Relationships between Anticoagulation, Risk Scores and Adverse Outcomes in Dialysis Patients with Atrial Fibrillation

Abstract

Atrial fibrillation (AF) is the commonest cardiac arrhythmia including in end-stage renal failure patients, but controversy remains whether these patients benefit from anticoagulation. We reviewed the characteristics, management and outcomes of end-stage renal failure patients on dialysis with AF. All patients started on dialysis at Middlemore Hospital between January 2000 and December 2008 who had AF were studied. Data regarding demographics, co-morbidities, renal disease, AF and embolic, bleeding and/or mortality events were recorded. There were 141 out of 774(18.2%) dialysis patients with AF followed-up for 4.4+/-2.5 years, and 41.8%(59) were on warfarin. Incidence of all embolic events, ischaemic stroke, all bleeding and intracranial bleed were 4.1, 3.1, 9.6 and 0.82/100 person years respectively. Warfarin anticoagulation was associated with increased risk of intracranial bleed (hazards ratio=11.1, P=0.038), but not total embolic, bleeding events or mortality during follow-up (P=0.317-0.980). All three scores (CHADS2, CHA2DS2-VASc and HAS-BLED) could detect all embolic events (c=0.808-0.838), but not bleeding events (c=0.459-0.498). Anticoagulation with warfarin didn't significantly reduce embolism or mortality in dialysis patients with AF, but increased the risk of intracranial bleeds. Convention risk scores predict embolic but not bleeding events in these patients.