Compliance with guidelines for the perioperative management of vitamin K antagonists

Guideline Adherence As An Indicator of the Extent of Antithrombotic Overuse and Underuse: A Systematic Review

Thromboembolic events are a common risk in adults with atrial fibrillation, those with previous cerebrovascular accidents and undergoing emergency or elective surgeries. The widespread availability of antithrombotic agents and differing guidelines contribute to practice variations and increased risk of complications and deaths. The objective of this review was to investigate the extent of overuse and underuse of antithrombotics for primary or secondary prevention as measured by deviation from prescribing guideline recommendations. We conducted a systematic review of Medline and EMBASE for quantitative articles published between 2000 and 2021 and used a modified version of the Hoy’s risk of bias assessment tool. Here we report evidence from the past decade about wide practice variations in hospitals and primary care, and discuss clinician and patient-driven determinants of non-adherence to guidelines. Finally, we summarise implications for practice, identify enhanced ways of measuring overuse and underuse, and propose potential solutions to the measurement challenges.

Perioperative consultative hematology: can you clear my patient for a procedure?

Periprocedural management of antithrombotics is a common but challenging clinical scenario that renders patients vulnerable to potential adverse events such as bleeding and thrombosis. Over the past decade, periprocedural antithrombotic approaches have changed considerably with the advent of direct oral anticoagulants (DOACs), as well as a paradigm shift away from bridging in many warfarin patients. Successfully navigating this high-risk period relies on a number of individualized patient assessments conducted within a framework of standardized, systematic approaches. It also requires a thorough understanding of antithrombotic pharmacokinetics, multidisciplinary coordination of care, and comprehensive patient education and empowerment. In this article, we provide clinicians with a practical, stepwise approach to periprocedural management of antithrombotic agents through case-based examples of relevant clinical scenarios.

[Pharmacological prophylaxis of thromboembolism in daily clinical practice: Evaluation of the clinical decision-making process]

BACKGROUND

Considering the amount of national and international scientific evidence regarding the use of anticoagulants in the periprocedural prevention of thromboembolism, the decision-making process when prescribing anticoagulants is complex. Due to frequent prescriptions for inpatients, the topic is of high significance. This decision-making process in our hospital is the main focus of the study.

METHODS

In a standardised survey, a target group of physicians was asked about their decision-making process with regard to the prescription of anticoagulants in the periprocedural period. For this study a questionnaire was developed consisting of 12 survey questions. Data from 130 participants was collected and analysed.

RESULTS

Generally, there was a high level of agreement on the importance of venous thromboembolism prophylaxis. Significant differences exist between medical specialities. A gap between scientific evidence and clinical practice among the respondents could be identified. The decision-making process when prescribing anticoagulants was not documented by the physicians.

CONCLUSIONS

A combined approach consisting of structured documentation with electronic decision support in combination with standardised treatment methods and educational measures can be a useful solution.

Guideline compliance for bridging anticoagulation use in vitamin-K antagonist patients; practice variation and factors associated with non-compliance

Background

Bridging anticoagulation is used in vitamin-K antagonist (VKA) patients undergoing invasive procedures and involves complex risk assessment in order to prevent thromboembolic and bleeding outcomes.

Objectives

Our aim was to assess guideline compliance and identify factors associated with bridging and especially, non-compliant bridging.

Methods

A retrospective review of 256 patient records in 13 Dutch hospitals was performed. Demographic, clinical, surgical and care delivery characteristics were collected. Compliance to the American College of Chest Physicians ninth edition guideline (AT9) was assessed. Multilevel regression models were built to explain bridging use and predict non-compliance.

Results

Bridging use varied from 15.0 to 83.3% (mean = 41.8%) of patients per hospital, whereas guideline compliance varied from 20.0 to 88.2% (mean = 68.5%) per hospital. Both established thromboembolic risk factors and characteristics outside thromboembolic risk assessment were associated with bridging use. Predictors for overuse were gastrointestinal surgery (OR 14.85, 95% CI 2.69-81.99), vascular surgery (OR 13.01, 95% CI 1.83-92.30), non-elective surgery (OR 8.67, 95% CI 1.67-45.14), lowest 25th percentile socioeconomic status (OR 0.33, 95% CI 0.11-1.02) and use of VKA reversal agents (OR 0.22, 95% CI 0.04-1.16).

Conclusion

Bridging anticoagulation practice was not compliant with the AT9 in 31.5% of patients. The aggregated AT9 thromboembolic risk was inferior to individual thromboembolic risk factors and other characteristics in explaining bridging use. Therefor the AT9 risk seems less important for the decision making in everyday practice. Additionally, a heterogeneous implementation of the guideline between hospitals was found. Further research and interventions are needed to improve bridging anticoagulation practice in VKA patients.

How reliable is perioperative anticoagulant management? Determining guideline compliance and practice variation by a retrospective patient record review

OBJECTIVES

Surgery in patients on anticoagulants requires careful monitoring and risk assessment to prevent harm. Required interruptions of anticoagulants and deciding whether to use bridging anticoagulation add further complexity. This process, known as perioperative anticoagulant management (PAM), is optimised by using guidelines. Optimal PAM prevents thromboembolic and bleeding complications. The purpose of this study was to assess the reliability of PAM practice in Dutch hospitals. Additionally, the variations between hospitals and different bridging dosages were studied.

DESIGN

A multicentre retrospective patient record review.

SETTING AND PARTICIPANTS

Records from 268 patients using vitamin-K antagonist (VKA) anticoagulants who underwent surgery in a representative random sample of 13 Dutch hospitals were reviewed, 259 were analysed.

PRIMARY AND SECONDARY OUTCOME MEASURES

Our primary outcome measure was the reliability of PAM expressed as the percentage of patients receiving guideline compliant care. Seven PAM steps were included. Secondary outcome measures included different bridging dosages used and an analysis of practice variation on the hospital level.

RESULTS

Preoperative compliance was lowest for timely VKA interruptions: 58.8% (95% CI 50.0% to 67.7%) and highest for timely preoperative assessments: 81% (95% CI 75.0% to 86.5%). Postoperative compliance was lowest for timely VKA restarts: 39.9% (95% CI 33.1% to 46.7%) and highest for the decision to apply bridging: 68.5% (95% CI 62.3% to 74.8%). Variation in compliance between hospitals was present for the timely preoperative assessment (range 41%-100%), international normalised ratio testing (range 21%-94%) and postoperative bridging (range 20%-88%). Subtherapeutic bridging was used in 50.5% of patients and increased with patients' weight.

CONCLUSIONS

Unsatisfying compliance for most PAM steps, reflect suboptimal reliability of PAM. Furthermore, the hospital performance varied. This increases the risk for adverse events, warranting quality improvement. The development of process measures can help but will be complicated by the availability of a strong supporting evidence base and integrated care delivery regarding PAM.

Genetic causes of resistance to vitamin K antagonists in Polish patients: a novel p.Ile123Met mutation in VKORC1 gene

: Mutations in the genes encoding vitamin K epoxide reductase complex subunit 1 (VKORC1) and cytochrome P450 2C9 (CYP2C9) largely contribute to the inter-individual variations in vitamin K antagonists (VKAs) dose requirements. Up to 50% of the dosage variability can be explained by genetic polymorphisms in these genes. We sought to identify the mutations responsible for VKA resistance in a series of Polish patients. Of the 607 patients treated with VKA, 35 (6%) individuals with the VKA resistance defined as a daily dose of acenocoumarol more than 8 mg (n = 15, 43%) or warfarin more than 10 mg (n = 20, 57%) were selected for further mutational analysis using Sanger sequencing (VKORC1) or real-time PCR genotyping (CYP2C9). The indications for anticoagulant treatment were venous thromboembolism (n = 28, 80%), atrial fibrillation (n = 6, 17%), or artificial heart valve (n = 1, 3%). Patients taking medication interfering with VKA were ineligible. Almost all of VKA-resistant patients (n = 34, 97%) possessed at least one VKORC1*3 (n = 29, 83%) or VKORC1*4 (n = 15, 43%) haplotypes. In a 70-year-old man atrial fibrillation patient on the daily acenocoumarol dose of 16 mg, a novel p.Ile123Met (c.369C>G) VKORC1 mutation was found. In-silico analysis showed that the p.Ile123Met can functionally underlie the acenocoumarol resistance, presumably by altering VKA binding. To our knowledge this is the first cohort of Polish patients resistant to VKA evaluated for the causal genetic background. We found one new detrimental mutation underlying VKA resistance. Our study highlights a key role of unidentified environmental factors in VKA resistance in daily clinical practice.