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.

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.

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.

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.

Adverse events in low versus normal body weight patients prescribed apixaban for atrial fibrillation.

Safety and efficacy of direct oral anticoagulants (DOAC) in low weight patients with atrial fibrillation (AF) is unclear due to few low body weight patients enrolled in clinical trials. To assess bleeding and thrombotic event rates for patients with AF that are prescribed apixaban and have a low versus normal body weight. We analyzed patients with AF prescribed apixaban from 2017 to 2020 with at least 12 months of follow-up. Patients were divided into low [< 60 kg (kg)] and normal (60-100 kg) weight cohorts. Bleeding and thrombotic event rates were compared. Poisson regression and Cox proportional hazard models were used to estimate adjusted adverse event rates. A total of 545 patients met inclusion criteria. In the unadjusted analysis, there was an increase in non-major bleeding events requiring an Emergency Department visit more often in the low versus normal weight cohort (10.8 versus 7.4 per 100 patient-years, p = 0.15). Thrombotic event rates also occurred more often in the lower versus normal weight cohort (2.4 versus 0.9 per 100 patient-years, p = 0.09). However, adjusted analysis found no statistically significant difference in bleeding or thrombotic events between low and normal weight cohorts. The adjusted hazard ratio for bleeding was similar between the two weight cohorts. The use of apixaban in low body weight patients was not associated with higher rates of bleeding or thrombotic events, compared to those with normal body weight, after adjusting for potential confounding covariates. Larger studies may offer further insight into the overall safety and efficacy of DOAC therapy in these patients.

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.

Outcomes in patients undergoing periprocedural interruption of warfarin or direct oral anticoagulants.

BACKGROUND: Differences in clinical outcomes following a temporary interruption of warfarin or a direct oral anticoagulant (DOAC) for a surgical procedure are not well described. Differences in patient characteristics from practice-based cohorts have not typically been accounted for in prior analyses. AIM: To describe risk-adjusted differences in postoperative outcomes following an interruption of warfarin vs DOACs. METHODS: Patients receiving care at six anticoagulation clinics participating in the Michigan Anticoagulation Quality Improvement Initiative were included if they had at least one oral anticoagulant interruption for a procedure. Inverse probability of treatment weighting (IPTW) was used to balance baseline differences between the warfarin cohort and DOAC cohort. Bleeding and thromboembolic events within 30 days following the procedure were compared between the IPTW cohorts using the Poisson distribution test. RESULTS: A total of 525 DOAC patients were matched with 1323 warfarin patients, of which 923 were nonbridged warfarin patients and 400 were bridged warfarin patients. The occurrence of postoperative minor bleeding (10.8% vs. 4.7%, p < .001), major bleeding (2.9% vs. 1.1%, p = .01) and clinically relevant nonmajor bleeding (CRNMB) (6.5% vs. 3.0%, p = .002) was greater in the DOAC cohort compared with the nonbridged warfarin cohort. The rates of postoperative bleeding outcomes were similar between the DOAC and the bridged warfarin cohorts. CONCLUSION: Perioperative interruption of DOACs, compared with warfarin without bridging, is associated with a higher incidence of 30-day minor bleeds, major bleeds, and CRNMBs. Further research investigating the perioperative outcomes of these two classes of anticoagulants is warranted.

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.

Adverse events in patients taking apixaban or rivaroxaban who have undergone bariatric surgery: a retrospective case series.

Clinical trials comparing direct oral anticoagulants (DOAC) to warfarin excluded patients with a history of bariatric surgery. The anatomic changes from bariatric procedures have several effects on drug absorption which can have serious consequences for these patients. We sought to describe real-world use of DOACs among adults that had a history of bariatric surgery or underwent a bariatric surgery while receiving a DOAC. We conducted a retrospective case series of adult patients, at a large academic medical center, who initiated any DOAC in 2016 thru 2019 and had a history of bariatric surgery or underwent a bariatric surgery while receiving a DOAC. Thrombotic and bleeding events were described using summary statistics and bleeding severity was described using the International Society on Thrombosis and Haemostasis criteria. Twenty-eight patients met the inclusion criteria of having bariatric surgery (Roux-en-Y gastric bypass, sleeve gastrectomy or gastric band) and receiving a DOAC. Twenty (71.4%) were prescribed apixaban and eight (28.6%) were prescribed rivaroxaban. Seven patients (25%) experienced at least one clinically relevant non-major bleeding event, including one patient (3.6%) that had a major bleeding event. Two patients (7.1%) had a thromboembolic event. Coagulation laboratory studies were infrequently performed at the time of the bleeding or clotting events. Among patients with a history of bariatric surgery, use of DOACs were commonly associated with clinically relevant non-major bleeding events and less commonly associated with major bleeding and thromboembolic events. Larger studies may offer further insight into the overall safety and efficacy of DOAC therapy in patients that have undergone bariatric surgery. The specific role of coagulation laboratory studies warrants further evaluation.

Standard Versus Higher Intensity Anticoagulation for Patients With Mechanical Aortic Valve Replacement and Additional Risk Factors for Thromboembolism.

Current guidelines recommend targeting an international normalized ratio (INR) of 2.5 to 3.5 for patients with mechanical aortic valve replacement (AVR) and additional risk factors for thromboembolic events. Available literature supporting the higher intensity (INR) goal is lacking. We aimed to evaluate the association of standard and higher intensity anticoagulation on outcomes in this patient population. The Michigan Anticoagulation Quality Improvement Initiative database was used to identify patients with mechanical AVR and at least one additional risk factor. Patients were classified into 2 groups based on INR goal: standard-intensity (INR goal 2.5) or higher-intensity (INR goal 3.0). Cox-proportional hazard model was used to calculate adjusted hazard ratios. One hundred and forty-six patients were identified of whom 110 (75.3%) received standard-intensity anticoagulation and 36 (24.7%) received higher intensity anticoagulation. Standard-intensity patients were older and more likely to be on aspirin. Atrial fibrillation was the most common additional risk factor for inclusion. The primary outcome of thromboembolic events, bleeding, or all-cause death was 13.9 and 19.5/100-person-years in the standard-intensity and higher intensity groups, respectively (adjusted HR 2.58, 95% confidence interval 1.28 to 5.18). Higher-intensity anticoagulation was significantly associated with any bleeding (adjusted HR 2.52, 95% confidence interval 1.27 to 5.00) and there were few thromboembolic events across both groups (5 events total). These results challenge current guideline recommendations for anticoagulation management of mechanical AVR in patients with additional risk factors.

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.