ORIGINAL RESEARCH
Time in Therapeutic Range and Outcomes After Warfarin Initiation in Newly Diagnosed Atrial Fibrillation Patients With Renal Dysfunction € ov, MD, PhD; Abdul Rashid Qureshi, MD, PhD; Karolina Szummer, MD, PhD; Alessandro Gasparini, MSc; Staffan Eliasson, MD; Johan Arnl€ Peter Barany, MD, PhD; Marie Evans, MD, PhD; Leif Friberg, MD, PhD; Juan Jesus Carrero, PharmMed, PhD
Background-—It is unknown whether renal dysfunction conveys poor anticoagulation control in warfarin-treated patients with atrial fibrillation and whether poor anticoagulation control associates with the risk of adverse outcomes in these patients. Methods and Results-—This was an observational study from the Stockholm CREatinine Measurements (SCREAM) cohort including all newly diagnosed atrial fibrillation patients initiating treatment with warfarin (n=7738) in Stockholm, Sweden, between 2006 and 2011. Estimated glomerular filtration rate (eGFR; mL/min per 1.73 m2) was calculated from serum creatinine. Time-in-therapeutic range (TTR) was assessed from international normalized ratio (INR) measurements up to warfarin cessation, adverse event, or end of follow-up (2 years). Adverse events considered a composite of intracranial hemorrhage, ischemic stroke, myocardial infarction, or death. During median 254 days, TTR was 83%, based on median 21 INR measurements per patient. TTR was 70% among patients with eGFR
Time in Therapeutic Range and Outcomes After Warfarin Initiation in Newly Diagnosed Atrial Fibrillation Patients With Renal Dysfunction € ov, MD, PhD; Abdul Rashid Qureshi, MD, PhD; Karolina Szummer, MD, PhD; Alessandro Gasparini, MSc; Staffan Eliasson, MD; Johan Arnl€ Peter Barany, MD, PhD; Marie Evans, MD, PhD; Leif Friberg, MD, PhD; Juan Jesus Carrero, PharmMed, PhD
Background-—It is unknown whether renal dysfunction conveys poor anticoagulation control in warfarin-treated patients with atrial fibrillation and whether poor anticoagulation control associates with the risk of adverse outcomes in these patients. Methods and Results-—This was an observational study from the Stockholm CREatinine Measurements (SCREAM) cohort including all newly diagnosed atrial fibrillation patients initiating treatment with warfarin (n=7738) in Stockholm, Sweden, between 2006 and 2011. Estimated glomerular filtration rate (eGFR; mL/min per 1.73 m2) was calculated from serum creatinine. Time-in-therapeutic range (TTR) was assessed from international normalized ratio (INR) measurements up to warfarin cessation, adverse event, or end of follow-up (2 years). Adverse events considered a composite of intracranial hemorrhage, ischemic stroke, myocardial infarction, or death. During median 254 days, TTR was 83%, based on median 21 INR measurements per patient. TTR was 70% among patients with eGFR
