Center-Related Determinants of VKA Anticoagulation Quality: A Prospective, Multicenter Evaluation

Oral anticoagulant management of patients with mechanical heart valves at the Salam Centre of Khartoum: Observations on quality of anticoagulation and thrombotic risk

INTRODUCTION

Rheumatic heart disease with mechanical heart valve (MHV) replacement is common in Africa. However, MHV requires long-life anticoagulation and managing this can be challenging.

METHODS AND RESULTS

We report data of a prospective observational study conducted between August 2018 and September 2019 in MHV patients in the Salam Centre for Cardiac Surgery built in Khartoum, by Emergency, an Italian Non-Governmental Organization, to evaluate the quality of anticoagulation control and the risk of thrombotic complications.

RESULTS

We studied 3647 patients (median age 25.1 years; 53.9 % female). Median Time in Therapeutic Range (TTR) was 53 % (interquartile range 37 % to 67 %) and 70 thrombotic events (rate 1.8 × 100 pt-years [95 % CI 1.38-2.23]) were recorded. Among patients in the first quartile of TTR (≤37 %), we recorded 34/70 (48.6 %) of all thrombotic events (rate 3.7 × 100 pt-years [95 % CI 2.5-5.1]), with a high mortality rate (2.2 × 100 pt-years [95 % CI 1.3-3.3]). In patients with guideline-recommended TTR (≥65 %) the event rate was 0.8 × 100 pt-years for thrombotic events [95 % CI 0.3-1.5] and 0.4 × 100 pt-years for mortality [95 % CI 0.1-0.9]. Multivariable analysis showed that having a TTR in the lowest quartile (≤37 %) and being noncompliant are significantly associated with increased thrombotic risk. Aspirin use or different valve type did not influence the thrombotic risk. Almost 40 % of all thromboembolic complications could have been potentially prevented by further improving VKA management to obtain a TTR > 37 %.

CONCLUSION

The thrombotic risk of MHV patients on VKAs living in a low-income country like Sudan is associated with low quality of anticoagulation control. Efforts should be made to decrease the number of non-compliant patients and to reach a guideline-recommended TTR of ≥65 %.

Gender Related Differences in Gastrointestinal Bleeding With Oral Anticoagulation in Atrial Fibrillation

Background: DOACs are characterized by a higher incidence of gastrointestinal bleeding and this may be different among males and females. Female patients were underrepresented in the DOAC pivotal trials. We aimed to assess real-world differences in gastrointestinal bleeding with oral anticoagulants (DOACs and VKAs) among males and females with atrial fibrillation. Methods: We performed a population-based retrospective analysis on linked administrative claims. Atrial fibrillation patients of 65 years and above were considered. Bleeding risk factors were assessed through HASBED and previous history of gastrointestinal disease. A time-to-event analysis compared gastrointestinal bleeding between males and females. Results: The overall cohort consisted of 15338 (55% female) DOAC and 44542 (50% female) VKA users. Most of the patients showed HASBED ≥2. Incidence rate of GI bleeding was higher in females as compared to males among DOAC users (0.90% vs 0.59%), and significant gender difference in GI bleeding was found, after adjustment, in the Cox regression analysis (HR 1.48, 95%CI 1.02-2.16). In the VKA group, no significant difference among genders was found in the time-to-event analysis. Conclusions: Our data suggest that female patients treated with DOACs have a higher risk of GI bleeding versus male patients; this difference is not observed in VKA patients.

Clinical history and gastrointestinal bleeding in patients taking oral anticoagulants

BACKGROUND

Common risk factors for gastrointestinal bleeding (GIB) are advanced age and the use of antiplatelet or anticoagulants drugs for the prevention of cardiovascular diseases.

METHODS

In this prospective real-world observational study, oral anticoagulated patients were recruited and followed between June 2013 and December 2019. The primary end-point was to evaluate a possible relationship between bleeding events and patients' clinical history of gastrointestinal disease prior to the start of the therapy. The secondary end-points were time of GIB appearance and the percentage of idiopathic or provoked events, i.e., bleeding due to a gastrointestinal disease. In case of GIB event all the patients were studied by means of endoscopic procedures. Cox regression was used to calculate the relative hazard ratios (HRs) of GIB for each considered clinical variable.

RESULTS

734 patients on both VKAs or DOACs were studied. Overall, 46 hemorrhagic events were recorded: 6 were major bleeding (0.42/100 patient-years) while 43 were clinically relevant non major bleeding (2.8/100 patient-years). The Cox regression analysis did not show any relationships among GIB and the variables considered.

CONCLUSION

The patients' clinical history is neither a predictor for GIB bleeding nor a guide to the choice of the oral anticoagulant to be administered. Routinely applying bleeding risk screening, such as occult blood in the stool, should be added to the periodic laboratory checks for early recognition of patients at higher risk of GIB.

The effect of management models on thromboembolic and bleeding rates in anticoagulated patients: an ecological study

The primary study objective is to compare the outcomes of patients taking oral anticoagulant medications in two distinct populations treated according to different management models (comprehensive vs. usual care). (Design: regional prospective cohort study; setting: hospital admission data from two regions). Eligible partecipants were patients taking oral anticoagulant drugs (vitamin K antagonist or direct oral anticoagulants), residents in the Vicenza and Cremona districts from February 1st, 2016 to June 30th, 2017. Patients were identified by accessing the administrative databases of patient drug prescriptions. The primary study outcome was admission to the Emergency Department for stroke, systemic arterial embolism, recurrence of venous thromboembolism or major bleeding. The study evaluated outcomes in 14,226 patients taking oral anticoagulants, of whom 6725 being followed in Cremona with a comprehensive management model. There were 19 and 45 thromboembolic events over 6205 and 6530 patient-years in the Cremona and Vicenza cohort, respectively (IRR 0.44, 95% CI 0.24-0.77). The reduction of events in the Cremona cohort was almost entirely explained by a decrease of events in patients taking VKA (IRR 0.41, 95% CI 0.20-0.78) but not DOACs (IRR 1.08, 95% CI 0.25-5.24). The rate of major bleeding was non-significantly higher in Cremona than in Vicenza (IRI 1.32; 95% CI 0.74-2.40). Across the two cohorts, the risk of bleeding was lower in patients being treated with DOACs rather than warfarin (10/4574 vs. 42/8161 event/person-years, respectively, IRR 0.42 95% CI 0.19-0.86). We conclude that a comprehensive management model providing centralized dose prescription and follow-up may significantly reduce the rate of thromboembolic complications, without substantially increasing the number of bleeding complications. Patients treated with direct oral anticoagulants appear to have a rate of thromboembolic complications comparable to VKA patients under the best management model, with a reduction of major bleeding.

Differences in the quality of oral anticoagulation therapy with vitamin K antagonists in German GP practices - results of the cluster-randomized PICANT trial (Primary Care Management for Optimized Antithrombotic Treatment)

Background

In Germany, patients receiving oral anticoagulation (OAC) are often treated by general practitioners (GPs), and large proportions of patients receive vitamin K antagonists (VKAs). The quality of OAC in German GP practices, differences between various practices, and improvement potential through implementation of case management, have not yet been investigated satisfactorily.

Based on results of a cluster-randomized controlled trial, we aimed to assess whether OAC quality can be improved, any variations between practices exist and determine practice- and patient-level factors.

Methods

The PICANT trial (2012–2015) was performed in 52 GP practices in Hesse, Germany. Adult patients with long-term indication for OAC received best practice case management in the intervention group. International normalized ratio (INR) values were recorded from anticoagulation passes. The Rosendaal method was used to calculate Time in Therapeutic Range (TTR) at patient level, and mean pooling to obtain center-specific TTR (cTTR) at practice level. The quality of OAC was assessed by TTR and cTTR. Linear model analyses were used to investigate associations between practice−/ patient-level factors and TTR.

Results

Inclusion of 736 patients (49.6% intervention and 50.4% control patients); 690 (93.8%) received phenprocoumon. Within 24 months, the TTR was 75.1% (SD 17.6) in the intervention versus 74.3% (SD 17.8) in the control group (p = 0.670). The cTTR averaged 75.1% (SD 6.5, range: 60.4 to 86.7%) in the intervention versus 74.3% (SD 7.2, range: 52.7 to 85.7%) in the control group (p = 0.668). At practice level, the TTR was significantly lower in practices with a male physician and certification in quality management. At patient level, the TTR was significantly higher in patients with moderate to high compliance, in men, and in patients that performed self-management. The TTR was significantly lower in patients with certain comorbidities, and who were hospitalized.

Conclusions

The intervention did not effectively improve OAC quality compared to routine care. Quality of INR control was generally good, but considerable variation existed between GP practices. The variability indicates optimization potential in some practices. The demonstrated association between patient-level factors and TTR highlights the importance of considering patient characteristics that may impede achieving high quality therapeutic outcomes.

Trial registration

ISRCTN registry, ISRCTN41847489, registered 27 February 2012.

Electronic supplementary material

The online version of this article (10.1186/s12913-019-4372-y) contains supplementary material, which is available to authorized users.

Mechanical prosthetic heart valves: Quality of anticoagulation and thromboembolic risk. The observational multicenter PLECTRUM study

BACKGROUND

Patients with a mechanical prosthetic heart valve implantation need to be treated with a vitamin K antagonist (VKA) due to a substantially high risk of thromboembolism. In this study we report data on patients with mechanical heart valves (MV), with the aim of evaluating the thromboembolic risk in relation to the type and site of implantation, quality of anticoagulation and risk factors associated with thromboembolism.

METHODS

Observational retrospective multicenter study among Centers affiliated to the Italian Federation of Anticoagulation Clinics (FCSA) on patients with MV implanted after 1990 and followed for the management of anticoagulation.

RESULTS

We analyzed 2357 patients with mechanical heart valves (55.2% males), followed for 24,081 years. During the follow-up, 164 thromboembolic events (0.67/100 pt-yrs) and 243 major bleedings (1.0/100 pt-yrs) occurred. The median Time in Therapeutic Range (TTR), calculated in all intended INR classes, was 60% (IQR 47-74%). The rates of thrombotic events were significantly higher in patients intended to stay at therapeutic ranges >INR 2.0-3.0. The presence of atrial fibrillation, history of thromboembolism and of mitral prosthesis were independently associated with thromboembolism. However, a bad quality of anticoagulation (TTR <47%, 25°percentile of our population) was not correlated with thromboembolism.

CONCLUSIONS

A low rate of bleeding and thromboembolic events in patients with mechanical heart valves were found, despite the sub-optimal anticoagulation control. The thromboembolic risk was not associated with the low TTR.

Optimizing quality care for the oral vitamin K antagonists (VKAs)

Vitamin K antagonists (VKAs) have been the only oral anticoagulants for decades. The management of anticoagulant therapy with VKA is challenging because of the intricate pharmacological properties of these agents. The success of VKA therapy depends on the quality of treatment that is ensured through continuing comprehensive communication and education. The educational program should address important issues of the VKA therapy such as beginning of treatment, pharmacological, dietary, and drug-drug interactions, as well as treatment temporary suspension during surgical interventions or invasive maneuvers. In addition, the initial and continuing patient education is of imperative importance. A major role in the educational process may be addressed by patient associations. The quality of treatment is better reached if patients are followed in anticoagulation clinics. Moreover, a federation of anticoagulation clinics may improve patient care through regular meetings to update knowledge on VKA treatment. Learning objectives of this paper is to allow readers to correctly approach patients starting VKA treatment, recognize possible pitfalls of treatment, and provide adequate solutions.

American Society of Hematology 2018 guidelines for management of venous thromboembolism: optimal management of anticoagulation therapy

BACKGROUND

Clinicians confront numerous practical issues in optimizing the use of anticoagulants to treat venous thromboembolism (VTE).

OBJECTIVE

These evidence-based guidelines of the American Society of Hematology (ASH) are intended to support patients, clinicians and other health care professionals in their decisions about the use of anticoagulants in the management of VTE. These guidelines assume the choice of anticoagulant has already been made.

METHODS

ASH formed a multidisciplinary guideline panel balanced to minimize potential bias from conflicts of interest. The McMaster University GRADE Centre supported the guideline development process, including updating or performing systematic evidence reviews. The panel prioritized clinical questions and outcomes according to their importance for clinicians and patients. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach was used to assess evidence and make recommendations, which were subject to public comment.

RESULTS

The panel agreed on 25 recommendations and 2 good practice statements to optimize management of patients receiving anticoagulants.

CONCLUSIONS

Strong recommendations included using patient self-management of international normalized ratio (INR) with home point-of-care INR monitoring for vitamin K antagonist therapy and against using periprocedural low-molecular-weight heparin (LMWH) bridging therapy. Conditional recommendations included basing treatment dosing of LMWH on actual body weight, not using anti-factor Xa monitoring to guide LMWH dosing, using specialized anticoagulation management services, and resuming anticoagulation after episodes of life-threatening bleeding.

Individual and monitoring centre influences upon anticoagulation control of AF patients on warfarin: A longitudinal multi-centre UK-based study

OBJECTIVES

Time within therapeutic INR range (TTR) predicts benefits/risk of warfarin therapy. Identification of individual- and centre-related factors that influence TTR, and addressing them to improve anticoagulation control, are important. This study examined the impact of individual and centre-related factors upon long-term anticoagulation control in atrial fibrillation patients in seven UK-based monitoring services.

METHODS

Data between 2000 and 2014 on 25 270 patients (equating to 203 220 patient years) [18 120 (71.7%) in general practice, 2348 (9.3%) in hospital-based clinics and 4802 (19.0%) in domiciliary service] were analysed.

RESULTS

TTR increased with increasing age, peaking around 77% at 70-75 years, and then declined, was lower in females than males, and in dependent home-monitored patients than those attending clinic (P < 0.0001). TTR, number of dose changes and INR monitoring events and the probability of TTR ≤ 65%, differed across the centres (P < 0.0001).

CONCLUSIONS

Although all the participating centres ostensively followed a standard dosing algorithm, our results indicate that variations in practice do occur between different monitoring sites. We suggest feedback on TTR for individual monitoring sites gauged against the average values reported by others would empower the individual centres to improve quality outcomes of anticoagulation therapy by identifying and adjusting contributory factors within their management system.

Direct oral anticoagulants: what can we learn?

Direct oral anticoagulants (DOACs) represent an innovation because they avoid periodic laboratory monitoring, and also reduce cerebral bleeding. An examination of the performance of DOACs versus warfarin in randomized clinical trials dedicated to atrial fibrillation would reveal the poor performance of warfarin because the percentage of major bleeding is always above 3%; however, the percentage of major bleeding is less than half of that when the management is done in anticoagulation clinics (ACs). Several years ago, a common opinion was that ACs would disappear as soon as DOACs enter the market. We proposed then that ACs could be transformed into thrombosis centres (TCs) because we envisaged many new activities in terms of diagnostic tools and therapeutic choices. After the introduction of DOACs, the role of the ACs has been re-evaluated because their role may be crucial in selecting both the most appropriate diagnostic approach and the best therapeutic option (including anti-vitamin K drugs) for the single patient. TCs can organize a regular follow-up to improve patient adherence to DOACs. Marketing might have a role in the decision making of the single doctor. Efforts should be made for limiting the relationships between doctors and pharmaceutical companies. It seems reasonable to better prepare doctors, during their university courses, for them to develop a greater scientific culture that would enable them to critically read clinical studies and acquire an independent opinion. Ideally, an expert in haemostasis and thrombosis should handle new and old anticoagulants.