Higher OAK (Oral Anticoagulation Knowledge) score at baseline associated with better TTR (Time in Therapeutic Range) in patients taking warfarin.

A lack in patient knowledge of warfarin therapy is associated with poor adherence. This knowledge gap may result in a lower INR Time in Therapeutic Range (TTR). To investigate association between patient anticoagulation knowledge and warfarin control. Michigan Anticoagulation Quality Improvement Initiative (MAQI2) is a Blue Cross Blue Shield of Michigan sponsored consortium of six anticoagulation management services. Patients prescribed warfarin at two MAQI2 sites completed a voluntary Oral Anticoagulation Knowledge (OAK) questionnaire at warfarin initiation and 6-month follow-up. The results of 20 OAK questions and TTRs (excluding 1st month post-initiation) were compared using chi-square tests, t-tests and multivariate analysis adjusting for SAMe-TT2R2 and days on warfarin. Of 1836 surveys distributed at warfarin initiation, 481 (26.2%) patients completed the baseline questionnaire (within 1 month post-initiation): mean OAK score: 14.6 ± 3.4. Of those, 147 (30.6%) completed 6-month follow-up surveys (OAK: 12.7 ± 5.8). Patients with TTR ≥ 70% at baseline scored higher on OAK tests than patients with TTR < 70% in unadjusted analyses (15.1 ± 3.2 v. 14.2 ± 3.5, p = 0.003) and adjusted analysis (p = 0.020). There was no unadjusted or adjusted difference in OAK scores at 6-month follow-up between patients with TTR ≥ 70% and TTR < 70%. For patients who completed baseline and follow-up surveys, there was a decrease of 2.4 points in OAK score between baseline and 6-month follow up (p < 0.001). Higher baseline, but not follow-up, OAK score is associated with better warfarin control and average OAK scores decreased between baseline and follow-up. Further studies are needed to determine what type of patient education may improve patient knowledge retention and warfarin control.

Creatinine monitoring patterns in the setting of direct oral anticoagulant therapy for non-valvular atrial fibrillation.

Guidelines and experts note that patients with atrial fibrillation require regular renal function monitoring to ensure safe use of direct oral anticoagulants (DOACs). Insufficient monitoring could lead to inappropriate dosing and adverse events. Our objective was to describe the frequency of insufficient creatinine monitoring among patients on DOACs, and to describe clinical factors associated with insufficient monitoring. We hypothesized that renal impairment would be associated with insufficient monitoring. A retrospective cohort study was performed with data from the Michigan Anticoagulant Quality Improvement Initiative. Patients were included if they initiated DOAC therapy for stroke prevention related to atrial fibrillation, remained on therapy for ≥ 1 year, and had baseline creatinine and weight measurements. Creatinine clearance (CrCl) was calculated via Cockcroft-Gault equation. Our outcome was the presence of insufficient creatinine monitoring, defined as: < 1 creatinine level/year for patients with CrCl > 50, or < 2 creatinine levels/year for patients with CrCl ≤ 50. Multivariable analysis was done via logistic regression. Study population included 511 patients. In overall, 14.0% of patients received insufficient monitoring. Among patients with CrCl > 50, 11.5% had < 1 creatinine level/year. Among patients with CrCl ≤ 50, 27.1% received < 2 creatinine levels/year. Baseline renal dysfunction was associated with a higher likelihood of insufficient creatinine monitoring (adjusted odds ratio 3.64, 95% confidence interval 1.81-7.29). This shows a significant gap in the monitoring of patients on DOACs-patients with renal impairment are already at higher risk for adverse events. Future studies are needed to describe the barriers in monitoring these patients and to identify how to optimally address them.

Mind the gap: results of a multispecialty survey on coordination of care for peri-procedural anticoagulation.

To understand how physicians from various specialties perceive coordination of care when managing peri-procedural anticoagulation. Cross-sectional survey of cardiologists, gastroenterologists, and primary care physicians (PCPs) in an integrated health system (N = 251). The survey began with a vignette of a patient with atrial fibrillation co-managed by his PCP, cardiologist, and an anticoagulation clinic who must hold warfarin for a colonoscopy. Respondents' experiences and opinions around responsibilities and institutional support for managing peri-procedural anticoagulation were elicited using multiple choice questions. We examined differences in responses across specialties using Chi square analysis. The response rate was 51% (n = 127). 52% were PCPs, 28% cardiologists, and 21% gastroenterologists. Nearly half (47.2%) of respondents believed that the cardiologist should be primarily responsible for managing peri-procedural anticoagulation, while fewer identified the PCP (25.2%), anticoagulation clinic (21.3%), or gastroenterologist (6.3%; p = 0.09). Respondents across specialties had significantly different approaches to deciding how to manage the clinical case presented (p < 0.001). Most cardiologists (60.0%) would decide whether to offer bridging without consulting with other providers or clinical resources, while most PCPs would decide after consulting clinical resources (57.6%). Gastroenterologists would most often (46.2%) defer the decision to another provider. A majority of all three specialties agreed that their institution could do more to help manage peri-procedural anticoagulation, and there was broad support (88.1%) for anticoagulation clinics' managing all aspects of peri-procedural anticoagulation. Providers across specialties agree that their institution could do more to help manage peri-procedural anticoagulation, and overwhelmingly support anticoagulation clinics' taking responsibility.

Warfarin for prevention of thromboembolism in atrial fibrillation: comparison of patient characteristics and outcomes of the "Real-World" Michigan Anticoagulation Quality Improvement Initiative (MAQI2) registry to the RE-LY, ROCKET-AF, and ARISTOTLE trials.

Randomized controlled trials (RCTs) examining warfarin use for stroke prevention in atrial fibrillation (AF) may not accurately reflect real-world populations. We aimed to determine the representativeness of the RCT populations to real-world patients and to describe differences in the characteristics of trial populations from trial eligible patients in a real-world setting. We hypothesized that a significant fraction of real-world patients would not qualify for the RE-LY, ROCKET-AF, and ARISTOTLE trials and that real-world patients qualifying for the studies may have more strokes and bleeding events. We compared the inclusion and exclusion criteria, patient characteristics, and clinical outcomes from RE-LY, ROCKET-AF, and ARISTOTLE against data from the Michigan Anticoagulation Quality Improvement Initiative (MAQI2), a regional network of six community- and academic-based anticoagulation clinics. Of the 1446 non-valvular AF patients in the MAQI2 registry taking warfarin, approximately 40-60% would meet the selection criteria used in RE-LY (788, 54.5%), ROCKET-AF (566, 39.1%), and ARISTOTLE (866, 59.9%). The most common reasons for exclusion from one or more trial were anemia (15.1%), other concurrent medications (11.2%), and chronic kidney disease (9.4%). Trial-eligible MAQI2 patients were older, more frequently female, with a higher rate of paroxysmal AF, and lower rates of congestive heart failure, previous stroke, and previous myocardial infarction than the trial populations. MAQI2 patients eligible for each trial had a lower rate of stroke and similar rate of major bleeding than was observed in the trials. A sizable proportion of real-world AF patients managed in anticoagulation clinics would not have been eligible for the RE-LY, ROCKET-AF, and ARISOTLE trials. The expected stroke risk reduction and bleeding risk among real-world AF patients on warfarin may not be congruent with published clinical trial data.

Structure and function of anticoagulation clinics in the United States: an AC forum membership survey.

Many anticoagulation clinics have adapted their services to provide care for patients taking direct oral anticoagulants (DOAC) in addition to traditional warfarin management. Anticoagulation clinic scope of service and operations in this transitional environment have not been well described in the literature. A survey was conducted of United States-based Anticoagulation Forum members to inquire about anticoagulation clinic structure, function, and services provided. Survey responses are reported using summary or non-parametric statistics, when appropriate. Unique clinic survey responses were received from 159 anticoagulation clinics. Clinic structure and staffing are highly variable, with approximately half of clinics (52%) providing DOAC-focused care in addition to traditional warfarin-focused care. Of those clinics managing DOAC patients, this accounts for only 10% of their clinic volume. These clinics commonly have a DOAC follow up protocol (75%). Clinics assign a median of 190.5 (interquartile range 50-300) patients per staff full-time-equivalent, with more patients assigned in phone-based care clinics than in face-to-face based care clinics. Most clinics (68.5%) report receiving reimbursement, which occur either through a combination of patient and insurance provider billing (78.2%), insurance reimbursement only (19.5%) or patient reimbursement only (2.3%). There is wide heterogeneity in anticoagulation clinic structure, function, and services provided. Half of all survey-responding anticoagulation clinics provide care for DOAC-treated patients. Understanding how changes in healthcare policy and reimbursement have impacted these clinics remains to be explored.

SAMe-TT2R2 predicts quality of anticoagulation in patients with acute venous thromboembolism: The MAQI2 experience.

A high SAMe-TT2R2 score predicted poor warfarin control and adverse events among atrial fibrillation patients. However, the SAMe-TT2R2 score has not been well validated in venous thromboembolism (VTE) patients. A cohort of 1943 warfarin-treated patients with acute VTE was analyzed to correlate the SAMe-TT2R2 score with time in therapeutic range (TTR) and clinical adverse events. A TTR <60% was more frequent among patients with a high (>2) versus low (0-1) SAMe-TT2R2 score (63.4% vs 52.3%, p<0.0001). A high SAMe-TT2R2 score (>2) correlated with increased overall adverse events (7.9 vs 4.5 overall adverse events/100 patient years, p=0.002), driven primarily by increased recurrent VTE rates (4.2 vs 1.5 recurrent VTE/100 patient years, p=0.0003). The SAMe-TT2R2 score had a modest predictive ability for international normalized ratio (INR) quality and adverse clinical events among warfarin-treated VTE patients. The utility of the SAMe-TT2R2 score to guide clinical decision-making remains to be investigated.

Prescribing trends of atrial fibrillation patients who switched from warfarin to a direct oral anticoagulant.

Direct oral anticoagulant (DOAC) agents offer several lifestyle and therapeutic advantages for patients relative to warfarin in the treatment of atrial fibrillation (AF). These alternative agents are increasingly used in the treatment of AF, however the adoption practices, patient profiles, and reasons for switching to a DOAC from warfarin have not been well studied. Through the Michigan Anticoagulation Quality Improvement Initiative, abstracted data from 3873 AF patients, enrolled between 2010 and 2015, were collected on demographics and comorbid conditions, stroke and bleeding risk scores, and reasons for anticoagulant switching. Over the study period, patients who switched from warfarin to a DOAC had similar baseline characteristics, risk scores, and insurance status but differed in baseline CrCl. The most common reasons for switching were patient related ease of use concerns (37.5%) as opposed to clinical reasons (16.5% of patients). Only 13% of patients that switched to a DOAC switched back to warfarin by the end of the study period.

Update in the management of type B aortic dissection.

Stanford type B aortic dissection (TBAD) is a life-threatening aortic disease. The initial management goal is to prevent aortic rupture, propagation of the dissection, and symptoms by reducing the heart rate and blood pressure. Uncomplicated TBAD patients require prompt medical management to prevent aortic dilatation or rupture during subsequent follow-up. Complicated TBAD patients require immediate invasive management to prevent death or injury caused by rupture or malperfusion. Recent developments in diagnosis and management have reduced mortality related to TBAD considerably. In particular, the introduction of thoracic stent-grafts has shifted the management from surgical to endovascular repair, contributing to a fourfold increase in early survival in complicated TBAD. Furthermore, endovascular repair is now considered in some uncomplicated TBAD patients in addition to optimal medical therapy. For more challenging aortic dissection patients with involvement of the aortic arch, hybrid approaches, combining open and endovascular repair, have had promising results. Regardless of the chosen management strategy, strict antihypertensive control should be administered to all TBAD patients in addition to close imaging surveillance. Future developments in stent-graft design, medical therapy, surgical and hybrid techniques, imaging, and genetic screening may improve the outcomes of TBAD patients even further. We present a comprehensive review of the recommended management strategy based on current evidence in the literature.

Renal function in atrial fibrillation patients switched from warfarin to a direct oral anticoagulant.

All available direct oral anticoagulants (DOACs) are at least partially eliminated by the kidneys. These agents are increasingly being used as alternatives to warfarin for stroke prevention in patients with atrial fibrillation. The aim of this study was to identify changes in renal function and associated DOAC dosing implications in a multicenter cohort of atrial fibrillation patients switched from warfarin to DOAC treatment. We included all patients in the Michigan Anticoagulation Quality Improvement Initiative cohort who switched from warfarin to a DOAC with atrial fibrillation as their anticoagulant indication between 2009 and 2014, and who had at least two creatinine values. Compliance with FDA-recommended dosing based on renal function was assessed. Of the 189 patients switched from warfarin to a DOAC, 34 (18.0 %) had a baseline creatinine clearance <50 mL/min and 23 (12.2 %) experienced important fluctuations in renal function. Of these 23 patients, 6 (26.1 %) should have impacted the DOAC dosing, but only 1 patient actually received an appropriate dose adjustment. Additionally, 15 (7.9 %) of patients on DOACs had a dose change performed, but only one patient demonstrated a change in renal function to justify the dose adjustment. Most atrial fibrillation patients who switched from warfarin to a DOAC had stable renal function. However, the majority of patients who had a change in renal function did not receive the indicated dose change. As the use of DOACs expands, monitoring of renal function and appropriate dose adjustments are critical.

Venous thromboembolism: Predicting recurrence and the need for extended anticoagulation.

Initial treatment for venous thromboembolism (VTE) includes the acute and intermediate phases, usually lasting for 3 months. The choice to extend therapy beyond the initial 3-month window involves assessing a combination of risk factors for VTE recurrence and bleeding, along with weighing patient preferences. In some cases, such as VTE provoked by a reversible surgical risk factor, the recurrence risk is sufficiently low that most patients should not receive extended therapy. In other cases, such as VTE associated with malignancy, the recurrence risk is sufficiently high that treatment should be extended beyond the initial 3 months. However, a large number of patients fall into a grey zone where the decision on extended therapy is less clear-cut. In this review, we summarize the evidence for VTE recurrence risk and the role for extended anticoagulation given a variety of patient-specific factors and laboratory results. We also review the role of VTE risk prediction tools and provide a recommended algorithm for approaching the decision of extended anticoagulation therapy. Various agents available for extended VTE therapy, including warfarin, aspirin and the direct oral anticoagulant agents, are discussed.

The Society for Vascular Medicine: the first quarter century.

The Society for Vascular Medicine was founded in 1989. During the subsequent 25 years, the Society has grown to approximately 500 members and has achieved international recognition while making important contributions to vascular disease education, clinical vascular medicine and biology research, and patient care. In celebration of the Society's 25th anniversary, its past and current presidents reflect on the Society's history, challenges, and achievements, and emphasize the vital role of the SVM in the discipline of vascular medicine.

Variation in practice patterns among specialties in the acute management of atrial fibrillation.

BACKGROUND: Atrial fibrillation (AF) is commonly managed by a variety of specialists. Current guidelines differ in their recommendations leading to uncertainty regarding important clinical decisions. We sought to document practice pattern variation among cardiologists, emergency physicians (EP) and hospitalists at a single academic, tertiary-care center. METHODS: A survey was created containing seven clinical scenarios of patients presenting with AF. We analyzed respondent choices regarding rate vs rhythm control, thromboembolic treatment and hospitalization strategies. Finally, we contrasted our findings with a comparable Australasian survey to provide an international reference. RESULTS: There was a 78% response rate (124 of 158), 37% hospitalists, 31.5% cardiologists, and 31.5% EP. Most respondents chose rate over rhythm control (92.2%; 95% CI, 89.1% - 94.5%) and thromboembolic treatment (67.8%; 95% CI, 63.8% - 71.7%). Compared to both hospitalists and EPs, cardiologists were more likely to choose thromboembolic treatment for new and paroxysmal AF (adjusted OR 2.38; 95% CI, 1.05 - 5.41). They were less likely to favor hospital admission across all types of AF (adjusted OR 0.36; 95% CI, 0.17 - 0.79) but thought cardiology consultation was more important (adjusted OR 1.88, 95% CI, 0.97 - 3.64). Australasian physicians were more aggressive with rhythm control for paroxysmal AF with low CHADS2 score compared to US physicians. CONCLUSIONS: Significant variation exists among specialties in the management of acute AF, likely reflecting a lack of high quality research to direct the provider. Future studies may help to standardize practice leading to decreased rates of hospitalization and overall cost.

The changing characteristics of atrial fibrillation patients treated with warfarin.

It has been suggested that direct oral anticoagulants are being preferentially used in low risk atrial fibrillation (AF) patients. Understanding the changing risk profile of new AF patients treated with warfarin is important for interpreting the quality of warfarin delivery through an anticoagulation clinic. Six anticoagulation clinics participating in the Michigan Anticoagulation Quality Improvement Initiative enrolled 1293 AF patients between 2010 and 2014 as an inception cohort. Abstracted data included demographics, comorbidities, medication use and all INR values. Risk scores including CHADS2, CHA2DS2-VASc, HAS-BLED, SAMe-TT2R2, and Charlson comorbidity index (CCI) were calculated for each patient at the time of warfarin initiation. The quality of anticoagulation was assessed using the Rosendaal time in the therapeutic range (TTR) during the first 6 months of treatment. Between 2010 and 2014, patients initiating warfarin therapy for AF had an increasing mean CHADS2 (2.0 ± 1.1 to 2.2 ± 1.4, p = 0.02) and CCI (4.7 ± 1.8 to 5.1 ± 2.0, p = 0.03), and a trend towards increasing mean CHA2DS2-VASc, HAS-BLED, and SAMe-TT2R2 scores. The actual TTR remained unchanged over the study period (62.6 ± 18.2 to 62.7 ± 17.0, p = 0.98), and the number of INR checks did not change (18.9 ± 5.2 to 18.5 ± 5.1, p = 0.06). Between 2010 and 2014, AF patients newly starting warfarin had mild increases in risk for stroke and death with sustained quality of warfarin therapy.

Warfarin use in atrial fibrillation patients at low risk for stroke: analysis of the Michigan Anticoagulation Quality Improvement Initiative (MAQI(2)).

To more accurately quantify the proportion of anticoagulated patients with atrial fibrillation (AF) that may be inappropriately treated with warfarin for stroke prevention. Patients with AF have an increased risk of stroke, which is lowered by the use of warfarin. However there is likely more potential harm than benefit in patients that do not have additional stroke risk factors. Studies have described overuse of warfarin for stroke prophylaxis in lowest risk patients. However, many of those studies did not assess for electrical cardioversion (ECV) or radiofrequency ablation (RFA) as indications for warfarin therapy. Data from 1852 non-valvular AF patients treated with warfarin between October 2009 and October 2011 at seven anticoagulation centers participating in the Michigan Anticoagulation Quality Improvement Initiative registry were analyzed. Low risk AF patients were risk stratified using the CHADS2 scoring systems, with a score of zero representing lowest risk. 193 (10.4 %) of AF patients receiving warfarin were identified as having the lowest risk of stroke by the CHADS2 score. Of the patients with CHADS2 = 0, 130 (67.4 %) had undergone a recent ECV and/or RFA. Of all AF patients, only 63 (3.4 %) had a CHADS2 score of 0 and no recent ECV or RFA. The vast majority of AF patients receiving anticoagulation in this multi-center registry are doing so in accordance with national and international guidelines. In contrast to prior population-based studies, very few low risk patients are receiving inappropriate warfarin therapy for stroke prophylaxis in AF, when procedure-based indications are also considered.

Prevalence of Guideline-Discordant Aspirin Use and Associated Adverse Events in Patients on Warfarin for Mechanical Valve Replacement.

BACKGROUND: For patients on warfarin for mechanical heart valve replacement, the 2020 American College of Cardiology and American Heart Association Guidelines recommend only adding aspirin in patients with a specific indication for antiplatelet therapy. This contrasts with prior guidelines, which recommended concomitant aspirin therapy. We sought to assess the prevalence of guideline-discordant aspirin use among patients on warfarin for mechanical heart valve replacement and to compare adverse event rates among patients with and without concomitant aspirin. METHODS: Patients on warfarin for mechanical heart valve replacement were identified from the Michigan Anticoagulation Quality Improvement Initiative registry. Patients with myocardial infarction, percutaneous coronary intervention, or coronary artery bypass within the past 12 months were excluded. Patients were divided into 2 groups based on aspirin use. Patient characteristics and bleeding and thromboembolic outcomes were compared. RESULTS: Four hundred forty-four patients met the inclusion criteria, with 341 (76.8%) on concomitant aspirin. The aspirin group was older (50.6 vs 46.3 years, P = .028) and had more hypertension (57.8% vs 46.6%, P = .046) but other patient characteristics were similar. The aspirin group had a higher rate of bleeding events (28.3 vs 13.3 per 100 patient-years, P < .001) and bleed-related emergency department visits (11.8 vs 2.9 per 100 patient-years, P = .001) compared with the non-aspirin group. There was no observed difference in rates of ischemic stroke (0.56 vs 0.48 per 100 patient-years, P = .89). CONCLUSIONS: A significant proportion of patients on warfarin for mechanical heart valve replacement are on guideline-discordant aspirin. Aspirin deprescribing in select patients may safely reduce bleeding events.

Feasibility and acceptability of patient- and clinician-level antithrombotic stewardship interventions to reduce gastrointestinal bleeding risk in patients using warfarin (Anticoagulation with Enhanced Gastrointestinal Safety): a factorial randomized controlled pilot trial.

Background: Overuse of antiplatelet therapy and underuse of gastroprotection contribute to preventable bleeding in patients taking anticoagulants. Objectives: (1) Determine the feasibility of a factorial trial testing patient activation and clinician outreach to reduce gastrointestinal (GI) bleeding risk in patients prescribed warfarin-antiplatelet therapy without proton pump inhibitor gastroprotection and (2) assess intervention acceptability. Methods: Pragmatic 2 × 2 factorial cluster-randomized controlled pilot comparing (1) a patient activation booklet vs usual care and (2) clinician notification vs clinician notification plus nurse facilitation was performed. The primary feasibility outcome was percentage of patients completing a structured telephone assessment after 5 weeks. Exploratory outcomes, including effectiveness, were evaluated using chart review, surveys, and semistructured interviews. Results: Among 47 eligible patients, 35/47 (74.5%; 95% CI, 58.6%-85.7%) met the feasibility outcome. In the subset confirmed to be high risk for upper GI bleeding, 11/29 (37.9%; 95% CI, 16.9%-64.7%) made a medication change, without differences between intervention arms. In interviews, few patients reported reviewing the activation booklet; barriers included underestimating GI bleeding risk, misunderstanding the booklet's purpose, and receiving excessive health communication materials. Clinicians responded to notification messages for 24/47 patients (51.1%; 95% CI, 26.4%-75.4%), which was lower for surgeons than nonsurgeons (22.7% vs 76.0%). Medical specialists but not surgeons viewed clinician notification as acceptable. Conclusion: The proposed trial design and outcome ascertainment strategy were feasible, but the patient activation intervention is unlikely to be effective as designed. While clinician notification appears promising, it may not be acceptable to surgeons, findings which support further refinement and testing of a clinician notification intervention.

Use of warfarin for venous thromboembolism prophylaxis following knee and hip arthroplasty: results of the Michigan Anticoagulation Quality Improvement Initiative (MAQI2).

Total knee arthroplasty (TKA) and total hip arthroplasty (THA) are associated with high rates of venous thromboembolism (VTE). Anticoagulants, such as warfarin, are commonly used to prevent VTE in such patients. The practice and effectiveness of warfarin in real world populations is not well documented. 595 TKA and THA patients treated with warfarin were followed by two anticoagulation clinics in the Michigan Anticoagulation Quality Improvement Initiative. Length of prescribed anticoagulation, percent time in therapeutic range (%TTR) and time to first therapeutic INR were calculated for each surgical group. For THA, all 300 patients received at least ten days with a 28-day median length of anticoagulation therapy. For TKA, all 295 patients received at least 10 days with a 28-day median length of anticoagulation therapy. For THA patients, time to first therapeutic INR was on average 12.0 ± 8.0 days with a mean %TTR of 36.6 ± 26.8% for goal INR 2.0-3.0. For THA patients, 39 (13%) never reached target INR. For TKA patients, time to first therapeutic INR was on average 12.8 ± 10.3 days with a mean %TTR of 36.0 ± 28.3% for goal INR 2.0-3.0. For TKA patients, 44 (14.9%) never reached target INR. Many orthopaedic surgeons who use warfarin for post-arthroplasty VTE prophylaxis do so in accordance with national guidelines. The time to first therapeutic INR is strikingly long and %TTR markedly low for these patients, raising questions about the efficacy of warfarin therapy in the first 1-2 post-operative weeks. Further studies to investigate the best target INR for warfarin prophylaxis, as well as the composite rates of VTE and clinically relevant bleeding from treatment with warfarin, LMWH and newer anticoagulants are needed.