Obesity paradox in patients with non -valvular atrial fibrillation regarding outcomes; fact or fiction?

Background: Obesity represents one of the most important risk factors for cardiovascular disease, cardiovascular death, and all-cause death. Atrial fibrillation (AF) is the commonest sustained cardiac arrhythmia, and the relationship between obesity and AF is well established. Our goal was to assess the role of obesity in outcomes of anticoagulation among patient with non-valvular AF regarding thromboembolic and bleeding complications and to check what was obesity paradox among patient with AF really exists in relation to body mass index (BMI). Methods: : The study included three hundred patients presented with non-valvular AF on oral anticoagulant treatment either vitamin K antagonist (VKA) or direct oral anticoagulants (DOACS). Patients were subjected to full history taking, physical examination, twelve leads ECG and echocardiographic assessment . Six months follow up was performed for any major adverse cardiovascular events (MACEs) including all-cause of death, cardiac death, stroke and thrombo-embolic complications. Results: : Of three hundred patients included in the final analysis, one hundred and ninety fifth were non-obese and one hundred and five were obese according to BMI. Our study focused on three outcomes among patients with NV-AF including :bleeding ,cerebrovascular stroke and cardiovascular death . After logistic regression analysis, diabetes mellitus (DM), hypertension (HTN), dyslipidemia, smoking, CHA 2 DS 2 -VASc score and number of AF episodes appeared as better independent prognostic factors for MACEs by multivariate analysis with significant P-values. Also, obesity was statistically significant (P=0.031). Among patients treated with warfarin, the prevalence of complication was significantly (P=0.037) higher among non-obese group compared to obese group . Dissimilarly, no difference was detected regarding the rate of complication among those treated with DOACs (P=0.236). Conclusion: Obese patients with non-valvular AF may be less vulnerable to develop complications regarding bleeding ,cerebrovascular stroke and cardiovascular death compared to non –obese patients .This paradox may be more evident among patients treated by vitamin K antagonist. Trial registration :Clinical trial registration no.,NCT03904329;first registration: 25/03 /2019.first recruited case 01/10/2020.URL:https://register.clinicaltrials.gov/prs/app/action/LoginUser?ts=2&cx=-jg9qo3