Chronic Kidney Disease, Time in Therapeutic Range and Adverse Clinical Outcomes in Anticoagulated Patients with Non-valvular Atrial Fibrillation: Observations from the SPORTIF Trials

• Chronic kidney disease (CKD) in atrial fibrillation (AF) patients is associated with several clinical factors.
• There is a linear association between creatinine clearance and time in therapeutic range (TTR).
• CKD is a risk factor for stroke and death, while TTR > 70% is a predictor for stroke, major bleeding and death.The concomitant presence of atrial fibrillation (AF) and chronic kidney disease (CKD) confers an increased risk of both ithromboembolism and bleeding. Oral anticoagulation with vitamin K antagonist (VKA) are an effective treatment in preventing thromboembolic events, but good anticoagulation control as reflected by a high time in therapeutic range (TTR) is crucial in reducing thromboembolic and bleeding adverse events. Our results showed a close relationship between CKD, TTR and adverse events. In the decision-making process of prescribing VKA, clinicians need to consider renal function as well as good anticoagulation control (e.g. TTR > 70%) to ensure best efficacy and safety.

BackgroundChronic kidney disease (CKD) is highly prevalent in atrial fibrillation (AF) patients and associated with an increased risk of adverse outcomes. Our objectives were to study clinical features associated with CKD in AF patients and the impact of CKD on anticoagulation control, as reflected by time in therapeutic range (TTR). We also determined the impact of CKD and TTR in predicting adverse outcomes.Methods and ResultsWe analysed pooled datasets from SPORTIF III and V trials, including 3646 patients assigned to warfarin with data on renal function. CKD (creatinine clearance < 60 ml/min) was present in 952 (26%) patients. TTR was higher in patients with normal renal function compared to those with CKD (p < 0.001).On logistic analysis, chronic AF and male sex were associated with TTR > 70%, whilst diabetes mellitus, aspirin use and CKD were inversely associated with TTR > 70%. On Cox regression analysis, CKD was an independent predictor for stroke (p = 0.006) and death (p < 0.001). TTR > 70% was independently associated with a lower risk of stroke (p = 0.024), death (p = 0.001) and major bleeding (p = 0.001).ConclusionsCKD is highly prevalent amongst AF patients and a risk factor for stroke and death. Adjusting for CKD, good quality anticoagulation control (TTR > 70%) was an independent predictor for lower risks of stroke, death and major bleeding.