Abstract 13093: Increased Arterial Thrombo-Embolic Events and Major Bleeding in Patients with Atrial Fibrillation and Chronic Kidney Disease on Vitamin K-Antagonist Treatment
Aim To analyze the risk of arterial thrombotic events(ATEs), major bleeding and its predictors in patients with chronic kidney disease(CKD) compared with non-CKD patients, treated with vitamin K-antagonists(VKAs) for atrial fibrillation(AF).
Methods Medical records of 417 CKD and 300 non-CKD(GFR>60ml/min) patients starting VKA therapy between 1997-2005 were searched for ATEs and major bleeding. ATE was defined by myocardial infarction, stroke/transient ischemic attack, claudicatio intermittens, unstable angina, carotid or peripheral bypass graft/angioplasty. Major bleeding was defined by bleeding being fatal, causing a drop in Hb level≥1,24mmol/L, requiring transfusion of≥2 units of whole blood/red cells, or being symptomatic in a critical area.
Results ATEs occurred in 108/737(14.7%,95%CI12.3-17.4) patients. Patients with a GFR<30ml/min were at increased risk of ATE compared with non-CKD patients(hazard ratio(HR)3.4(95%CI2.1-5.6). ATEs occurred as frequent in patients with GFR30-60ml/min as in non-CKD patients(HR1.1,95%CI0.7-1.7). Major bleeding occurred in 115/737 patients(15.6%,95%CI13.2-18.4). The risk of major bleeding increased in patients with a GFR<30ml/min compared with non-CKD patients(HR1.8,95%CI1.1-3.0). Major bleeding risk was not increased in patients with a GFR30-60ml/min compared with non-CKD patients(HR 0.9,95%CI0.6-1.4). Low GFR levels were associated with high variability within a patients INR values (correlation term-0.17,P=<0.001) and low serum albumin levels (correlation term-0.13,P0.03). Both INR variability>0.5(HR1.5,95%1.0-2.4) and serum albumin<34g/L(HR 1.7,95%CI1.0-3.0) increased the major bleeding risk.
Conclusion Patients with a GFR<30ml/min are at increased risk of ATEs and major bleeding compared with non-CKD patients. The increased bleeding risk may be due to low serum albumin levels and high INR variability, a marker of suboptimal VKA therapy.
- © 2012 by American Heart Association, Inc.