Comparing DOAC and warfarin outcomes in an obese population using the 'real-world' Michigan Anticoagulation Quality Improvement Initiative (MAQI2) registry.

INTRODUCTION: Direct oral anticoagulants (DOACs) have overtaken warfarin in the treatment of nonvalvular atrial fibrillation (AF) and venous thromboembolism (VTE). Limited data explore the safety of DOACs in obesity. METHODS: This multicenter retrospective study between June 2015 and September 2019 uses the Michigan Anticoagulation Quality Improvement Initiative (MAQI2) registry to compare DOACs and warfarin across weight classes (not obese: body mass index (BMI) ⩾ 18.5 and < 30; obese: BMI ⩾ 30 and < 40; severely obese: BMI ⩾ 40). Primary outcomes include major, clinically relevant nonmajor (CRNM), and minor bleeding events per 100 patient-years. Secondary outcomes include stroke, recurrent VTE, and all-cause mortality. RESULTS: DOACs were prescribed to 49% of the 4089 patients with AF and 46% of the 3162 patients with VTE. Compared to patients treated with warfarin, those treated with DOACs had a higher estimated glomerular filtration rate across BMI categories regardless of indication. In the AF population, severely obese patients treated with DOACs had more major (3.4 vs 1.8, p = 0.004), CRNM (8.6 vs 5.9, p = 0.019), and minor bleeding (11.4 vs 9.9, p = 0.001). There was no difference in stroke or all-cause mortality. In the VTE population, both CRNM (7.5 vs 6.7, p = 0.042) and minor bleeding (19.3 vs 10.5, p < 0.001) events occurred at higher rates in patients treated with DOACs. There was no difference in recurrent pulmonary embolism, stroke, or all-cause mortality. CONCLUSION: There is a higher rate of bleeding in severely obese patients with VTE and AF treated with DOACs compared to warfarin, without a difference in secondary outcomes. Further studies to compare the anticoagulant classes and understand bleeding drivers in this population are needed.

Outcomes of direct oral anticoagulants with aspirin vs warfarin with aspirin: a registry-based cohort study.

Background: For patients anticoagulated with direct oral anticoagulants (DOACs) or warfarin and on aspirin (ASA) for nonvalvular atrial fibrillation and/or venous thromboembolism, it is unclear if bleeding outcomes differ. Objectives: To assess bleeding rates for ASA with DOACs vs warfarin and one another. Methods: Registry-based cohort study of patients followed by a 6-center quality improvement collaborative in Michigan using data from 2009 to 2022. The study included adults on ASA with warfarin or DOACs for atrial fibrillation and/or venous thromboembolism without a recent myocardial infarction or heart valve replacement. Results: After propensity matching by anticoagulant class, we compared 2 groups of 1467 patients followed for a median of 18.0 months. Any bleeding and nonmajor bleeding was increased with DOACs + ASA compared with warfarin + ASA (32.2 vs 27.8 and 27.1 vs 22.9 events/100 patient-years; relative risks [RRs], 1.1 and 1.2; 95% CIs, 1.1-1.2 and 1.1-1.3, respectively). After matching by drug, patients on apixaban + ASA vs warfarin + ASA had more bleeding (31.2 vs 27.8 events/100 patient-years; RR, 1.1; 95% CI, 1.0-1.2) and nonmajor bleeding but less major bleeding (3.8 vs 4.7 events/100 patient-years; RR, 0.8; 95% CI, 0.6-1.0) and emergency room visits for bleeding. Patients on rivaroxaban + ASA vs warfarin + ASA had more bleeding (39.3 vs 26.3 events/100 patient-years, RR, 1.5; 95% CI, 1.3-1.6), nonmajor bleeding, and thrombosis. Patients on apixaban + ASA vs rivaroxaban + ASA had significantly less bleeding (22.5 vs 39.3/100 patient-years; RR, 0.6; 95% CI, 0.5-0.7), nonmajor bleeding, major bleeding (2.1 vs 5.5 events/100 patient-years; RR, 0.4; 95% CI, 0.2-0.6), emergency room visits for bleeding, and thrombotic events. Conclusion: Patients on DOAC + ASA without a recent myocardial infarction or heart valve replacement had more nonmajor bleeding but otherwise similar outcomes compared with warfarin + ASA. Patients treated with rivaroxaban + ASA experienced more adverse clinical events compared with warfarin + ASA or apixaban + ASA.

Timing of Off-Label Dosing of Direct Oral Anticoagulants in Three Large Health Systems.

BACKGROUND: While direct oral anticoagulants (DOACs) may be viewed as simpler to manage then warfarin, they present their own unique management challenges resulting in frequent off-label dosing. It is unknown to what extent off-label dosing occurs when a patient is started on a DOAC versus later in their treatment. OBJECTIVES: We aimed to better characterize when off-label DOAC dosing is occurring and to evaluate the effectiveness of prescribing oversight using a registry-based intervention. METHODS: We evaluated data from the Michigan Anticoagulation Quality Improvement Initiative (MAQI2) registry, a retrospective quality-improvement process using data abstractors, from 2018 to 2022 on the number of "alerts" that are generated in response to dosing deviating from the U.S. Food and Drug Administration instructions for atrial fibrillation (AF) and venous thromboembolism (VTE). RESULTS: Among a sample of 789 to 1,022 annual AF patients and 381 to 484 annual VTE patients prescribed a DOAC in the MAQI2 registry, off-label dosing was relatively common. Over the 5-year period (2018-2022), there were 569 alerts for AF patients and 162 alerts for VTE patients. Alerts occurred more frequently during follow-up than at the time of initial prescribing in AF patients (78.2 vs. 21.8%), but more commonly at initial prescribing in VTE patients (59.9 vs. 40.1%). After initial review by quality-improvement abstractors, 19.3% of AF alerts and 14.8% of VTE alerts resulted in contact to the prescriber. When the prescriber was contacted, it led to an intervention about 75% of the time for both populations. The most common intervention was a change in DOAC dosing. CONCLUSION: This study demonstrates the benefit of DOAC prescribing oversight using a registry-based intervention to monitor for off-label dosing for the entirety of the time period a patient is prescribed DOAC, particularly for patients with AF, as off-label prescribing occurs frequently during the follow-up period.

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.

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.

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.

Anticoagulation Changes Following Major and Clinically Relevant Nonmajor Bleeding Events in Non-valvular Atrial Fibrillation Patients.

Background: Bleeding events are common complications of oral anticoagulant drugs, including both warfarin and the direct oral anticoagulants (DOACs). Some patients have their anticoagulant changed or discontinued after experiencing a bleeding event, while others continue the same treatment. Differences in anticoagulation management between warfarin- and DOAC-treated patients following a bleeding event are unknown. Methods: Patients with non-valvular atrial fibrillation from six anticoagulation clinics taking warfarin or DOAC therapy who experienced an International Society of Thrombosis and Haemostasis (ISTH)-defined major or clinically relevant non-major (CRNM) bleeding event were identified between 2016 and 2020. The primary outcome was management of the anticoagulant following bleeding (discontinuation, change in drug class, and restarting of same drug class). DOAC- and warfarin-treated patients were propensity matched based on the individual elements of the CHA2DS2-VASc and HAS-BLED scores as well as the severity of the bleeding event. Results: Of the 509 patients on warfarin therapy and 246 on DOAC therapy who experienced a major or CRNM bleeding event, the majority of patients continued anticoagulation therapy. The majority of warfarin (231, 62.6%) and DOAC patients (201, 81.7%) restarted their previous anticoagulation. Conclusion: Following a bleeding event, most patients restarted anticoagulation therapy, most often with the same type of anticoagulant that they previously had been taking.

Length of Anticoagulation in Provoked Venous Thromboembolism: A Multicenter Study of How Real-World Practice Mirrors Guideline Recommendations.

Background For more than a decade, guidelines have recommended a limited 3 months of anticoagulation for the treatment of provoked venous thromboembolism (VTE). How closely real-world practice follows guideline recommendations is not well described. Methods and Results In our multicenter, retrospective cohort study, we evaluated trends in anticoagulation duration for patients enrolled in the MAQI2 (Michigan Anticoagulation Quality Improvement Initiative) registry who were receiving anticoagulation for a provoked VTE. The MAQI2 registry comprises 6 centers in Michigan that manage patients' long-term anticoagulation. We identified 474 patients on warfarin and 302 patients on direct oral anticoagulants who were receiving anticoagulation for a primary indication of provoked VTE between 2008 and 2020. Using a predefined threshold of 120 days (3 months plus a buffer period), predictors of extended anticoagulant use were identified using multivariable logistic regression. Most patients received >120 days of anticoagulation, regardless of which medication was used. The median (25th-75th percentile) length of treatment for patients taking warfarin was 142 (91-234) days and for direct oral anticoagulants was 180 (101-360) days. Recurrent VTE (odds ratio [OR], 2.75 [95% CI, 1.67-4.53]), history of myocardial infarction (OR, 3.92 [95% CI, 1.32-11.7]), and direct oral anticoagulant rather than warfarin use (OR, 2.22 [95% CI, 1.59-3.08]) were independently associated with prolonged anticoagulation. Conclusions In our cohort of patients with provoked VTE, most patients received anticoagulation for longer than the guideline-recommended 3 months. This demonstrates a potential opportunity to improve care delivery and reduce anticoagulant-associated bleeding risk.

Assessment of an Intervention to Reduce Aspirin Prescribing for Patients Receiving Warfarin for Anticoagulation.

Importance: For some patients receiving warfarin, adding aspirin (acetylsalicylic acid) increases bleeding risk with unclear treatment benefit. Reducing excess aspirin use could be associated with improved clinical outcomes. Objective: To assess changes in aspirin use, bleeding, and thrombosis event rates among patients treated with warfarin. Design, Setting, and Participants: This pre-post observational quality improvement study was conducted from January 1, 2010, to December 31, 2019, at a 6-center quality improvement collaborative in Michigan among 6738 adults taking warfarin for atrial fibrillation and/or venous thromboembolism without an apparent indication for concomitant aspirin. Statistical analysis was conducted from November 26, 2020, to June 14, 2021. Intervention: Primary care professionals for patients taking aspirin were asked whether an ongoing combination aspirin and warfarin treatment was indicated. If not, then aspirin was discontinued with the approval of the managing clinician. Main Outcomes and Measures: Outcomes were assessed before and after intervention for the primary analysis and before and after 24 months before the intervention (when rates of aspirin use first began to decrease) for the secondary analysis. Outcomes included the rate of aspirin use, bleeding, and thrombotic outcomes. An interrupted time series analysis assessed cumulative monthly event rates over time. Results: A total of 6738 patients treated with warfarin (3160 men [46.9%]; mean [SD] age, 62.8 [16.2] years) were followed up for a median of 6.7 months (IQR, 3.2-19.3 months). Aspirin use decreased slightly from a baseline mean use of 29.4% (95% CI, 28.9%-29.9%) to 27.1% (95% CI, 26.1%-28.0%) during the 24 months before the intervention (P < .001 for slope before and after 24 months before the intervention) with an accelerated decrease after the intervention (mean aspirin use, 15.7%; 95% CI, 14.8%-16.8%; P = .001 for slope before and after intervention). In the primary analysis, the intervention was associated with a significant decrease in major bleeding events per month (preintervention, 0.31%; 95% CI, 0.27%-0.34%; postintervention, 0.21%; 95% CI, 0.14%-0.28%; P = .03 for difference in slope before and after intervention). No change was observed in mean percentage of patients having a thrombotic event from before to after the intervention (0.21% vs 0.24%; P = .34 for difference in slope). In the secondary analysis, reducing aspirin use (starting 24 months before the intervention) was associated with decreases in mean percentage of patients having any bleeding event (2.3% vs 1.5%; P = .02 for change in slope before and after 24 months before the intervention), mean percentage of patients having a major bleeding event (0.31% vs 0.25%; P = .001 for change in slope before and after 24 months before the intervention), and mean percentage of patients with an emergency department visit for bleeding (0.99% vs 0.67%; P = .04 for change in slope before and after 24 months before the intervention), with no change in mean percentage of patients with a thrombotic event (0.20% vs 0.23%; P = .36 for change in slope before and after 24 months before the intervention). Conclusions and Relevance: This quality improvement intervention was associated with an acceleration of a preexisting decrease in aspirin use among patients taking warfarin for atrial fibrillation and/or venous thromboembolism without a clear indication for aspirin therapy. Reductions in aspirin use were associated with reduced bleeding. This study suggests that an anticoagulation clinic-based aspirin deimplementation intervention can improve guideline-concordant aspirin use.

Management strategies following slightly out-of-range INRs: watchful waiting vs dose changes.

Patients' international normalized ratios (INRs) often fall slightly out of range. In these cases, the American College of Chest Physicians (ACCP) guidelines suggest maintaining the current warfarin dose and retesting the INR within the following 2 weeks (watchful waiting). We sought to determine whether watchful waiting or dose changes for slightly out-of-range INRs is more effective in obtaining in-range INRs at follow-up. INRs and management strategies of warfarin-treated patients within the Michigan Anticoagulation Quality Improvement Initiative registry were analyzed. Management strategies included watchful waiting or dose changes. INRs slightly out of range (target range 2.0-3.0) and their associated management were identified. Multilevel mixed-effects logistic regression was used to estimate the probability of the next INR being in range, adjusted for clustering due to multiple out-of-range INRs per patient. A total of 45 351 slightly out-of-range INRs (ranging 1.50-1.99 and 3.01-3.49) from 8288 patients were identified. The next INR was slightly less likely to be in range with watchful waiting than with a dose change (predicted probabilities 58.9% vs 60.0%, P = 0.024). Although a significant statistical difference was detected in the probabilities of the next INR being back in range when managed by a dose change compared with watchful waiting following a slightly out-of-range INR, the magnitude of the difference was small and unlikely to represent clinical importance. Our study supports the current guideline recommendations for watchful waiting in cases of slightly out-of-range INRs values.

Association of Fibromuscular Dysplasia and Pulsatile Tinnitus: A Report of the US Registry for Fibromuscular Dysplasia.

Background Fibromuscular dysplasia (FMD) is a nonatherosclerotic arterial disease that has a variable presentation including pulsatile tinnitus (PT). The frequency and characteristics of PT in FMD are not well understood. The objective of this study was to evaluate the frequency of PT in FMD and compare characteristics between patients with and without PT. Methods and Results Data were queried from the US Registry for FMD from 2009 to 2020. The primary outcomes were frequency of PT among the FMD population and prevalence of baseline characteristics, signs/symptoms, and vascular bed involvement in patients with and without PT. Of 2613 patients with FMD who were included in the analysis, 972 (37.2%) reported PT. Univariable analysis and multivariable logistic regression were performed to explore factors associated with PT. Compared with those without PT, patients with PT were more likely to have involvement of the extracranial carotid artery (90.0% versus 78.6%; odds ratio, 1.49; P=0.005) and to have higher prevalence of other neurovascular signs/symptoms including headache (82.5% versus 62.7%; odds ratio, 1.82; P<0.001), dizziness (44.9% versus 22.9%; odds ratio, 2.01; P<0.001), and cervical bruit (37.5% versus 15.8%; odds ratio, 2.73; P<0.001) compared with those without PT. Conclusions PT is common among patients with FMD. Patients with FMD who present with PT have higher rates of neurovascular signs/symptoms, cervical bruit, and involvement of the extracranial carotid arteries. The coexistence of the 2 conditions should be recognized, and providers who evaluate patients with PT should be aware of FMD as a potential cause.

Comparison of temporary interruption with continuation of direct oral anticoagulants for low bleeding risk procedures.

INTRODUCTION: Limited data is available on the rates of bleeding and thromboembolic events for patients undergoing low bleeding risk procedures while taking direct oral anticoagulants (DOAC). METHODS: Adults taking DOAC in the Michigan Anticoagulation Quality Improvement Initiative (MAQI2) database who underwent a low bleeding risk procedure between May 2015 and Sep 2019 were included. Thirty-day bleeding (of any severity), thromboembolic events, and death were compared between DOAC temporarily interrupted and continued uninterrupted groups. Adverse event rates were compared using an inverse probability weighting propensity score. RESULTS: There were 820 patients who underwent 1412 low risk procedures. DOAC therapy was temporarily interrupted in 371 (45.2%) patients (601 [42.6%] procedures) and continued uninterrupted in 449 (54.8%) patients (811 [57.4%] procedures). DOAC patients with temporary interruptions were more likely to have diabetes, prior stroke or TIA, prior bleeding, higher CHA2DS2-VASc, and higher modified HAS-BLED scores. DOAC interruption was common for gastrointestinal endoscopy, electrophysiology device implantation, and cardiac catheterization while it was less common for cardioversion, dermatologic procedures, and subcutaneous injection. After propensity score adjustment, bleeding risk was lower in the DOAC temporary interruption group (OR 0.62, 95% CI 0.41-0.95) as compared to the group with continuous DOAC use. Rates of thromboembolic events and death did not differ significantly between the two groups. CONCLUSIONS: DOAC-treated patients undergoing low bleeding risk procedures may experience lower rates of bleeding when DOAC is temporarily interrupted. Prospective studies focused on low bleeding risk procedures are needed to identify the safety DOAC management strategy.

Adverse Events Associated With the Addition of Aspirin to Direct Oral Anticoagulant Therapy Without a Clear Indication.

Importance: It is unclear how many patients treated with a direct oral anticoagulant (DOAC) are using concomitant acetylsalicylic acid (ASA, or aspirin) and how this affects clinical outcomes. Objective: To evaluate the frequency and outcomes of prescription of concomitant ASA and DOAC therapy for patients with atrial fibrillation (AF) or venous thromboembolic disease (VTE). Design, Setting, and Participants: This registry-based cohort study took place at 4 anticoagulation clinics in Michigan from January 2015 to December 2019. Eligible participants were adults undergoing treatment with a DOAC for AF or VTE, without a recent myocardial infarction (MI) or history of heart valve replacement, with at least 3 months of follow-up. Exposures: Use of ASA concomitant with DOAC therapy. Main Outcomes and Measures: Rates of bleeding (any, nonmajor, major), rates of thrombosis (stroke, VTE, MI), emergency department visits, hospitalizations, and death. Results: Of the study cohort of 3280 patients (1673 [51.0%] men; mean [SD] age 68.2 [13.3] years), 1107 (33.8%) patients without a clear indication for ASA were being treated with DOACs and ASA. Two propensity score-matched cohorts, each with 1047 patients, were analyzed (DOAC plus ASA and DOAC only). Patients were followed up for a mean (SD) of 20.9 (19.0) months. Patients taking DOAC and ASA experienced more bleeding events compared with DOAC monotherapy (26.0 bleeds vs 31.6 bleeds per 100 patient years, P = .01). Specifically, patients undergoing combination therapy had significantly higher rates of nonmajor bleeding (26.1 bleeds vs 21.7 bleeds per 100 patient years, P = .02) compared with DOAC monotherapy. Major bleeding rates were similar between the 2 cohorts. Thrombotic event rates were also similar between the cohorts (2.5 events vs 2.3 events per 100 patient years for patients treated with DOAC and ASA compared with DOAC monotherapy, P = .80). Patients were more often hospitalized while undergoing combination therapy (9.1 vs 6.5 admissions per 100 patient years, P = .02). Conclusion and Relevance: Nearly one-third of patients with AF and/or VTE who were treated with a DOAC received ASA without a clear indication. Compared with DOAC monotherapy, concurrent DOAC and ASA use was associated with increased bleeding and hospitalizations but similar observed thrombosis rate. Future research should identify and deprescribe ASA for patients when the risk exceeds the anticipated benefit.

Reduction in epistaxis and emergency department visits in patients taking warfarin after implementation of an education program.

BACKGROUND: Anticoagulated patients are often seen unnecessarily in the emergency department (ED) for epistaxis, leading to increased healthcare costs. Patients are often unaware of preventative and management techniques for handling epistaxis in the home. METHODS: In 2016, the Michigan Anticoagulation Quality Improvement Initiative (MAQI2), a Blue Cross Blue Shield of Michigan-sponsored consortium of 6 anticoagulation clinics in Michigan, implemented an epistaxis-management educational program for warfarin-treated patients with the goal of reducing unnecessary ED visits. A pre-implementation cohort (2014-2015) consisted of patients who did not receive epistaxis-related educational materials. A post-implementation cohort (2017-2018) received epistaxis educational materials covering home treatment and prevention strategies. Patient characteristics and outcomes (rates of epistaxis and epistaxis ED visits) were compared using Chi-square, Poisson regression, and t-tests. RESULTS: Of the 4473 patients included, 2634 (58.9%) initiated warfarin in the pre-implementation phase and 1839 (41.1%) initiated warfarin in the post-implementation phase. The post-implementation cohort had a lower overall epistaxis rate (13.4 vs 10.4 per 100 patient-year, pre- vs. post-implementation; p = 0.029), a lower epistaxis-related ED visit rate (5.6 vs. 3.1 per 100 patient-year; p = 0.003), and a lower proportion of nosebleeds that led to an ED visit (42% vs. 30%; p = 0.032). After controlling for antiplatelet use, renal disease, and time in therapeutic range, both cohorts were equally likely to have nosebleeds (RR 0.77, 95% CI: 0.58-1.02); however, the post-implementation cohort was less likely to visit the ED for epistaxis (RR 0.52, 95% CI: 0.32-0.84). CONCLUSION: An epistaxis education program was associated with a reduction in epistaxis-related ED visits among warfarin-treated patients.

Periprocedural bridging anticoagulation in patients with venous thromboembolism: A registry-based cohort study.

BACKGROUND: Use of bridging anticoagulation increases a patient's bleeding risk without clear evidence of thrombotic prevention among warfarin-treated patients with atrial fibrillation. Contemporary use of bridging anticoagulation among warfarin-treated patients with venous thromboembolism (VTE) has not been studied. METHODS: We identified warfarin-treated patients with VTE who temporarily stopped warfarin for a surgical procedure between 2010 and 2018 at six health systems. Using the 2012 American College of Chest Physicians guideline, we assessed use of periprocedural bridging anticoagulation based on recurrent VTE risk. Recurrent VTE risk and 30-day outcomes (bleeding, thromboembolism, emergency department visit) were each assessed using logistic regression adjusted for multiple procedures per patient. RESULTS: During the study period, 789 warfarin-treated patients with VTE underwent 1529 procedures (median, 2; interquartile range, 1-4). Unadjusted use of bridging anticoagulation was more common in patients at high risk for VTE recurrence (99/171, 57.9%) than for patients at moderate (515/1078, 47.8%) or low risk of recurrence (134/280, 47.86%). Bridging anticoagulation use was higher in high-risk patients compared with low- or moderate-risk patients in both unadjusted (P = .013) and patient-level cluster-adjusted analyses (P = .031). Adherence to American College of Chest Physicians guidelines in high- and low-risk patients did not change during the study period (odds ratio, 0.98 per year; 95% confidence interval, 0.91-1.05). Adverse events were rare and not statistically different between the two treatment groups. CONCLUSIONS: Bridging anticoagulation was commonly overused among low-risk patients and underused among high-risk patients treated with warfarin for VTE. Adverse events were rare and not different between the two treatment groups.

Higher admission rates and in-hospital mortality for acute type A aortic dissection during Influenza season: a single center experience.

Triggering events for acute aortic dissections are incompletely understood. We sought to investigate whether there is an association between admission for acute type A aortic dissection (ATAAD) to the University of Michigan Medical Center and the reported annual influenza activity by the Michigan Department of Health and Human Services. From 1996-2019 we had 758 patients admitted for ATAAD with 3.1 admissions per month during November-March and 2.5 admissions per month during April-October (p = 0.01). Influenza reporting data by the Michigan Department of Health and Human Services became available in 2009. ATAAD admissions for the period 2009-2019 (n = 455) were 4.8 cases/month during peak influenza months compared to 3.5 cases/month during non-peak influenza months (p = 0.001). ATAAD patients admitted during influenza season had increased in-hospital mortality (11.0% vs. 5.8%, p = 0.024) and increased 30-day mortality (9.7 vs. 5.4%, p = 0.048). The results point to higher admission rates for ATAAD during months with above average influenza rates. Future studies need to investigate whether influenza virus infection affects susceptibility for aortic dissection, and whether this risk can be attenuated with the annual influenza vaccine in this patient population.

The Clinical Impact of Imaging Surveillance and Clinic Visit Frequency after Acute Aortic Dissection.

BACKGROUND: Guidelines recommend frequent follow-up after acute aortic dissection (AAD), but optimal rates of follow-up are not clear. METHODS: We examined rates of imaging and clinic visits in 267 individuals surviving AAD during recommended intervals (≤1, > 1-3, > 3-6, > 6-12 months, then annually), frequency of adverse imaging findings, and the relationship between follow-up and mortality. RESULTS: Type A and B AAD were noted in 46 and 54% of patients, respectively. Mean follow-up was 54.7 ± 13.3 months, with 52 deaths. Adverse imaging findings peaked at 6 to 12 months (5.6%), but rarely resulted in an intervention (3.4% peak at 6-12 months). Compared with those with less frequent imaging, patients with imaging for 33 to 66% of intervals (p = 0.22) or ≥66% of intervals (p = 0.77) had similar adjusted survival. In comparison to patients with fewer clinic visits, those with visits in 33 to 66% of intervals experienced lower adjusted mortality (hazards ratio: 0.47, 95% confidence interval: 0.23-0.97, p = 0.04), with no difference seen in those with ≥66% (vs. < 33%) interval visits (p = 0.47). Imaging at 6 to 12 months (vs. none) was associated with decreased adjusted mortality (hazards ratio: 0.50, 95% confidence interval: 0.27-0.91, p = 0.02), while imaging during other intervals, or clinic visits during any specific intervals, was not associated with a difference in mortality (p > 0.05 for each). CONCLUSIONS: Adverse imaging findings following AAD are common, but rarely require prompt intervention. Patients with the lowest and highest rates of clinic visits experienced increased mortality. While the overall rate of surveillance imaging did not correlate with mortality, adverse imaging findings and related interventions peaked at 6 to 12 months after AAD, and imaging during this time was associated with improved survival.