Discontinued Warfarin Research Articles

Treatment of atrial fibrillation with warfarin among older adults with end stage renal disease.

There is increasing evidence questioning the use of warfarin for atrial fibrillation (AF) among older adults with end stage renal disease (ESRD). We assessed the patterns and determinants of warfarin utilization among these patients in the US. We assembled a cohort of older adults (age ≥65) undergoing dialysis with incident AF from July 2007 to November 2011 from the US Renal Data System (USRDS). We used descriptive statistics to characterize warfarin utilization within 30 days of AF discharge, and logistic regression to quantify patient characteristics associated with warfarin initiation. Among 5730 older adults undergoing dialysis with incident AF, 15.5% initiated warfarin. Among 2906 patients with high risk of bleeding, 12.7% initiated warfarin; whereas 14.9% initiated warfarin among 4824 patients with high risk of stroke. After adjustment for patient characteristics, warfarin initiation was lower among patients who were older [odds ratio (OR) = 0.74 per 10-year increase, 95% confidence interval (CI) 0.66-0.83] and those with a history of diabetes (OR = 0.75, 95% CI 0.63-0.90), myocardial infarction (OR = 0.64, 95% CI 0.50-0.80), or bleeding (OR = 0.63, 95% CI 0.50-0.80). There was no association between sex, race, or dialysis modality and warfarin initiation. Among patients who initiated warfarin, 46.8% discontinued warfarin use after a median treatment length of 8.6 months. Despite the unclear benefit and increased bleeding risk of warfarin treatment in patients with ESRD, 1 in 8 older adults undergoing dialysis with incident AF in the US who had high risk of bleeding used warfarin. Changes to warfarin therapy due to discontinuation were common after initiation.

Patients’ and physicians’ experiences of atrial fibrillation consultations and anticoagulation decision-making: A multi-perspective IPA design

Objective: To explore patients’ and physicians’ experiences of atrial fibrillation (AF) consultations and oral anticoagulation decision-making.Design: Multi-perspective interpretative phenomenological analyses.Methods: Participants included small homogeneous subgroups: AF patients who accepted (n = 4), refused (n = 4) or discontinued (n = 3) warfarin, and four physician subgroups (n = 4 each group): consultant cardiologists, consultant general physicians, general practitioners and cardiology registrars. Semi-structured interviews were conducted. Transcripts were analysed using multi-perspective interpretative phenomenological analysis (IPA) analyses to attend to individuals within subgroups and making comparisons within and between groups.Results: Three themes represented patients’ experiences: Positioning within the physician–patient dyad, Health–life balance, and Drug myths and fear of stroke. Physicians’ accounts generated three themes: Mechanised metaphors and probabilities, Navigating toward the ‘right’ decision and Negotiating systemic factors.Conclusions: This multi-perspective IPA design facilitated an understanding of the diagnostic consultation and treatment decision-making which foregrounded patients’ and physicians’ experiences. We drew on Habermas’ theory of communicative action to recommend broadening the content within consultations and shifting the focus to patients’ life contexts. Interventions including specialist multidisciplinary teams, flexible management in primary care and multifaceted interventions for information provision may enable the creation of an environment that supports genuine patient involvement and participatory decision-making.

Computational investigation of potential dosing schedules for a switch of medication from warfarin to rivaroxaban-an oral, direct Factor Xa inhibitor.

The long-lasting anticoagulant effect of vitamin K antagonists can be problematic in cases of adverse drug reactions or when patients are switched to another anticoagulant therapy. The objective of this study was to examine in silico the anticoagulant effect of rivaroxaban, an oral, direct Factor Xa inhibitor, combined with the residual effect of discontinued warfarin. Our simulations were based on the recommended anticoagulant dosing regimen for stroke prevention in patients with atrial fibrillation. The effects of the combination of discontinued warfarin plus rivaroxaban were simulated using an extended version of a previously validated blood coagulation computer model. A strong synergistic effect of the two distinct mechanisms of action was observed in the first 2–3 days after warfarin discontinuation; thereafter, the effect was close to additive. Nomograms for the introduction of rivaroxaban therapy after warfarin discontinuation were derived for Caucasian and Japanese patients using safety and efficacy criteria described previously, together with the coagulation model. The findings of our study provide a mechanistic pharmacologic rationale for dosing schedules during the therapy switch from warfarin to rivaroxaban and support the switching strategies as outlined in the Summary of Product Characteristics and Prescribing Information for rivaroxaban.

Periprocedural stroke and bleeding complications in patients undergoing catheter ablation of atrial fibrillation with different anticoagulation management: results from the Role of Coumadin in Preventing Thromboembolism in Atrial Fibrillation (AF) Patients Undergoing Catheter Ablation (COMPARE) randomized trial.

Periprocedural thromboembolic and hemorrhagic events are worrisome complications of catheter ablation for atrial fibrillation (AF). The periprocedural anticoagulation management could play a role in the incidence of these complications. Although ablation procedures performed without warfarin discontinuation seem to be associated with lower thromboembolic risk, no randomized study exists. This was a prospective, open-label, randomized, parallel-group, multicenter study assessing the role of continuous warfarin therapy in preventing periprocedural thromboembolic and hemorrhagic events after radiofrequency catheter ablation. Patients with CHADS2 score ≥1 were included. Patients were randomly assigned in a 1:1 ratio to the off-warfarin or on-warfarin arm. The incidence of thromboembolic events in the 48 hours after ablation was the primary end point of the study. The study enrolled 1584 patients: 790 assigned to discontinue warfarin (group 1) and 794 assigned to continuous warfarin (group 2). No statistical difference in baseline characteristics was observed. There were 39 thromboembolic events (3.7% strokes [n=29] and 1.3% transient ischemic attacks [n=10]) in group 1: two events (0.87%) in patients with paroxysmal AF, 4 (2.3%) in patients with persistent AF, and 33 (8.5%) in patients with long-standing persistent AF. Only 2 strokes (0.25%) in patients with long-standing persistent AF were observed in group 2 (P<0.001). Warfarin discontinuation emerged as a strong predictor of periprocedural thromboembolism (odds ratio, 13; 95% confidence interval, 3.1-55.6; P<0.001). This is the first randomized study showing that performing catheter ablation of AF without warfarin discontinuation reduces the occurrence of periprocedural stroke and minor bleeding complications compared with bridging with low-molecular-weight heparin. http://www.clinicaltrials.gov. Unique identifier: NCT01006876.

Abstract W P330: Antithrombotic Treatment Patterns Among Patients with Non-Valvular Atrial Fibrillation in a Managed Care Setting

Background: Antithrombotic therapy (warfarin or aspirin (ASA)) has been recommended to reduce the risk of stroke in patients with NVAF. The purpose of this study was to describe antithrombotic treatment patterns and baseline differences for managed care patients newly diagnosed with NVAF. Methods: Patients age ≥18 years and newly diagnosed with NVAF (index date) were identified between 01/01/2006_12/31/2011 within Kaiser Permanente Southern California databases and followed until 12/31/2012. Prescriptions, anticoagulation clinic information, and international normalized ratio (INR) monitoring were used to create 4 treatment groups: 1) continuous warfarin, 2) discontinuous warfarin (≥1 treatment gap &gt;80 days), 3) ASA only, and 4) no antithrombotic therapy. Descriptive statistics were used to compare groups. Results: A total of 28,776 patients were identified with median follow up of 2.5 years. Among the 81% of patients (23,297) with ≥1 CHADS 2 risk factor for stroke at baseline: 27.4% were continuously treated with warfarin, 22.0% discontinued warfarin, 28.5% were on ASA only, and 22.1% received no therapy. Using the Rosendaal method, median time in INR range 2-3 for all warfarin-treated patients was 59%, which does not include patient-specific ranges. ASA users were older (mean±SD age: 77.6±10.8) compared to continuous warfarin users (73.7±9.6, p&lt;0.001). Continuous warfarin users had higher rates of comorbidities: hypertension, diabetes, and stroke compared to the ASA group (stroke: 4.4% vs. 2.2% respectively, p&lt;0.001), whereas the ASA and no therapy groups had higher rates of congestive heart failure, myocardial infarction, and bleeding (bleeding: 9.0% ASA, 9.8% no therapy, 6.5% continuous warfarin, p&lt;0.001). CHADS 2 scores were slightly higher for ASA users compared to continuous warfarin or no therapy (2.04±0.92 ASA, 2.01±0.90 continuous warfarin, 1.93±0.93 no therapy, p&lt;0.001). Conclusion: Patients with newly diagnosed NVAF have varied treatment patterns and baseline comorbidities including rates of stroke and bleed. Future studies should evaluate risks and benefits associated with these real world treatment patterns.

Warfarin Use and Stroke Risk Among Patients With Nonvalvular Atrial Fibrillation in a Large Managed Care Population

Stroke prevention is a goal of atrial fibrillation (AF) management, but discontinuation of warfarin anticoagulation therapy is common. To investigate the association between warfarin discontinuation and hospitalization for stroke among nonvalvular AF (NVAF) patients enrolled in managed care. Patients with NVAF who initiated warfarin therapy from January 2005 through June 2009 were included. Warfarin discontinuation was defined as a supply gap >60 days without evidence of International Normalized Ratio measurements. Follow-up, which was a variable time period from warfarin initiation until the earlier of death, disenrollment from the health plan, or June 30, 2010, was divided into periods of warfarin treatment and discontinuation. Stroke events were identified based on claims for inpatient stays with a primary diagnosis of stroke or transient ischemic attack. Cox proportional hazards models were constructed to assess the relationship between warfarin discontinuation and incident stroke while adjusting for baseline demographics, stroke and bleeding risk, and comorbidities, as well as time-dependent antiplatelet use, stroke, and bleeding events in the previous warfarin treatment period. Among warfarin initiators with NVAF (N = 16,253), 51.4% discontinued warfarin therapy at least once during a mean follow-up of 668 days. Stroke risk was significantly greater during warfarin discontinuation periods compared with therapy periods (hazard ratio = 1.60; 95% CI, 1.35-1.90; P < 0.001). More than half of patients on warfarin had treatment gaps or discontinued therapy. Therapy gaps were associated with increased stroke risk.

Anticoagulated Patients Undergoing Coronary Angiography: Continue or Discontinue Warfarin?

Anticoagulated Patients Undergoing Coronary Angiography: Continue or Discontinue Warfarin?

Use of Warfarin Therapy Among Residents Who Developed Venous Thromboembolism in the Nursing Home

BackgroundTreatment of venous thromboembolism (VTE) in long-term care (LTC) settings has received little empirical study. ObjectiveAmong residents with VTE in nursing homes, this analysis evaluated frequency of anticoagulant use, the proportion of residents newly started on warfarin who persisted on therapy (≥3 months), and the association of key resident characteristics, including bleeding risk, with warfarin use and persistence. MethodsUsing the AnalytiCare LTC database (US), eligible residents had deep vein thrombosis or pulmonary embolism coded in the Minimum Data Set (MDS) 2.0 during the uptake period April 1, 2007 through December 31, 2008 (earliest VTE was index date) and had 1 or more MDS assessment(s) over the 90-day preindex period, each negative for VTE. Logistic regression evaluated the association of resident characteristics with warfarin use. Cox regression evaluated persistence with warfarin therapy. ResultsThe median age of residents with VTE included in the analysis (N = 489) was 80 years; 73% received anticoagulant therapy and 66% were prescribed warfarin ±45 days of the index date. Multivariate logistic regression identified several factors significantly associated with warfarin use: location in South Central region (odds ratio [OR] = 1.94, P = 0.019) and the Western region (OR = 2.53, P = 0.005) [both vs reference South Atlantic]; body mass index categories normal (OR = 2.73, P = 0.045), overweight (OR = 4.21, P = 0.005), and obese (OR = 3.82, P = 0.010) (both vs reference underweight); Alzheimer's/dementia (OR = 0.52, P = 0.024); cancer (OR = 0.39, P = 0.008); and moderate-dependent versus independent physical functioning (OR = 2.59, P = 0.003). Of residents newly started on warfarin therapy with no history of cancer (n = 149), 28% discontinued warfarin within 90 days of initiation. Peripheral vascular disease (PVD) (OR = 4.07, P < 0.001), Alzheimer's disease/dementia (OR = 2.55, P = 0.046), and antipsychotic use (OR = 4.60, P < 0.001) were all significantly associated with discontinuation. ConclusionsPatients in specific geographic regions who were underweight, had Alzheimer's disease/dementia or cancer, or had independent physical functioning were less likely to receive warfarin. Nonpersistence of warfarin therapy was strongly related to antipsychotic use, presence of dementia, or PVD.

No Increased Bleeding Events with Continuation of Oral Anticoagulation Therapy for Patients Undergoing Cardiac Device Procedure

Switching warfarin for heparin has been a practice for managing periprocedural anticoagulation in high-risk patients undergoing device-related procedures. We sought to investigate whether continuation of warfarin sodium therapy without heparin bridging is safe and, when it is continued, the optimal international normalized ratio (INR) without increased bleeding risk at time of device-related procedure. We retrospectively studied 766 consecutive patients taking warfarin long term who underwent device-related procedures. Patients were grouped by treatment: discontinued warfarin (-warfarin, n = 243), no interruption of warfarin (+warfarin, n = 324), and discontinued warfarin with heparin bridging (+heparin, n = 199). The study primary endpoint was systemic bleeding or formation of moderate or severe pocket hematoma within 30 days of the procedure. Thirty-one (4%) patients had bleeding events, including pocket hematoma in 29 patients. The bleeding events occurred more often for +heparin (7.0%) than -warfarin (2.1%) or +warfarin (3.7%, P = 0.029). For +warfarin group, INR of 2.0-2.5 at time of procedure did not increase bleeding risk compared with INR less than 1.5 (3.7% vs 3.4%; P = 0.72), but INR greater than 2.5 increased the bleeding risk (10.0% vs 3.4%; P = 0.029). Concomitant aspirin use with warfarin significantly increased bleeding risk than warfarin alone (5.6% vs 1.4%, P = 0.02). Median length of hospitalization was significantly shorter for +warfarin than +heparin (1 vs 6 days; P < 0.001). Continuation of oral anticoagulation therapy with an INR level of <2.5 does not impose increased risk of bleeding for device-related procedures, although precaution is necessary to avoid supratherapeutic anticoagulation levels.

Continue or Discontinue Warfarin for Fecal Occult Blood Testing in 2010? Does the Published Evidence Provide an Answer?

Whether to continue or discontinue warfarin before fecal occult blood testing (FOBT) requires comparison of the risks and benefits of both choices. Clinical practice varies on this issue, and guidelines are silent. A small body of evidence about the effect of warfarin on test characteristics of FOBT is inconclusive, although it suggests no effect. Retrospective studies on this topic may be prone to transfer bias, which affects the composition of the groups assembled for study. Considering the risks and benefits of discontinuing warfarin qualitatively, along with the published literature and clinical context in 2010, where tolerance for false-positive results is higher than it used to be and where immunochemical FOBT is a better screening test than older, guaiac-based FOBT, "no" seems like the "commonsense" answer.

Perioperative Management of Anticoagulant Therapy during Cutaneous Surgery: 2005 Survey of Mohs Surgeons

The perioperative management of anticoagulation and antiplatelet therapy is a controversial topic in the field of dermatologic surgery. Dermasurgeons must weigh the risk of bleeding against the risk of thrombotic complications when deciding how to manage perioperative anticoagulation. Our aim is to present a summary of current practice in anticoagulation management perioperatively during cutaneous surgery. We compare our results to those found in a similar survey in 2002. A questionnaire surveying current practice in perioperative management of anticoagulant therapy was mailed to 720 dermasurgeons. Thirty-eight percent of dermasurgeons responded to the questionnaire. Of the responding physicians, 87% discontinue prophylactic aspirin therapy, 37% discontinue medically necessary aspirin, 44% discontinue warfarin, 77% discontinue nonsteroidal anti-inflammatory drugs (NSAIDs), and 77% discontinue vitamin E therapy perioperatively at least some of the time. Although clopidogrel was not surveyed, 78 physicians included comments about the management of this agent. Dermasurgeons were more likely to continue medically necessary aspirin and warfarin in 2005 compared to 2002, with the most dramatic shift evident in the management of warfarin. They were more likely to discontinue prophylactic aspirin, NSAIDs, and vitamin E. Surgeons were concerned about bleeding with the antiplatelet agent clopidogrel. More evidence-based medicine is necessary to set guidelines for the management of anticoagulation and antiplatelet therapy perioperatively.

The safety of open inguinal herniorraphy in patients on chronic warfarin therapy

Background The perioperative management of warfarin therapy increases the complexity of open inguinal herniorraphy. Methods One thousand consecutive patients undergoing open inguinal herniorraphy were retrospectively reviewed. Patients on warfarin therapy were categorized into 3 groups: continued warfarin (CW), discontinued warfarin (DW), and discontinued warfarin with anticoagulation bridge (DWB). Results Eighty-eight patients were on chronic warfarin therapy. Warfarin was continued in 19 patients, discontinued in 54, and discontinued with bridge in 15 patients. Operative times were similar between the 3 groups. Length of stay was longest in the discontinued warfarin with bridge group (CW 0.74, DW 0.54, and DWB 3.33 days; P < .0001). There was no significant difference in postoperative complications. The incidence of surgical site hematoma was higher in the continued warfarin and discontinued warfarin with bridge groups (CW 11%, DW 2%, and DWB 13%; P = .14). Conclusions Continuation of warfarin may be a safe alternative to discontinuation of warfarin therapy in select patients undergoing open inguinal herniorraphy.

Perioperative management of anticoagulants and platelet inhibitors for cutaneous surgery: a survey of current practice.

Perioperative management of therapy with anticoagulants or platelet inhibitors for patients having cutaneous surgery presents dilemmas for dermatologic surgeons. To outline the current spectrum of practice for perioperative management. Questionnaires were mailed to 504 dermatologic surgeons. Data included use of warfarin, aspirin, and nonsteroidal anti-inflammatory drugs (NSAIDs) perioperatively and involvement of other physicians in making management decisions. Of the responding physicians, 83% routinely ask primary physicians or cardiologists for recommendations about perioperative management, 80% discontinue warfarin therapy perioperatively at least some of the time, 26% always discontinue aspirin therapy, 38% manage aspirin and NSAIDs in the same manner, and 53% withhold therapy with NSAIDs for less time than with aspirin. Dermatologic surgeons use various perioperative management strategies. Despite no published evidence of increased hemorrhagic risk with anticoagulant or platelet inhibitor therapy during cutaneous surgery, many physicians discontinue therapy perioperatively.