Supervised Patient Self-Testing of Warfarin Therapy Using an Online System

Background

Point-of-care international normalized ratio (INR) monitoring devices simplify warfarin management by allowing selected patients to monitor their own therapy in their homes. Patient self-testing (PST) has been shown to improve the clinical outcomes of warfarin therapy compared to usual care.

Objective

To compare management of warfarin therapy using PST combined with online supervision by physicians via a custom system with usual warfarin management, which involved laboratory testing and physician dosing.

Methods

Interested patients were recruited via community pharmacies to participate in a warfarin PST training program. Participants were required to have a long-term indication for warfarin, have been taking warfarin for at least 6 months, and have Internet access in their home. The training involved two sessions covering theoretical aspects of warfarin therapy, use of the CoaguChek XS, and the study website. Following training, patients monitored their INR once weekly for up to 3 months. Patients and physicians utilized a secure website to communicate INR values, dosage recommendations, and clinical incidents. Physicians provided a 6-12 month history of INR results for comparison with study results. The percentage of time spent within the therapeutic INR range (TTR) was the primary outcome, with participants acting as their own historical controls. The percentage of INR tests in range and participant satisfaction were secondary outcomes.

Results

Sixteen patients completed training requirements. The mean age of participants was 69.8 (SD 10.1) years. TTR improved significantly from 66.4% to 78.4% during PST (P=.01), and the number of tests within the target range also improved significantly (from 66.0% at prior to the study to 75.9% during PST; P=.04). Patients and physicians expressed a high degree of satisfaction with the monitoring strategy and online system.

Conclusions

PST supported by an online system for supervision was associated with improved INR control compared to usual care in a small group of elderly patients. Further research is warranted to investigate the clinical outcomes and cost-effectiveness of online systems to support patients monitoring medications and chronic conditions in the home.     

Potential use of NOACs in developing countries: pros and cons

Purpose

Although vitamin K antagonists (VKAs) are effective for long-term thromboprophylaxis in atrial fibrillation (AF), their limitations have led to widespread underutilisation, especially in the developing world. Novel oral anticoagulants (NOACs) have emerged as promising alternatives to VKAs, although there are some particular considerations and challenges to their introduction in developing countries. This review summarises the current state of antithrombotic management of AF in the developing world, explores the early evidence for the NOACs and describes some of the special considerations that must be taken into account when considering the role of the NOACs within developing countries’ health care systems.

Methods

A literature search was conducted via PubMed and Google Scholar to find articles published in English between the years 2000 to 2014. Search terms used were “atrial fibrillation”, “oral anticoagulants”, “warfarin”, “NOACs”, “dabigatran”, “rivaroxaban”, “apixaban”, “edoxaban”, “time in therapeutic range”, “International Normalized Ratio” “cost-effectiveness”, “stroke”, “adverse-drug reactions” and “drug–drug interactions”, together with the individual names of developing countries as listed by the World Bank. We reviewed the results of randomized clinical trials, relevant retrospective and prospective studies, case-studies and review articles.

Results

Many developing countries lack or have sporadic data on the quality of AF management, making it difficult to anticipate the potential impact of NOACs in these settings. The utilisation of anticoagulants for AF appears highly variable in developing countries. Given the issues associated with VKA therapy in many developing countries, NOACs offer some potential advantages; however, there is insufficient evidence to advocate the widespread replacement of warfarin at present. VKAs may continue to have a role in selected patients or countries, especially if alternative monitoring strategies can be utilised.

Conclusion

The evaluation of the introduction of NOACs should consider safety, budget concerns and the quality of oral anticoagulation care achieved by each country. Prospective registries will be important in developing countries to better elucidate the comparative safety, efficacy and cost-effectiveness of NOACs and VKAs as NOACs are introduced into practice.     

PPI use in patients commenced on clopidogrel: a retrospective cross‐sectional evaluation

Background/Aims: Antiplatelet therapy with aspirin and clopidogrel is an important component of the management of acute coronary syndrome, but it also increases the risk of bleeding. There are no formal guidelines about the use of a proton pump inhibitor (PPI) for gastroprotection in patients on clopidogrel. This study assessed how many patients in the Royal Darwin Hospital (RDH) and the Royal Hobart Hospital (RHH) prescribed clopidogrel and at risk of bleeding were co‐prescribed PPIs. Methods: We conducted a retrospective cohort study using a pharmacy database to select all patients commenced on clopidogrel in a 1‐year period. We identified all patients newly prescribed clopidogrel and determined the proportion that had a risk factor for bleeding and also received a PPI. We also assessed the effect of the use of PPIs on the number of reported bleeds. Results: The final study cohort consisted of 385 patients who had been newly prescribed clopidogrel. Of all patients discharged on clopidogrel, 95·6% (368/385) had ≥1 risk factor for bleeding. One hundred and twenty‐eight of these patients [128/368, (34·8%)] were discharged on a PPI. Patients on dual antiplatelet therapy with an additional risk factor for bleeding and not discharged on a PPI were more likely to develop a major bleed than patients on dual antiplatelet therapy without a risk factor for bleeding not discharged on a PPI (11·1% vs. 1·8%; P < 0·01). Patients on dual antiplatelet therapy with an additional risk factor for bleeding not discharged on a PPI had a higher probability (borderline significance) of major bleeding, compared with patients on dual antiplatelet therapy with an additional risk factor for bleeding discharged on a PPI [PPI: 1/60, (1·7%) vs. no PPI: 6/54, (11·1%); P = 0·05]. Conclusions: Our results indicate that PPIs may only lower the probability of major bleeding in patients treated with dual antiplatelet therapy, who possess additional risk factor(s) for bleeding.     

A Summary of the Literature Evaluating Adherence and Persistence with Oral Anticoagulants in Atrial Fibrillation

Atrial fibrillation (AF) is a growing public health concern and remains an independent risk factor for ischemic stroke. Warfarin, a commonly used oral anticoagulant, is associated with a 60–70 % relative reduction in stroke risk and a reduction in mortality of 26 %. However, warfarin has several limitations, including a narrow therapeutic window, variable dose response, multiple interactions with other drugs and concurrent illnesses, and the need for frequent laboratory monitoring. In recent years, the direct acting oral anticoagulants (DOACs), including dabigatran, rivaroxaban, apixaban and edoxaban, have been developed to overcome the limitations of warfarin therapy. These treatment strategies are either comparable or superior to warfarin in stroke prevention in AF. Despite the documented effectiveness of oral anticoagulants in AF, patients may not derive optimal benefit if they fail to adhere or fail to continue with their medication. This may lead to treatment failure, increased hospitalization and mortality. This review summarizes the literature regarding adherence and persistence (or discontinuation) rates with oral anticoagulants in the management of AF; the impact of non-adherence and non-persistence on treatment outcomes; and the effectiveness of strategies to improve adherence and persistence with oral anticoagulant therapy.