Use of oral anticoagulation therapy in the first 3 months after the diagnosis of atrial fibrillation in Israel: A population-based study.

INTRODUCTION: Oral anticoagulation (OAC) therapy reduces the risk of ischemic stroke in patients with atrial fibrillation (AF) while increasing the risk of bleeding. Recently, non-vitamin K antagonist oral anticoagulants (NOACs) have become available with lower rates of intracranial bleeding, and some of them have presented a reduced risk of major bleeding. The purpose of this study is to evaluate the change in purchasing patterns of OACs (both warfarin and NOACs) over time in patients with AF according to stroke and bleeding risk, in the first 3 months after diagnosis. METHODS AND RESULTS: We conducted a historical cohort study using the Clalit Health Services electronic medical records database. The study population included all members aged ≥21 years, with a new diagnosis of nonvalvular AF between 2008 and 2015. A total of 58 385 cases were identified. The mean age was 73.1 (±14.1) years, and 52.3% of the patients were women. The median CHA2 DS2 -VASc score was 4 (interquartile range, 3-5). OACs were purchased by 19 705 patients (33.8%) within the first 3 months of first diagnosis of AF, with patients at higher embolic risk as stratified by the CHA2 DS2 -VASc score and having higher purchasing rates (37.1%). Between 2008 and 2010, 29% of patients purchased a vitamin K antagonist, the only available OAC at the time. OAC purchasing increased to 41.4% between 2014 and 2015, with half of the patients purchasing an NOAC. CONCLUSION: In this real-world, population-based cohort study of patients with newly diagnosed AF, we found a lower than expected rate of OAC prescription within 3 months of diagnosis but an encouraging increase in OAC purchasing over time. The use of NOACs has risen exponentially within just a few years, accounting for a greater pool of patients with being prescribed an OAC.

Amiodarone-induced thyroid dysfunction: brand-name versus generic formulations.

BACKGROUND: Amiodarone is associated with dysfunction of the thyroid. Concerns have arisen regarding the potential for adverse effects with generic formulations of amiodarone. We evaluated and compared the risk of thyroid dysfunction between patients using brand-name versus generic formulations of amiodarone and identified risk factors for thyroid dysfunction. METHODS: We conducted a retrospective cohort study of patients with atrial fibrillation aged 66 years and older. We used administrative databases that linked information on demographics and clinical characteristics, claims for prescription drugs and discharges from hospital. We estimated thyroid dysfunction using person-year incidence. RESULTS: Of the 60,220 patients in the cohort, 2804 (4.7%) used the brand-name formulation of amiodarone and 6278 (10.4%) used the generic formulation. Baseline characteristics between these two groups were comparable. The median maintenance dose of amiodarone was 200 mg/d for both groups. The total incidence rate for thyroid dysfunction was 14.1 per 100 person-years for both formulations. The mean time to clinical dysfunction of the thyroid was 4.32 years for the brand-name formulation and 4.09 years for the generic formulation. In a multivariate analysis, there was no significant difference in the incidence rates of thyroid dysfunction between the generic and brand formulations (hazard ratio 0.97, 95% confidence interval 0.87-1.08). Factors associated with an increased risk of thyroid dysfunction were being a woman, increasing age and having chronic obstructive pulmonary disease. INTERPRETATION: In this population-based study, we saw no difference between brand-name and generic formulations of amiodarone in terms of incidence of thyroid dysfunction.

Comparison of the Effect of Thiazide Diuretics and Other Antihypertensive Drugs on Central Blood Pressure: Cross-Sectional Analysis Among Nondiabetic Patients.

Thiazide diuretics (TDs) are a cost-effective first-line therapy for uncomplicated hypertension; however, they are less prescribed than other options. The authors aimed to assess the noninferiority of TDs relative to different classes of antihypertensive medications in relation to central blood pressure. Cross-sectional data from the Quebec CARTaGENE project was used. Nondiabetic hypertensive participants on monotherapy for hypertension were studied. Separate adjusted models were constructed to establish noninferiority of TDs to non-TD antihypertensive medications for central blood pressure measurements. Models included a set of potential confounders. Of the 1194 hypertensive participants, 7.4% were taking TDs. We found that TDs were comparable with non-TD antihypertensive medications for central systolic blood pressure (adjusted regression coefficient, 0.45; 95% confidence interval, -1.61 to 2.50). No differences in other central measurements were noted. The results provide additional support that TDs are at least as effective as other first-line medications for treating uncomplicated hypertension.