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.

Development of a multicomponent implementation strategy to reduce upper gastrointestinal bleeding risk in patients using warfarin and antiplatelet therapy, and protocol for a pragmatic multilevel randomized factorial pilot implementation trial.

BACKGROUND: The concomitant use of anticoagulant and antiplatelet medications increases the risk of upper gastrointestinal (GI) bleeding. Two underused evidence-based practices (EBPs) can reduce the risk: de-prescribe unnecessary antiplatelet therapy or initiate a proton pump inhibitor. We describe the development of a multicomponent intervention to increase use of these EBPs in patients treated with warfarin and followed by an anticoagulation monitoring service (AMS), and the design of a pilot pragmatic implementation trial. METHODS: A participatory planning group iteratively used Implementation Mapping and the Multiphase Optimization Strategy to develop implementation strategies and plan the trial. Informed by qualitative interviews with patients and clinicians, we drew on several implementation science theories, as well as self-determination theory, to design interventions. For patients, we developed an activation guide to help patients discuss the EBPs with their clinicians. For clinicians, we developed two electronic health record (EHR)-based interventions: (1) clinician notification (CN) consists of a templated message that identifies a patient as high risk, summarizes the EBPs, and links to a guidance statement on appropriate use of antiplatelet therapy. (2) Clinician notification with nurse facilitation (CN+NF) consists of a similar notification message but includes additional measures by nursing staff to support appropriate and timely decision-making: the nurse performs a chart review to identify any history of vascular disease, embeds indication-specific guidance on antiplatelet therapy in the message, and offers to assist with medication order entry and patient education. We will conduct a pilot factorial cluster- and individual-level randomized controlled trial with a primary objective of evaluating feasibility. Twelve clinicians will be randomized to receive either CN or CN+NF for all their patients managed by the AMS while 50 patients will be individually randomized to receive either the activation guide or usual care. We will explore implementation outcomes using patient and clinician interviews along with EHR review. DISCUSSION: This pilot study will prepare us to conduct a larger optimization study to identify the most potent and resource conscious multicomponent implementation strategy to help AMSs increase the use of best practices for upper GI bleeding risk reduction. TRIAL REGISTRATION: ClinicalTrials.gov NCT05085405 . Registered on October 19, 2021-retrospectively registered.

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.

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.