Cost-effectiveness of direct oral anticoagulants versus vitamin K antagonist in atrial fibrillation: A study protocol using Real-World Data from Catalonia (FantasTIC Study).

BACKGROUND: Anticoagulant therapy is used for stroke prevention and proved to be effective and safe in the long term. The study aims to analyse the cost-effectiveness relationship of using of direct-acting oral anticoagulants vs vitamin K antagonists to prevent ischaemic stroke in patients with nonvalvular atrial fibrillation, including all the active ingredients marketed in Spain, prescribed for 2 years in the Primary Care service of the Institut Català de la Salut. METHODS: Population-based cohort study, in which the cost of the 2 treatment groups will be evaluated. Direct costs (pharmacy, primary care, emergency and hospitalization) and indirect costs (lost productivity) will be included from a social perspective. Effectiveness (assessed as the occurrence of a health event, the 1 of primary interest being stroke) will be determined, with a 2-year time horizon and a 3% discount rate. The average cost of the 2 groups of drugs will be compared using a regression model to determine the factors with the greatest influence on determining costs. We will carry out a univariate ('one-way') deterministic sensitivity analysis. DISCUSSION: We hope to provide relevant information about direct and indirect costs of oral anticoagulants, which, together with aspects of effectiveness and safety, could help shape the consensual decision-making of evaluating bodies.

Economic evaluation of a pharmacogenetic dosing algorithm for coumarin anticoagulants in The Netherlands.

AIM: To investigate the cost-effectiveness of a pharmacogenetic dosing algorithm versus a clinical dosing algorithm for coumarin anticoagulants in The Netherlands. MATERIALS & METHODS: A decision-analytic Markov model was used to analyze the cost-effectiveness of pharmacogenetic dosing of phenprocoumon and acenocoumarol versus clinical dosing. RESULTS: Pharmacogenetic dosing increased costs by €33 and quality-adjusted life-years (QALYs) by 0.001. The incremental cost-effectiveness ratios were €28,349 and €24,427 per QALY gained for phenprocoumon and acenocoumarol, respectively. At a willingness-to-pay threshold of €20,000 per QALY, the pharmacogenetic dosing algorithm was not likely to be cost effective compared with the clinical dosing algorithm. CONCLUSION: Pharmacogenetic dosing improves health only slightly when compared with clinical dosing. However, availability of low-cost genotyping would make it a cost-effective option.

Safety of Outpatient Implantation of the Implantable Cardioverter-defibrillator.

INTRODUCTION AND OBJECTIVES: Strategies are needed to reduce health care costs and improve patient care. The objective of our study was to analyze the safety of outpatient implantation of cardioverter-defibrillators. METHODS: A retrospective study was conducted in 401 consecutive patients who received an implantable cardioverter-defibrillator between 2007 and 2012. The rate of intervention-related complications was compared between 232 patients (58%) whose implantation was performed in the outpatient setting and 169 patients (42%) whose intervention was performed in the inpatient setting. RESULTS: The mean age (standard deviation) of the patients was 62 (14) years; 336 (84%) were male. Outpatients had lower left ventricular ejection fraction and a higher percentage had an indication for primary prevention of sudden death, compared to inpatients. Only 21 outpatients (9%) required subsequent hospitalization. The rate of complications until the third month postimplantation was similar for outpatients (6.0%) and inpatients (5.3%); P = .763. In multivariate analysis, only previous anticoagulant therapy was related to the presence of complications (odds ratio = 3.2; 95% confidence interval, 1.4-7.4; P < .01), mainly due to an increased rate of pocket hematomas. Each outpatient implantation saved approximately €735. CONCLUSIONS: Outpatient implantation of implantable cardioverter-defibrillators is safe and reduces costs. Close observation is recommended for patients receiving chronic anticoagulation therapy due to an increased risk of complications.

Pharmacogenetic-guided dosing of coumarin anticoagulants: algorithms for warfarin, acenocoumarol and phenprocoumon.

Coumarin derivatives, such as warfarin, acenocoumarol and phenprocoumon are frequently prescribed oral anticoagulants to treat and prevent thromboembolism. Because there is a large inter-individual and intra-individual variability in dose-response and a small therapeutic window, treatment with coumarin derivatives is challenging. Certain polymorphisms in CYP2C9 and VKORC1 are associated with lower dose requirements and a higher risk of bleeding. In this review we describe the use of different coumarin derivatives, pharmacokinetic characteristics of these drugs and differences amongst the coumarins. We also describe the current clinical challenges and the role of pharmacogenetic factors. These genetic factors are used to develop dosing algorithms and can be used to predict the right coumarin dose. The effectiveness of this new dosing strategy is currently being investigated in clinical trials.

[Dabigatran versus acenocumarol for the prevention of stroke in atrial fibrillation: budget impact analysis in one health department in Spain]. / Dabigatrón versus acenocumarol para la prevención del ictus en la fibrilación atrial: análisis de impacto presupuestario en un departamento sanitario.

BACKGROUND: To Estimate, in the context of a Health Department of the Valencia Health Agency, the budgetary impact of the widespread use of dabigatran at doses of 110 and 150 mg in patients with non-valvular atrial fibrillation (AF), regarding the current scenario with acenocoumarol therapy. METHODS: Budget impact analysis of three scenarios of oral anticoagulation use in AF: a) current treatment with acenocoumarol, b) widespread replacement of acenocoumarol for Dabigatran 110 mg and, c) idem at doses of 150 mg. The analysis was conducted from the perspective of the Valencia Health Agency with a time horizon of one year (2009). The effectiveness and adverse effects were extrapolated from the RE-LY study, while prevalence and cost data correspond to the Health Department estimates in 2009. RESULTS: We included 5889 patients (2.4% of the population > 18 years) diagnosed with AF, of which 3726 (63.2%) were treated with acenocoumarol. The total costs of each scenario were € 1,119,412 (€ 300 patient/year) for acenocoumarol, € 4,985,095 (€ 1,337 patient/year) for dabigatran 110 and € 4,981,226 (€ 1,336 patient/year) for dabigatran 150, with a budget impact of 1,037 euros/year per patient shifted from acenocumarol to dabigatran-150. CONCLUSIONS: The high budgetary impact of moving to a scenario of widespread substitution of warfarin for Dabigatran supports the restriction of this therapeutic strategy to subgroups of patients at high risk or difficult control.

A multiplex assay to detect variations in the CYP2C9, VKORC1, CYP4F2 and APOE genes involved in acenocoumarol metabolism.

OBJECTIVES: We have developed a genotyping system to determine the alleles of genes related to interindividual variability in acenocoumarol dosage requirements. This genotyping system is intended for routine clinical use and therefore it is essential that it be simple, fast and inexpensive. DESIGN AND METHODS: We developed a PCR multiplex SNaPshot reaction that targets 6 SNPs (single nucleotide polymorphisms) in CYP2C9, CYP4F2, VKORC1 and APOE genes, which are associated with acenocoumarol dose requirements. RESULTS: We tested the multiplex in 152 samples and found it to be 100% concordant with the results of other methods. CONCLUSIONS: We successfully produced a reliable multiplex system for simultaneously typing 6 SNPs. This system may be used as a model for accurate, simple and inexpensive genotyping of SNPs related to dose requirements. This information allows the prediction of drug efficiency in patients prior to treatment with acenocoumarol and the prevention of adverse drug reactions.

Abrupt versus gradual withdrawal of vitamin K antagonist treatment in patients with venous thromboembolic disease: assessment of hypercoagulability and clinical outcome.

BACKGROUND: It is yet unclear whether vitamin K antagonist treatment should be stopped abruptly or gradually after an episode of venous thromboembolism. The mode of withdrawal might influence a potential development of a hypercoagulable state, which could influence the risk for recurrent disease. METHODS: We prospectively studied 37 consecutive patients in whom acenocoumarol was discontinued either abrupt (18) or gradually (19) (2/3 and 1/3 of the initial dose for one week). Blood sampling was performed at various time points up to 18 days after complete withdrawal and was analysed for INR, prothrombin fragment F1 + 2 and D-dimer. All patients were clinically followed-up for the assessment of the association between hypercoagulability and occurrence of disease such as recurrent venous thromboembolism or malignancy. RESULTS: An approximately fourfold increase was observed (median increase from 0.3 to 1.3 nmol/l) in the F1 + 2 levels after both abrupt and gradual withdrawal and in the D-dimer concentrations in the abrupt withdrawal group (0.10 to 0.44 mg/l), while those in whom acenocoumarol was discontinued gradually showed a less pronounced increase of the D-dimer levels (0.11 to 0.29 mg/L) (not significant). During follow-up one recurrent venous thromboembolic event occurred in each group, and a diagnosis of cancer was made four times. All these patients had the highest D-dimer concentrations measured in the entire study group. CONCLUSIONS: This study indicates the potential for a hypercoagulable state after acenocoumarol discontinuation, which was not prevented by tapering the acenocoumarol dose. D-dimer, measured 2 to 3 weeks after acenocoumarol withdrawal, might be an important tool to identify patients at risk for recurrent venous thromboembolism and/or for the presence of an underlying malignancy.

Assessment of patient capability to self-adjust oral anticoagulant dose: a multicenter study on home use of portable prothrombin time monitor (COAGUCHECK).

BACKGROUND AND OBJECTIVES: Self-testing and self-monitoring with portable prothrombin time (PT) monitors has been shown to be feasible and safe. However the ability of patients on chronic oral anticoagulant therapy (OAT) to self-adjust their dose without specific training has never been properly evaluated. The aims of this study were to evaluate: 1) the ability of patients on chronic OAT to self-adjust their dose without specific training; 2) the integration of a portable PT monitor (Coagucheck, Roche Diagnostics, Germany) for home use into routine patient care in anticoagulation clinics. DESIGN AND METHODS: A nested case-control study was conducted in four centers of the Italian Federation of Anticoagulation Clinics (FCSA). Patients (n=78) on stable OAT for at least 6 months (cases: 47 men, 31 women, age range: 18-75 years) were enrolled on a volunteer basis after passing an Abbreviated Mental Test and providing informed consent. After three instruction sessions on the use of Coaguchek, subjects performed the PT test at home, communicated the INR results to the Center and suggested the dose adjustment and date for next control as they thought appropriate. However, they were requested to follow the prescription made by the Center. Controls (78 subjects) matched by age (+/- 5 years), sex and therapeutic range with the cases, were selected from among those who attended the anticoagulation clinics and managed by usual care. RESULTS: When compared with the dose prescribed by the Clinic, the dose suggested by warfarin and acenocoumarol users was equal to or within +/- 6% of the mean weekly dose in 80% and 82% of suggestions, respectively. Time spent in the therapeutic range during the study was the same (80%) for cases and controls. INTERPRETATION AND CONCLUSIONS: Selected patients on chronic anticoagulant therapy can acquire a satisfactory ability for self-adjustment of OAT dose without specific training.

Assessment of therapeutic quality control in a long-term anticoagulant trial in post-myocardial infarction patients.

Various methods have been described to evaluate efficacy of anticoagulant therapy using the international normalized ratio (INR). We compared the following approaches: (1) total INR's or the most recent measurement; (2) percent time within therapeutic range, with INR changing directly or halfway between visits; and (3) total observation time assuming INR changing linearly. The study population comprised 1700 post myocardial infarction patients. Treatment comprised 3725 patient-years. There were 61,471 INR assessments with target therapeutic level of 2.8-4.8. Acenocoumarol as well as phenprocoumon were employed. Therapeutic achievement in the first months of treatment was low: less than 60% of INR's were in range. Treatment stabilized after 6 months. Patients on acenocoumarol were within range 70% of the time compared to 80% for phenprocoumon. Method 3 is preferred because it incorporates time and is capable of calculating incidence rates at different INR levels. Our findings call for an urgent improvement of standard of anticoagulant control in the first months following commencement of treatment.

[Checking oral anticoagulation in capillary blood]. / Control de la anticoagulación oral en sangre capilar.

PURPOSE: To check out the reproducibility and costs of prothrombin time (PT) determination as a control of oral anticoagulant therapy (OAT) in plasma and capillary blood. PATIENTS AND METHODS: The study was carried out in two phases: along two years, 1,700 patients with OAT were controlled, 700 of them in the hospital outpatient clinic. In 149 patients INR was simultaneously determined in both capillary and venous blood. The 700 patients receiving acenocoumarin who had been controlled in 1991 according to the conventional plasma-sample fashion, were controlled in the second year (i.e., 1992) by means of capillary blood testing, a comparison of the costs of each method and the need for anticoagulant drugs being undertaken. Venous blood PT was assessed with reagent thromboplastin (Tromborel S) in an Electra-1000 (MLA) system. An automated Trombotrack system was used for the capillary blood tests using Thrombotest as current procedure. The results were expressed as INR in both methods. The statistical evaluation of the results was carried out by means of Student's t, variance analysis, and correlation study. RESULTS: No significant differences were found in the anticoagulation intervals attained from venous or capillary blood samples. No significant differences were seen in 87 patients on whom the test was repeated in two samples drawn from a single capillary puncture. The weekly OAT doses of 30 patients along six months were analysed. The need for anticoagulant drugs was similar (17.4 vs 17.2 mg/patient/week). The mean INR in 1991 was 2.82 and the mean drug-need was 15.24 mg/week, whereas in 1992 the mean INR was 2.86 and the need for anticoagulant was 15.49 mg/week. The costs of the conventional method were 103.6 Pta, this being 70 Pta for capillary blood, which means a 32% savings. CONCLUSIONS: OAT control by means of PT performed on capillary blood must be considered a substitutive method for the venous blood assay due to its efficacy, simplicity and lower costs.