Comparative risks of bleeding, ischemic stroke and mortality with direct oral anticoagulants versus phenprocoumon in patients with atrial fibrillation

Pharmacodynamic Drug-Drug Interactions and Bleeding Outcomes in Patients with Atrial Fibrillation Using Non-Vitamin K Antagonist Oral Anticoagulants: a Nationwide Cohort Study

PURPOSE

Pharmacodynamic drug-drug interactions (PD DDIs) may influence the safety of non-vitamin K antagonist oral anticoagulants (NOACs), but the extent to which PD DDIs increase bleeding risks, remains unclear. Therefore, the impact of PD DDIs on bleeding outcomes in NOAC-treated patients with atrial fibrillation (AF) was investigated.

METHODS

Using Belgian nationwide data, NOAC-treated AF patients were included between 2013-2019. Concomitant use of PD interacting drugs when initiating NOAC treatment was identified.

RESULTS

Among 193,072 patients, PD DDIs were identified in 114,122 (59.1%) subjects. After multivariable adjustment, concomitant use of PD interacting drugs was associated with significantly higher risks of major or clinically-relevant non-major bleeding (adjusted hazard ratio (aHR) 1.19, 95% confidence interval (CI) (1.13-1.24)), gastrointestinal (aHR 1.12, 95%CI (1.03-1.22)), urogenital (aHR 1.21, 95%CI (1.09-1.35)) and other bleeding (aHR 1.28, 95%CI (1.20-1.36)), compared to NOAC-treated AF patients without PD interacting drug use. Increased bleeding risks were most pronounced with P2Y12 inhibitors (aHR 1.62, 95%CI (1.48-1.77)) and corticosteroids (aHR 1.53, 95%CI (1.42-1.66)), followed by selective serotonin or serotonin and norepinephrine reuptake inhibitors (SSRI/SNRI, aHR 1.26, 95%CI (1.17-1.35)), low-dose aspirin (aHR 1.14, 95%CI (1.08-1.20)) and non-steroidal anti-inflammatory drugs (NSAID, aHR 1.10, 95%CI (1.01-1.21)). Significantly higher intracranial bleeding risks in NOAC users were observed with SSRI/SNRIs (aHR 1.50, 95%CI (1.25-1.81)) and corticosteroids (aHR 1.49, 95%CI (1.21-1.84)).

CONCLUSION

Concomitant use of PD interacting drugs, especially P2Y12 inhibitors and corticosteroids, was associated with higher major, gastrointestinal, urogenital, and other bleeding risks in NOAC-treated AF patients. Remarkably, higher intracranial bleeding risks were observed with SSRI/SNRIs and corticosteroids.

Drug-drug interactions with direct oral anticoagulants for the prevention of ischemic stroke and embolism in atrial fibrillation: a narrative review of adverse events

INTRODUCTION

In randomized trials, direct oral anticoagulants (DOAC) were non-inferior to the vitamin-K-antagonist (VKA) warfarin in preventing stroke/embolism in patients with atrial fibrillation (AF). DOAC are substrates for P-glycoprotein (P-gp), CYP3A4 and CYP2C9. The activity of these enzymes is modulated by several drugs which might induce pharmacokinetic drug-drug interactions (DDI). Drugs affecting platelet function have the potential for pharmacodynamic DDI of DOAC.

AREAS COVERED

The literature was searched for: 'dabigatran,' 'rivaroxaban,' 'edoxaban,' or 'apixaban' and drugs affecting platelet function, CYP3A4-, CYP2C9- or P-gp-activity. Reports about bleeding and embolic events attributed to DDI with DOAC in AF-patients were found for 43 of 171 drugs with interacting potential (25%), most frequently with antiplatelet and nonsteroidal anti-inflammatory drugs. Whereas a co-medication of platelet-affecting drugs is invariably reported to increase the bleeding risk, the findings regarding P-gp-, CYP3A4- and CYP2C9- activity-affecting drugs are ambiguous.

EXPERT OPINION

Tests for plasma DOAC-levels and information about DDI of DOAC should be widely available and user-friendly. If advantages and disadvantages of DOAC and VKA can be investigated exhaustively, individualized anticoagulant therapy can be offered to patients, considering co-medication, comorbidities, genetic and geographic factors and the health care system.

Clinical outcomes in patients with atrial fibrillation treated with DOACs in a specialized anticoagulation center: Critical appraisal of real-world data

AIMS

Direct oral anticoagulants (DOAC) are progressively replacing vitamin K antagonists in the prevention of thromboembolism in patients with atrial fibrillation. However, their real-world clinical outcomes appear to be contradictory, with some studies reporting fewer and others reporting higher complications than the pivotal randomized controlled trials. We present the results of a clinical model for the management of DOACs in real clinical practice and provide a review of the literature.

METHODS

The MACACOD project is an ongoing, observational, prospective, single-center study with unselected patients that focuses on rigorous DOAC selection, an educational visit, laboratory measurements, and strict follow-up.

RESULTS

A total of 1,259 patients were included. The composite incidence of major complications was 4.93% py in the whole cohort vs 4.49% py in the edoxaban cohort. The rate of all-cause mortality was 6.11% py for all DOACs vs 5.12% py for edoxaban. There weren't differences across sex or between Edoxaban reduced or standard doses. However, there were differences across ages, with a higher incidence of major bleeding complications in patients >85 years (5.13% py vs 1.69% py in <75 years).

CONCLUSIONS

We observed an incidence of serious complications of 4.93% py, in which severe bleeding predominated (3.65% py). Considering our results, more specialized attention seems necessary to reduce the incidence of severe complications and also a more critical view of the literature. Considering our results, and our indirect comparison with many real-world studies, more specialized attention seems necessary to reduce the incidence of severe complications in AF patients receiving DOACs.

Long-term comparative effectiveness and safety of dabigatran, rivaroxaban, apixaban and edoxaban in patients with atrial fibrillation: A nationwide cohort study

Background: Although non-vitamin K antagonist oral anticoagulants (NOACs) are recommended over vitamin K antagonists (VKAs) in atrial fibrillation (AF) management, direct long-term head-to-head comparisons are lacking. Therefore, their risk-benefit profiles were investigated compared to VKAs and between NOACs. Methods: AF patients initiating anticoagulation between 2013-2019 were identified in Belgian nationwide data. Inverse probability of treatment weighted Cox regression was used to investigate effectiveness and safety outcomes and were additionally stratified by NOAC dose. Results: Among 254,478 AF patients (328,796 person-years of follow-up), NOACs were associated with significantly lower risks of stroke or systemic embolism (stroke/SE) (hazard ratio (HR) 0.68, 95% confidence interval (CI) (0.64-0.72)), all-cause mortality (HR 0.76, 95%CI (0.74-0.79)), major or clinically relevant non-major bleeding (MB/CRNMB) (HR 0.94, 95%CI (0.91-0.98)) and intracranial hemorrhage (HR 0.73, 95%CI (0.66-0.79)), but non-significantly different risks of myocardial infarction, gastrointestinal and urogenital bleeding compared to VKAs. Despite similar stroke/SE risks, dabigatran and apixaban were associated with significantly lower MB/CRNMB risks compared to rivaroxaban (HR 0.86, 95%CI (0.83-0.90); HR 0.86, 95%CI (0.83-0.89), respectively) and edoxaban (HR 0.91, 95%CI (0.83-0.99); HR 0.86, 95%CI (0.81-0.91), respectively), and apixaban with significantly lower major bleeding risks compared to dabigatran (HR 0.86, 95%CI (0.80-0.92)) and edoxaban (HR 0.79, 95%CI (0.72-0.86)). However, higher mortality risks were observed in some risk groups including with apixaban in patients with diabetes or concomitantly using digoxin compared to dabigatran and edoxaban, respectively. Conclusion: NOACs had better long-term risk-benefit profiles than VKAs. While effectiveness was comparable, apixaban was overall associated with a more favorable safety profile followed by dabigatran.

Vitamin-K-antagonist phenprocoumon versus direct oral anticoagulants in patients with atrial fibrillation: a real-world analysis of German claims data

OBJECTIVES

Direct oral anticoagulants (DOACs) were introduced based on randomised controlled trials (RCTs) comparing them to vitamin-K-antagonist (VKA) warfarin. In Germany, almost exclusively phenprocoumon is used as VKA. RCTs with phenprocoumon being absent we analysed the benefits and harms of DOACs and phenprocoumon for patients with atrial fibrillation (AF) in a real-world setting.

DESIGN

In a retrospective observational cohort study, claims data covering inpatient and outpatient care from 2015 to 2019 were analysed by Cox regression and propensity score matching (PSM).

SETTING

Data from a group of small-sized to medium-sized health insurance companies in Germany.

PARTICIPANTS

We analysed datasets of 71 961 patients with AF and first prescription of phenprocoumon (n=20 179) or DOAC in standard dose (n=51 782). Patients with reduced dose of DOACs were excluded (n=21 724).

OUTCOME MEASURES

Outcomes were thromboembolic events, major bleeding and death during a 12-month follow-up period.

RESULTS

The regression analysis widely showed similarity between phenprocoumon and standard dose DOACs regarding effectiveness and safety. There were only three statistically significant differences: a lower bleeding risk with composite DOACs and apixaban (HR (95% CI) = 0.67 (0.59 to 0.76) and 0.54 (0.46 to 0.63), respectively) and a higher risk of death with rivaroxaban (1.21 (1.10 to 2.34)). The analysis after PSM was consistent with the first two results regarding composite DOACs and apixaban (number needed to treat, NNT 101 and 78) and showed a lower bleeding risk with rivaroxaban (NNT 156). Absolute differences were small.

CONCLUSIONS

The small superiority or non-inferiority of DOACs over warfarin seen in the RCTs might not translate into relevant advantages of DOACs over phenprocoumon. To confirm the hypothesis, an RCT with phenprocoumon is needed. Next to the safety and effectiveness assessments other factors might also play a substantial role in the decision on the right OAC for stroke prevention.

[Prescribing behavior of Bavarian general practitioners at the inpatient-outpatient interface within the context of the Bavarian active substance agreement-qualitative results of the WirtMed Study]

Hintergrund und Ziel

Zur transparenten Steuerung der Arzneimittelausgaben im Rahmen des Wirtschaftlichkeitsgebots (§ 12 Fünftes Buch Sozialgesetzbuch (SGB V)) hat die Kassenärztliche Vereinigung Bayerns im Jahr 2014 die Wirkstoffvereinbarung (WSV) eingeführt. Diese hat die Richtgrößensystematik abgelöst. Mit Bezug auf die Rolle der WSV werden im Artikel die Gründe der Hausärzt*innen (HÄ) für oder gegen eine Weiterverordnung von Arzneimitteln aus dem Krankenhaus beschrieben.

Material und Methode

In einem qualitativen Studiendesign wurden im Zeitraum 11/2019 bis 03/2020 mit bayerischen HÄ Einzelinterviews (n = 18) und 2 Fokusgruppen (n = 10) durchgeführt und nach der qualitativen Inhaltsanalyse ausgewertet.

Ergebnisse

Mit der Einführung der WSV nahmen die Regresssorgen der HÄ insgesamt ab. Große Bedeutung bei Verordnungen haben – vor der Wirtschaftlichkeit – die patient*innenorientierte Versorgung und fachliche Richtigkeit von Therapieentscheidungen. Mit der Entlassmedikation ergeben sich wirtschaftliche Herausforderungen, besonders mit dem Leitsubstanzziel der oralen Antikoagulation, den Generikazielen bei Antidiabetika und bei Therapeutika für das Herz-Kreislauf-System. Allgemein kritisiert werden Rabattverträge, die oft zu Umstellungen von Arzneimitteln führen. Vereinzelt wird von einer „Vormachtstellung“ der Klinikärzt*innen berichtet, die dem hausärztlichen wirtschaftlichen Handeln entgegenstehen. Es fehlt laut HÄ eine sektorenübergreifende Kostenverantwortung.

Diskussion

Ein reibungsloser Schnittstellenübergang ist aus Sicht der HÄ trotz des Rahmenvertrags Entlassmanagement und der neuen Steuerungssystematik der WSV im ambulanten Sektor noch nicht vorhanden. Für eine wirtschaftliche Arzneimittelversorgung bedarf es weiterhin einer sektorenübergreifenden, aber auch bundesländerübergreifenden politischen Diskussion.

Zusatzmaterial online

Im Onlinematerial sind vertiefende Informationen zu der Methodik (Onlinematerial 1: Interview- und Fokusgruppenleitfaden) sowie zur Auswertung (Onlinematerial 2: Kategoriensystem) dieser Studie (10.1007/s00103-022-03563-6) verfügbar.

Effectiveness and Safety of Dabigatran Compared to Vitamin K Antagonists in Non-Asian Patients with Atrial Fibrillation: A Systematic Review and Meta-Analysis

BACKGROUND AND OBJECTIVE

Real-life data about the use of dabigatran in patients with non-valvular atrial fibrillation are warranted. The objective of this systematic review and meta-analysis was to assess the effectiveness and safety of dabigatran, globally and stratified by dose (110/150 mg twice daily), vs vitamin K antagonists in non-Asian patients with non-valvular atrial fibrillation from "real-world" studies.

METHODS

A systematic review was performed according to Cochrane methodological standards. The results were reported according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analyses Statement) statement. The ROBINS-I tool was used to assess bias risk. MEDLINE and EMBASE, from inception up to May 2021, using appropriate controlled vocabulary and free search terms, were searched.  RESULTS: A total of 34 studies, corresponding to 37 articles involving 1,600,722 participants (1,154,283 exposed to vitamin K antagonists and 446,439 to dabigatran) were eligible for this review. Dabigatran 150 mg reduced the risk of ischemic stroke compared with vitamin K antagonists, with a 14% risk reduction (hazard ratio [HR] 0.86, 95% confidence interval [CI] 0.74-0.98). Globally, dabigatran reduced the risk of all-cause mortality compared with vitamin K antagonists (HR 0.76, 95% CI 0.69-0.84), with a greater effect observed with dabigatran 150 mg (HR 0.65, 95% CI 0.58-0.73). There was a trend towards a lower risk of myocardial infarction with dabigatran 150 mg (HR 0.86, 95% CI 0.71-1.04). Regarding the primary safety outcomes, dabigatran (either at a dose of 150 mg or 110 mg) reduced the risk of major bleeding compared with vitamin K antagonists (HR 0.77, 95% CI 0.70-0.83), as well as the risk of intracranial bleeding (HR 0.44, 95% CI 0.39-0.50) and fatal bleeding (HR 0.76, 95% CI 0.60-0.95), but with a slight increase in gastrointestinal bleeding risk (HR 1.16, 95% CI 1.08-1.26).

CONCLUSIONS

Dabigatran has a favorable impact on effectiveness and safety outcomes compared with vitamin K antagonists in real-world populations.

Different Risk Profiles of European Patients Using Direct Oral Anticoagulants or Vitamin K Antagonists: a Rapid Review

Purpose of Review

We investigated the risk profiles of patients using direct oral anticoagulants (DOAC) or vitamin K antagonists (VKA) in European cohort studies to estimate the importance of potential (measured or unmeasured) confounding factors in analyses comparing these drugs. We searched MEDLINE and EMBASE (2008–2018) for relevant studies and extracted information on age, sex, comorbidity, Charlson comorbidity index, HAS-BLED score (assessing risk of bleeding) and CHA2DS2-VASc score (assessing risk of stroke).

Recent Findings

Overall, 66 studies with 2,808,757 patients were included. Most patients were from France (37%), Denmark (24%) and Germany (23%). In 56 studies (85%), the focus was on patients with atrial fibrillation. Of the 43 studies comparing DOAC with VKA users, 33% reported a higher and 16% a lower age of DOAC compared with VKA users. The mean age varied by about 1 year in most of these studies. Rivaroxaban was used in the widest age range. Patients with DOAC more often had a history of stroke or bleedings, and patients with VKA more often had a history of diabetes, renal failure, cancer, heart failure or other heart diseases. Most studies did not observe differences regarding the HAS-BLED score or the CHA2DS2-VASc score between groups.

Summary

Our review suggests that there are relevant differences in the risk profiles of DOAC versus VKA users and between users of individual DOACs. Reported HAS-BLED or CHA2DS2-VASc scores did not reflect these differences. These patterns require careful consideration in the interpretation of observational studies comparing the effectiveness and the risks of these drugs, also when comparing the results of studies conducted in different countries.

Comparing stroke prevention therapy of direct oral anticoagulants and vitamin K antagonists in patients with atrial fibrillation: a nationwide retrospective observational study

BACKGROUND

Direct oral anticoagulants (DOACs) are not only increasingly being used for the initial stroke prevention therapy but progressively also substitute vitamin K antagonist (VKA) treatment in patients with non-valvular atrial fibrillation (AF). DOACs have been compared regarding therapeutic efficacy and adverse outcomes to warfarin in several pivotal studies and showed non-inferiority in terms of stroke prevention and superiority in terms of bleeding complications. However, comprehensive comparative studies are lacking for phenprocoumon, a VKA prescribed frequently outside the USA and the UK and accounting for 99% of all VKA prescriptions in Germany. Patients treated with phenprocoumon seem to meet more often international normalized ratio values in the therapeutic range, which may have implications concerning their efficacy and safety. This study aims at comparing the risk of stroke and bleeding in phenprocoumon- and DOAC-treated patients with AF in an adequately powered observational study population.

METHODS

Retrospective analysis of stroke and bleeding incidence of 837,430 patients (1.27 million patient years) treated with DOAC or phenprocoumon for stroke prevention in German ambulatory care between 2010 and 2017. Relative risks of stroke and bleeding were estimated by calculating cox regression-derived hazard ratios (HR) and 95% confidence intervals (CI) of propensity score-matched cohorts.

RESULTS

Patients treated with DOAC had an overall higher risk for stroke (HR 1.32; CI 1.29-1.35) and a lower risk for bleeding (0.89; 0.88-0.90) compared to phenprocoumon. When analyzed separately, the risk for stroke was higher for dabigatran (1.93; 1.82-2.03), apixaban (1.52; 1.46-1.58), and rivaroxaban (1.13; 1.10-1.17) but not for edoxaban (0.88; 0.74-1.05). The risk for bleeding was lower for dabigatran (0.85; 0.83-0.88), apixaban (0.71; 0.70-0.73), and edoxaban (0.29; 0.17-0.51) but not for rivaroxaban (1.03; 1.01-1.04).

CONCLUSIONS

This study provides a comprehensive view of the stroke and bleeding risks associated with phenprocoumon and DOAC use in Germany. Phenprocoumon may be preferable to DOAC treatment for the prevention of strokes in AF in a real-world population cared for in ambulatory care.

Comparing risk of major bleeding between users of different oral anticoagulants in patients with nonvalvular atrial fibrillation

AIMS

The introduction of direct oral anticoagulants (DOACs) has broadened the treatment arsenal for nonvalvular atrial fibrillation, but observational studies on the benefit-risk balance of DOACs compared to vitamin K antagonists (VKAs) are needed. The aim of this study was to characterize the risk of major bleeding in DOAC users using longitudinal data collected from electronic health care databases from 4 different EU-countries analysed with a common study protocol.

METHODS

A cohort study was conducted among new users (≥18 years) of DOACs or VKAs with nonvalvular atrial fibrillation using data from the UK, Spain, Germany and Denmark. The incidence of major bleeding events (overall and by bleeding site) was compared between current use of DOACs and VKAs. Cox regression analysis was used to calculate hazard ratios and 95% confidence intervals (CI) and adjust for confounders.

RESULTS/CONCLUSION

Overall, 251 719 patients were included across the 4 study cohorts (mean age ~75 years, % females between 41.3 and 54.3%), with overall hazard ratios of major bleeding risk for DOACs vs VKAs ranging between 0.84 (95% CI: 0.79-0.90) in Denmark and 1.13 (95% CI 1.02-1.25) in the UK. When stratifying according to the bleeding site, risk of gastrointestinal bleeding was increased by 48-67% in dabigatran users and 30-50% for rivaroxaban users compared to VKA users in all data sources except Denmark. Compared to VKAs, apixaban was not associated with an increased risk of gastrointestinal bleeding in all data sources and seemed to be associated with the lowest risk of major bleeding events compared to dabigatran and rivaroxaban.

Risk of Major Gastrointestinal Bleeding With New vs Conventional Oral Anticoagulants: A Systematic Review and Meta-analysis

BACKGROUND & AIMS

There is controversy over whether use of non-vitamin K antagonist oral anticoagulants (NOACs) associates with increased risk of major gastrointestinal bleeding (GIB) compared with conventional therapies (such as vitamin K antagonists or anti-platelet agents). We performed a systematic review and meta-analysis of data from randomized controlled trials and high-quality real-world studies.

METHODS

We performed a systematic search of the MEDLINE, EMBASE, Cochrane Library, and ClinicalTrials.gov Website databases (through Oct 12, 2018) for randomized controlled trials and high-quality real-world studies that reported major GIB events in patients given NOACs or conventional therapy. Relative risks (RRs) for randomized controlled trials and adjusted hazard ratios (aHRs) for real-world studies were calculated separately using random-effects models.

RESULTS

We analyzed data from 43 randomized controlled trials (183,752 patients) and 41 real-world studies (1,879,428 patients). The pooled major rates of GIB for patients on NOACs (1.19%) vs conventional treatment (0.92%) did not differ significantly (RR from randomized controlled trials, 1.09; 95% CI, 0.91-1.31 and aHR from real-world studies, 1.02; 95% CI, 0.94-1.10; P_interaction=.52). Rivaroxaban, but not other NOACs, was associated with an increased risk for major GIB (RR from randomized controlled trials, 1.39; 95% CI, 1.17-1.65 and aHR from real-world studies, 1.14; 95% CI, 1.04-1.23; P_interaction = .06). Analyses of subgroups, such as patients with different indications, dosage, or follow-up time, did not significantly affect results. Meta-regression analysis failed to detect any potential confounding to impact the primacy outcome.

CONCLUSIONS

In a systematic review and meta-analysis of data from randomized controlled trials and real-world studies, we confirmed that there is no significant difference in risk of major GIB between patients receiving NOACs vs conventional treatment. Rivaroxaban users had a 39% increase in risk for major GIB.

Mortality risk in atrial fibrillation: the role of aspirin, vitamin K and non-vitamin K antagonists

Background As an alternative to vitamin K antagonist and low-dose aspirin (< 325 mg), non-vitamin K oral anticoagulants are available for the prevention of stroke in patients with atrial fibrillation. However, the mortality risk associated with these drugs in daily practice remains unclear. Objective To evaluate the risk of all-cause mortality associated with non-Vitamin K antagonist oral anticoagulants, vitamin K antagonists or aspirin in patients with atrial fibrillation. Setting A cohort study conducted among atrial fibrillation patients using the UK Clinical Practice Research Datalink (March 2008-October 2014). Method New users of vitamin K antagonists, non vitamin K oral anticoagulants, low-dose aspirin, or combination therapy were followed from the date of first prescription to the date of death, as recorded in the UK datalink. Cox proportional hazard models estimated the hazard ratio (HR) of all-cause mortality for users of NOACs, aspirin, or combination use, as compared to vitamin K antagonist. Analyses were adjusted for confounders. Main outcome measure All-cause mortality. Results We identified 31,497 patients. Non vitamin K antocoagulant use (adjusted HR [aHR] = 1.42; 95% Confidence Interval [CI] 1.18-1.71) and aspirin use (aHR = 1.64; 95% CI 1.57-1.77) were both significantly associated with a higher mortality risk than use of vitamin K antagonists. The higher mortality risk for the non vitamin K anticoagulant use was observed in men (aHR = 1.72; 95% CI 1.25-2.36), but not in women (aHR = 1.28; 95% CI 0.92-1.79. Compared to  vitamin K antagonists, mortality risk associated with the non vitamin K anticoagulants and aspirin use was significantly increased in patients with higher stroke risk (CHA₂DS₂-VASc > 2). Conclusion Non vitamin K oral anticoagulants are  associated with a higher risk on all-cause mortality, particularly in men and in patients with higher stroke risk.

Drug interactions with oral anticoagulants in German nursing home residents: comparison between vitamin K antagonists and non-vitamin K antagonist oral anticoagulants based on two nested case-control studies

BACKGROUND

Vitamin K antagonists (VKAs) are susceptible to drug-drug interactions. Non-VKA oral anticoagulants (NOACs) have a decreased sensitivity to pharmacokinetic interactions and might be therefore considered superior in patients treated with multiple drugs. The objective of this study was to compare the risk of serious bleeding associated with interacting drugs in German nursing home residents treated with VKA or NOAC.

METHODS

Using claims data of new nursing home residents aged ≥ 65 years (2010-2014) we conducted separate nested case-control analyses within two cohorts of patients treated with VKA or NOAC, respectively. Cases were defined as patients hospitalized for serious bleeding. For each case, up to 20 controls were selected by risk-set sampling. Conditional logistic regression was used to obtain confounder-adjusted odds ratios (aORs) and 95% confidence intervals (CI) for the risk of bleeding associated with VKA or NOAC use and interacting drugs compared with the use of the respective oral anticoagulant alone.

RESULTS

Among 127,227 new nursing home residents, 16,804 patients received oral anticoagulation. Based on 372 cases and 7281 matched controls, the highest risk of bleeding in VKA users was observed for the concomitant use of antibiotics (aOR 3.00; CI 2.11-4.27) vs. VKA use alone, followed by non-steroidal anti-inflammatory drugs (1.66; 1.13-2.43). Among 243 NOAC cases and 4776 matched controls, elevated risks for bleeding were observed for the use of heparins (2.05; 1.25-3.36) and platelet inhibitors (1.92; 1.36-2.72).

CONCLUSIONS

Concomitant medication needs to be prescribed cautiously and monitored closely in nursing home residents treated with oral anticoagulants.

Comparative effectiveness of rivaroxaban versus a vitamin K antagonist in patients with renal impairment treated for non-valvular atrial fibrillation in Germany - A retrospective cohort study

Background

The risk of thromboembolic events is increased in patients with non-valvular atrial fibrillation (NVAF) and renal impairment. The risk of bleeding events is increased if these patients are treated with anticoagulants and further increased in those with active cancer.

Methods

RELOAD, a retrospective database study, assessed the outcomes of patients with NVAF prescribed rivaroxaban versus phenprocoumon. Here, we present a subgroup analysis evaluating effectiveness and safety of rivaroxaban versus phenprocoumon in patients with NVAF and renal impairment. Analyses were additionally stratified by patients with and without evidence of cancer at baseline.

Results

When using the ‘one tablet per day’ definition of estimating drug exposure time, the incidence of the primary endpoint of ischaemic stroke was significantly lower in patients (without evidence of cancer at baseline) receiving rivaroxaban 15 mg or 20 mg once daily versus those receiving phenprocoumon (2.40 vs 3.51 events per 100 patient-years, respectively; hazard ratio [HR] = 0.72, 95% confidence interval [CI] 0.55–0.94, p = 0.015); with the incidence of the primary safety outcome of intracranial haemorrhage being numerically lower (0.57 vs 0.89 events per 100 patient-years, respectively; HR = 0.66, 95% CI 0.38–1.14, p = 0.14). Similar results were observed when using the ‘empirical defined daily dose’ definition to estimate drug exposure time and when including patients with evidence of cancer.

Conclusion

The prescription of rivaroxaban in patients with NVAF and renal impairment was associated with a lower incidence of ischaemic stroke and intracranial haemorrhage versus phenprocoumon in patients without evidence of cancer.

Cost-benefit analysis of VKA versus NOAC treatment in German patients with atrial fibrillation utilizing patient self-testing

BACKGROUND

Clinical complications of long-term anticoagulation in patients with atrial fibrillation cause significant morbidity and have a substantial economic impact on the healthcare system.

OBJECTIVE

To assess the cost-benefit by implementing patient self-testing (PST) in German patients anticoagulated with vitamin K antagonists (VKA) compared to treatment with the new oral anticoagulant drugs (NOAC) apixaban, dabigatran, edoxaban, and rivaroxaban.

METHODS

A deterministic decision-analytic model was developed simulating the number of major bleedings, ischemic strokes, and hemorrhagic strokes and their associated costs by utilizing PST compared to those of treatment with NOAC. Data on the rates of these adverse events in both groups during the 1st year of treatment was taken from the NOAC approval studies. Direct costs were evaluated from the perspective of the Statutory Health Insurance (SHI) considering the use of resources directly related to PST testing and costs incurred by hospital treatment of the adverse events. Univariate sensitivity analysis was performed to examine the extent to which our calculations were affected by varying the parameters considered in our model within plausible extremes. To capture the interactions between multiple inputs, we also provided a probabilistic sensitivity analysis (PSA).

RESULTS

When achieving an average time in therapeutic range (TTR) of 78%, implementing PST in VKA patients reduces cost per patient compared to NOAC treatment between €603.38 [USD 681.52] (edoxaban) and €762.64 [USD 861.40] (rivaroxaban) during the 1-year observation period. In line with the TTR increase, the initially higher number of adverse events per VKA patient compared to NOACtreated patients in the approval studies becomes largely aligned; the difference in associated hospital costs per patient in the NOAC groups is then only €1.03 [USD 1.16] (in favor of dabigatran), €23.41 [USD 26.44] (in favor of apixaban), €0.53 [USD 0.60] (in favor of edoxaban) and €52.62 [USD 59.43] (in favor of VKA anticoagulation in the rivaroxaban group).In PSA, implementation of self-management results on average in a cost saving between €619.20 [USD 699.39] and €785.24 [USD 886.93] per VKA patient in favor of the SHI. Under all reasonable assumptions, PST remains constantly less expensive irrespective of which NOAC is administered.

CONCLUSION

Implementing PST in German VKA patients may significantly reduce SHI expenditures compared to utilizing NOAC.