Incidence and cost of bleeding events requiring hospitalization in patients with atrial fibrillation treated with acenocoumarol in Greece.

BACKGROUND: To estimate the incidence of hemorrhagic events in patients with atrial fibrillation (AF) treated with acenocoumarol, and the management cost of those requiring hospitalization in Greece. METHODS: A nationwide telephone survey was conducted between December 2017 and January 2018, to identify cardiologists who treat AF patients with acenocoumarol. A total of 300 cardiologists were selected and reported the number of AF acenocoumarol-treated patients during the past 12 months and the number of those who experienced a hemorrhagic event. The hospital charges to sickness fund and the cost of resource utilization of AF patients hospitalized between January 2013 and June 2017 at a tertiary hospital in Athens due to acenocoumarol-related bleedings were retrieved. RESULTS: Out of 48,255 AF patients, 12,633 (26.2%) were treated with acenocoumarol. In all, 5.1% of patients experienced a hemorrhagic event with the incidence of bleeding requiring hospitalization being 1.7%. The most common bleeding site was the gastrointestinal system (51.5%). The mean (95% CI) management cost per bleeding event requiring hospitalization was €1,202 (€1,058-€1,420). The higher cost was that of intracranial bleeding €3,887 (€2,700-€5,046). The expected annual economic burden for the management of bleedings related to acenocoumarol and requiring hospitalization was estimated at €1,463,955. CONCLUSIONS: The incidence of bleeding events in AF acenocoumarol-treated patients in Greece as well as the estimated annual economic burden for the management of bleeding events requiring hospitalization, emphasize the need to comply with the current guidelines and to optimize therapeutic strategies for the management of AF side effects with oral anticoagulants, particularly in patients with high bleeding risk.

Predictors for total hospital and cardiology cost claims among patients with atrial fibrillation initiating dabigatran or acenocoumarol in The Netherlands.

AIMS: The prevalence of atrial fibrillation (AF) has increased over the past years due to aging of the population, and healthcare costs associated with AF reflect a significant financial burden. The aim of this study was to explore predictors for the real-world AF-related in-hospital costs in patients that recently initiated anticoagulation with acenocoumarol or dabigatran. METHODS: Predictors for claimed total hospital care costs and cardiology costs in AF patients were explored by using hospital financial claims data from propensity score matched patient groups in a large Dutch community hospital. This study analyzed the total dataset (n = 766) and carried out a secondary analysis for all matched pairs of anticoagulation naïve AF patients (n = 590) by ordinal regression. RESULTS: Dabigatran was a predictor for significantly lower cardiology and total hospital care costs (Odds Ratio [OR] = 0.43, 95% confidence interval (CI) = 0.33-0.57; and OR = 0.60, 95% CI = 0.46-0.79, respectively). Female gender was a predictor for lower total hospital care costs. Predictors for an increase in total hospital care costs were the occurrence of stroke or systemic embolism, major bleeding, and minor bleeding. The costs predictors were comparable when limiting the analysis to patients that were anticoagulation naïve. Age and CHA2DS2-VASc were not predictors for either cardiology or total hospital care costs in both analyses. CONCLUSION: Dabigatran treatment was as a predictor for lower cardiology costs and lower total hospital care costs in AF patients that initiated oral anticoagulation.

Identification and weighting of the most critical "real-life" drug-drug interactions with acenocoumarol in a tertiary care hospital.

PURPOSE: The objective of this study was to identify the most clinically relevant drug-drug interactions (DDIs) at risk of affecting acenocoumarol safety in our tertiary care university hospital, a 2,000 bed institution. METHODS: We identified DDIs occurring with acenocoumarol by combining two different sources of information: a 1-year retrospective analysis of acenocoumarol prescriptions and comedications from our Computerized Physician Order Entry (CPOE) system (n = 2,439 hospitalizations) and a retrospective study of clinical pharmacology consultations involving acenocoumarol over the past 14 years (1994-2007) (n = 407). We classified these DDIs using an original risk-analysis method. A criticality index was calculated for each associated drug by multiplying three scores based on mechanism of interaction, involvement in a supratherapeutic international normalized ratio (INR) (≥ 6) and involvement in a severe bleeding. RESULTS: One hundred and twenty-six DDIs were identified and weighted. Twenty-eight drugs had a criticality index ≥ 20 and were therefore considered at high risk for interacting with acenocoumarol by increasing its effect: 75% of these drugs involved a pharmacokinetic mechanism and 14 % a pharmacodynamic mechanism. An unknown mechanism of interaction was involved in 11 % of drugs. CONCLUSION: Twenty-eight specific drugs were identified as being at high risk for interacting with acenocoumarol in our hospital using an original risk-analysis method. Most analyzed drugs interact with acenocoumarol via a pharmacokinetic mechanism. Actions such as the implementation of alerts in our CPOE system should be specifically developed for these drugs.

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.