Browsing by Author "Damaraju, Chandrasekharrao, V"

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Citation - WoS: 30
Citation - Scopus: 29
Out-Of Inr Values and Outcomes Among New Warfarin Patients With Non-Valvular Atrial Fibrillation
(2015) Schein, Jeffrey R; Wang, Li; Damaraju, Chandrasekharrao, V; Nelson, Winnie W; Başer, Onur
Background Although efficacious in stroke prevention in non-valvular atrial fibrillation, many warfarin patients are sub-optimally managed. Objective To evaluate the association of international normalized ratio control and clinical outcomes among new warfarin patients with non-valvular atrial fibrillation. Setting Adult non-valvular atrial fibrillation patients (a parts per thousand yen18 years) initiating warfarin treatment were selected from the US Veterans Health Administration dataset between 10/2007 and 9/2012. Method Valid international normalized ratio values were examined from the warfarin initiation date through the earlier of the first clinical outcome, end of warfarin exposure or death. Each patient contributed multiple in-range and out-of-range time periods. Main outcome measure The relative risk ratios of clinical outcomes associated with international normalized ratio control were estimated. Results 34,346 patients were included for analysis. During the warfarin exposure period, the incidence of events per 100 person-years was highest when patients had international normalized ratio < 2:13.66 for acute coronary syndrome; 10.30 for ischemic stroke; 2.93 for transient ischemic attack; 1.81 for systemic embolism; and 4.55 for major bleeding. Poisson regression confirmed that during periods with international normalized ratio < 2, patients were at increased risk of developing acute coronary syndrome (relative risk ratio: 7.9; 95 % confidence interval 6.9-9.1), ischemic stroke (relative risk ratio: 7.6; 95 % confidence interval 6.5-8.9), transient ischemic attack (relative risk ratio: 8.2; 95 % confidence interval 6.1-11.2), systemic embolism (relative risk ratio: 6.3; 95 % confidence interval 4.4-8.9) and major bleeding (relative risk ratio: 2.6; 95 % confidence interval 2.2-3.0). During time periods with international normalized ratio > 3, patients had significantly increased risk of major bleeding (relative risk ratio: 1.5; 95 % confidence interval 1.2-2.0). Conclusion In a Veterans Health Administration non-valvular atrial fibrillation population, exposure to out-of-range international normalized ratio values was associated with significantly increased risk of adverse clinical outcomes.
Citation - WoS: 8
Citation - Scopus: 8
Out-Of International Normalized Ratio Values and Healthcare Cost Among New Warfarin Patients With Non-Valvular Atrial Fibrillation
(2015) Wang, Li; Nelson, Winnie W.; Schein, Jeffrey R.; Damaraju, Chandrasekharrao, V; Başer, Onur
Patients with out-of-range international normalized ratio (INR) values <2.0 and >3.0 have been associated with increased risk of thromboembolic and bleeding events. INR monitoring is costly, because of associated physician and nurse time, laboratory resource use, and dose adjustments.
Citation - WoS: 3
Citation - Scopus: 3
Patterns of International Normalized Ratio Values Among New Warfarin Patients With Nonvalvular Atrial Fibrillation
(2016) Schein, Jeffrey R; Wang, Li; Nelson, Winnie W.; Damaraju, Chandrasekharrao, V; Milentijevic, Dejan; Başer, Onur
Limited information exists regarding the relationship between international normalized ratio (INR) control/stability and the discontinuation of warfarin therapy among patients with nonvalvular atrial fibrillation (NVAF). This study evaluated the association between INR stabilization and warfarin discontinuation and assessed INR patterns before and after INR stabilization among patients (18 years) with NVAF who newly initiated warfarin (Veterans Health Administration datasets; October 1, 2007 through September 30, 2012). Achievement of INR stabilization (3 consecutive in-range therapeutic INR measurements 7 days apart) was examined from warfarin initiation through the end of warfarin exposure. Proportion of time in therapeutic range during warfarin exposure was calculated (Rosendaal method) and categorized as at least 60% or less than 60%. Among 34346 patients, 49.4% achieved INR stabilization (mean time to stabilization, 98 days). Approximately 40% of INR values were out-of-range, even after achieving stabilization. During 30 days following an INR 4.0 or higher, patients had more INR testing than the overall mean (2.51 vs. 1.67 tests). Warfarin discontinuation was 4.2 times more likely among patients without INR stabilization versus those with INR stabilization (P<0.00001). Patients with poor INR control (time in therapeutic range <60%) were 1.76 times more likely to discontinue warfarin within 1 year (P<0.0001). INR stabilization is a better predictor of warfarin discontinuation than poor INR control. Improved approaches are necessary to maintain appropriate anticoagulation levels among patients with NVAF.