Safety Of The Use Of Direct Oral Anticoagulants (Doacs) In Morbidly Obese Patients With Non-Valvular Atrial Fibrillation (Nvaf) Undergoing Elective Direct-Current Cardioversion (Dccv)

Introduction Direct Oral Anticoagulants (DOACs) are rapidly replacing warfarin as drugs of choice for stroke prophylaxis in patients with non-valvular atrial fibrillation (NVAF). Advantage of DOACs over warfarin include fixed dosing, predictable pharmacokinetics, less interaction with food/ medication and no requirement for frequent monitoring of their therapeutic efficacy. Obesity is a risk factor for the development of AF. However, robust scientific data assessing the safety of DOACs in obese patients is lacking. The International Society of Thrombosis and Haemostasis (ISTH) suggests that DOACs should not be used in patients with a Body Mass Index (BMI) \u003e 40 kg/m2 or a weight \u003e120kg, and if a DOAC is used in these patients, a peak and trough level should be obtained to ensure the levels fall within the expected range. On the other hand, the European Heart Rhythm Association (EHRA) recommends only estimating trough levels at extremes of body weight. Aims The objective of this study was to evaluate the safety of the use of DOACs in obese patients with NVAF undergoing elective Direct Current Cardioversion (DCCV) in a tertiary cardiology centre. Methods Retrospective, single-centre cohort analysis of all adult patients ≥18 years of age with body weight \u003e120kg, undergoing elective DCCV for NVAF between January 2018 and January 2020 while anticoagulated with either DOACs or therapeutic warfarin for ≥3 weeks prior to the procedure. Patients on DOACs were compared with those on warfarin. Shocks were delivered using a biphasic defibrillator starting at 150 Joules in a well established nurse-led Cardioversion Service. Results Of the 486 DCCV procedures undertaken during the study period, 52 (10.7%) were in patients weighing \u003e120kg. Six patients underwent the procedure twice. The cohorts’ mean age was 59.7 ± 8.2 years (median: 59.5; range: 38-75); 76.9% were male; the mean weight was 134.40 ± 13.65 kg (median: 130; range: 120-167.8) and mean body mass index (BMI) was 43.26 ± 5.51 kg/m2 (median: 42.8; range: 32.9-58.8). Majority (33/52, 63.5%) of the procedures were undertaken in patients with a BMI of ≥40 kg/m2 (morbidly obese) and while on DOACs (36/52, 69.2% versus warfarin: 16/52, 30.8%). Distribution of DOACs was as follows: rivaroxaban 25/52 (48.1%), apixaban 9/52 (17.3%) and dabigatran 2/52 (3.8%). DOAC trough levels were estimated in 18/36 (50%) patients prior to the procedure. Mean CHA2DS2VASc score was 2 ± 1 (median: 2; range: 0-4). Sinus rhythm was restored in 38/52 (73.1%) procedures using a mean of 2.2 ±1.3 shocks (median: 2, range: 1-5). Conclusions/Implications The results of this single-centre study suggest that in this population of morbidly obese patients undergoing DCCV, the recommendations of ISTH and EHRA were only partially adhered to. While healthcare professionals were preferring warfarin over DOACs in very heavy patients, a majority still received the latter drug. Non-adherence to the recommendations with regards to measuring trough levels of patients on DOACs to ensure efficacy was seen with only half having their levels estimated. However, DOACs appeared to be safe in this population with no adverse events at 30 days. The results of this study are relevant in view of rising levels of obesity and NVAF worldwide with a potential for increased demand for DCCV in such patients in the future. Conflict of Interest None