Dabigatran versus warfarin in patients with mechanical heart valves

Novel Oral Anticoagulants: Efficacy, Laboratory Measurement, and Approaches to Emergent Reversal

Warfarin, the most commonly used of the vitamin K antagonists, has been a mainstay of oral anticoagulation for decades. However, its usage is limited by morbidity and mortality secondary to bleeding as well as a cumbersome therapeutic monitoring process. In the past several years, a number of competing novel oral anticoagulants (NOACs) have been developed, each of which aspires to match or exceed warfarin's effectiveness while mitigating bleeding risk and eliminating therapeutic monitoring requirements. At present, 1 oral direct thrombin inhibitor and 2 direct factor Xa inhibitors are approved by the US Food and Drug Administration. Here, we compare the clinical efficacy and safety profiles of these new drugs. In addition, we discuss various laboratory assays that may be useful to measure these drugs in certain clinical circumstances. Finally, we discuss emerging strategies to reverse these agents in an emergency. The purpose of this article is to provide a framework for practicing pathologists to advise clinicians on NOAC laboratory measurement and management of NOAC-associated bleeding.

Antithrombotic treatment and intracerebral haemorrhage: between Scylla and Charybdis

In patients who have intracerebral haemorrhage while on antithrombotic treatment, there is no evidence from randomised clinical trials to support decisions with regard to antithrombotic medication. In the acute phase, we advise stopping all antithrombotic treatment with rapid reversal of antithrombotic effects of oral anticoagulants. After the acute phase, we discourage restarting oral anticoagulants in patients with a lobar haematoma caused by cerebral amyloid angiopathy because of the high risk of recurrent bleeding. In these patients, even treatment with platelet inhibitors needs careful weighing of the risks of bleeding and ischaemic stroke. In patients with non-lobar intracerebral haemorrhage, we suggest considering restarting optimal antithrombotic treatment. This includes treatment with oral anticoagulants for patients with atrial fibrillation and/or mechanical valve prosthesis. After intracerebral haemorrhage during oral anticoagulant therapy in patients with atrial fibrillation, direct anticoagulants may be better than vitamin K antagonists, but we await confirmation of this from ongoing trials.

Management of oral anticoagulation in the surgical patient

New oral anticoagulants (NOACs) have recently emerged as an alternative for vitamin K antagonists and are now widely available. Although there is good evidence for their roles in the appropriate clinical settings, so far no reversal agent is currently available. Likewise, there is no readily available laboratory test to quantify drug levels but coagulation assays may provide qualitative information about the presence of some NOACs. We aim to review the current literature regarding the optimal management of oral anticoagulation in the perioperative setting.

Dabigatran for the prevention and treatment of thromboembolic disorders

Dabigatran, an oral direct thrombin inhibitor, was the first of a new class of drugs referred to as non-vitamin K oral anticoagulants. Dabigatran is better than warfarin for stroke prevention in non-valvular atrial fibrillation (dose of 150 mg twice a day), non-inferior to enoxaparin for venous thromboembolism prevention after orthopedic surgery and non-inferior to warfarin in preventing recurrence after acute venous thromboembolism. The safety profile is similar to standard anticoagulants, with significant reduction observed in intracranial hemorrhage. Other advantages include a rapid onset of action and a predictable pharmacokinetic profile, allowing a fixed-dose regimen without the need for routine anticoagulation monitoring. In the event of bleeding, general support measures are recommended and if severe, the use of non-specific hemostatic agents such as prothrombin complex concentrates and recombinant factor VIIa must be considered. A specific reversal agent (idarucizumab) is in development.

[Prospective study of the new oral anticoagulants in private practice: cautious optimism]

BACKGROUND

The new direct oral anticoagulants (DOA) such as dabigatran, rivaroxaban or apixaban are an evolution in the management of patients requiring curative anticoagulation. However, behind the simplicity of prescribing and monitoring, several questions remain about their daily use. The aim of this prospective study was to measure the feelings of general practitioners (GP), angiologists (AP) and cardiologists (CP), potential prescribers of this new anticoagulant family.

METHOD

Between December 2012 and May 2013, a questionnaire including five open questions and 11 questions using a positioning on an analogic visual scale (AVS 0 to 10) was subjected to GP, AP and CP in Alsace.

RESULTS

Responses from 224 physicians (150 GP, 35 AP and 39 CP) were collected. Thus, 83% of GP, 83% of AP and 100% of CP were prescribers of DOA. However, among these prescribing doctors, the feeling was not the same and the trend of prescription was lower in GP (2.0 [1.1-3.2] AVS units) than in AP (3.1 [2.0-5.6]) and in CP (5.0 [1.2-8.7]) (P<0.0001 in multivariate analysis). The female doctors tended to prescribe DOA in younger patients than male doctors (respectively 66.1 [52.5-76.7] vs. 75.0 [65.7-81.0] years; P=0.004). The DOA were more considered as progress by AP and CP (respectively 7.8 [5.3-9.0] and 7.9 [7.0-8.7] AVSu) than by GP (6.1 [4.8-8.2] AVSu; P=0.02 in multivariate analysis). The answer about the eventual replacement of vitamin K antagonists by the DOA was very mixed whatever the practitioner group (5.1 [3.0-7.8] AVSu; P=0.139). The ease to use and the lack of biological monitoring were the main arguments leading to the prescription but the attitude of practitioners was very balanced by the lack of experience on the bleeding risk and the lack of available antidote.

CONCLUSIONS

If the DOA are considered as an improvement for the physicians, the enthusiasm remains cautious whatever the type of practiced medicine. The results of clinical trials and the clinical experience should better appreciate the ongoing change in the field of anticoagulation.

Overview of the new oral anticoagulants: opportunities and challenges

The non-vitamin K antagonist oral anticoagulants (NOACs) are replacing warfarin for many indications. These agents include dabigatran, which inhibits thrombin, and rivaroxaban, apixaban, and edoxaban, which inhibit factor Xa. All 4 agents are licensed in the United States for stroke prevention in atrial fibrillation and for treatment of venous thromboembolism and rivaroxaban and apixaban are approved for thromboprophylaxis after elective hip or knee arthroplasty. The NOACs are at least as effective as warfarin, but are not only more convenient to administer because they can be given in fixed doses without routine coagulation monitoring but also are safer because they are associated with less intracranial bleeding. As part of a theme series on the NOACs, this article (1) compares the pharmacological profiles of the NOACs with that of warfarin, (2) identifies the doses of the NOACs for each approved indication, (3) provides an overview of the completed phase III trials with the NOACs, (4) briefly discusses the ongoing studies with the NOACs for new indications, (5) reviews the emerging real-world data with the NOACs, and (6) highlights the potential opportunities for the NOACs and identifies the remaining challenges.

Antiplatelet and anticoagulant therapy after intracerebral hemorrhage

Management of patients with an indication for long-term oral antithrombotic therapy who have an intracerebral hemorrhage (ICH) presents a therapeutic dilemma. Should antithrombotic therapy be resumed, and if so, when, using what agent, and for whom? There is no consensus for answers to these questions. In the absence of randomized trials, management of antithrombotic therapy after ICH is based on a combination of observational data, pathophysiologic concepts, and decision analysis. At the heart of the decision is an assessment of the individual patient's risk of thromboembolism off antithrombotic therapy versus risk of ICH recurrence on antithrombotic therapy.

[Oral anticogulation for non-valvular atrial fibrilation in the elderly]

Anticoagulation in elderly people with non-valvular atrial afibrillation (AF) is a challenge, due to the thromboembolic, as well as the haemorrhagic risks. The correct use of anticoagulants in these patients has shown a higher net clinical benefit when comparing it with a younger population. Non-vitamin K antagonist oral anticoagulants (NOACs) have been compared to oral vitamin K antagonists in several studies that included a sufficient number of elderly people. Favourable results for non-vitamin K antagonist oral anticoagulants were obtained in these studies, making them the preferred treatment for this group of patients. Basing the estimations on indirect comparisons, the ideal anticoagulant and the specific dose for each particular case has been determined. Finally, a new algorithm has been developed that relates these parameters. Geriatric assessment is the key to the indication for an anticoagulation, the type of anticoagulant needed, and also the best way to optimise all the factors for a safe anticoagulation. The arrival of non-vitamin K antagonist oral anticoagulants will enhance the efficient thromboembolic prophylaxis rate in elderly people with AF. This new treatment will remove different controversial prophylaxis, such as antiaggregants.

Management of atrial fibrillation: What is new in the 2014 ACC/AHA/HRS guideline?

Recently, the American College of Cardiology, the American Heart Association, and the Heart Rhythm Society published an updated guideline on the management of atrial fibrillation (AF). This document is a complete revision of the 2006 guideline. Prominent changes in the 2014 guideline include the use of the CHA2DS2-VASc score for risk stratification of stroke, recommendations on when and how to use newer oral anticoagulants for thromboprophylaxis, downgrading of the use of aspirin for thromboprophylaxis of moderate-risk patients, and the use of catheter ablation in selected patients as first-line therapy for paroxysmal AF. In regard to rate control, the 2014 guideline reverts back to a previous recommendation for stricter targets for mean and maximum heart rate on therapy. The current guideline incorporates many recent trials in updating existing recommendations from the 2006 guideline. The 2014 guideline will be a vital tool in guiding physicians in the management of AF.

The association of direct thrombin inhibitor anticoagulants with cardiac thromboses

Direct thrombin inhibitor (anti-factor IIa) anticoagulants, now established for treatment and prevention of cardiac thromboembolism and VTE, have been repeatedly associated with a significantly increased frequency of thrombosis on abnormal cardiac endothelium when compared head-to-head with indirectly acting therapeutic anticoagulants in studies of sufficient patient number and duration. Although there is uncertainty as to the mechanism, the weight of evidence as a class effect warrants prescribing effective anticoagulants other than direct thrombin inhibitors.

Update for 2014 on clinical cardiology, geriatric cardiology, and heart failure and transplantation

In the present article, we review publications from the previous year in the following 3 areas: clinical cardiology, geriatric cardiology, and heart failure and transplantation. Among the new developments in clinical cardiology are several contributions from Spanish groups on tricuspid and aortic regurgitation, developments in atrial fibrillation, syncope, and the clinical characteristics of heart disease, as well as various studies on familial heart disease and chronic ischemic heart disease. In geriatric cardiology, the most relevant studies published in 2014 involve heart failure, degenerative aortic stenosis, and data on atrial fibrillation in the geriatric population. In heart failure and transplantation, the most noteworthy developments concern the importance of multidisciplinary units and patients with preserved systolic function. Other notable publications were those related to iron deficiency, new drugs, and new devices and biomarkers. Finally, we review studies on acute heart failure and transplantation, such as inotropic drugs and ventricular assist devices.

Cardiological aspects of stroke prevention

Many cardiac disorders and their treatment are associated with an increased risk for ischemic or hemorrhagic stroke, so it is important for cardiologists to be aware of recent advances in the field of stroke prevention. Atrial fibrillation (AF) is the most common cardiac disorder associated with a substantial risk for ischemic stroke (IS). The availability of implantable cardiac monitoring devices has substantially increased the detection rate of occult AF after IS. The 4 new oral anticoagulants have advantages when compared with warfarin, the standard therapy in AF to prevent IS, demonstrating a reduced risk for IS or intracerebral hemorrhage. Patients with cardiomyopathy, cardiac valve replacement, recent myocardial infarction, larger aortic arch atheroma and patent foramen ovale all have some level of increased risk for IS. The best approach for IS prevention in these disorders remains unsettled and varying approaches are recommended.

Left atrial thrombus formation and resolution during dabigatran therapy: A Japanese Heart Rhythm Society report

BACKGROUND

Protocols on the use of novel oral anticoagulants for stroke prevention in patients with atrial fibrillation (AF) undergoing electrical cardioversion (ECV) are lacking.

AIM

The study was aimed at evaluating the efficacy of dabigatran (Dabi) treatment in preventing peri-ECV stroke.

METHODS

A retrospective survey of the incidence and fate of left atrial (LA) thrombus during Dabi therapy in patients with AF was conducted between December 2012 and January 2013 by the Japanese Heart Rhythm Society.

RESULTS

A total of 198 patients from 299 institutions underwent transesophageal echocardiography (TEE) to rule out LA thrombus before ECV. Of these, LA thrombus was found in eight patients (4%), who tended to be older (67.3 vs. 61.3 years, p=0.175), had higher CHADS2 scores (1.88 vs. 0.95, p=0.058), and a higher prevalence of prior stroke or transient ischemic attack (22.2% vs. 2.6%, p=0.034) than those without LA thrombus. Of the eight patients with LA thrombus, one had LA thrombus during a Dabi 150 mg b.i.d treatment, whereas the remaining seven were receiving 110 mg b.i.d for 3 weeks or longer. In 6 of the 8 patients with LA thrombus, a second TEE was performed, revealing complete resolution of LA thrombus in five; among these five patients, one received Dabi dosage of 150 mg b.i.d unchanged, two received an increased dosage from 110 mg to 150 mg b.i.d, and two were switched to warfarin. Two patients had a stroke 3 and 15 days after ECV, and one had a major large intestine bleeding episode during Dabi therapy.

CONCLUSIONS

LA thrombus developed in 4% of patients with AF receiving Dabi. Older patients with a higher CHADS2 score receiving a lower Dabi dosage were more likely to develop LA thrombus, which was resolved with a prolonged or increased dosage. A higher Dabi dosage may be more beneficial before ECV but prospective randomized studies would be needed to confirm these results.

Advances in stroke prevention

Stroke remains to be a leading cause of disability. However, optimal strategies can prevent up to 80% of strokes. A large body of evidence supports many strategies for primary and secondary prevention of stroke. The purpose of this paper is to highlight recent major advances for management of modifiable medical and behavioral risk factors of stroke. Specific studies are highlighted, including those related to atrial fibrillation (AF), hypertension, revascularization, hyperlipidemia, antiplatelets, smoking, diet, and physical activity. Effective strategies include the use of novel oral anticoagulants for AF, antiplatelet therapy, and intensive lowering of atherosclerosis risk factors.

A network of pulmonary vein thrombi is a risk factor for ischemic stroke, especially after cardiac surgery: A case report and mini review

Stroke remains a devastating complication following cardiac surgery. Pulmonary vein thrombi (PVT) are believed to be rare, but I have reported 37 cases of PVT in elderly patients with chest pain since 2012, indicating that PVT are not unusual. The present case showed that PVT can make a network among four pulmonary veins and left atrium. Currently, PVT are not recognized as a risk factor for ischemic stroke, especially following cardiac surgery.

A 76-year-old male was examined by 64-slice multidetector CT (64-MDCT) to assess chest pain. The 64-MDCT scan revealed thrombi in the left upper and lower pulmonary veins, the right upper and lower pulmonary veins and the left atrium (LA) as the defects of contrast enhancements. The LA thrombi seemed to be connected to PVT forming a network of thrombi.

To avoid stroke following cardiac surgery, it is important to cope with PVT. How to treat PVT during cardiac surgery should be developed.

Oral anticoagulation: a critique of recent advances and controversies

There have recently been significant advances in the field of oral anticoagulation, but these have also led to many controversies. Warfarin is still the commonest drug used for clotting disorders but its use is complicated owing to wide inter-individual variability in dose requirement and its narrow therapeutic index. Warfarin dose requirement can be influenced by both genetic and environmental factors. Two recent randomized controlled trials (RCTs) came to different conclusion regarding the utility of genotype-guided dosing; we critically explore the reasons for the differences. The new generation of oral anticoagulants have been demonstrated to be as efficacious as warfarin, but further work is needed to evaluate their safety in real clinical settings.

Transitioning to and from the novel oral anticoagulants: a management strategy for clinicians

Vitamin K antagonists have been the only available oral anticoagulant therapy for decades until the recent introduction of novel (new) oral anticoagulants. This breakthrough provides patients with alternative treatment choices that have predictable pharmacokinetics and do not require routine coagulation monitoring. Though more convenient from patient perspective, these drugs have distinct pharmacological properties that are particularly important to recognize when transitioning anticoagulant therapies. The following review focuses on transitioning to and from the novel oral anticoagulants, employing a practical pharmacokinetic- and pharmacodynamic-based approach.

Novel oral anticoagulants and valvular atrial fibrillation: are they always contraindicated?

Atrial fibrillation (AF) is the most common sustained cardiac dysrhythmia, and is associated with an increased risk of death, stroke, and other thromboembolic events. Valvular heart disease (VHD) frequently coexists with AF, mostly in elderly patients. After the introduction of novel oral anticoagulants (NOACs) approved for the prevention of stroke in non-valvular atrial fibrillation (NVAF) on the basis of recent trials, the importance of a universal definition of NVAF was raised in clinical practice. In the most recent guidelines, the term valvular AF is used to imply that AF is related to rheumatic valvular disease (predominantly mitral stenosis), or prosthetic heart valves. In all the trials comparing NOACs and warfarin, a significant percentage of patients presented any type of VHD, excluding rheumatic mitral stenosis and mechanical heart valve. The subgroups analysis performed, so far showed no significant differences in terms of efficacy in the VHD subgroup compared to the general AF population. A restrictive definition of valvular AF (i.e., rheumatic mitral stenosis and mechanical heart valve) seems to be the most appropriate to contraindicate treatment with NOACs for AF thromboprophylaxis. In the remaining AF patients with significant valvular disease who per se would not require oral anticoagulation, NOACs should be allowed.

Quality of oral anticoagulation with phenprocoumon in regular medical care and its potential for improvement in a telemedicine-based coagulation service--results from the prospective, multi-center, observational cohort study thrombEVAL

BACKGROUND

The majority of studies on quality of oral anticoagulation (OAC) therapy with vitamin K-antagonists are performed with short-acting warfarin. Data on long-acting phenprocoumon, which is frequently used in Europe for OAC therapy and is considered to enable more stable therapy adjustment, are scarce. In this study, we aimed to assess quality of OAC therapy with phenprocoumon in regular medical care and to evaluate its potential for optimization in a telemedicine-based coagulation service.

METHODS

In the prospective observational cohort study program thrombEVAL we investigated 2,011 patients from regular medical care in a multi-center cohort study and 760 patients from a telemedicine-based coagulation service in a single-center cohort study. Data were obtained from self-reported data, computer-assisted personal interviews, and laboratory measurements according to standard operating procedures with detailed quality control. Time in therapeutic range (TTR) was calculated by linear interpolation method to assess quality of OAC therapy. Study monitoring was carried out by an independent institution.

RESULTS

Overall, 15,377 treatment years and 48,955 international normalized ratio (INR) measurements were analyzed. Quality of anticoagulation, as measured by median TTR, was 66.3% (interquartile range (IQR) 47.8/81.9) in regular medical care and 75.5% (IQR 64.2/84.4) in the coagulation service (P <0.001). Stable anticoagulation control within therapeutic range was achieved in 63.8% of patients in regular medical care with TTR at 72.1% (IQR 58.3/84.7) as compared to 96.4% of patients in the coagulation service with TTR at 76.2% [(IQR 65.6/84.7); P = 0.001)]. Prospective follow-up of coagulation service patients with pretreatment in regular medical care showed an improvement of the TTR from 66.2% (IQR 49.0/83.6) to 74.5% (IQR 62.9/84.2; P <0.0001) in the coagulation service. Treatment in the coagulation service contributed to an optimization of the profile of time outside therapeutic range, a 2.2-fold increase of stabile INR adjustment and a significant decrease in TTR variability by 36% (P <0.001).

CONCLUSIONS

Quality of anticoagulation with phenprocoumon was comparably high in this real-world sample of regular medical care. Treatment in a telemedicine-based coagulation service substantially improved quality of OAC therapy with regard to TTR level, frequency of stable anticoagulation control, and TTR variability.

TRIAL REGISTRATION

ClinicalTrials.gov, unique identifier NCT01809015, March 8, 2013.

Novel oral anticoagulants: what dermatologists need to know

The development of novel oral anticoagulants provides clinicians and patients a welcome alternative to the challenges of warfarin therapy. Dermatologists must be aware of the potential impact of novel oral anticoagulants on their surgical and medical practice. This review provides a concise summary of the novel oral anticoagulants for dermatologists with particular emphasis on: (1) the pharmacokinetic properties of these drugs and how they differ from warfarin, (2) suggested management during cutaneous surgery, (3) adverse drug interactions with commonly prescribed medications in dermatology, and (4) potential use within dermatology for treatment of disorders of cutaneous thrombosis.

Mechanical circulatory support: balancing bleeding and clotting in high-risk patients

Mechanical circulatory support (MCS) provides a bridge to heart transplant in children and adults with life-threatening heart failure and sustains patients ineligible for transplant. Extracorporeal membrane oxygenation (ECMO) provides temporary support for patients in cardiac or pulmonary failure through external gas exchange and continuous flow of blood. Because the median time to heart transplant exceeds event-free time on ECMO, pulsatile left ventricular assist devices (LVADs) are used to support infants and children. Continuous flow LVADs are preferred in adolescents and adults due to increased pump durability and improved overall survival. The shear stress created by the mechanical pumps cause changes in the hematologic system; acquired von Willebrand syndrome occurs in almost all patients treated with MCS. Despite the improvements in survival, major bleeding occurs in one-third of patients with a LVAD and ischemic stroke and LVAD thrombosis can affect 12% of adults and 29% of children. An antithrombotic strategy to mitigate LVAD bleeding and thrombotic complications has been tested in a randomized trial in children, but intensity of antithrombotic therapy in adults varies widely. Consensus guidelines for antithrombotic therapy during ECMO were created due to significant differences in management across centers. Because of the high risk for both bleeding and thrombotic complications, experts in hemostasis can significantly impact care of patients requiring mechanical circulatory support and are a necessary part of the management team.

VAD therapy 20/20: moving beyond the myopic view of a nascent therapy

The past five years have seen remarkable growth in the use of durable, continuous flow left ventricular assist devices (LVAD) with associated improvements in mortality, quality of life, functionality and end-organ function. To sustain the growth of this important therapy, the LVAD community must now address key issues focused around the costs of LVAD care, refined patient selection, and reducing complications associated with this therapy. In this perspective piece, we discuss many of these issues.

Future prospects for contact factors as therapeutic targets

Anticoagulants currently used in clinical practice to treat or prevent thromboembolic disease are effective, but place patients at increased risk for serious bleeding because they interfere with plasma enzymes (thrombin and factor Xa) that are essential for hemostasis. In the past 10 years, work with genetically altered mice and studies in baboons and rabbits have demonstrated that the plasma contact proteases factor XI, factor XII, and prekallikrein contribute to the formation of occlusive thrombi despite having limited roles in hemostasis. In the case of factor XI, epidemiologic data from human populations indicate that elevated levels of this protein increase risk for stroke and venous thromboembolism and may also influence risk for myocardial infarction. These findings suggest that inhibiting contact activation may produce an antithrombotic effect without significantly compromising hemostasis. This chapter reviews strategies that are being developed for therapeutic targeting of factor XI and factor XII and their performances in preclinical and early human trials.

Prevention and treatment of venous thromboembolism in patients with cancer

Robust evidence remains scarce in guiding best practice in the prevention and treatment of venous thromboembolism in patients living with cancer. Recommendations from major consensus guidelines are largely based on extrapolated data from trials performed mostly in noncancer patients, observational studies and registries, studies using surrogate outcomes, and underpowered randomized controlled trials. Nonetheless, a personalized approach based on individual risk assessment is uniformly recommended for inpatient and outpatient thromboprophylaxis and there is consensus that anticoagulant prophylaxis is warranted in selected patients with a high risk of thrombosis. Prediction tools for estimating the risk of thrombosis in the hospital setting have not been validated, but the use of prophylaxis in the ambulatory setting in those with a high Khorana score is under active investigation. Symptomatic and incidental thrombosis should be treated with anticoagulant therapy, but little is known about the optimal duration. Pharmacologic options for prophylaxis and treatment are still restricted to unfractionated heparin, low molecular weight heparin, and vitamin K antagonists because there is currently insufficient evidence to support the use of target-specific, non-vitamin K-antagonist oral anticoagulants. Although these agents offer practical advantages over traditional anticoagulants, potential drug interaction with chemotherapeutic agents, gastrointestinal problems, hepatic and renal impairment, and the lack of rapid reversal agents are important limitations that may reduce the efficacy and safety of these drugs in patients with active cancer. Clinicians and patients are encouraged to participate in clinical trials to advance the care of patients with cancer-associated thrombosis.

Guidelines for the primary prevention of stroke: a statement for healthcare professionals from the American Heart Association/American Stroke Association

The aim of this updated statement is to provide comprehensive and timely evidence-based recommendations on the prevention of stroke among individuals who have not previously experienced a stroke or transient ischemic attack. Evidence-based recommendations are included for the control of risk factors, interventional approaches to atherosclerotic disease of the cervicocephalic circulation, and antithrombotic treatments for preventing thrombotic and thromboembolic stroke. Further recommendations are provided for genetic and pharmacogenetic testing and for the prevention of stroke in a variety of other specific circumstances, including sickle cell disease and patent foramen ovale.

Sex differences in treatment quality of self-managed oral anticoagulant therapy: 6,900 patient-years of follow-up

Background

Patient-self-management (PSM) of oral anticoagulant therapy with vitamin K antagonists has demonstrated efficacy in randomized, controlled trials. However, the effectiveness and efficacy of PSM in clinical practice and whether outcomes are different for females and males has been sparsely investigated.The objective is to evaluate the sex-dependent effectiveness of PSM of oral anticoagulant therapy in everyday clinical practice.

Methods

All patients performing PSM affiliated to Aarhus University Hospital and Aalborg University Hospital, Denmark in the period 1996–2012 were included in a case-series study. The effectiveness was estimated using the following parameters: stroke, systemic embolism, major bleeding, intracranial bleeding, gastrointestinal bleeding, death and time spent in the therapeutic international normalized ratio (INR) target range. Prospectively registered patient data were obtained from two databases in the two hospitals. Cross-linkage between the databases and national registries provided detailed information on the incidence of death, bleeding and thromboembolism on an individual level.

Results

A total of 2068 patients were included, representing 6,900 patient-years in total. Males achieved a significantly better therapeutic INR control than females; females spent 71.1% of the time within therapeutic INR target range, whereas males spent 76.4% (p<0.0001). Importantly, death, bleeding and thromboembolism were not significantly different between females and males.

Conclusions

Among patients treated with self-managed oral anticoagulant therapy, males achieve a higher effectiveness than females in terms of time spent in therapeutic INR range, but the incidence of major complications is low and similar in both sexes.