Improving the quality of anticoagulation of patients with atrial fibrillation in managed care organizations: results of the managing anticoagulation services trial

Clinical service organisation for adults with atrial fibrillation

BACKGROUND

Atrial fibrillation (AF) is an increasingly prevalent heart rhythm condition in adults. It is considered a common cardiovascular condition with complex clinical management. The increasing prevalence and complexity in management underpin the need to adapt and innovate in the delivery of care for people living with AF. There is a need to systematically examine the optimal way in which clinical services are organised to deliver evidence-based care for people with AF. Recommended approaches include collaborative, organised multidisciplinary, and virtual (or eHealth/mHealth) models of care.

OBJECTIVES

To assess the effects of clinical service organisation for AF versus usual care for people with all types of AF.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, and CINAHL to October 2022. We also searched ClinicalTrials.gov and the WHO ICTRP to April 2023. We applied no restrictions on date, publication status, or language.

SELECTION CRITERIA

We included randomised controlled trials (RCTs), published as full texts and as abstract only, involving adults (≥ 18 years) with a diagnosis of any type of AF. We included RCTs comparing organised clinical service, disease-specific management interventions (including e-health models of care) for people with AF that were multicomponent and multidisciplinary in nature to usual care.

DATA COLLECTION AND ANALYSIS

Three review authors independently selected studies, assessed risk of bias, and extracted data from the included studies. We calculated risk ratio (RR) for dichotomous data and mean difference (MD) or standardised mean difference (SMD) for continuous data with 95% confidence intervals (CIs) using random-effects analyses. We then calculated the number needed to treat for an additional beneficial outcome (NNTB) using the RR. We performed sensitivity analyses by only including studies with a low risk of selection and attrition bias. We assessed heterogeneity using the I² statistic and the certainty of the evidence according to GRADE. The primary outcomes were all-cause mortality and all-cause hospitalisation. The secondary outcomes were cardiovascular mortality, cardiovascular hospitalisation, AF-related emergency department visits, thromboembolic complications, minor cerebrovascular bleeding events, major cerebrovascular bleeding events, all bleeding events, AF-related quality of life, AF symptom burden, cost of intervention, and length of hospital stay.

MAIN RESULTS

We included 8 studies (8205 participants) of collaborative, multidisciplinary care, or virtual care for people with AF. The average age of participants ranged from 60 to 73 years. The studies were conducted in China, the Netherlands, and Australia. The included studies involved either a nurse-led multidisciplinary approach (n = 4) or management using mHealth (n = 2) compared to usual care. Only six out of the eight included studies could be included in the meta-analysis (for all-cause mortality and all-cause hospitalisation, cardiovascular mortality, cardiovascular hospitalisation, thromboembolic complications, and major bleeding), as quality of life was not assessed using a validated outcome measure specific for AF. We assessed the overall risk of bias as high, as all studies had at least one domain at unclear or high risk of bias rating for performance bias (blinding) in particular. Organised AF clinical services probably result in a large reduction in all-cause mortality (RR 0.64, 95% CI 0.46 to 0.89; 5 studies, 4664 participants; moderate certainty evidence; 6-year NNTB 37) compared to usual care. However, organised AF clinical services probably make little to no difference to all-cause hospitalisation (RR 0.94, 95% CI 0.88 to 1.02; 2 studies, 1340 participants; moderate certainty evidence; 2-year NNTB 101) and may not reduce cardiovascular mortality (RR 0.64, 95% CI 0.35 to 1.19; 5 studies, 4564 participants; low certainty evidence; 6-year NNTB 86) compared to usual care. Organised AF clinical services reduce cardiovascular hospitalisation (RR 0.83, 95% CI 0.71 to 0.96; 3 studies, 3641 participants; high certainty evidence; 6-year NNTB 28) compared to usual care. Organised AF clinical services may have little to no effect on thromboembolic complications such as stroke (RR 1.14, 95% CI 0.74 to 1.77; 5 studies, 4653 participants; low certainty evidence; 6-year NNTB 588) and major cerebrovascular bleeding events (RR 1.25, 95% CI 0.79 to 1.97; 3 studies, 2964 participants; low certainty evidence; 6-year NNTB 556). None of the studies reported minor cerebrovascular events.

AUTHORS' CONCLUSIONS

Moderate certainty evidence shows that organisation of clinical services for AF likely results in a large reduction in all-cause mortality, but probably makes little to no difference to all-cause hospitalisation compared to usual care. Organised AF clinical services may not reduce cardiovascular mortality, but do reduce cardiovascular hospitalisation compared to usual care. However, organised AF clinical services may make little to no difference to thromboembolic complications and major cerebrovascular events. None of the studies reported minor cerebrovascular events. Due to the limited number of studies, more research is required to compare different models of care organisation, including utilisation of mHealth. Appropriately powered trials are needed to confirm these findings and robustly examine the effect on inconclusive outcomes. The findings of this review underscore the importance of the co-ordination of care underpinned by collaborative multidisciplinary approaches and augmented by virtual care.

New Internet-Based Warfarin Anticoagulation Management Approach After Mechanical Heart Valve Replacement: Prospective, Multicenter, Randomized Controlled Trial

BACKGROUND

Mechanical heart valve replacement (MHVR) is an effective method for the treatment of severe heart valve disease; however, it subjects patient to lifelong warfarin therapy after MHVR with the attendant risk of bleeding and thrombosis. Whether internet-based warfarin management reduces complications and improves patient quality of life remains unknown.

OBJECTIVE

This study aimed to compare the effects of internet-based warfarin management and the conventional approach in patients who received MHVR in order to provide evidence regarding alternative strategies for long-term anticoagulation.

METHODS

This was a prospective, multicenter, randomized, open-label, controlled clinical trial with a 1-year follow-up. Patients who needed long-term warfarin anticoagulation after MHVR were enrolled and then randomly divided into conventional and internet-based management groups. The percentage of time in the therapeutic range (TTR) was used as the primary outcome, while bleeding, thrombosis, and other events were the secondary outcomes.

RESULTS

A total of 721 patients were enrolled. The baseline characteristics did not reach statistical differences between the 2 groups, suggesting the random assignment was successful. As a result, the internet-based group showed a significantly higher TTR (mean 0.53, SD 0.24 vs mean 0.46, SD 0.21; P<.001) and fraction of time in the therapeutic range (mean 0.48, SD 0.22 vs mean 0.42, SD 0.19; P<.001) than did those in the conventional group. Furthermore, as expected, the anticoagulation complications, including the bleeding and embolic events had a lower frequency in the internet-based group than in the conventional group (6.94% vs 12.74%; P=.01). Logistic regression showed that internet-based management increased the TTR by 7% (odds ratio [OR] 1.07, 95% CI 1.05-1.09; P<.001) and reduced the bleeding and embolic risk by 6% (OR 0.94, 95% CI 0.92-0.96; P=.01). Moreover, low TTR was found to be a risk factor for bleeding and embolic events (OR 0.87, 95% CI 0.83-0.91; P=.005).

CONCLUSIONS

The internet-based warfarin management is superior to the conventional method, as it can reduce the anticoagulation complications in patients who receive long-term warfarin anticoagulation after MHVR.

TRIAL REGISTRATION

Chinese Clinical Trial Registry ChiCTR1800016204; http://www.chictr.org.cn/showproj.aspx?proj=27518.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

RR2-10.1136/bmjopen-2019-032949.

The SAMe-TT2R2 score as an indicator of warfarin control for patients with deep vein thrombosis in Queensland, Australia

Oral anticoagulation options for patients with venous thromboembolism (VTE) include vitamin K antagonists like warfarin. Good warfarin control is linked to outcomes of therapy, and the SAMe-TT₂R₂ model has been reported to predict control in atrial fibrillation patients with scores ≥ 2 linked to poor control. There has been limited and conflicting data in VTE populations, therefore this study aimed at determining the predictive ability of this model in Australian patients with deep vein thrombosis. Retrospective data of patients receiving warfarin care at a private pathology clinic in Queensland was collected. The time in therapeutic range (TTR) and SAMe-TT₂R₂ score was calculated for individual patients. Mean TTR and patients with TTR ≥ 65% were used for analysis and comparison across patients categorised as a score of 0-1 and ≥ 2. Of the 533 patients, the majority had a SAMe-TT₂R₂ score of 0-1. No significant difference was found in mean TTR between patients with a score of 0-1 and ≥ 2 but there was a significantly higher percentage of patients with a TTR ≥ 65% between groups (93.8% vs. 69.2%, p < 0.0001, respectively). The SAMe-TT₂R₂ score may assist in identifying patients with VTE likely to achieve good control (TTR ≥ 65%), but further investigation is required to determine the most suitable model for predicting warfarin control in this population.

Quality of life in patients with nonvalvular atrial fibrillation treated with oral anticoagulants

OBJECTIVES

Health-related quality of life (HRQL) is a key factor in making anticoagulant treatment decisions. The objective of this study was to assess the HRQL of patients with nonvalvular atrial fibrillation by treatment type: direct oral anticoagulants (DOACs) or vitamin K antagonists (VKAs).

METHODS

We carried out a cross-sectional observational study with clinical practice data, gathering demographic and clinical variables. HRQL was measured using the 5-level 5-dimension EuroQol questionnaire (EQ-5D-5L). Differences between the study groups in HRQL as measured by the EQ-5D-5L were analyzed using two-part multivariate regression models. First, using logistic regression, the adjusted probability, p(x), of having perfect health was estimated in each subgroup. Secondly, generalized linear models were used to estimate mean disutility values, w(x), in a population that does not have perfect health, i.e. utility less than 1 or 1-w(x).

RESULTS

We recruited 333 patients, of whom 126 were on DOACs and 207 on VKAs. A significant difference was observed in the EQ-5D-5L anxiety/depression dimension, with a higher percentage of patients classified in the 'no problems' category in the DOAC group. The same type of analysis did not identify significant differences in any of the other dimensions (mobility, self-care, usual activities or pain/discomfort).

DISCUSSION

In the multivariate model, utility was significantly higher in the DOAC group than in the VKA group, although the difference was small (0.0121). This difference is attributable to patients on DOACs having less anxiety/depression.

CONCLUSION

Patients treated with DOACs report a slightly better quality of life than those treated with VKAs.

AF-React study: atrial fibrillation management strategies in clinical practice-retrospective longitudinal study from real-world data in Northern Portugal

OBJECTIVES

To determine the prevalence of atrial fibrillation (AF) and to assess how these patients are being cared for: what anticoagulants are being prescribed and are they being prescribed as recommended?

DESIGN

Retrospective longitudinal study.

SETTING

This study was conducted in the Regional Health Administration of Northern Portugal.

PARTICIPANTS

This study used a database that included 63526 patients with code K78 of the International Classification of Primary Care between January 2016 and December 2018.

RESULTS

The prevalence of AF among adults over 40 years in the northern region of Portugal was 2.3% in 2016, 2.8% in 2017 and 3% in 2018. From a total of 63 526 patients, 95.8% had an indication to receive anticoagulation therapy. Of these, 44 326 (72.9%) are being treated with anticoagulants: 17 936 (40.5%) were prescribed vitamin K antagonists (VKAs) and 26 390 (59.5%) were prescribed non-VKA anticoagulants. On the other hand, 2688 patients of the total (4.2%) had no indication to receive anticoagulation therapy. Of these 2688 patients, 1100 (40.9%) were receiving anticoagulants.

CONCLUSIONS

The prevalence of AF is 3%. Here, we report evidence of both undertreatment and overtreatment. Although having an indication, a considerable proportion of patients (27.1%) are not anticoagulated, and among patients with AF without an indication to receive anticoagulation therapy, a considerable proportion (40.9%) are receiving anticoagulants. The AF-React study brings extremely relevant conclusions to Portugal and follows real-world studies in patients with AF in Europe, presenting some data not yet studied.

Budget Impact Analysis of Anticoagulation Clinics in Patients with Atrial Fibrillation under Chronic Therapy with Oral Anticoagulants

OBJECTIVES

To assess budget impact of the implementation of an anticoagulation clinic (AC) compared to usual care (UC), in patients with non-valvular atrial fibrillation (NVAF).

METHOD

A decision tree was designed to analyze the cost and events rates over a 1-year horizon. The patients were distributed according to treatment, 30% Direct Oral Anticoagulant (DOAC) regimens and the rest to warfarin. The thromboembolism and bleeding were derived from observational studies which demonstrated that ACs had important impact in reducing the frequency of these events compared with UC, due to higher adherence with DOACs and proportion of time in therapeutic range (TTR) with warfarin. Costs were derived from the transactional platform of Colombian government, healthcare authority reimbursement and published studies. The values were expressed in American dollars (USD). The exchanged rate used was COP $3.693 per dollar.

RESULTS

During 1 year of follow-up, in a cohort of 228 patients there were estimated 48 bleedings, 6 thromboembolisms in AC group versus 84 bleedings, and 12 thromboembolisms events in patients receiving UC. Total costs related to AC were $126 522 compared with $141 514 in UC. The AC had an important reduction in the cost of clinical events versus UC ($52 085 vs $110 749) despite a higher cost of care facilities ($74 436 vs $30 765). A sensibility analysis suggested that in the 83% of estimations, the AC produced savings varied between $27 078 and $135 391.

CONCLUSIONS

This study demonstrated that AC compared with UC, produced an important savings in the oral anticoagulation therapy for patients with NVAF.

Cost saving analysis of specialized, eHealth-based management of patients receiving oral anticoagulation therapy: Results from the thrombEVAL study

To evaluate the cost-saving of a specialized, eHealth-based management service (CS) in comparison to regular medical care (RMC) for the management of patients receiving oral anticoagulation (OAC) therapy. Costs of hospitalization were derived via diagnosis-related groups which comprise diagnoses (ICD-10) and operation and procedure classification system (OPS), which resulted in OAC-related (i.e. bleeding/ thromboembolic events) and non-OAC-related costs for both cohorts. Cost for anticoagulation management comprised INR-testing, personnel, and technical support. In total, 705 patients were managed by CS and 1490 patients received RMC. The number of hospital stays was significantly lower in the CS cohort compared to RMC (CS: 23.4/100 py; RMC: 68.7/100 py); with the most pronounced difference in OAC-related admissions (CS: 2.8/100 py; RMC: 13.3/100 py). Total costs for anticoagulation management amounted to 101 EUR/py in RMC and 311 EUR/py in CS, whereas hospitalization costs were 3261 [IQR 2857-3689] EUR/py in RMC and 683 [504-874] EUR/py in CS. This resulted in an overall cost saving 2368 EUR/py favoring the CS. The lower frequency of adverse events in anticoagulated patients managed by the telemedicine-based CS compared to RMC translated into a substantial cost-saving, despite higher costs for the specialized management of patients.Trial registration: ClinicalTrials.gov, unique identifier NCT01809015, March 8, 2013.

Wild P, H. Prochaska J. Telemedicine-Based Specialized Care Improves the Outcome of Anticoagulated Individuals with Venous Thromboembolism-Results from the thrombEVAL Study

Venous thromboembolism (VTE) is a life-threatening disease with risk of recurrence. Oral anticoagulation (OAC) with vitamin K antagonists (VKA) is effective to prevent thromboembolic recurrence. We aimed to investigate the quality of OAC of VTE patients in regular medical care (RMC) compared to a telemedicine-based coagulation service (CS). The thrombEVAL study (NCT01809015) is a prospective, multi-center study to investigate OAC treatment (recruitment: January 2011-March 2013). Patients were evaluated using clinical visits, computer-assisted personal interviews, self-reported data and laboratory measurements according to standard operating procedures. Overall, 360 patients with VTE from RMC and 254 from CS were included. Time in therapeutic range (TTR) was higher in CS compared to RMC (76.9% (interquartile range [IQR] 63.2-87.1%) vs. 69.5% (52.3-85.6%), p < 0.001). Crude rate of thromboembolic events (rate ratio [RR] 11.33 (95% confidence interval [CI] 1.85-465.26), p = 0.0015), clinically relevant bleeding (RR 6.80 (2.52-25.76), p < 0.001), hospitalizations (RR 2.54 (1.94-3.39), p < 0.001) and mortality under OAC (RR 5.89 (2.40-18.75), p < 0.001) were consistently higher in RMC compared with CS. Patients in RMC had higher risk for primary outcome (clinically relevant bleedings, thromboembolic events and mortality, hazard ratio [HR] 5.39 (95%CI 2.81-10.33), p < 0.0001), mortality (HR 5.54 (2.22-13.84), p = 0.00025), thromboembolic events (HR 6.41 (1.51-27.24), p = 0.012), clinically relevant bleeding (HR 5.31 (1.89-14.89), p = 0.0015) and hospitalization (HR 1.84 (1.34-2.55), p = 0.0002). Benefits of CS care were still observed after adjusting for comorbidities and TTR. In conclusion, anticoagulation quality and outcome of VTE patients undergoing VKA treatment was significantly better in CS than in RMC. Patients treated in CS had lower rates of adverse events, hospitalizations and lower mortality. CS was prognostically relevant, beyond providing advantages of improved international ratio (INR) monitoring.

Impact of a pharmacist-led education and follow-up service on anticoagulation control and safety outcomes at a tertiary hospital in China: a randomised controlled trial

OBJECTIVES

This study was designed to evaluate the impact of a pharmacist-led anticoagulation service on international normalised ratio (INR) control and other outcomes among patients receiving warfarin therapy at a tertiary hospital in Zhuhai, China.

METHODS

In this randomised controlled trial, adult patients who were newly initiated on warfarin with intended treatment duration of at least 3 months were recruited. Participants were randomly allocated to receive the pharmacist-led education and follow-up service (PEFS) or usual care (UC). Anticoagulation control was calculated as the proportions of time within the target INR range (TTR) and time within the expanded target range (TER).

KEY FINDINGS

A total of 152 participants (77 in the PEFS group and 75 in the UC group) were included. Within 180 days after hospital discharge, the PEFS group spent more TER than the UC group (54.4% versus 42.0%; P = 0.024), whereas the difference in TTR did not reach statistical significance (35.9% versus 29.5%; P = 0.203). No major bleeding events were observed, and the cumulative incidences of major thromboembolic events (6.5% versus 9.3%) and mortality (1.3% versus 1.3%) were similar between the two groups (P> 0.05). At 30 days postdischarge, the PEFS group had better warfarin knowledge by answering 57.5% of questions correctly, compared with the UC group (43.0%) (P = 0.003).

CONCLUSIONS

The PEFS markedly enhanced anticoagulation control and warfarin knowledge but there was room for improvement. The expansion of pharmacists' clinical role and the development of more effective education and follow-up strategies are warranted to optimise anticoagulation management services in China.

Role of the anticoagulant monitoring service in 2018: beyond warfarin

The direct oral anticoagulants (DOACs) have a wide therapeutic index, few drug interaction, no dietary interactions and do not require dose adjustment according to the results of routine coagulation testing. Despite these advantages over warfarin, the DOACs remain high risk medications. There is evidence that non-adherence, off-label dosing and inadequate care transitions during DOAC therapy increase the risk of bleeding and thromboembolic complications. Although DOACs are approved for a growing number of indications, there remain patient populations who are not good candidates. Existing expertise within an Anticoagulation Management Service (AMS) should be leveraged to optimize all anticoagulant therapies including the DOACs. The AMS can facilitate initial drug therapy selection and dose management, reinforce patient education and adherence as well as managing drug interactions and invasive procedures. In the event that a transition to warfarin is warranted, the AMS is already engaged which limits the risk of fragmented patient care and ensures that therapeutic anticoagulation is re-established in a timely manner. The AMS of the future will provide comprehensive management for all patients receiving anticoagulant medications and continue to provide anticoagulation expertise to the healthcare team.

Health Care Resource Utilization and Costs Among Newly Diagnosed and Oral Anticoagulant-Naive Nonvalvular Atrial Fibrillation Patients Treated with Dabigatran or Warfarin in the United States

BACKGROUND

Warfarin has a long history of use to reduce the risk of stroke in patients with atrial fibrillation (AF), but it requires frequent laboratory monitoring to maintain international normalized ratio levels in the therapeutic range. Dabigatran, a novel oral anticoagulant (OAC), has demonstrated efficacy in reducing the risk of stroke and systemic embolism and does not require laboratory monitoring.

OBJECTIVE

To compare health care resource utilization (HCRU) and costs of OAC-naive patients newly diagnosed with nonvalvular atrial fibrillation (NVAF), using dabigatran or warfarin.

METHODS

This retrospective observational study used data from medical and pharmacy claims extracted from the HealthCore Integrated Research Database representing commercial and Medicare Advantage members. Adults aged > 18 years with a medical diagnosis claim of NVAF were identified between October 1, 2010, and December 31, 2011. The date of first observed OAC prescription claim was the index date. Patients were followed for up to 12 months after the index date. Patients were assigned to the dabigatran or warfarin treatment groups based on their first OAC prescription fills. To reduce potential for selection bias, the cohorts were matched on baseline characteristics using propensity score matching. HCRU was measured and compared between groups on a per-patient-per-month (PPPM) basis for all-cause HCRU, as well as stroke, myocardial infarction, and bleed-specific HCRU. Pharmacy, medical, and total costs were also compared and adjusted to 2012 U.S. dollars. Generalized linear models were conducted to compare all-cause health care costs between cohorts.

RESULTS

After propensity score matching, 1,648 patients were included in the analysis (824 each in the dabigatran and warfarin treatment groups). In the post-index period, patients in the dabigatran group had significantly fewer all-cause PPPM physician office visits (mean [SD] 1.29 [± 0.95] vs. 2.02 [± 1.53], P < 0.001) and outpatient visits (mean [SD] 2.17 [± 2.90] vs. 3.52 [± 3.32], P < 0.001) compared with those in the warfarin group. There were no between-group differences in outcomes for the number of stroke, myocardial infarction, or bleeding-related office visits. All-cause medical costs for the dabigatran cohort were lower than the warfarin cohort; however, the difference did not reach statistical significance ($2,696 [SD ± $6,699] vs. $2,893 [± $6,819], P = 0.179). All-cause pharmacy costs were higher in the dabigatran group versus the warfarin group ($455 [± $429] vs. $328 [± $517], P < 0.001). The dabigatran cohort also had significantly higher stroke-related ($32 [± $71] vs. $20 [± $55], P = 0.006) and nonstroke-related pharmacy costs ($423 [± $422] vs. $308 [± $515], P < 0.001). Despite higher pharmacy costs for the dabigatran cohort, both treatment groups had statistically similar all-cause total costs ($3,151 [± $6,744] vs. $3,221 [± $6,869], P = 0.701).

CONCLUSIONS

This real-world study showed that among patients newly diagnosed with NVAF who were OAC naive, dabigatran use was associated with significantly less HCRU in terms of physician and outpatient visits but higher pharmaceutical costs in up to 12 months of follow-up. Similar to other real-world studies, this research supports the finding that higher pharmacy costs for dabigatran users was offset by lower medical costs, making total health care costs comparable between dabigatran and warfarin.

DISCLOSURES

This work was supported by Boehringer Ingelheim Pharmaceuticals, which is the manufacturer of dabigatran, one of the products included in the analysis of this work. The authors were responsible for all content and editorial decisions. Jain and Tan are employed by HealthCore, a research consultancy which was funded by Boehringer Ingelheim Pharmaceuticals for work on this study. Fu was employed by HealthCore at the time of this study. Lim, Wang, Elder, and Sander are employees of Boehringer Ingelheim Pharmaceuticals. Study concept and design were contributed by Wang, Sander, and Tan, along with Fu and Jain. Fu, Tan, and Jain collected the data, and data interpretation was performed by Lim, Wang, and Sander, along with Jain, Tan, and Fu. The manuscript was written by Jain, Elder, Tan, and Wang, along with Lim and Fu, and revised by Jain, Wang, Elder, and Tan. Some of the results of this study were presented at Quality of Care and Outcomes Research in Cardiovascular Disease and Stroke (QCOR) 2014 Scientific Sessions on June 2-4, 2014, in Baltimore, Maryland.

The patients' perspective of international normalized ratio self-testing, remote communication of test results and confidence to move to self-management

AIMS AND OBJECTIVES

To elicit the perceptions of patients, who self-tested their international normalized ratio and communicated their results via a text or phone messaging system, to determine their satisfaction with the education and support that they received and to establish their confidence to move to self-management.

BACKGROUND

Self-testing of international normalized ratio has been shown to be reliable and is fast becoming common practice. As innovations are introduced to point of care testing, more research is needed to elicit patients' perceptions of the self-testing process.

DESIGN

This three site study used a cross-sectional prospective descriptive survey.

METHODS

Three hundred and thirty patients who were prescribed warfarin and using international normalized ratio self-testing were invited to take part in the study. The anonymous survey examined patient profile, patients' usage, issues, perceptions, confidence and satisfaction with using the self-testing system and their preparedness for self-management of warfarin dosage.

RESULTS

The response rate was 57% (n = 178). Patients' confidence in self-testing was high (90%). Patients expressed a high level of satisfaction with the support received, but expressed the need for more information on support groups, side effects of warfarin, dietary information and how to dispose of needles. When asked if they felt confident to adjust their own warfarin levels 73% agreed. Chi-squared tests for independence revealed that none of the patient profile factors examined influenced this confidence. The patients cited the greatest advantages of the service were reduced burden, more autonomy, convenience and ease of use. The main disadvantages cited were cost and communication issues.

CONCLUSION

Patients were satisfied with self-testing. The majority felt they were ready to move to self-management.

RELEVANCE TO CLINICAL PRACTICE

The introduction of innovations to remote point of care testing, such as warfarin self-testing, needs to have support at least equal to that provided in a hospital setting.

Factors influencing medication knowledge and beliefs on warfarin adherence among patients with atrial fibrillation in China

OBJECTIVES

Warfarin is often used for ischemic stroke prevention in patients with atrial fibrillation (AF), but the factors affecting patient adherence to warfarin therapy have not been fully understood.

METHODS

A cross-sectional survey was conducted in AF patients undergoing warfarin therapy at least 6 months prior to the study. The clinical data collected using questionnaires by phone interviews included the following: 1) self-reported adherence measured by the Morisky Medication Adherence Scale-8^©; 2) beliefs about medicines surveyed by Beliefs about Medicines Questionnaire (BMQ); and 3) drug knowledge as measured by the Warfarin Related Knowledge Test (WRKT). Demographic and clinical factors associated with warfarin adherence were identified using a logistic regression model.

RESULTS

Two hundred eighty-eight patients completed the survey and 93 (32.3%) of them were classified as nonadherent (Morisky Medication Adherence Scale-8 score <6). Major factors predicting warfarin adherence included age, cardiovascular disorders, WRKT, and BMQ; WRKT and BMQ were independently correlated with adherence to warfarin therapy by multivariate logistic regression analysis. Adherents were more likely to have greater knowledge scores and stronger beliefs in the necessity of their specific medications ([odds ratio {OR} =1.81, 95% confidence interval {CI} =1.51-2.15] and [OR =1.17, 95% CI =1.06-1.29], respectively). Patients with greater concerns about adverse reactions and more negative views of general harm were more likely to be nonadherent ([OR =0.76, 95% CI =0.69-0.84] and [OR =0.82, 95% CI =0.73-0.92], respectively).

CONCLUSION

BMK and WRKT are related with patient behavior toward warfarin adherence. BMQ can be applied to identify patients at increased risk of nonadherence.

Quality of Anticoagulation Monitoring in Nonvalvular Atrial Fibrillation Patients: Comparison of Anticoagulation Clinic versus Usual Care

Background:

Prior research suggests that receiving specialized anticoagulation services enables patients to achieve better clinical outcomes.

Objective:

To assess the quality of anticoagulation therapy in patents with atrial fibrillation who were enrolled in an anticoagulation clinic (ACC) versus usual care (UC).

Methods:

Using Sharp Rees-Stealy physician group claims data, we estimated time spent in therapeutic range and time to first major bleeding episode or stroke for ACC and UC patients. t-Tests were used to compare time h therapeutic range proportions, and Kaplan-Meier survival analysis was performed to compare rates of bleeding and stroke between groups.

Results:

We identified 1107 patients (351 ACC, 756 UC) treated with anticoagulation therapy for atrial fibrillation with more than one international normalized ratio (INR) reported between March 2001 and March 2004. ACC patients spent a greater proportion (68.14%) of time in therapeutic range compared with UC patients (42.07%; p < 0.001). There was a significant difference between groups in average time between INR tests (ACC = 14.31 days, UC = 18.39 days; p < 0.001). ACC patients were 59% less likely to experience a bleed following the index date than were UC patients (HR = 0.41; 95% CI 0.2444 to 0.6999; p = 0.001), but type of care was not a significant predictor for stroke (HR = 0.95; 95% CI 0.5125 to 1.7777; p value NS).

Conclusions:

Results from this observational study reinforce the positive impact that anticoagulation services have on anticoagulation therapy outcomes, emphasizing the importance of providing such services for patients undergoing treatment with warfarin.

At-Home Versus In-Clinic INR Monitoring: A Cost-Utility Analysis from The Home INR Study (THINRS)

BACKGROUND

Effective management of patients using warfarin is resource-intensive, requiring frequent in-clinic testing of the international normalized ratio (INR). Patient self-testing (PST) using portable at-home INR monitoring devices has emerged as a convenient alternative. As revealed by The Home INR Study (THINRS), event rates for PST were not significantly different from those for in-clinic high-quality anticoagulation management (HQACM), and a cumulative gain in quality of life was observed for patients undergoing PST.

OBJECTIVE

To perform a cost-utility analysis of weekly PST versus monthly HQACM and to examine the sensitivity of these results to testing frequency.

PATIENTS/INTERVENTIONS

In this study, 2922 patients taking warfarin for atrial fibrillation or mechanical heart valve, and who demonstrated PST competence, were randomized to either weekly PST (n = 1465) or monthly in-clinic testing (n = 1457). In a sub-study, 234 additional patients were randomized to PST once every 4 weeks (n = 116) or PST twice weekly (n = 118). The endpoints were quality of life (measured by the Health Utilities Index), health care utilization, and costs over 2 years of follow-up.

RESULTS

PST and HQACM participants were similar with regard to gender, age, and CHADS2 score. The total cost per patient over 2 years of follow-up was $32,484 for HQACM and $33,460 for weekly PST, representing a difference of $976. The incremental cost per quality-adjusted life year gained with PST once weekly was $5566 (95 % CI, -$11,490 to $25,142). The incremental cost-effectiveness ratio (ICER) was sensitive to testing frequency: weekly PST dominated PST twice weekly and once every 4 weeks. Compared to HQACM, weekly PST was associated with statistically significant and clinically meaningful improvements in quality of life. The ICER for weekly PST versus HQACM was well within accepted standards for cost-effectiveness, and was preferred over more or less frequent PST. These results were robust to sensitivity analyses of key assumptions.

CONCLUSION

Weekly PST is a cost-effective alternative to monthly HQACM and a preferred testing frequency compared to twice weekly or monthly PST.

Bringing the Benefits of Anticoagulation Management Services to the Community

Background:

While warfarin is efficacious for the prevention of thromboembolic disorders, many patients are undertreated. To optimize therapy, anticoagulation management services (AMSs) deliver a coordinated, focused approach to this care; however, AMSs are limited in their ability to impact patients outside of tertiary care settings.

Objective:

To describe the methods used to develop community-based AMSs across Alberta.

Methods:

Through a three-staged approach, this project created community-based, pharmacist-managed AMSs for patients requiring warfarin therapy. Stage I was the initiation of a central or “core” AMS, located at a quaternary referral centre. Starting with the core enabled us to develop and test the program and create an environment to serve as a training and support centre for future aspects of the program. Next, an educational program was developed and implemented (Stage II) for a diverse group of pharmacists to establish and manage a community-based or “satellite” AMS (Stage III) at their practice site. All three stages are undergoing detailed evaluation, capturing project-specific (patient outcome) data as well as system-level (integration within the health care infrastructure) data.

Conclusion:

By offering a focused, coordinated, and consistent approach to warfarin management, with ongoing collaboration with other providers, the ultimate goal of this program is to optimize patient outcomes. Utilizing pharmacists as central players within a collaborative setting will enhance the use of our current infrastructure. This program may serve as a model for other health regions and other chronic diseases.

Routine Unselected Access to Day Case Electrical Cardioversion of Persistent Atrial Fibrillation: Anticoagulant Preparation is the Key Factor

Objectives: To determine the routine efficacy of a day case cardioversion system operating in a remote geographical area with an unselected case referral base and a proportion of direct GP access. Design: Prospective analysis of all admitted cases in a 13 week period. Participants: 47 consecutive patients admitted for 49 planned episodes of electrical cardioversion. Measurements: Pre procedural investigations and preparation, immediate and three-month outcome of rhythm following ECV Results: We found a predominant use by the cardiac unit despite working within a general medical service unit suggesting low case selection from non-cardiac sources. We suspected and confirmed a high rate of point of care treatment cancellation. Poor management of anticoagulation was the dominant reason for canceling planned treatment. Procedural preparation in terms of anti arrhythmic drug therapy and investigations seemed well preserved. Conclusion: New strategies for initiating and sustaining adequate outpatient warfarin therapy are needed to allow such systems to operate efficiently.

The impact of frequency of patient self-testing of prothrombin time on time in target range within VA Cooperative Study #481: The Home INR Study (THINRS), a randomized, controlled trial

Anticoagulation (AC) is effective in reducing thromboembolic events for individuals with atrial fibrillation (AF) or mechanical heart valve (MHV), but maintaining patients in target range for international normalized ratio (INR) can be difficult. Evidence suggests increasing INR testing frequency can improve time in target range (TTR), but this can be impractical with in-clinic testing. The objective of this study was to test the hypothesis that more frequent patient-self testing (PST) via home monitoring increases TTR. This planned substudy was conducted as part of The Home INR Study, a randomized controlled trial of in-clinic INR testing every 4 weeks versus PST at three different intervals. The setting for this study was 6 VA centers across the United States. 1,029 candidates with AF or MHV were trained and tested for competency using ProTime INR meters; 787 patients were deemed competent and, after second consent, randomized across four arms: high quality AC management (HQACM) in a dedicated clinic, with venous INR testing once every 4 weeks; and telephone monitored PST once every 4 weeks; weekly; and twice weekly. The primary endpoint was TTR at 1-year follow-up. The secondary endpoints were: major bleed, stroke and death, and quality of life. Results showed that TTR increased as testing frequency increased (59.9 ± 16.7 %, 63.3 ± 14.3 %, and 66.8 ± 13.2 % [mean ± SD] for the groups that underwent PST every 4 weeks, weekly and twice weekly, respectively). The proportion of poorly managed patients (i.e., TTR <50 %) was significantly lower for groups that underwent PST versus HQACM, and the proportion decreased as testing frequency increased. Patients and their care providers were unblinded given the nature of PST and HQACM. In conclusion, more frequent PST improved TTR and reduced the proportion of poorly managed patients.

A rolling-horizon pharmacokinetic pharmacodynamic model for warfarin inpatients in transient clinical states

Aim: To design a pharmacokinetic pharmacodynamic model to make individualized and adaptive international normalized ratio (INR) predictions for warfarin inpatients in changing clinical status. Methods: We tested a new model on 60 inpatients at Columbia University. The model personalizes four submodels and minimizes the number of parameters to be estimated. Prediction accuracy was assessed by prediction error, absolute prediction error and percentage absolute prediction error. Results: The INRs were accurately predicted 5 days into the future. Median prediction error: 0.01–0.12; median absolute prediction error: 0.17–0.5 and median percentage absolute prediction error: 9.85–26.06%. Conclusion: Patients exhibit interindividual and intertemporal variability. The model captures the variability and provides accurate and personalized INR predictions.

Venous thromboembolism in Latin America: a review and guide to diagnosis and treatment for primary care

There are various region-specific challenges to the diagnosis and effective treatment of venous thromboembolism in Latin America. Clear guidance for physicians and patient education could improve adherence to existing guidelines. This review examines available information on the burden of pulmonary embolism and deep vein thrombosis in Latin America and the regional issues surrounding the diagnosis and treatment of pulmonary embolism and deep vein thrombosis. Potential barriers to appropriate care, as well as treatment options and limitations on their use, are discussed. Finally, an algorithmic approach to the diagnosis and treatment of venous thromboembolism in ambulatory patients is proposed and care pathways for patients with pulmonary embolism and deep vein thrombosis are outlined for primary care providers in Latin America.

Oral anticoagulants for stroke prevention in atrial fibrillation: current status, special situations, and unmet needs

In patients with non-valvular atrial fibrillation, oral anticoagulation with vitamin K antagonists reduces the risk of stroke by more than 60%. But vitamin K antagonists have limitations, including causing serious bleeding such as intracranial haemorrhage and the need for anticoagulation monitoring. In part related to these limitations, they are used in only about half of patients who should be treated according to guideline recommendations. In the past decade, oral agents have been developed that directly block the activity of thrombin (factor IIa), as well as drugs that directly inhibit activated factor X (Xa), which is the first protein in the final common pathway to the activation of thrombin. These novel non-vitamin K antagonist oral anticoagulants (NOACs) have been shown to be at least as good as warfarin for stroke prevention in atrial fibrillation and they have proved to have better safety profiles. Their net advantage is underscored by significantly lower all-cause mortality compared with warfarin in large clinical trials. Because of these features and their ease of use, they are recommended for stroke prevention in atrial fibrillation. They have also a fast onset and offset of action, but they currently lack specific antidotes. This paper addresses the role of anticoagulation for stroke prevention in atrial fibrillation in the era of NOACs, with a focus on special situations including management in the event of bleeding and around the time of procedures including cardioversion, catheter ablation, and device implantation. Also their use in patients with concomitant coronary artery disease, with advanced age, with chronic kidney disease, or with valvular heart disease will be discussed as well as the interaction of NOACs with other cardiac medication, and switching between anticoagulants.

Atrial Fibrillation

Atrial fibrillation (AF) is a supraventricular tachyarrhythmia that results from the chaotic depolarization of atrial tissue. AF is the most common sustained cardiac dysrhythmia and the most common dysrhythmia diagnosed in US emergency departments. All patients with AF must have their cardioembolic risk assessed, even if sinus rhythm is restored. Novel oral anticoagulants may be considered instead of vitamin K antagonists for anticoagulation in patients with nonvalvular AF.

Tailored interventions to address determinants of practice

BACKGROUND

Tailored intervention strategies are frequently recommended among approaches to the implementation of improvement in health professional performance. Attempts to change the behaviour of health professionals may be impeded by a variety of different barriers, obstacles, or factors (which we collectively refer to as determinants of practice). Change may be more likely if implementation strategies are specifically chosen to address these determinants.

OBJECTIVES

To determine whether tailored intervention strategies are effective in improving professional practice and healthcare outcomes. We compared interventions tailored to address the identified determinants of practice with either no intervention or interventions not tailored to the determinants.

SEARCH METHODS

We conducted searches of The Cochrane Library, MEDLINE, EMBASE, PubMed, CINAHL, and the British Nursing Index to May 2014. We conducted a final search in December 2014 (in MEDLINE only) for more recently published trials. We conducted searches of the metaRegister of Controlled Trials (mRCT) in March 2013. We also handsearched two journals.

SELECTION CRITERIA

Cluster-randomised controlled trials (RCTs) of interventions tailored to address prospectively identified determinants of practice, which reported objectively measured professional practice or healthcare outcomes, and where at least one group received an intervention designed to address prospectively identified determinants of practice.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed quality and extracted data. We undertook qualitative and quantitative analyses, the quantitative analysis including two elements: we carried out 1) meta-regression analyses to compare interventions tailored to address identified determinants with either no interventions or an intervention(s) not tailored to the determinants, and 2) heterogeneity analyses to investigate sources of differences in the effectiveness of interventions. These included the effects of: risk of bias, use of a theory when developing the intervention, whether adjustment was made for local factors, and number of domains addressed with the determinants identified.

MAIN RESULTS

We added nine studies to this review to bring the total number of included studies to 32 comparing an intervention tailored to address identified determinants of practice to no intervention or an intervention(s) not tailored to the determinants. The outcome was implementation of recommended practice, e.g. clinical practice guideline recommendations. Fifteen studies provided enough data to be included in the quantitative analysis. The pooled odds ratio was 1.56 (95% confidence interval (CI) 1.27 to 1.93, P value < 0.001). The 17 studies not included in the meta-analysis had findings showing variable effectiveness consistent with the findings of the meta-regression.

AUTHORS' CONCLUSIONS

Despite the increase in the number of new studies identified, our overall finding is similar to that of the previous review. Tailored implementation can be effective, but the effect is variable and tends to be small to moderate. The number of studies remains small and more research is needed, including trials comparing tailored interventions to no or other interventions, but also studies to develop and investigate the components of tailoring (identification of the most important determinants, selecting interventions to address the determinants). Currently available studies have used different methods to identify determinants of practice and different approaches to selecting interventions to address the determinants. It is not yet clear how best to tailor interventions and therefore not clear what the effect of an optimally tailored intervention would be.

Anticoagulation management by community pharmacists in New Zealand: an evaluation of a collaborative model in primary care

Objectives

Despite the introduction of new oral anticoagulants, vitamin K antagonists remain the mainstay of the prevention and treatment of thromboembolism. The advent of affordable point-of-care testing presents an opportunity for community pharmacists to provide anticoagulation management services, better utilizing their training, reducing the workload on medical practices and improving accessibility and convenience for patients. This study aimed to determine the effectiveness of anticoagulation management by community pharmacists.

Methods

All patients enrolled in a pilot programme for a community pharmacy anticoagulation management service using point-of-care international normalized ratio testing and computer-assisted dose adjustment were included in a follow-up study, including before–after comparison. Outcomes included time in therapeutic range (TTR), time above and below range, number and proportion of results outside efficacy and safety thresholds, and a comparison of care led by pharmacists and care led by a primary-care general practitioner (GP).

Key findings

A total of 693 patients were enrolled, predominantly males over 65 years of age with atrial fibrillation. The mean TTR was 78.6% (95% CI 49.3% to 100%). A subgroup analysis (n = 221) showed an increase in mean TTR from 61.8% under GP-led care to 78.5% under pharmacist-led care (P &lt; 0.001), reflecting a reduction in the time above and, in particular, below the range. The mean TTR by pharmacy ranged from 71.4% to 84.1%. The median number of tests per month was not statistically different between GP- and pharmacist-led care.

Conclusions

Community-pharmacist-led anticoagulation care utilizing point-of-care testing and computerized decision support is safe and effective, resulting in significant improvements in TTR. Our results support wider adoption of this model of collaborative care.

Predicting anticoagulant-related bleeding in patients with venous thromboembolism: a clinically oriented review

Diagnosis of venous thromboembolism (VTE) requires prompt treatment with anticoagulants in therapeutic doses. Since these drugs are associated with the occurrence of haemorrhage, identification of patients at increased risk of major bleeding is of utmost clinical importance for defining the optimal treatment regimen and duration of anticoagulation. Current suggested prediction scores for bleeding risk in VTE patients have been derived from observational studies of moderate quality, or from patients with various indications for therapeutic anticoagulation other than VTE. To date, none of the scores have been adequately validated in cohorts that underwent dedicated monitoring and independent adjudication of bleeding complications. In addition, while the scarce available evidence has focused on patients treated with heparins and/or vitamin K antagonists, risk stratification scores for bleeding complications in VTE patients treated with non-vitamin K dependent anticoagulants have not yet been developed. This clinically oriented review covers the incidence and risk factors of anticoagulation-related bleeding in VTE patients treated with different anticoagulant drugs as well as the available bleeding-prediction scores. Further, we attempt to provide guidance for bleeding-prevention in clinical practice and speculate on developments in the near future that may fundamentally change our current thinking on VTE management.

Quality of vitamin K antagonist control and outcomes in atrial fibrillation patients: a meta-analysis and meta-regression

BACKGROUND

Atrial fibrillation (AF) patients frequently require anticoagulation with vitamin K antagonists (VKAs) to prevent thromboembolic events, but their use increases the risk of hemorrhage. We evaluated time spent in therapeutic range (TTR), proportion of international normalized ratio (INR) measurements in range (PINRR), adverse events in relation to INR, and predictors of INR control in AF patients using VKAs.

METHODS

We searched MEDLINE, CENTRAL and EMBASE (1990-June 2013) for studies of AF patients receiving adjusted-dose VKAs that reported INR control measures (TTR and PINRR) and/or reported an INR measurement coinciding with thromboembolic or hemorrhagic events. Random-effects meta-analyses and meta-regression were performed.

RESULTS

Ninety-five articles were included. Sixty-eight VKA-treated study groups reported measures of INR control, while 43 studies reported an INR around the time of the adverse event. Patients spent 61% (95% CI, 59-62%), 25% (95% CI, 23-27%) and 14% (95% CI, 13-15%) of their time within, below or above the therapeutic range. PINRR assessments were within, below, and above range 56% (95% CI, 53-59%), 26% (95% CI, 23-29%) and 13% (95% CI, 11-17%) of the time. Patients receiving VKA management in the community spent less TTR than those managed by anticoagulation clinics or in randomized trials. Patients newly receiving VKAs spent less TTR than those with prior VKA use. Patients in Europe/United Kingdom spent more TTR than patients in North America. Fifty-seven percent (95% CI, 50-64%) of thromboembolic events and 42% (95% CI, 35 - 51%) of hemorrhagic events occurred at an INR <2.0 and >3.0, respectively; while 56% (95% CI, 48-64%) of ischemic strokes and 45% of intracranial hemorrhages (95% CI, 29-63%) occurred at INRs <2.0 and >3.0, respectively.

CONCLUSIONS

Patients on VKAs for AF frequently have INRs outside the therapeutic range. While, thromboembolic and hemorrhagic events do occur patients with a therapeutic INR; patients with an INR <2.0 make up many of the cases of thromboembolism, while those >3.0 make up many of the cases of hemorrhage. Managing anticoagulation outside of a clinical trial or anticoagulation clinic is associated with poorer INR control, as is, the initiation of therapy in the VKA-naïve. Patients in Europe/UK have better INR control than those in North America.

Measures of vitamin K antagonist control reported in atrial fibrillation and venous thromboembolism studies: a systematic review

OBJECTIVE

To aid trialists, systematic reviewers and others, we evaluated the degree of standardisation of control measure reporting that has occurred in atrial fibrillation (AF) and venous thromboembolism (VTE) studies since 2000; and attempted to determine whether the prior recommendation of reporting ≥2 measures per study has been employed.

DESIGN

Systematic review.

SEARCH STRATEGY

We searched bibliographic databases (2000 to June 2013) to identify AF and VTE studies evaluating dose-adjusted vitamin K antagonists (VKAs) and reporting ≥1 control measure. The types of measures reported, proportion of studies reporting ≥2 measures and mean (±SD) number of measures per study were determined for all studies and compared between subgroups.

DATA EXTRACTION

Through the use of a standardised data extraction tool, we independently extracted all data, with disagreements resolved by a separate investigator.

RESULTS

148 studies were included, 57% of which reported ≥2 control measures (mean/study=2.13±1.36). The proportion of time spent in the target international normalised ratio range (TTR) was most commonly reported (79%), and was frequently accompanied by time above/below range (52%). AF studies more frequently reported ≥2 control measures compared with VTE studies (63% vs 37%; p=0.004), and reported a greater number of measures per study (mean=2.36 vs 1.53; p<0.001). Observational studies were more likely to provide ≥2 measures compared with randomised trials (76% vs 33%; p<0.001) and report a greater number of measures (mean=2.58 vs 1.63; p<0.001). More recent studies (2004-2013) reported ≥2 measures more often than older (2000-2003) studies (59% vs 35%; p=0.05) and reported more measures per study (mean=2.23 vs 1.48; p=0.02).

CONCLUSIONS

While TTR was often utilised, studies reported ≥2 measures of VKA control only about half of the time and lacked consistency in the types of measures reported. A trend towards studies reporting greater numbers of VKA control measures over time was observed over our review time horizon, particularly, with AF and observational studies.

The clinical profile and pathophysiology of atrial fibrillation: relationships among clinical features, epidemiology, and mechanisms

Atrial fibrillation (AF) is the most common arrhythmia (estimated lifetime risk, 22%-26%). The aim of this article is to review the clinical epidemiological features of AF and to relate them to underlying mechanisms. Long-established risk factors for AF include aging, male sex, hypertension, valve disease, left ventricular dysfunction, obesity, and alcohol consumption. Emerging risk factors include prehypertension, increased pulse pressure, obstructive sleep apnea, high-level physical training, diastolic dysfunction, predisposing gene variants, hypertrophic cardiomyopathy, and congenital heart disease. Potential risk factors are coronary artery disease, kidney disease, systemic inflammation, pericardial fat, and tobacco use. AF has substantial population health consequences, including impaired quality of life, increased hospitalization rates, stroke occurrence, and increased medical costs. The pathophysiology of AF centers around 4 general types of disturbances that promote ectopic firing and reentrant mechanisms, and include the following: (1) ion channel dysfunction, (2) Ca(2+)-handling abnormalities, (3) structural remodeling, and (4) autonomic neural dysregulation. Aging, hypertension, valve disease, heart failure, myocardial infarction, obesity, smoking, diabetes mellitus, thyroid dysfunction, and endurance exercise training all cause structural remodeling. Heart failure and prior atrial infarction also cause Ca(2+)-handling abnormalities that lead to focal ectopic firing via delayed afterdepolarizations/triggered activity. Neural dysregulation is central to atrial arrhythmogenesis associated with endurance exercise training and occlusive coronary artery disease. Monogenic causes of AF typically promote the arrhythmia via ion channel dysfunction, but the mechanisms of the more common polygenic risk factors are still poorly understood and under intense investigation. Better recognition of the clinical epidemiology of AF, as well as an improved appreciation of the underlying mechanisms, is needed to develop improved methods for AF prevention and management.

New oral anticoagulants in patients with nonvalvular atrial fibrillation: a review of pharmacokinetics, safety, efficacy, quality of life, and cost effectiveness

Atrial fibrillation (AF) continues to be a leading cause of cerebrovascular morbidity and mortality resulting from cardioembolic stroke. Oral anticoagulation therapy has been shown to decrease the incidence of cardioembolic stroke in patients with AF by more than 50%. Appropriate use of anticoagulation with vitamin K antagonists requires precise adherence and monitoring. A number of factors that potentially induce patients’ dissatisfaction reduce quality of patient life. New direct oral anticoagulants, such as the direct factor Xa inhibitors rivaroxaban, apixaban, edoxaban, and the thrombin inhibitor dabigatran, were developed to overcome the limitations of the conventional anticoagulant drugs. However, models to optimize the benefit of therapy and to ensure that therapy can be safely continued are missing for the new oral anticoagulants. This review will briefly describe the new oral anticoagulants dabigatran, rivaroxaban, apixaban, and edoxaban with focus on their use for prevention of embolic events in AF. Moreover, it will discuss the safety, efficacy, cost data, and benefit for patients’ quality of life and adherence.

Oral anticoagulant therapy and clinical outcomes in patients with atrial fibrillation: a pilot study from a single center registry

The data on the successful use of oral anticoagulation (OAC) in patients with atrial fibrillation are inconclusive. We aimed to describe the indications and the utilization patterns of OAC therapy in patients with atrial fibrillation who have been admitted to a quaternary hospital. Patients who were admitted to a quaternary hospital from January 2011 to January 2012 with atrial fibrillation were included in the study. The data on patient demographics, atrial fibrillation classification, CHA2DS2VASc scores, and the use of OAC were collected. Of the patients admitted, 301 patients met the inclusion criteria. Of these, 277 (92%) had a CHA2DS2VASc score at least 2. Of the patients who met criteria for treatment with OAC, 104 (36.6%) were not on OAC therapy. The reason for this discrepancy was tendency and history of bleeding (29.8%). Of those 180 patients who were on OAC, the time in therapeutic range was higher in those patients less than 50 years as compared with those between ages 65-74 and more than 75 (78.2 versus 42 and 36.1%, P < 0.05). The overall time in therapeutic range of patients on OAC was 47.4%. We found that approximately one-third of the patients who have indications for OAC are not being treated as per guidelines due to history of and tendency for bleeding. Furthermore, of those on OAC, only half of the patients achieved successful anticoagulation.

The quality of oral anticoagulation in general practice in patients with atrial fibrillation

BACKGROUND

The aims of this study were to evaluate the quality of oral anticoagulation (OAC) in AF patients in the practices of general practitioners (GPs) in Germany and to investigate possible causal factors which influence OAC quality.

METHODS

We conducted a multi-center, non-interventional, prospective observational cohort study among general practitioners (GPs) in Germany. To assess the quality of OAC on the basis of the prospectively documented international normalized ratio (INR) values, the time in therapeutic range (TTR) was calculated using the Rosendaal linear trend method. The causes of poor OAC quality were identified by a multivariate analysis model (logistical regression; poor OAC quality: TTR <60%).

RESULTS AND CONCLUSIONS

For 525 OAC patients (66.8%; patients with at least 2 prospectively documented INR values) the average TTR (target range of 2.0-3.0) was 67.6%. About 34.7% of the patients had a TTR <60%. None of the variables representing characteristics of the medical practices were capable of explaining the occurrence of poor OAC quality. However, with regard to care provision-based variables, the existence of a brief discontinuation of medication was important. As the existence of adherence barriers increased, the probability of poor anticoagulation quality increased. In conclusion, the provision of OAC in the German health care system is to be regarded as good, but far from ideal. Our causal analysis shows that patient-based factors should be addressed through the provision of improved training and that the rationale behind the interruption of OAC treatment should be critically examined.

Monitoring anticoagulation in atrial fibrillation

BACKGROUND

Randomized control trials and observational studies show high-quality warfarin therapy leads to safe and effective stroke prophylaxis. In usual community practice, patient, physician and health care system factors are barriers to optimal anticoagulation. We examined the predictive relationship between inpatient and outpatient INR values in chronic non-valvular atrial fibrillation (AF) patients hospitalized for ischemic stroke (S), bleed (B) and control events (C) in usual community practice.

METHODS

This nested case-control analysis identified AF patients hospitalized for S, B and C using medical and pharmacy claims spanning 4.5 years ('98-'03) and validating diagnosis with chart abstraction. AF was defined as 2 medical claims for AF >or= 42 days apart with a related prescription claim for warfarin. INRs from both outpatient and inpatient settings were used to yield a continuous history of coagulation status. Time-in-therapeutic-range (TTR) was calculated by Rosendaal's linear interpolation method. Correlation of inpatient and prognostic utility of last outpatient INRs was tested with S or B hospitalizations using univariate and multivariate logistic regression.

RESULTS

Overall, 614 hospitalizations (means: age 73.9, CHADS(2) = 3.24; 52% male) included S (n = 98), B (n = 101) and C (n = 415) events. Average TTR was 28.6% (49.4% at INR <2.0, 21.9% at INR >3.0). First INR on admission (INR <2.0 or >3.0) was associated with S and B hospitalizations (OR-adjusted [95%CI], 1.68 [1.04-2.73] and 1.72 [1.02-2.90]), respectively. Last outpatient INR <2.0 was not associated with S (OR-adjusted [95%CI], 1.12 [0.77-1.81]), and INR >3.0 was not associated with B (OR-adjusted [95%CI], 1.25 [0.67-2.32]). Last outpatient INR measurement occurred at 28, 22 and 24 days (median; S, B & C, respectively) before hospitalization.

CONCLUSION

Patients were observed within therapeutic range less than 30% of their time on warfarin. While inpatient INRs were clearly associated with both ischemic stroke and bleed events, last outpatient INR before event was not predictive.

Management of stroke prevention in canadian patients with atrial fibrillation at moderate to high risk of stroke

BACKGROUND

Many patients with atrial fibrillation who are at moderate to high risk of stroke do not receive anticoagulation with vitamin K antagonists (VKAs) in accordance with recommendations.

OBJECTIVE

To determine (1) why Canadian patients with atrial fibrillation who are potentially eligible for VKA do not receive this therapy, (2) why Canadian primary care physicians discontinue VKA therapy, and (3) why VKA therapy is perceived as difficult to manage.

METHODS

The study involved a chart review of 3 cohorts of patients with nonvalvular atrial fibrillation at moderate to high risk of stroke: patients who had never received VKA treatment (VKA-naive), those whose treatment had been discontinued, and those whose VKA treatment was considered difficult to manage.

RESULTS

Charts for 187 patients (mean age 78.4 years, standard deviation 8.9 years) treated at 39 primary care sites were reviewed (62 treatment-naive, 42 with therapy discontinued, and 83 whose therapy was considered difficult to manage). Atrial fibrillation was paroxysmal in 82 (44%) of the patients, persistent in 47 patients (25%), and permanent in 58 (31%). One patient in each of the 3 cohorts had experienced a stroke during the 6 months before study participation. Bleeding events were more frequent among patients who had discontinued VKA therapy than in the other 2 groups. Among those whose therapy was discontinued and those whose therapy was difficult to manage, the mean time in the therapeutic range was 46.3% and 56.4%, respectively. The most common reason for not initiating VKA therapy in treatment-naive patients was the transient nature of atrial fibrillation (25/62 [40%]). The most common reason for discontinuation of VKA therapy was a bleeding event (10/42 [24%]). The presence of a concomitant chronic disease was the most common reason that a patient's therapy was considered difficult to manage (46/83 [55%]).

CONCLUSIONS

VKA therapy was not initiated or was discontinued for various reasons. Multiple comorbid conditions made management of VKA therapy more difficult. These findings reflect the challenges that primary care physicians experience in managing the care of patients with atrial fibrillation.

Selection of Medications to Prevent Stroke Among Individuals With Atrial Fibrillation : Update on Prevention of Stroke in Patients with AF

OPINION STATEMENT

Vitamin K antagonists have been the only available orally active anticoagulants for decades. Although effective, their numerous limitations have driven the introduction of new oral anticoagulants (NOAs) that showed effectiveness at fixed doses without the need for routine coagulation monitoring. However, the safety and efficacy observed in controlled clinical trials may be hard to translate in clinical practice. Clinical conditions as well as drug interactions may considerably impact on patient outcomes. Moreover, the inability to monitor the pharmacological activity of NOAs and the absence of any antidote in the setting of bleeding or emergent invasive procedures may limit their use. Vitamin K antagonists will be still used in many circumstances, including patients with an optimal control of the INR, with mechanical heart valves, and other indications for which these new agents have not been investigated. Nevertheless, these new agents will reduce the burden of anticoagulation management at the patient as well as Health Care level.

Pilot study of a novel patient self-management program for warfarin therapy using venipuncture-acquired international normalized ratio monitoring

STUDY OBJECTIVE

To compare clinical and safety outcomes of warfarin therapy before and after implementation of a novel patient self-management (PSM) program in which patients received their venipuncture-derived international normalized ratio (INR) results through a secure online messaging system and adjusted their warfarin dosages and follow-up visits according to provided support tools.

DESIGN

Prospective, open-label, 3-month, pilot study.

SETTING

Centralized clinical pharmacy anticoagulation service.

PATIENTS

Forty-four patients with atrial fibrillation who were receiving warfarin for more than 6 months were enrolled in the trial between January 1, 2011, and February 28, 2011; 39 patients completed the trial. Patients acted as their own controls.

INTERVENTION

Patients received dosing decision support tools during a 2-hour live PSM training class. Those who then demonstrated proficiency in PSM assumed responsibility for their warfarin therapy management.

MEASUREMENTS AND MAIN RESULTS

Outcomes of warfarin therapy were measured in each patient before and after implementation of the PSM program. Study variables included time in the therapeutic INR range (TTR), numbers of INR tests performed, and episodes of major bleeding or thrombosis. No significant difference in TTR occurred between the 90 days before PSM program participation and the 90 days of PSM (82.9% vs 81.2%, p=0.65). The mean number of INR tests performed for each patient increased from 2.97 before PSM program participation to 4.38 during PSM (p<0.01). No bleeding or thrombotic events occurred during the PSM phase.

CONCLUSION

Patients were trained to engage in PSM using support tools and venipuncture-derived INR results received by an online messaging system to adjust warfarin dosage and frequency of INR testing. No significant difference in TTR occurred in these patients before and during the PSM. This novel PSM model appears to be a feasible method of managing warfarin therapy in carefully selected patients; however, a larger, randomized controlled trial is needed to evaluate the safety and efficacy of the model and its effect on anticoagulation service workload.

Patterns of warfarin use and subsequent outcomes in atrial fibrillation in primary care practices

BACKGROUND

Warfarin is recommended for stroke prevention in high-risk patients with atrial fibrillation. However, it is often underutilized and inadequately managed in actual clinical practice.

OBJECTIVES

To examine the patterns of warfarin use and their relationship with stroke and bleeding in atrial fibrillation patients in community-based primary care practices.

DESIGN

Retrospective longitudinal cohort study.

PARTICIPANTS

A total of 1141 atrial fibrillation patients were selected from 17 primary care practices with a shared electronic medical record and characterized by stroke risk, potential barriers to anticoagulation, and comorbid conditions.

MAIN MEASURES

Duration and number of warfarin exposures, interruptions in warfarin exposure > 45 days, stroke, and bleeding events.

RESULTS

Among 1141 patients with a mean age of 70 years (standard deviation 13.3) and mean follow-up of 3.4 years (standard deviation 3.0), 764 (67%) were treated with warfarin. Warfarin was discontinued within 1 year in 194 (25.4%), and 349 (45.7%) remained on warfarin at the end of follow-up. Interruptions in warfarin use were common, occurring in 32.6% (249 of 764) of patients. Those with two or more interruptions were younger and at lower baseline stroke risk when compared to those with no interruptions. There were 76 first strokes and 73 first-bleeding events in the follow-up period. When adjusted for baseline stroke risk, time to warfarin start, and total exposure time, two or more interruptions in warfarin use was associated with an increased risk of stroke (relative risk, 2.29; 95% confidence interval: 1.29-4.07). There was no significant association between warfarin interruptions and bleeding events.

CONCLUSION

Warfarin was underutilized in a substantial portion of eligible atrial fibrillation patients in these community-based practices. In addition, prolonged interruptions in anticoagulation were common in this population, and multiple interruptions were associated with over twice the risk of stroke when compared to those treated continuously.

Novel anticoagulants in atrial fibrillation stroke prevention

This review article evaluates novel oral anticoagulants in comparison with warfarin for thromboembolism prophylaxis in patients with atrial fibrillation (AF). AF is the most frequently diagnosed arrhythmia in the United States. The most serious side effect of AF is stroke. Warfarin has several decades of proven efficacy in AF-related stroke prevention but the drug's numerous drawbacks make its implementation difficult for practitioners and patients. The difficulties of warfarin have prompted the development of alternative anticoagulants for AF-related stroke prevention with better efficacy, safety, and convenience. The oral direct thrombin inhibitor, dabigatran, and the oral factor Xa inhibitors, rivaroxaban and apixaban, have been evaluated in a large phase III trial. Dabigatran, rivaroxaban and apixaban were shown to be noninferior compared with warfarin in the prevention of stroke. Dabigatran and apixaban were found to be statistically superior to warfarin. All three may also have a better safety profile than warfarin. In conclusion, novel anticoagulants have a different pharmacologic profile compared with warfarin that may eliminate many of the treatment inconveniences. Practitioners must also be aware of the disadvantages these new drugs possess when choosing a management strategy for their patients. Drug selection may become clearer as these new drugs are used more extensively.

Preventative Measures of Stroke in Patients With Atrial Fibrillation

Atrial fibrillation (AF) is the commonest sustained cardiac arrhythmia and is associated with increased morbidity and mortality due to stroke and thrombo-embolism. In patients with AF, strokes are usually more severe, resulting in longer hospital stays, worse disability and considerable healthcare costs. The prevention of stroke therefore is crucial in the management of AF. Stroke risk stratification tools can be used to determine patients at higher risk of stroke, and if no contraindications are present oral anticoagulation (OAC) therapy can be initiated. Despite the strong evidence for the benefit of OAC in stroke prevention in patients with AF, the use of thromboprophylaxis remains inadequate. The key measures to prevent stroke in patients with AF include: adequate stroke risk assessment and thrombo-prophylaxis; prompt initiation of OAC and avoidance of interruptions; earlier detection of AF; and education to overcome the under-usage of OAC in elderly patients.