Use of Vitamin K Antagonist Therapy in Geriatrics: A French National Survey from the French Society of Geriatrics and Gerontology (SFGG)

Medico-economic comparison of two anticoagulant treatment strategies: Vitamin K antagonists vs. direct oral anticoagulants in older adults in nursing homes in France. The "MIKADO" study

OBJECTIVES

Currently, two classes of oral anticoagulants are available in nursing home residents: vitamin K antagonists (VKA) and direct oral anticoagulants (DOAC). DOACs have a higher net clinical benefit than VKAs but DOACs are about 10 times more expensive than VKAs. The objective of our study was to assess and compare the overall costs of anti-coagulant strategy (VKA or DOAC), i.e., including drugs, laboratory costs and time spent in human capital (nurses and medical time) in nursing homes in France.

METHODS

This was an observational, multicenter, prospective study including nine nursing homes in France. Among these nursing homes, 241 patients aged 75 years and older and treated with VKA (n = 140) or DOAC (n = 101) therapy accepted to participate in the study.

RESULTS

During the 3-month follow-up period, the adjusted mean costs per patient were higher for VKA than DOACs for nurse care (€327 (57) vs. €154 (56), p<.0001) for general practitioner care (€297 (91) vs. €204 (91), p = 0.02), for coordinating physicians care (€13 (7) vs. €5 (7), p < 0.07), for laboratory tests (€23 (5) vs. €5 (5), p<.0001), but were lower for drug costs (€8 (3) vs. €165 (3), p<.0001). The average overall cost for 3 months per patient was €668 (140) with VKA vs. €533 (139) with DOAC (p = 0.02).

CONCLUSION

Our study showed that in nursing homes despite a higher drug cost, DOAC therapy is associated with a lower total cost and less time used by nurses and physicians for drug monitoring when compared to VKA.

The Prescription of Vitamin K Antagonists in a Very Old Population: A Cross-Sectional Study of 8696 Ambulatory Subjects Aged Over 85 Years

We compared very elderly people taking vitamin K antagonists (VKA) and those not taking VKA (noVKA). Individuals were included in the noVKA group if there was no VKA on their reimbursed prescriptions during the study period. We also compared three subgroups, constituted by VKA type (fluindione, warfarin, or acenocoumarol). We included individuals aged over 85 years, affiliated to Mutualité Sociale Agricole of Burgundy, who were refunded for prescribed VKA in September 2017. The VKA and noVKA groups were compared in terms of demographic conditions, registered chronic diseases (RCD), number of drugs per prescription and cardiovascular medications. The three VKA subgroups were compared for the same items plus laboratory monitoring, novel and refill VKA prescriptions, and prescriber specialty. Of the 8696 included individuals, 1157 (13.30%) were prescribed VKA. Mean age was 90 years. The noVKA group had fewer women (53.67 vs 66.08%), more RCD (93.43 vs. 71.96%) and more drugs per prescription (6.65 vs. 5.18) than the VKA group (all p < 0.01). Except for direct oral anticoagulants and platelet aggregation inhibitors, the VKA group took significantly more cardiovascular medications. The most commonly prescribed VKA was fluindione (59.46%). Mean age was higher in the warfarin (90.42) than in the acenocoumarol (89.83) or fluindione (89.71) subgroups (p < 0.01). No differences were observed for sex (women were predominant) or RCD. 13% of subjects in this population had a VKA prescription. Fluindione was the most commonly prescribed VKA.

Assessment of agreement and time in therapeutic range of capillary versus venous international normalised ratio in frail elderly people in a nursing home

Vitamin K antagonists are widely used, yet have a slim therapeutic margin and high iatrogenicity. Patients are monitored through international normalised ratio (INR) by venipuncture, but coagulometers could measure INR by capillary puncture. This prospective study evaluated the clinical concordance of capillary INR versus venous INR in 31 nursing home patients. Concordance was good and mean time in therapeutic range (TTR) markedly increased. Capillary INR is thus reliable, could improve TTR and decrease iatrogenicity.

[Time in therapeutic range (TTR) and follow-up of patients on vitamin K antagonist: A cohort analysis]

INTRODUCTION

Despite the increasing utilization of direct oral anticoagulant (DOAC) prescriptions, vitamin K antagonists (VKAs) remain the treatment of choice for treating and preventing thromboembolic events. The morbidity and mortality of VKAs are partly due to the difficulty of keeping the patient within the therapeutic range. For patients treated by VKA, time in therapeutic range (TTR) is a quality parameter of treatment, widely used in clinical trials but rarely by prescribers. It is well established that its use correlates with the risk of hemorrhage, thrombosis or mortality. We studied this parameter in a cohort of patients to evaluate the quality of their therapeutic follow-up and tried to identify risk factors for low TTR.

METHODS

The study was made in collaboration with LaboSud Oc Biologie for a duration of 4 months. It included 3387 patients representing 2,4029 INR. We calculated the patients' TTR. The laboratory transmitted to us the sex and age of each patient and the VKA molecule used, the therapeutic range and the specialty of the prescriber. We then analyzed the odds ratio associated with these different factors.

RESULTS

The mean TTR was 68%, close to the TTR recommended by scientific societies. Patient's sex was the only statistically correlated factor, with a worse equilibrium in females taking VKAs (OR=1.22, 95% CI: 1.06-1.39, P=0.00552). Many factors usually correlated with poor equilibrium under VKA have not been studied due to lack of information.

CONCLUSION

Given the context of economic restriction and the TTR of our cohort close to the recommended 70%, there would be no benefit in terms of safety to prefer DOAC for the patients involved in this study. Regular monitoring of the individual patient's as well as the cohort's TTR should optimize the management of patients receiving VKAs.

[Oral anticoagulants adherence in elderly patients treated for atrial fibrillation in the era of direct oral anticoagulants]

BACKGROUND

The aim of this study was to determine the level of adherence to oral anticoagulants in the population of elderly patients treated for a non-valvular atrial fibrillation (AF) in the era of direct oral anticoagulants.

PATIENTS AND METHOD

This transversal study used Morisky scale to assess adherence to oral anticoagulants. We also collected patients' reviews about the treatment and factors explaining a poor adherence.

RESULTS

Between January and June 2015, 64 patients were included in Loire Atlantique. Average age was 77.8 years, CHA₂DS₂-VASc score was 4.06 and treatment (vitamin K antagonists [VKAs] in 78% patients) was prescribed since 4.3 years. According to Morisky scale, 84.4% of patients had a good adherence. There was 88% of good adherence with AVK versus 71% with direct oral anticoagulant, there was no statistically significant difference. The prescriber and the knowledge of anticoagulant treatment role seemed to be determinant factors.

CONCLUSIONS

The level of adherence for oral anticoagulant appears higher than in most published studies. Diversification of therapeutic options could constitute an aid to personalize the prescription in order to improve it.

Atrial fibrillation in women: treatment

Sex-specific differences in the epidemiology, pathophysiology, presentation, prognosis, and treatment of atrial fibrillation (AF) are increasingly recognized. Women with AF generally experience worse symptoms, poorer quality of life, and have higher risk of stroke and death than men with AF. Effective treatment of the arrhythmia in women is critical to reduce the rate of adverse events. We review the current evidence on sex-specific differences in the utilization and outcomes of treatments for AF, including rate-control and rhythm-control strategies, and stroke-prevention therapy. In addition, we provide a critical evaluation of potential disparities and biases in health-care use that might be associated with differences in the outcomes between women and men. We underscore current knowledge gaps that need to be addressed in future studies to improve the management of AF in women. In particular, we suggest several strategies to produce high-quality evidence from randomized clinical trials for women with AF.

Non-vitamin K oral anticoagulant treatment in elderly patients with atrial fibrillation and coronary heart disease

Atrial fibrillation (AF) is the most frequent sustained arrhythmia. Overall prevalence is estimated to 5.5% and the incidence increases with age. As the population ages, the prevalence and costs of AF are expected to increase. AF is the most important cause of stroke in patients >75years. Until recently, Vitamin K antagonists (VKAs) were the only available oral anticoagulants (OACs) evaluated for long-term treatment of patients with AF with or without coronary heart disease (CHD). This situation was challenged by introduction of non-VKA oral anticoagulants (NOACs). In AF, use of NOACs seems to be as effective and safe as VKAs, especially in elderly patients. AF and CHD are frequently associated and the question of antithrombotic management in aging patients is delicate. In elderly patients experiencing a new AF episode after an acute coronary syndrome, triple antithrombotic therapy should be as short as possible in order to decrease the risk of major bleedings. To date, there is no specific study or available guidelines regarding the NOACs use specifically in elderly patients experiencing both AF and CHD. In this review, we try to provide a perspective on NOACs future incorporation into clinical practice in elderly patients with both AF and CHD.

Impact of age on long-term anticoagulation and how gender and monitoring setting affect it: implications for decision making and patient management

AIMS

Stabilization of anticoagulation control is seminal to reducing the risk of adverse effects of vitamin K antagonists. Reliable information on how ageing influences this is lacking. We set out to assess the true age-related changes in anticoagulation control, how gender and patient setting influence this, and the possible implications of these for patient outcomes and management.

METHODS

In atrial fibrillation (AF) patients of a unified anticoagulant service monitoring patients in general practice or hospital-based clinics and housebound patients at home, international normalized ratio (INR) and warfarin dose data between 2000 and 2013 were extracted via the DAWN dosing program. Anticoagulation control was assessed by calculating percentage time spent within target INR (TTR).

RESULTS

A total of 2094 AF patients [938 (44.8%) in general practice (GP) and 531 (25.4%) in hospital (H)-based clinics and 625 (29.8%) through the domiciliary service (D)] were evaluated. The frequency of warfarin dose changes and INR monitoring events declined until about age 67, then increased as patients got older. The TTR according to age was significantly lower and the probability of having a TTR ≤65% according to age was higher for D than for H and GP, and females had a greater probability of having a TTR ≤65% than age-matched males.

CONCLUSION

Identification of factors underlying poorer anticoagulation control in older housebound patients and the introduction of effective modifications to improve the clinical effectiveness of anticoagulation in such patients is needed.

Anticoagulation Stability Depends on CHADS2 Score and Hepatorenal Function in Warfarin-treated Patients, Including Those with Atrial Fibrillation

AIM

Although warfarin remains important despite the widespread use of nonvitamin K antagonist oral anticoagulants (NOACs), to date, the reality of warfarin use in the "NOACs era" is unclear. This multicenter observational study aimed to clarify the key factors contributing to warfarin treatment stability.

METHODS

The practical use of warfarin, stability of warfarin therapy, and factors contributing to this stability were investigated in community-based hospitals through a real-world study. Clinical data were retrospectively extracted from the medical records of warfarin-treated Japanese patients (age, 71.3±5.5 years) with atrial fibrillation (AF), prosthetic heart valve, or other concerns requiring anticoagulation. Treatment stability was considered as time in therapeutic range of international normalized ratio of prothrombin time (TTR: %). The factors contributing to TTR were investigated, including CHADS₂ score components.

RESULTS

Mean CHADS₂ score was highest (1.38±0.88, p＜0.001), and most CHADS₂ score components in addition to hepatorenal dysfunction were factors contributing to the low TTR in patients with AF (n=176). The similarity was found in overall patients who were prescribed warfarin (n= 518). TTR decreased according to the CHADS₂ score component accumulation. Gender, dose and prescription interval of warfarin, and co-administration of antiplatelet agents did not correlate with the low TTR.

CONCLUSIONS

This retrospective study demonstrated that the CHADS₂ score component accumulation and hepatorenal dysfunction are factors significantly contributing to the low TTR, which is indicative of poor warfarin treatment stability, in patients such as those with AF.

Decreased levels of procoagulant phospholipids in bleeding patients treated by vitamin K antagonists

International Normalized Ratio (INR) is currently used to monitor vitamin K antagonist therapy, and the bleeding incidence becomes exponential for INR>4.5. Inversely, more than 50% of patients with a supratherapeutic INR are asymptomatic. Therefore it could be of interest to identify patients with a higher bleeding risk. Microparticles derived from different cell types express procoagulant phospholipids (PPL) which can be evaluated by a chronometric coagulation assay where a shortening of the clotting times is associated with increased levels of PPL. In a series of 174 consecutive patients referred to our Emergency Department with an INR>5, median level of PPL was significantly (p=0.004) lower (38.2s) in the 119 asymptomatic patients than in patients with nonmajor (43.6s, n=35) or major bleeding (46.6s, n=19), indicating higher levels of procoagulant phospholipids in asymptomatic patients. By receiver operating characteristic curve analysis, a cut-off of 43.5s discriminated patients with higher haemorrhagic risk (area under the curve=0.648). In contrast, thrombomodulin levels, quantified either by immunological or functional assays were not significantly different between both groups. In conclusion, evaluation of PPL could be of interest to define the haemorrhagic risk of VKA- treated patients.

Comorbidities against quality control of VKA therapy in non-valvular atrial fibrillation: a French national cross-sectional study

Background

Given the prevalence of non-valvular atrial fibrillation in the geriatric population, thromboembolic prevention by means of vitamin K antagonists (VKA) is one of the most frequent daily concerns of practitioners. The effectiveness and safety of treatment with VKA correlates directly with maximizing the time in therapeutic range, with an International Normalized Ratio (INR) of 2.0-3.0. The older population concentrates many of factors known to influence INR rate, particularly concomitant medications and concurrent medical conditions, also defined as comorbidities.

Objective

Determine whether a high burden on comorbidities, defined by a Charlson Comorbidity Index (CCI) of 3 or greater, is associated a lower quality of INR control.

Study-Design

Cross-sectional study.

Settings

French geriatric care units nationwide.

Participants

2164 patients aged 80 and over and treated with vitamin K antagonists.

Measurements

Comorbidities were assessed using the Charlson Comorbidity Index (CCI). The recorded data included age, sex, falls, kidney failure, hemorrhagic event, VKA treatment duration, and the number and type of concomitant medications. Quality of INR control, defined as time in therapeutic range (TTR), was assessed using the Rosendaal method.

Results

487 patients were identified the low-quality control of INR group. On multivariate logistic regression analysis, low-quality control of INR was independently associated with a CCI ≥3 (OR = 1.487; 95% CI [1.15; 1.91]). The other variables associated with low-quality control of INR were: hemorrhagic event (OR = 3.151; 95% CI [1.64; 6.07]), hospitalization (OR = 1.614, 95% CI [1.21; 2.14]).

Conclusion

An elevated CCI score (≥3) was associated with low-quality control of INR in elderly patients treated with VKA. Further research is needed to corroborate this finding.

Direct oral anticoagulants in the treatment of acute venous thromboembolism: a systematic review and meta-analysis

INTRODUCTION

Acute venous thromboembolism (VTE) is a common disease associated to significant morbidity and mortality.

MATERIALS AND METHODS

We systematically reviewed and meta-analysed clinical outcomes with direct oral anticoagulants (DOAC: dabigatran, rivaroxaban, apixaban or edoxaban) for treatment of acute VTE. We used MEDLINE and CENTRAL, clinical trials registers, conference proceedings, and websites of regulatory agencies to identify randomised clinical trials of DOAC compared with conventional treatment [parenteral anticoagulant followed by a vitamin K antagonist (VKA)] for acute VTE. Two investigators independently extracted data. Relative risk of recurrent VTE, bleeding events, deaths and a net clinical endpoint (composite of recurrent VTE, major bleeding, and death) were estimated using a random effect meta-analysis (RevMan software).

RESULTS

Six trials including 27,127 patients were selected. The risk of recurrent VTE was similar with the DOAC and standard treatment (relative risk 0.91, 95% confidence interval 0.79 to 1.06). The DOAC reduced the risk of major bleeding in comparison with standard treatment (0.62, 0.45 to 0.85) (absolute risk difference, -0.6%; 95% confidence interval -1.0% to -0.3%), but there was heterogeneity across trials in the relative risk of bleeding. No between treatment differences were found in the relative risk of all-cause mortality (0.98, 0.84 to 1.14). The DOAC and conventional treatment differed on the net clinical endpoint (0.85, 0.75 to 0.97). Subgroup analyses in relevant subgroups (index pulmonary embolism, heparin lead-in, age, gender, renal function, presence of cancer), as well as sensitivity analyses, were consistent with the main analysis.

CONCLUSIONS

The DOAC seem as effective as, and probably safer than standard treatment of acute VTE. The relative efficacy and safety of the DOAC was consistent across a wide range of patients.