Younos Abdulsattar

Stroke associated with discontinuation of warfarin therapy for atrial fibrillation

Abstract Objective: The objective of this study was to determine the association between warfarin discontinuation and stroke among patients with nonvalvular atrial fibrillation (NVAF). Research design and methods: This was a retrospective, observational study of adult NVAF patients (≥18 years) who were on warfarin in the Truven MarketScan commercial claims and encounters and Medicare supplemental and coordination of benefits databases (1 January 2008 to 30 June 2012). Warfarin discontinuation was defined as a gap of ≥45 days in warfarin prescription within 1 year after initiation. Patients who did and did not discontinue warfarin were matched at a 1:1 ratio using a propensity score method. Matched patients were followed for up to 1 year to determine risks of ischemic stroke, transient ischemic attack (TIA), and hemorrhagic stroke. A multivariate Cox proportional hazards model was used to further adjust for the effects of potential confounders. Results: A total of 27,000 patients were included. Patients who discontinued warfarin had higher rates of ischemic stroke compared to persistent patients (1.0 vs. 0.5 per 100 patient years, P < 0.01), but similar rates of TIA (1.2 vs. 0.9 per 100 patient years, respectively; P = 0.07) and hemorrhagic stroke (0.3 vs. 0.2 per 100 patient years, P = 0.31). After adjustment for potential confounders, warfarin discontinuation was significantly associated with increased risk of ischemic stroke (hazard ratio [HR]: 2.04; 95% confidence interval [CI]: 1.47–2.84), TIA (HR: 1.36; 95% CI: 1.04–1.78), and ischemic stroke or TIA (HR: 1.50; 95% CI: 1.20–1.87). Conclusions: Warfarin discontinuation is associated with increased risk of ischemic stroke and TIA. Health care providers may need to take a more active role in the management of warfarin discontinuation and clinical outcomes, e.g., by considering newer anticoagulants with favorable risk–benefit profiles. Key limitations of the study include unavailability of important clinical factors and measures in claims data.

Comparing the efficacy of eletriptan for migraine in women during menstrual and non-menstrual time periods: a pooled analysis of randomized controlled trials.

To assess the efficacy and tolerability of eletriptan in treating migraine attacks occurring within the defined menstrual time period of 1 day before and 4 days after onset of menstruation (menses days –1 to +4) compared with attacks occurring during non‐menstrual time periods (occurring outside of menses days –1 to +4).

REAL-WORLD COMPARISON OF INPATIENT BLEEDING RISK, BLEEDING-RELATED HOSPITALIZATION RATES AND COSTS AMONG NON-VALVULAR ATRIAL FIBRILLATION PATIENTS ON APIXABAN, DABIGATRAN, RIVAROXABAN: COHORTS COMPRISING NEW INITIATORS AND/OR SWITCHERS FROM WARFARIN

Information about the risk of bleeding and bleeding-related resource use and costs among non-Vitamin K antagonist oral anticoagulants (NOACs) in the real-world setting is scarce. This study aim was to compare inpatient bleeding risks, bleeding-related hospitalization rates and costs among non-

Estimated prevalence of undiagnosed atrial fibrillation in the United States

Introduction As atrial fibrillation (AF) is often asymptomatic, it may remain undiagnosed until or even after development of complications, such as stroke. Consequently the observed prevalence of AF may underestimate total disease burden. Methods To estimate the prevalence of undiagnosed AF in the United States, we performed a retrospective cohort modeling study in working age (18–64) and elderly (≥65) people using commercial and Medicare administrative claims databases. We identified patients in years 2004–2010 with incident AF following an ischemic stroke. Using a back-calculation methodology, we estimated the prevalence of undiagnosed AF as the ratio of the number of post-stroke AF patients and the CHADS2-specific stroke probability for each patient, adjusting for age and gender composition based on United States census data. Results The estimated prevalence of AF (diagnosed and undiagnosed) was 3,873,900 (95%CI: 3,675,200–4,702,600) elderly and 1,457,100 (95%CI: 1,218,500–1,695,800) working age adults, representing 10.0% and 0.92% of the respective populations. Of these, 698,900 were undiagnosed: 535,400 (95%CI: 331,900–804,400) elderly and 163,500 (95%CI: 17,700–400,000) working age adults, representing 1.3% and 0.09% of the respective populations. Among all undiagnosed cases, 77% had a CHADS2 score ≥1, and 56% had CHADS2 score ≥2. Conclusions Using a back-calculation approach, we estimate that the total AF prevalence in 2009 was 5.3 million of which 0.7 million (13.1% of AF cases) were undiagnosed. Over half of the modeled population with undiagnosed AF was at moderate to high risk of stroke.

ECONOMIC BURDEN OF UNDIAGNOSED NONVALVULAR ATRIAL FIBRILLATION IN THE UNITED STATES

Atrial fibrillation (AF) may be clinically silent and remain undiagnosed. To date, no estimates of the direct medical cost of undiagnosed AF exist. We estimated the US incremental cost burden of undiagnosed nonvalvular AF using administrative claims for working age and Medicare patients. To