CFS score) was assigned to each patient at the beginning and during the FU; patients were classified into three categories: non-frail (CFS 1-4), mild-to-moderately frail (CFS 5-6), and severely frail (CFS 7-9). RESULTS From a total of 1040 NVAF patients, 690 (63.5%) were treated with DOAC (61 dabigatran, 95 rivaroxaban, 254 edoxaban and 280 apixaban) and 350 with VKA. In the VKA group, the mean TTR was 52.8%. Demographic characteristics and CFS score are summarized in table 1. Kaplan-Meier analysis (median FU: 16.5 months) showed a significantly high incidence of stroke/systemic embolism among VKA patients vs DOAC patients (4.2 vs 0.5 events per 100 patient-years, p