Cessation of oral anticoagulation in relation to mortality and the risk of thrombotic events in patients with atrial fibrillation

Clinical outcomes of oral anticoagulant discontinuation in atrial fibrillation: a systematic review and meta-analysis

INTRODUCTION

Oral anticoagulants (OACs) should generally be continued lifelong in patients with atrial fibrillation (AF) to ensure optimal benefits, unless contraindications arise. However, discontinuation of OACs might occur for various reasons, potentially affecting clinical outcomes. In this review, we synthesized evidence on the clinical outcomes following OAC discontinuation in patients with AF.

METHODS

We conducted a systematic review and meta-analysis using PubMed, Embase and Scopus. Cohort or case-control studies were included if data were available on clinical outcomes of OAC discontinuation, compared with continuation, in patients with AF. A random-effect meta-analyses were conducted for key outcomes of stroke, mortality, and major bleeding.

RESULTS

Eighteen observational studies having a total of 283,418 patients were included. Discontinuation significantly increased the risk of stroke (hazard ratio [HR] 1.88; 95% confidence interval [CI] 1.58-2.23), all-cause (HR 1.90; 95% CI 1.40-2.59) and cardiovascular (HR 1.83; 95% CI 1.06-3.18) mortality. The risk of major bleeding was not significantly different between the discontinued and continued groups (HR 1.04; 95% CI 0.72-1.52).

CONCLUSIONS

Discontinuation of OAC therapy was associated with an increased risk of stroke and mortality, with no difference in the risk of major bleeding. Acknowledging heterogeneity among the studies, the findings underline the need to ensure continuity of OAC therapy in patients with AF to prevent thrombotic complications and associated mortality.

PROSPERO REGISTRATION NUMBER

CRD42020186116.

Impact of treatment adherence on the effectiveness and safety of oral anticoagulants in patients with atrial fibrillation: a retrospective cohort study

AIMS

The impact of adherence to oral anticoagulation has not been reported in terms of absolute risk, which would enhance patients' understanding and treatment adherence.

METHODS AND RESULTS

This retrospective cohort study analysed data from the National Health Insurance Database of Korea, from January 2010 to December 2018, on 84 227 patients with non-valvular atrial fibrillation (NVAF). The participants were analysed according to their overall adherence to oral anticoagulants (OACs) and further divided into four groups: non-vitamin K antagonist oral anticoagulant (NOAC) adherent, vitamin K antagonist (VKA) adherent, NOAC non-adherent, and VKA non-adherent. The incidence of ischaemic stroke, major bleeding, and death was compared between the four groups using risk difference, number needed to treat and number needed to harm. Among the participants, 50 178 were adherent to (OACs), while 34 049 were non-adherent. The incidence of major bleeding was higher in the adherent group (4.49%; 95% confidence interval, 4.11-4.85%) than in the non-adherent group (3.61%; 3.16-4.06%), and the incidence of ischaemic stroke was higher in the non-adherent group (7.68%; 7.08-8.33%) than in the adherent group (5.61%; 5.17-6.07%). In terms of risk difference, adherence to OACs increased the risk of major bleeding by 0.87% and decreased the risk of ischaemic stroke by 2.08%. This finding suggests that one additional major bleeding event occurred for every 115 adherent patients, and one additional ischaemic stroke event was prevented for every 48 adherent patients.

CONCLUSION

The benefits of OAC adherence in NVAF patients for ischaemic stroke prevention exceeding the risk of bleeding are shown more clearly in terms of absolute risk.

A comparison of front-line oral anticoagulants for the treatment of non-valvular atrial fibrillation: Effectiveness and safety of direct oral anticoagulants in the FANTASIIA registry

INTRODUCTION

For a long time, vitamin K antagonists (VKA) were the only oral anticoagulation therapy available to reduce adverse events in atrial fibrillation (AF) patients. Direct-acting oral anticoagulants (DOAC) are at least as effective and safe as VKA with few drug interactions, rapid onset and short half-life. Four DOACs, dabigatran, apixaban, rivaroxaban and edoxaban have demonstrated efficacy and safety for treatment in AF patients.

AREAS COVERED

The purpose of this review article is to analyze the current evidence in clinical trials and in real-world populations and performed a new analysis with the estimated effect of those DOACs over the VKA population from the FANTASIIA registry. We present in this manuscript original data analysis from FANTASIIA population as well as data obtained through a search of PubMed for the clinical trials comparing DOAC in the main randomized trials of each DOAC and observational data of the real-world effects of DOACs compared to VKAs.

EXPERT OPINION

In the absence of randomized, controlled head-to-head comparisons between DOACs, high-quality observational data can provide useful information on the comparative effectiveness of DOACs. Current clinical guidelines recommend the management of oral anticoagulation in AF patients with DOACs over VKA for stroke prevention; however, many guidelines generally do not suggest a specific DOAC choice in clinical practice. The revised evidence in this manuscript and our real experience reflects that apixaban and dabigatran show the best efficacy and safety profile.

Discontinuation of direct oral anticoagulants among patients with atrial fibrillation according to gender and cohabitation status: a nationwide cohort study

AIMS

The aim of this study was to evaluate the risk of discontinuing treatment with direct oral anticoagulants (DOACs) among patients with atrial fibrillation (AF) according to cohabitation status and gender.

METHODS AND RESULTS

Using the Danish national registers, we identified 32 364 patients with AF aged 40-90 years undergoing treatment with DOACs. The study period was from 2013 to 2017, and patients were followed for 2 years, or until death, outcome, or emigration. The main outcome was discontinuation of DOAC treatment for at least 30 days. The absolute 2-year risk of DOAC discontinuation was highest among men living alone [35.7%, 95% confidence interval (CI): 37.3-34.1%]. Men living alone had a 4.6% (95% CI: 6.4-2.8%) higher absolute risk of discontinuation and a 12% [hazard ratio (HR): 1.12, 95% CI: 1.04-1.20] higher relative risk of discontinuation compared with men living with a partner. Female patients living alone likewise had a higher absolute risk of DOAC discontinuation (2.6%, 95% CI: 4.4-0.09%) compared with female patients living with a partner, yet no statistically significant difference in relative risk. In an analysis evaluating gender, we found male gender to be associated with a significantly higher relative risk of DOAC discontinuation (HR: 1.33, 95% CI: 1.26-1.40) compared with female gender (P-value for interaction with cohabitant status = 0.5996).

CONCLUSION

In this nationwide population study, male gender and living alone were associated with a higher risk of DOAC discontinuation among patients with AF.

Risks associated with discontinuation of oral anticoagulation in newly diagnosed patients with atrial fibrillation: Results from the GARFIELD-AF Registry

BACKGROUND

Oral anticoagulation (OAC) in atrial fibrillation (AF) reduces the risk of stroke/systemic embolism (SE). The impact of OAC discontinuation is less well documented.

OBJECTIVE

Investigate outcomes of patients prospectively enrolled in the Global Anticoagulant Registry in the Field-Atrial Fibrillation study who discontinued OAC.

METHODS

Oral anticoagulation discontinuation was defined as cessation of treatment for ≥7 consecutive days. Adjusted outcome risks were assessed in 23 882 patients with 511 days of median follow-up after discontinuation.

RESULTS

Patients who discontinued (n = 3114, 13.0%) had a higher risk (hazard ratio [95% CI]) of all-cause death (1.62 [1.25-2.09]), stroke/systemic embolism (SE) (2.21 [1.42-3.44]) and myocardial infarction (MI) (1.85 [1.09-3.13]) than patients who did not, whether OAC was restarted or not. This higher risk of outcomes after discontinuation was similar for patients treated with vitamin K antagonists (VKAs) and direct oral anticoagulants (DOACs) (p for interactions range = 0.145-0.778). Bleeding history (1.43 [1.14-1.80]), paroxysmal vs. persistent AF (1.15 [1.02-1.29]), emergency room care setting vs. office (1.37 [1.18-1.59]), major, clinically relevant nonmajor, and minor bleeding (10.02 [7.19-13.98], 2.70 [2.24-3.25] and 1.90 [1.61-2.23]), stroke/SE (4.09 [2.55-6.56]), MI (2.74 [1.69-4.43]), and left atrial appendage procedures (4.99 [1.82-13.70]) were predictors of discontinuation. Age (0.84 [0.81-0.88], per 10-year increase), history of stroke/transient ischemic attack (0.81 [0.71-0.93]), diabetes (0.88 [0.80-0.97]), weeks from AF onset to treatment (0.96 [0.93-0.99] per week), and permanent vs. persistent AF (0.73 [0.63-0.86]) were predictors of lower discontinuation rates.

CONCLUSIONS

In GARFIELD-AF, the rate of discontinuation was 13.0%. Discontinuation for ≥7 consecutive days was associated with significantly higher all-cause mortality, stroke/SE, and MI risk. Caution should be exerted when considering any OAC discontinuation beyond 7 days.

Continuation or discontinuation of oral anticoagulants after HAS-BLED scores increase in patients with atrial fibrillation

BACKGROUND

The bleeding risk profile of patients with atrial fibrillation (AF) may change over time, and the increment of HAS-BLED score is perceived to result in discontinuations of oral anticoagulants (OACs).

OBJECTIVES

To investigate the changes of HAS-BLED scores of AF patients initially with a low bleeding risk. The associations between continuation or discontinuation of OACs and clinical outcomes after patients' bleeding risk profile worsened (ie HAS-BLED increased) were studied.

METHODS

The present study used Taiwan nationwide health insurance research database. From year 2000 to 2015, a total of 24,990 AF patients aged ≥ 20 years with a CHA₂DS₂-VASc score  ≥ 1 (males) or  ≥ 2 (females) having an HAS-BLED score of 0-2 who were treated with OACs were identified and followed up for changes of the HAS-BLED scores. Patients who did not refill OACs within 90 days after their HAS-BLED scores increased to  ≥ 3 were defined as discontinuations of OACs. The risks of clinical outcomes were compared between patients who continued or stopped OACs once their HAS-BLED scores increased to  ≥ 3.

RESULTS

Mean HAS-BLED score of study population increased from 1.54 to 3.33. At end of 1 year, 5,229 (20.9%) patients had an increment of their HAS-BLED scores to  ≥ 3, mainly due to newly diagnosed hypertension, stroke, bleeding, and concomitant drug therapies. Among 4777 patients who consistently had an HAS-BLED score  ≥ 3, 1,062 (22.2%) stopped their use of OACs. Patients who kept on OACs (n = 3715; 77.8%) even after their HAS-BLED scores increased to ≥ 3 were associated with a lower risk of ischemic stroke (aHR 0.60, 95%CI 0.53-0.69), major bleeding (aHR 0.78, 95%CI 0.67-0.91), all-cause mortality (aHR 0.88, 95%CI 0.79-0.97), and any adverse events (aHR 0.75, 95%CI 0.68-0.82) adjusted for age, sex, heart failure, and HAS-BLED score. These results were consistent among the cohorts after propensity matching.

CONCLUSIONS

For patients whose HAS-BLED scores increased to ≥ 3, the continuation of OACs was associated with better clinical outcomes. An increased HAS-BLED score in anticoagulated AF patients may not be the only reason to withhold OACs, but reminds physicians to correct modifiable bleeding risk factors and follow up patients more closely. Associations between Continuation or Discontinuation of Oral Anticoagulants and Risks of Clinical Outcomes after HAS-BLED Scores Increased AF atrial fibrillation; aHR adjusted hazard ratio; ICH intra-cranial hemorrhage; OACs oral anticoagulants.

Compliance of atrial fibrillation treatment with the ABC pathway in patients with concomitant diabetes mellitus in the Middle East based on the Gulf SAFE registry

INTRODUCTION

Atrial fibrillation (AF) and diabetes mellitus (DM) constitute a heavy burden on healthcare expenditure due to their negative impact on clinical outcomes in the Middle East. The Atrial fibrillation Better Care (ABC) pathway provides a simple strategy of integrated approach of AF management: A-Avoid stroke; B-Better symptom control; C-Cardiovascular comorbidity risk management.

AIMS

Evaluation of the AF treatment compliance to ABC pathway in DM patients in the Middle East. Assessment of the impact of ABC pathway adherence on all-cause mortality and the composite outcome of stroke/systemic embolism, all-cause death and cardiovascular hospitalisations.

METHODS

From 2043 patients in the Gulf SAFE registry, 603 patients (mean age 63; 48% male) with DM were included in an analysis of ABC pathway compliance: A-appropriate use of anticoagulation according to CHA₂ DS₂ -VASc score; B-AF symptoms management according to the European Heart Rhythm Association (EHRA) scale; C-Optimised cardiovascular comorbidities management.

RESULTS

86 (14.3%) patients were treated in compliance with the ABC pathway. During 1-year follow-up, 207 composite outcome events and 87 deaths occurred. Mortality was significantly lower in the ABC group vs non-ABC (5.8% vs 15.9%, P = .0014, respectively). On multivariate analysis, ABC compliance was associated with a lower risk of all-cause death and the composite outcome after 6 months (OR 0.18; 95% CI: 0.42-0.75 and OR 0.54; 95% Cl: 0.30-1.00, respectively) and at 1 year (OR 0.30; 95% Cl: 0.11-0.76 and OR 0.57; 95% Cl: 0.33-0.97, respectively) vs the non-ABC group.

CONCLUSIONS

Compliance with the ABC pathway care was independently associated with the reduced risk of all-cause death and the composite outcome in DM patients with AF, highlighting the importance of an integrated approach to AF management.

Atrial Fibrillation and Stroke

Atrial fibrillation (AF) is the most common cardiac arrythmia and a major cause of stroke, heart failure, sudden death, and cardiovascular morbidity. AF increases risk of thromboembolic stroke via stasis in the left atrium and subsequent embolization to the brain. In patients with acute ischemic stroke, it is essential that clinicians undertake careful investigation to search for AF. In these patients, up to 23.7% eventually are found to have underlying AF. Oral anticoagulation is effective in prevention of strokes secondary to AF, reducing overall stroke numbers by approximately 64%. Left atrial appendage occlusion is promising for prevention of stroke in AF.

Real-world safety and efficacy of direct oral anticoagulants in atrial fibrillation: a systematic review and meta-analysis of 605 771 patients

AIMS

To analyse the safety and efficacy of direct oral anticoagulants (DOACs) in real-world studies including atrial fibrillation (AF) patients.

METHODS AND RESULTS

Systematic review and meta-analysis of observational studies including AF patients on DOACs. Primary endpoints: any, major, gastrointestinal (GI), intracranial haemorrhage (ICH), and haemorrhagic stroke (HS). Secondary endpoints: ischaemic stroke (IS), systemic embolism (SE), myocardial infarction (MI), and all-cause of death. A set of pair-wise meta-analyses using a random effect model and a random effect network meta-analysis under a Bayesian framework were performed. Prospero registration number: CRD42019137111. We included 21 studies with 605 771 AF patients. Apixaban was associated with lower major and GI bleeding compared with Rivaroxaban [hazard ratio (HR) 2.0, 95% confidence interval (CI) 1.6-2.5] and Dabigatran (HR 1.6, 95% CI 1.3-2.1). The latter drug performed better than Rivaroxaban (HR 1.2, 95% CI 1.0-1.5). Dabigatran and Apixaban had a similar association with HS, but Apixaban performed better than Rivaroxaban (HR 1.8, 95% CI 1.1-3.0). Apixaban had a similar association with Rivaroxaban and Dabigatran for ICH, the latter drug performing better than Rivaroxaban (HR 1.3, 95% CI 1.0-1.7). Rankograms showed that Apixaban was likely to be the first-choice treatment in relation to any (65%) major (100%) and GI bleeding (100%) followed by Dabigatran (46%, 100%, 99%, respectively). Dabigatran and Apixaban had similar rank as first choice for ICH (44% and 55%) and HS (52% and 48%). DOACs showed similar association with IS/SE, MI, all-cause of death.

CONCLUSIONS

Analysis of real-world studies shows significant differences for safety among DOACs.

Statin use and mortality in atrial fibrillation: A systematic review and meta-analysis of 100,287 patients

Statins are effective for reducing cardiovascular disease in patients at risk or with cardiovascular disease. The benefit of statin therapy on adverse cardiovascular outcomes in patients with non-valvular atrial fibrillation (AF) is not clear. We performed a systematic review and meta-analysis of studies retrieved from MEDLINE via PubMed and Cochrane (CENTRAL) database of studies investigating the efficacy of statins in AF patients. The principal endpoint was all-cause mortality. Other endpoints were cardiovascular mortality, ischemic stroke, composite endpoints and any bleeding. We included 14 studies (2 post-hoc analysis of randomized clinical trials, 8 prospective and 4 retrospective) with 100,287 AF patients, of whom 23,228 were on statins. The pooled hazard ratio (HR) for all-cause mortality was 0.59 (95 % Confidence Interval [CI] 0.54-0.65). This association was consistent by aging, sex and prevalent cardiovascular or cerebrovascular disease. and the beneficial effect was evident already after 12 months of therapy. The absolute risk reduction for all-cause mortality in patients treated with statins was 10 % (95 % CI 9-10). The pooled HR for statins against cardiovascular mortality was 0.75 (95 % CI 0.58-0.96). No association was found with other secondary endpoints. Regarding bleeding events, the pooled HR for statin use was 0.60 (95 % CI 0.48-0.76). Our meta-analysis shows that in AF patients, statin therapy was associated with a reduction in all-cause and cardiovascular mortality are reduced by 41 % and 25 %, respectively. Randomized clinical trials in AF patients are necessary, as well as clarity on AF-specific LDL cholesterol targets.

Discontinuation of oral anticoagulation in atrial fibrillation and risk of ischaemic stroke

OBJECTIVE

To evaluate associations between oral anticoagulant (OAC) discontinuation and risk of ischaemic stroke (IS) among patients with atrial fibrillation (AF).

METHODS

We undertook a population-based cohort study with nested case-control analysis using UK primary care electronic health records (IQVIA Medical Research Data-UK) and linked registries from the Region of Southern Denmark (RSD). Patients with AF (76 882 UK, 41 526 RSD) were followed to identify incident IS cases during 2016-2018. Incident IS cases were matched by age and sex to controls. Adjusted ORs for OAC discontinuation (vs current OAC use) were calculated using logistic regression.

RESULTS

We identified 616 incident IS cases in the UK and 643 in the RSD. ORs for IS with any OAC discontinuation were 2.99 (95% CI 2.31 to 3.86, UK) and 2.30 (95% CI 1.79 to 2.95, RSD), for vitamin K antagonist discontinuation they were 2.38 (95% CI 1.72 to 3.30, UK) and 1.83 (95% CI 1.34 to 2.49, RSD), and for non-vitamin K antagonist oral anticoagulant discontinuation they were 4.59 (95% CI 2.97 to 7.08, UK) and 3.37 (95% CI 2.35 to 4.85, RSD). ORs were unaffected by time since discontinuation and duration of use. Annually, up to 987 IS cases in the UK and 132 in Denmark could be preventable if OAC therapy is not discontinued.

CONCLUSIONS

Our results suggest that patients with AF who discontinue OAC therapy have a significant twofold to threefold higher risk of IS compared with those who continue therapy. Addressing OAC discontinuation could potentially result in a significant reduction in AF-attributed IS.

Practice-derived data on non-vitamin K antagonist oral anticoagulant therapy to complement observations from randomized trials

Anticoagulation is fundamental in the management of patients with atrial fibrillation (AF). The study aims to provide a comparative review of the major phase III randomized clinical trials (RCTs) and real-world data (RWD) from reliable, high-grade Phase IV studies that assess the efficacy and safety of non-vitamin K antagonist oral anticoagulants (NOACs) vs. vitamin K antagonists (VKAs). Observational studies based on nationwide or health insurance database records on the use of NOACs vs. VKAs in patients with AF were included. We performed a comparison of the efficacy and safety characteristics associated with NOACs vs. VKAs in RCTs and RWD. Although RCTs provide strong support for evidence-based practice, RWD may be used to reflect the broader picture of various clinical settings, provide supplementary insight and fulfil knowledge gaps. Both study types confirmed the safety and efficacy of NOACs in preventing stroke and thromboembolism in patients with AF. In comparison to VKAs, NOACs were associated with reduced risk of ischaemic events and lower rates of adverse events such as major bleeding or intracranial haemorrhage. Administration of NOACs might be associated with increased risk of dose-related gastrointestinal bleeding and myocardial ischaemic events, especially in the early treatment period after switching from VKAs. Special care should be taken in challenging clinical situations like severe renal or hepatic impairment when the treatment regimen needs to be considered individually. Randomized clinical trial and RWD studies are complementary and present comparable findings, affirming that NOACs are safe and effective for anticoagulation of patients with AF in daily clinical practice.

Family History of Atrial Fibrillation and Risk of Cardiovascular Events: A Multicenter Prospective Cohort Study

BACKGROUND

To investigate the association between family history of atrial fibrillation (AF) with cardiovascular events (CVEs), major adverse cardiac events (MACE), and cardiovascular mortality.

METHODS

Multicenter prospective observational cohort study including 1722 nonvalvular AF patients from February 2008 to August 2019 in Italy. Family history of AF was defined as the presence of AF in a first-degree relative: mother, father, sibling, or children. Primary outcome was a composite of CVEs including fatal/nonfatal ischemic stroke and myocardial infarction, and cardiovascular death. Second, we analyzed the association with major adverse cardiac event.

RESULTS

Mean age was 74.6±9.4 years; 44% of women. Family history of AF was detected in 368 (21.4%) patients, and 3.5% had ≥2 relatives affected by AF. Age of AF onset progressively decreased from patients without family history of AF, compared with those with single and multiple first-degree affected relatives (P<0.001). During a mean follow-up of 23.7 months (4606 patients/y) 145 CVEs (3.15%/y), 98 major adverse cardiac event (2.13%/y), and 57 cardiovascular deaths (0.97%/y) occurred. After adjustment for cardiovascular risk factors, family history of AF was associated with a higher risk of CVEs (hazard ratio, 1.524 [95% CI, 1.021-2.274], P=0.039), major adverse cardiac event (hazard ratio, 1.917 [95% CI, 1.207-3.045], P=0.006), and cardiovascular mortality (hazard ratio, 2.008 [95% CI, 1.047-3.851], P=0.036). Subgroup analysis showed that this association was modified by age, sex, and prior ischemic heart disease.

CONCLUSIONS

In a cohort of elderly patients with a high atherosclerotic burden, family history of AF is evident in >20% of patients and was associated with an increased risk for CVEs and mortality. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT01882114.

A Delphi consensus on the management of oral anticoagulation in patients with non-valvular atrial fibrillation in Spain: ACOPREFERENCE study

OBJECTIVE

To evaluate the level of agreement between cardiologists regarding the management of oral anticoagulation (OAC) in patients with non-valvular atrial fibrillation (NVAF) in Spain.

MATERIALS AND METHODS

A two-round Delphi study was performed using an online survey. In round 1, panel members rated their level of agreement with the questionnaire items on a 9-point Likert scale. Item selection was based on acceptance by ≥66.6% of panellists and the agreement of the scientific committee. In round 2, the same panellists evaluated those items that did not meet consensus in round 1.

RESULTS

A total of 238 experts participated in round 1; of these, 217 completed the round 2 survey. In round 1, 111 items from 4 dimensions (Thromboembolic and bleeding risk evaluation for treatment decision-making: 18 items; Choice of OAC: 39 items; OAC in specific cardiology situations: 12 items; Patient participation and education: 42 items) were evaluated. Consensus was reached for 92 items (83%). Over 80% of the experts agreed with the use of DOACs as the initial anticoagulant treatment when OAC is indicated. Panellists recommended the use of DOACs in patients at high risk of thromboembolic complications (CHA2DS2-VASc ≥3) (83%), haemorrhages (HAS-BLED ≥3) (89%) and poor quality of anticoagulation control (SAMe-TT2R2 >2) (76%), patients who fail to achieve an optimal therapeutic range after 3 months on VKA treatment (93%), and those who are to undergo cardioversion (80%). Panellists agreed that the efficacy and safety profile of each DOAC (98%), the availability of a specific reversal agent (72%) and patient's preference (85%) should be considered when prescribing a DOAC. A total of 97 items were ultimately accepted after round 2.

CONCLUSIONS

This Delphi panel study provides expert-based recommendations that may offer guidance on clinical decision-making for the management of OAC in NVAF. The importance of patient education and involvement has been highlighted.

Ischemic Stroke and Transient Ischemic Attack Risk Following Vitamin K Antagonist Cessation in Newly Diagnosed Atrial Fibrillation: A Cohort Study

Background In nonvalvular atrial fibrillation (AF), oral anticoagulants prevent ischemic strokes and transient ischemic attacks (TIAs), but nonpersistence with vitamin K antagonist (VKA) oral anticoagulant therapy (20-50% at 1 year) is problematic. The precise risk of stroke/TIA after VKA cessation and its time course during extended follow-up is unknown. Methods and Results The study cohort of incident AF in patients receiving initial VKA between 2001 and 2013 was identified from the UK Clinical Practice Research Datalink (linked hospitalizations and causes of death). Using a nested case-control analysis, patients with incident stroke/TIA were matched to patients without stroke/TIA (controls). Relative risk with time since VKA cessation compared with current VKA use was approximated from conditional logistic regression. We studied 16 696 patients with incident AF and initial VKA treatment. There were 489 stroke/TIA cases matched to 2137 controls (mean CHA₂DS₂-VASc score 4.3). Compared with current VKA use, the excess incidence rate of stroke/TIA following VKA cessation in the first year after AF diagnosis was 2.29 (95% CI, 0.98-3.90) per 100 person-years of VKA cessation or 1 additional stroke/TIA per 43 patients per year discontinuing VKA, compared with 1.43 (95% CI, 0.97-1.88) per 100 person-years corresponding to 1 additional stroke/TIA per 70 patients per year, when VKA was discontinued more than 1 year after AF diagnosis. Conclusions VKA cessation is associated with a continuous excess thromboembolic stroke/TIA risk. Increasing oral anticoagulant persistence, especially in the year after AF diagnosis, should be a therapeutic target to reduce stroke/TIA in AF.

Tailored Practical Management of Patients With Atrial Fibrillation: A Risk Factor-Based Approach

The management of antithrombotic therapy for thromboprophylaxis in patients with atrial fibrillation (AF) has been recently evolved by the progressive replacement of vitamin K antagonists with the non-vitamin K antagonist oral anticoagulants (NOACs). However, while these drugs are effective in reducing ischemic stroke/systemic embolism, a still high rate of cardiovascular events is present in the AF population. A tailored integrated approach to patients with AF is therefore necessary to reduce both thromboembolic events and cardiovascular disease. This approach should consist in the assessment of individual risk factors for ischemic and bleeding events in order to choose the most appropriate anticoagulant treatment according to patient's characteristics and preference. To this purpose, several risk scores have been developed and validated to stratify thromboembolic and hemorrhagic risk. This review provides an individual-based strategy for the management of patients with AF, from a risk-factor based approach to a tailored prescription and monitoring of NOACs. In particular, we reported an updated practical management strategy for AF patients in specific clinical situations such as those (1) experiencing a major bleeding, (2) requiring a switch to another antithrombotic regimen, (3) restarting anticoagulation after acute ischemic stroke, (4) suffering from an acute coronary artery disease (acute coronary syndrome or undergoing cardiac revascularization).

Real-world comparison of bleeding risks among non-valvular atrial fibrillation patients prescribed apixaban, dabigatran, or rivaroxaban

Limited real-world data are available regarding the comparative safety of non-vitamin K antagonist oral anticoagulants (NOACs). The objective of this retrospective claims observational cohort study was to compare the risk of bleeding among non-valvular atrial fibrillation (NVAF) patients prescribed apixaban, dabigatran, or rivaroxaban. NVAF patients aged ≥18 years with a 1-year baseline period were included if they were new initiators of NOACs or switched from warfarin to a NOAC. Cox proportional hazards modelling was used to estimate the adjusted hazard ratios of any bleeding, clinically relevant non-major (CRNM) bleeding, and major inpatient bleeding within 6 months of treatment initiation for rivaroxaban and dabigatran compared to apixaban. Among 60,227 eligible patients, 8,785 were prescribed apixaban, 20,963 dabigatran, and 30,529 rivaroxaban. Compared to dabigatran or rivaroxaban patients, apixaban patients were more likely to have greater proportions of baseline comorbidities and higher CHA₂DS₂-VASc and HAS-BLED scores. After adjusting for baseline clinical and demographic characteristics, patients prescribed rivaroxaban were more likely to experience any bleeding (HR: 1.35, 95% confidence interval [CI]: 1.26–1.45), CRNM bleeding (HR: 1.38, 95% CI: 1.27–1.49), and major inpatient bleeding (HR: 1.43, 95% CI: 1.17–1.74), compared to patients prescribed apixaban. Dabigatran patients had similar bleeding risks as apixaban patients. In conclusion, NVAF patients treated with rivaroxaban appeared to have an increased risk of any bleeding, CRNM bleeding, and major inpatient bleeding, compared to apixaban patients. There was no significant difference in any bleeding, CRNM bleeding, or inpatient major bleeding risks between patients treated with dabigatran and apixaban.

Temporal trends of time in therapeutic range and incidence of cardiovascular events in patients with non-valvular atrial fibrillation

BACKGROUND

Optimal time in therapeutic range (TTR) of vitamin K antagonists (VKAs) is crucial for cardiovascular events (CVEs) prevention in non-valvular atrial fibrillation (NVAF). The relationship between temporal changes of TTR and the incidence of CVEs has been poorly investigated. We investigated 1) temporal trends of TTR in a long-term follow-up of NVAF patients; 2) the incidence of CVEs according to changes of TTR.

METHODS

Prospective observational study including 1341 NVAF outpatients (mean age 73.5 years, 42.5% male) starting VKAs. Patients were divided into 4 groups: Group 0: Optimal TTR, consistently ≥70% (n = 241); Group 1: Temporally worsening TTR, from above to below 70% (n = 263); Group 2: Temporally improving TTR, from below to above 70% (n = 270); Group 3: Suboptimal TTR, consistently <70% (n = 567).

RESULTS

In a mean follow-up of 37.7 months (4214.2 patient-years), 108 CVEs occurred (2.6%/year). Survival analysis showed a graded increased risk of CVEs in relation to temporal changes in TTR, with the worst outcomes in Groups 1 and 3 (log-rank test p = 0.013). Multivariable Cox proportional hazards regression analysis showed that Group 1 vs. 0 (HR: 2.096; 95%CI 1.061-4.139, p = 0.033), Group 3 vs. 0 (HR: 2.292; 95%CI 1.205-4.361, p = 0.011), CHA₂DS₂VASc score (HR:1.316; 95%CI 1.153-1.501, p < 0.001) and PPIs (HR:0.453; 95%CI 0.285-0.721, p = 0.001) were independently associated with CVEs.

CONCLUSION

A decrease of TTR <70% over time is observed in almost 20% of NVAF patients. Patients with worsening TTR temporally (ie. from initially above 70% to below 70%) have similar risk of CVEs of patients with consistently suboptimal anticoagulation.

Nonvitamin K Oral Anticoagulants in Patients With Atrial Fibrillation and Severe Renal Dysfunction

Both atrial fibrillation (AF) and chronic kidney disease (CKD) are highly prevalent, especially with increasing age and associated comorbidities, such as hypertension, diabetes, heart failure, and vascular disease. The relationship between both AF and CKD seems to be bidirectional: CKD predisposes to AF while onset of AF seems to lead to progression of CKD. Stroke prevention is the cornerstone of AF management, and AF patients with CKD are at higher risk of stroke, mortality, cardiac events, and bleeding. Stroke prevention requires use of oral anticoagulants, which are either vitamin K antagonists (eg, warfarin), or the nonvitamin K antagonist oral anticoagulants (NOACs). While NOACs have been shown to be effective in mild-to-moderate renal dysfunction, there are a paucity of data regarding NOACs in severe and end-stage renal dysfunction. This review first discusses the evidence for NOACs in CKD. Second, we summarize the current knowledge regarding the efficacy and safety of NOACs to prevent AF-related stroke and systemic embolism in severe and end-stage renal disease.

Fitting the right non-vitamin K antagonist oral anticoagulant to the right patient with non-valvular atrial fibrillation: an evidence-based choice

Atrial fibrillation (AF) is the most prevalent arrhythmia and is associated with an increased risk of ischemic stroke (IS) and systemic embolism (SE). Stroke prevention is a key element for the overall management of AF patients. The non-vitamin K antagonist oral anticoagulants (NOACs), such as dabigatran, rivaroxaban, apixaban and edoxaban, are at least as effective as warfarin in reducing IS/SE with a lower rate of major bleeding. Various analyses from the large Phase III randomized trials demonstrated different efficacy and safety of NOACs in specific subgroups of patients. The randomized trials are supplemented by effectiveness and safety data from real-world observational cohorts following the availability of these drugs for use in everyday clinical practice. Given the clinical heterogeneity of AF patients, the available data from trials and real-world studies allow us to fit the right NOAC to the particular patient's characteristics, with the aim of optimizing outcomes for the individual patient. This review article aims to provide a summary of the evidence on the performance of NOACs in AF patients with specific clinical characteristics. Evidence-based suggestions are presented to provide a simple and viable strategy for clinicians for the choice of a particular NOAC. KEY MESSAGE Given the different performance of the new-oral anticoagulants in patients with the different clinical situation, evidence-based choice of fitting the right new-oral anticoagulants to the patients is provided in this review article.

Choosing a particular oral anticoagulant and dose for stroke prevention in individual patients with non-valvular atrial fibrillation: part 1

Patients with atrial fibrillation (AF) have a high risk of stroke and mortality, which can be considerably reduced by oral anticoagulants (OAC). Recently, four non-vitamin-K oral anticoagulants (NOACs) were compared with warfarin in large randomized trials for the prevention of stroke and systemic embolism. Today's clinician is faced with the difficult task of selecting a suitable OAC for a patient with a particular clinical profile or a particular pattern of risk factors and concomitant diseases. We reviewed analyses of subgroups of patients from trials of vitamin K antagonists vs. NOACs for stroke prevention in AF with the aim to identify patient groups who might benefit from a particular OAC more than from another. In the first of a two-part review, we discuss the choice of NOAC for stroke prevention in the following subgroups of patients with AF: (i) stable coronary artery disease or peripheral artery disease, including percutaneous coronary intervention with stenting and triple therapy; (ii) cardioversion, ablation and anti-arrhythmic drug therapy; (iii) mechanical valves and rheumatic valve disease, (iv) patients with time in therapeutic range of >70% on warfarin; (v) patients with a single stroke risk factor (CHA2DS2VASc score of 1 in males, 2 in females); and (vi) patients with a single first episode of paroxysmal AF. Although there are no major differences in terms of efficacy and safety between the NOACs for some clinical scenarios, in others we are able to suggest that particular drugs and/or doses be prioritized for anticoagulation.

Differences among western European countries in anticoagulation management of atrial fibrillation

Due to improved implementation of guidelines, new scoring approaches to improve risk categorisation, and introduction of novel oral anticoagulants, medical management of patients with atrial fibrillation (AF) is continuously improving. The PREFER in AF registry enrolled 7,243 consecutive patients with ECG-confirmed AF in seven European countries in 2012–2013 (mean age: 71.5 ± 10.7 years; 60.1% males; mean CHA2DS 2 -VASc score: 3.4). While patient characteristics were generally homogeneous across countries, anticoagulation management showed important differences: the proportion of patients taking vitamin K antagonists (VKAs) varied between 86.0% (in France) and 71.4% (in Italy). Warfarin was used predominantly in the UK and Italy (74.9% and 62.0%, respectively), phenprocoumon in Germany (74.1%), acenocoumarol in Spain (67.3%), and fluindione in France (61.8 %). The major sites for international normalised ratio (INR) measurements were biology laboratories in France anticoagulation clinics in Italy, Spain, and the UK, and physicians’ offices or self-measurement in Germany. Temporary VKA discontinuation and bridging with other anticoagulants was frequent (at least once in the previous 12 months for 22.9% of the patients, on average; ranging from 29.7% in Germany to 14.9% in the UK). Time in therapeutic range (TTR), defined as at least two of the last three available INR values between 2.0–3.0 prior to enrolment, ranged from 70.3% in Spain to 81.4% in Germany. TTR was constantly overestimated by physicians. While the type and half-lives of VKA as well as the mode of INR surveillance differed, overall quality of anticoagulation management by TTR was relatively homogenous in AF patients across countries.

Efficacy and safety of edoxaban in comparison with dabigatran, rivaroxaban and apixaban for stroke prevention in atrial fibrillation

Large Phase 3 clinical trials for stroke prevention in atrial fibrillation (AF) have compared non-vitamin K antagonist oral anticoagulants (NOACs) against warfarin, with the edoxaban trial only recently reported. In the absence of head to head trials directly comparing these NOACs against each other, we compared the efficacy and safety of edoxaban to other agents by an indirect comparison analysis. We performed an indirect comparison analysis of edoxaban (2 dose strategies) against apixaban (1 dose), dabigatran etexilate (2 doses) and rivaroxaban (1 dose), for their relative efficacy and safety against each other. For high-dose edoxaban vs apixaban, there were no significant differences in efficacy endpoints, mortality, myocardial infarction and major bleeding. Apixaban was associated with less major or clinically relevant non-major bleeding (hazard ratio [HR] 0.79; 95% confidence interval [CI] 0.70–0.90) and gastrointestinal bleeding (HR 0.72; 95% CI 0.53–0.99). For dabigatran 110 mg twice daily, there were no significant differences in the main efficacy or safety endpoints. Dabigatran 150 mg bid was associated with lower stroke/systemic embolism (SE) (HR 0.75; 95% CI 0.56–0.99), stroke (HR 0.73; 95% CI 0.55–0.96) and haemorrhagic stroke (HR 0.48; 95% CI 0.23–0.99). There were no significant differences between high-dose edoxaban vs rivaroxaban for efficacy endpoints or mortality, but rivaroxaban had more major and/or clinically relevant non-major bleeding. When compared to low-dose edoxaban, apixaban was associated with lower stroke/SE (HR 0.70; 95% CI 0.55–0.89), stroke (HR 0.70; 95% CI 0.55–0.92) and ischaemic stroke (HR 0.65; 95% CI 0.50–0.89), but more major bleeding (HR 1.47; 95% CI 1.20–1.80). For dabigatran 110 mg bid, there were no significant differences in the efficacy endpoints, but dabigatran 110 mg bid had higher major (and gastrointestinal) bleeding. Dabigatran 150 mg bid and rivaroxaban were associated with lower stroke/SE and ischaemic stroke, but higher bleeding rates. In the present analysis, we have provided for the first time, comparisons of efficacy and safety of edoxaban against other NOACs. Notwithstanding the significant limitations of an indirect comparison analysis, some differential effects are evident with the NOACs for stroke prevention, allowing us to allow the prescriber a ‘choice’ to be able to fit the drug to the patient clinical profile (and vice versa).

Note: The review process for this paper was fully handled by Christian Weber, Editor in Chief.

Stroke prevention in atrial fibrillation: An Asian perspective

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia. In 2050, it is estimated that there will be 72 million AF patients in Asia, accounting for almost 2.9 million patients suffering from AF-associated stroke. Asian AF patients share similar risk factor profiles as non-Asians, except that more Asians have a history of previous stroke. Clinical challenges are evident in the field of stroke prevention in AF, amongst Asians. Existing stroke and bleeding risk scores have not been well-validated in Asians. Asians are prone to bleeding when treated with warfarin, and the optimal international normalised ratio (INR) for warfarin use is yet to be determined in Asians, though Asian physicians tend to keep it in a lower range (e.g. INR 1.6–2.6) for elderly patients despite limited evidence to justify this. In general, warfarin is ‘difficult’ to use in Asians due to higher risk of bleeding and higher stroke rate in Asians than in non-Asians, as shown in randomised controlled trials. Excess of bleeding was not found in Asians when novel oral anticoagulants (NOACs) were used. Besides, the superiority of NOACs to warfarin in reducing thromboembolism was maintained in Asians. Therefore NOACs are preferentially indicated in Asians in terms of both efficacy and safety. Also, some preliminary data suggest that Asian patients with AF might not be the same. Future prospective randomised trials are needed for the selection of NOACs according to different ethnic background.

Note: The review process for this manuscript was fully handled by Christian Weber, Editor in Chief.

Validation of the SAMe-TT2R2 score in a nationwide population of nonvalvular atrial fibrillation patients on vitamin K antagonists

The SAMe-TT2R2 score has been proposed to identify patients with non valvular atrial fibrillation (AF) who maintain a high average time in therapeutic range (TTR) on vitamin K antagonists treatment (VKA). This score has been validated in several studies, either monocentric or including very selected populations in a specialised setting. Our objective was to validate this score in a nationwide cohort of AF patients. From November 2013 to March 2014 we included in this study the first 10 patients with AF on VKA consecutively seen in 120 outpatient cardiology clinics in Spain. The SAMe-TT2R2 score was calculated for each patient and TTR in the preceding six months was estimated by Rosendaal method. A total of 1,056 patients were recruited (mean age 73.6 ± 9.8 years, 42 % female). Mean value of TTR was 63.8 ± 25.9 % (median 66.8 %, interquartile range 45.6 %-85.4 %). We found a progressive decline in mean TTR from a score of 0 (67.5 % ± 24.6 %) to4 (52.7 ± 28.7 %, p< 0.01). The score was able to discriminate which patients had a good anticoagulation control (TTR65 %) with a C-statistic of 0.57 (95 %CI 0.53–0.60, p< 0.0005). A SAMe-TT2R2 score of 0–1 was associated with a good anticoagulation control with a sensitivity, specificity, positive and negative predictive values of 64 %, 48 %, 58 % and 54 %, respectively; and the odds ratio of having a TTR< 65 % if the score was2 was 1.64 (95 % confidence interval 1.33–1.95, p< 0.001). In conclusion, in this nationwide population with AF on VKA, the SAMe-TT2R2 score had a significant, although moderate, ability to identify patients with a good anticoagulation control.

Genotype-guided versus standard vitamin K antagonist dosing algorithms in patients initiating anticoagulation

Variability in vitamin K antagonist (VKA) dosing is partially explained by genetic polymorphisms. We performed a meta-analysis to determine whether genotype-guided VKA dosing algorithms decrease a composite of death, thromboembolic events and major bleeding (pri-mary outcome) and improve time in therapeutic range (TTR). We searched MEDLINE, EMBASE, CENTRAL, trial registries and conference proceedings for randomised trials comparing genotype-guided and standard (non genotype-guided) VKA dosing algorithms in adults initiating anticoagulation. Data were pooled using a random effects model. Of the 12 included studies (3,217 patients), six reported all components of the primary outcome of mortality, thromboembolic events and major bleeding (2,223 patients, 87 events). Our meta-analysis found no significant difference between groups for the primary outcome (relative risk 0.85, 95 % confidence interval [CI] 0.54–1.34; heterogeneity X2=4.46, p=0.35, I2=10 %). Based on 10 studies (2,767 patients), TTR was significantly higher in the genotype-guided group (mean difference (MD) 4.31 %; 95 % CI 0.35, 8.26; heterogeneity X2=43.31, p< 0.001, I2=79 %). Pre-specified exploratory analyses demonstrated that TTR was significantly higher when geno-type-guided dosing was compared with fixed VKA dosing (6 trials, 997 patients: MD 8.41 %; 95 % CI 3.50,13.31; heterogeneity X2=15.18, p=0.01, I2=67 %) but not when compared with clinical algorithm-guided dosing (4 trials, 1,770 patients: MD –0.29 %; 95 % CI –2.48,1.90; heterogeneity X2=1.53, p=0.68, I2=0 %; p for interaction=0.002). In conclusion, genotype-guided compared with standard VKA dosing algorithms were not found to decrease a composite of death, thromboembolism and major bleeding, but did result in improved TTR. An improvement in TTR was observed in comparison with fixed VKA dosing algorithms, but not with clinical algorithms.

Cessation of oral anticoagulation is an important risk factor for stroke and mortality in atrial fibrillation patients

Oral anticoagulation (OAC) is highly effective preventing stroke and mortality in AF, but withdrawal is common in the elderly, when high bleeding risk and when are difficulties achieving an optimal time in therapeutic range (TTR). We analysed the rate of OAC cessation, predisposing factors to cessation and the relation to clinical outcomes in a large ‘real world’ cohort of AF patients over a long follow-up period. Consecutive non-valvular AF outpatients clinically stables for six months were recruited. Rates of cardiovascular events, major bleeding and mortality were recorded and related to OAC cessation. We included 1361 patients (48.7 % male; aged 76, IQR 71–81), followed-up for a median of 6.5 years. During follow-up, 244 patients suffered thrombotic events, 250 suffered from major bleeding and 551 patients died. 10 % of patients stopped OAC. After OAC withdrawal, there were 36 thromboembolic events (22 strokes), 10 major bleedings and 75 deaths. OAC cessation was independently associated with adverse cardiovascular events (HR 1.45; 95 % CI 1.01–2.08), stroke/TIA (HR 1.85; 1.17–2.94) and all-cause mortality (HR 1.30; 1.02–1.67). Independent predictors of OAC cessation were age ≥80 (HR 2.29; 1.60–3.29), previous coronary artery disease (HR 0.32; 0.15–0.71), major bleeding (HR 5.00; 3.49–7.15), heart failure (HR 2.38; 1.26–4.47), cancer (HR 5.24; 3.25–8.44) and renal impairment developed during follow-up (HR 2.70; 1.26–5.75). In conclusion, in non-valvular AF patients, cessation of OAC was independently associated with the risk of stroke, adverse cardiovascular events and mortality. Bleeding events and some variables associated with higher bleeding risk are responsible for OAC cessation.

Note: The review process for this manuscript was fully handled by Christian Weber, Editor in Chief.

Supplementary Material to this article is available online at www.thrombosis-online.com.

Use of the SAMe-TT2R2 score to predict anticoagulation control in atrial fibrillation and venous thromboembolism patients receiving vitamin K antagonists: A review

Identifying patients who are likely to achieve and maintain a therapeutic international normalized ratio when prescribed a vitamin K antagonist for stroke prevention in atrial fibrillation (AF) and venous thromboembolism (VTE) is challenging. The SAMe-TT₂R₂ score was developed on the basis of common clinical factors that can highlight patients who may be unable to achieve and maintain good anticoagulation control and for whom a "trial of warfarin" would be inadvisable. This review summarizes the main published prospective and retrospective studies that have validated the SAMe-TT₂R₂ score in patients with AF and VTE treated with a vitamin K antagonist and how the SAMe-TT₂R₂ score could aid clinical decision making; 19 studies were included. Taken together, validation studies suggest that the SAMe-TT₂R₂ score is able to predict good or poor anticoagulation control in patients with AF and VTE, although data on patients with VTE are limited (3 studies). The available evidence suggests that the SAMe-TT₂R₂ score may be a useful tool to aid clinical decision making for oral anticoagulants in patients with AF and VTE.

Antithrombotic treatment in patients undergoing transcatheter aortic valve implantation (TAVI)

Transcatheter aortic valve implantation (TAVI) is an established treatment option for symptomatic patients with severe aortic valvular disease who are not suitable for conventional surgical aortic valve replacement. Despite improving experience and techniques, ischaemic and bleeding complications after TAVI remain prevalent and impair survival in this generally old and comorbid-rich population. Due to changing aetiology of complications over time, antiplatelet and anticoagulant therapy after TAVI should be carefully balanced. Empirically, a dual antiplatelet strategy is generally used after TAVI for patients without an indication for oral anticoagulation (OAC; e. g. atrial fibrillation, mechanical mitral valve prosthesis), including aspirin and a thienopyridine. For patients on OAC, a combination of OAC and aspirin or thienopyridine is generally used. This review shows that current registries are unfit to directly compare antithrombotic regimens. Small exploring studies suggest that additional clopidogrel after TAVI only affects bleeding and not ischemic complications. However, these studies are lack in quality in terms of Cochrane criteria. Currently, three randomised controlled trials are recruiting to gather more knowledge about the effects of clopidogrel after TAVI.

Poor predictive value of contemporary bleeding risk scores during long-term treatment of venous thromboembolism

Bleeding is a common and feared complication of oral anticoagulant therapy. Several prediction models have been recently developed, but there is a lack of evidence in patients with venous thromboembolism (VTE). The aim of this study was to validate currently available bleeding risk scores during long-term oral anticoagulation for VTE. We retrospectively included adult patients on vitamin K antagonists for VTE secondary prevention, followed by five Italian Anticoagulation Clinics (Cuneo, Livorno, Mantova, Napoli, Varese), between January 2010 and August 2012. All bleeding events were classified as major bleeding (MB) or clinically-relevant-non-major-bleeding (CRNMB). A total of 681 patients were included (median age 63 years; 52.0% female). During a mean follow-up of 8.82 (± 3.59) months, 50 bleeding events occurred (13 MB and 37 CRNMB), for an overall bleeding incidence of 9.99/100 patient-years. The rate of bleeding was higher in the first three months of treatment (15.86/100 patient-years) than afterwards (7.13/100 patient-years). The HAS-BLED showed the best predictive value for bleeding complications during the first three months of treatment (area under the curve [AUC] 0.68, 95% confidence interval [CI] 0.59–0.78), while only the ACCP score showed a modest predictive value after the initial three months (AUC 0.61, 95%CI 0.51–0.72). These two scores had also the highest sensitivity and the highest negative predictive value. None of the scores predicted MB better than chance. Currently available bleeding risk scores had only a modest predictive value for patients with VTE. Future studies should aim at the creation of a new prediction rule, in order to better define the risk of bleeding of VTE patients.

Importance of time in therapeutic range on bleeding risk prediction using clinical risk scores in patients with atrial fibrillation

Bleeding risk with vitamin K antagonists (VKAs) is closely related to the quality of anticoagulation in atrial fibrillation (AF) patients, reflected by time in therapeutic range (TTR). Here we compared the discrimination performance of different bleeding risk scores and investigated if adding TTR would improve their predictive value and clinical usefulness. We included 1361 AF patients stables on VKA for at least 6 months. Bleeding risk was assessed by the HAS-BLED, ATRIA, ORBIT and HEMORR₂HAGES scores. Major bleeding events were recorded after a median of 6.5 years follow-up. In this period 250 patients suffered major bleeds. Comparison of receiver operating characteristic (ROC) curves demonstrated that HAS-BLED had the best discrimination performance, but adding the ‘labile INR’ criteria (i.e. TTR <65%) to ATRIA, ORBIT and HEMORR₂HAGES increased their ability of discrimination and predictive value, with significant improvements in reclassification and discriminatory performance. Decision curve analyses (DCA) showed improvements of the clinical usefulness and a net benefit of the modified risk scores. In summary, in AF patients taking VKAs, the HAS-BLED score had the best predictive ability. Adding ‘labile INR’ to ATRIA, ORBIT and HEMORR₂HAGES improved their predictive value for major bleeding leading to improved clinical usefulness compared to the original scores.

Non-vitamin K antagonist oral anticoagulants for heart diseases

Non-vitamin K antagonist oral anticoagulants (NОАСs) are highly effective drugs that prevent venous thrombosis and stroke in atrial fibrillation. Their use has difficulties that are associated with the need for laboratory control and with the influence of many factors on the activity of these medications. The emerged direct oral anticoagulants have some advantages over NOACs. Nevertheless, there are a number of pathological conditions, in which NOACs remain first-line drugs. These include prosthetic mechanical heart valves, a glomerular filtration rate less than 60 mL/min/1.73 m2, and left atrial thrombus.

Integrating genotypes in the SAMe-TT2R2 score for the prediction of anticoagulation control in Chinese patients with atrial fibrillation on warfarin

INTRODUCTION

The SAMe-TT₂R₂ score has been proposed to predict whether patients with atrial fibrillation (AF) would be well anti-coagulated with warfarin or not. However, it might over-estimate the number of patients under suboptimal warfarin treatment in non-Caucasians. This study was designed to modify the SAMe-TT₂R₂ score with genotypes and validate it in Chinese AF patients treated with warfarin.

MATERIAL AND METHODS

Consented Chinese-Han patients (n=510) with AF under the treatment of warfarin for at least 3months were randomly divided into a derivation (n=310) and a validation cohort (n=200). For each patient, CYP2C9*3 and VKORC1 -1639 A/G genotyping was performed, and the time in therapeutic range (TTR) was calculated over this period.

RESULTS

The modified SAMe-TT₂R₂ score was established by adding "warfarin genotype bins" to replace "the non-white race" variable. In the validation cohort, the discrimination performance of the modified score for good anticoagulation control (TTR≥70%) was significantly improved (c- index increased from 0.60 to 0.67). Significantly increased risks of major bleedings (HR: 4.91; 95% CI: 1.03-23.37; adjusted p=0.04) and all bleedings (HR: 1.93; 95% CI: 1.14-3.25; adjusted p=0.01) were found in patients with modified scores ≥2, as compared with patients with modified scores of 0-1.

CONCLUSIONS

The modified SAMe-TT₂R₂ score could improve the ability for the identification of good anticoagulation control, and the prediction of major bleeding events in Chinese patients with AF treated by warfarin.

The Patterns of Non-vitamin K Antagonist Oral Anticoagulants (NOACs) Use in Patients with Atrial Fibrillation in Seven Balkan Countries: a Report from the BALKAN-AF Survey

INTRODUCTION

Data on management of atrial fibrillation (AF) in the Balkan Region are scarce. To capture the patterns in AF management in contemporary clinical practice in the Balkan countries a prospective survey was conducted between December 2014 and February 2015, and we report results pertinent to the use of non-vitamin K antagonist oral anticoagulants (NOACs).

METHODS

A 14-week prospective, multicenter survey of consecutive AF patients seen by cardiologists or internal medicine specialists was conducted in Albania, Bosnia and Herzegovina, Bulgaria, Croatia, Montenegro, Romania, and Serbia (a total of about 50 million inhabitants).

RESULTS

Of 2712 enrolled patients, 2663 (98.2%) had complete data relevant to oral anticoagulant (OAC) use (mean age 69.1 ± 10.9 years, female 44.6%). Overall, OAC was used in 1960 patients (73.6%) of whom 338 (17.2%) received NOACs. Malignancy [odds ratio (OR), 95% confidence interval (CI) 2.06, 1.20-3.56], rhythm control (OR 1.64, 1.25-2.16), and treatment by cardiologists were independent predictors of NOAC use (OR 2.32, 1.51-3.54) [all p < 0.01)], whilst heart failure and valvular disease were negatively associated with NOAC use (both p < 0.01). Individual stroke and bleeding risk were not significantly associated with NOAC use on multivariate analysis.

CONCLUSIONS

NOACs are increasingly used in AF patients in the Balkan Region, but NOAC use is predominantly guided by factors other than evidence-based decision-making (e.g., drug availability on the market or reimbursement policy). Efforts are needed to establish an evidence-based approach to OAC selection and to facilitate the optimal use of OAC, thus improving the outcomes in AF patients in this large region.

Dual Versus Single Antiplatelet Regimen With or Without Anticoagulation in Transcatheter Aortic Valve Replacement: Indirect Comparison and Meta-analysis

INTRODUCTION AND OBJECTIVES

There is uncertainty on the correct management of antithrombotic therapies after transcatheter aortic valve replacement (TAVR), with dual antiplatelet therapy (DAPT) being currently recommended on an empirical basis. The aim of the present meta-analysis was to assess the safety and effectiveness of DAPT in patients undergoing TAVR.

METHODS

Studies comparing different antithrombotic regimens after TAVR were included. The primary endpoint was 30-day overall mortality.

RESULTS

We included 9 studies, 5 comparing DAPT with aspirin monotherapy and 4 comparing DAPT with monoantiplatelet therapy (MAPT) + oral anticoagulation. Among 7991 patients, 72% were on DAPT. The median follow-up was 3.5 months. Mortality was significantly lower in the DAPT group (12.2% vs 14.4%; OR, 0.81; 95%CI, 0.70-0.93; P = .003; P_het = .93), with similar benefits compared with aspirin monotherapy (OR, 0.80; 95%CI, 0.69-0.93; P = .004; P_het = .60), which were not statistically significant when compared with MAPT + oral anticoagulation (OR, 0.86; 95%CI, 0.55-1.35; P = .51; P_het = .97). A similar trend for DAPT was observed for stroke (OR, 0.83 95%CI, 0.63-1.10; P = .20; P_het = .67), with no increase in the rate of major bleedings (OR, 1.69; 95%CI, 0.86-3.31; P = .13; P_het< .0001). On indirect comparison analysis, no benefit in survival, stroke, or bleedings was identified for additional oral anticoagulation.

CONCLUSIONS

The present meta-analysis supports the use of DAPT after TAVR, reducing mortality and offering slight benefits in stroke, with no increase in major bleedings compared with MAPT. The strategy of aspirin + oral anticoagulation did not provide significant benefits compared with MAPT or DAPT.

Gut-Derived Serum Lipopolysaccharide is Associated With Enhanced Risk of Major Adverse Cardiovascular Events in Atrial Fibrillation: Effect of Adherence to Mediterranean Diet

BACKGROUND

Gut microbiota is emerging as a novel risk factor for atherothrombosis, but the predictive role of gut-derived lipopolysaccharide (LPS) is unknown. We analyzed (1) the association between LPS and major adverse cardiovascular events (MACE) in atrial fibrillation (AF) and (2) its relationship with adherence to a Mediterranean diet (Med-diet).

METHODS AND RESULTS

This was a prospective single-center study including 912 AF patients treated with vitamin K antagonists (3716 patient-years). The primary end point was a composite of MACE. Baseline serum LPS, adherence to Med-diet (n=704), and urinary excretion of 11-dehydro-thromboxane B2 (TxB2, n=852) were investigated. Mean age was 73.5 years; 42.9% were women. A total of 187 MACE (5.0% per year) occurred: 54, 59, and 74 in the first, second, and third tertile of LPS, respectively (log-rank test P=0.004). Log-LPS (hazard ratio 1.194, P=0.009), age (hazard ratio 1.083, P<0.001), and previous cerebrovascular (hazard ratio 1.634, P=0.004) and cardiac events (hazard ratio 1.822, P<0.001) were predictors of MACE. In the whole cohort, AF (versus sinus rhythm) (β 0.087, P=0.014) and low-density lipoprotein cholesterol (β 0.069, P=0.049) were associated with circulating LPS. Furthermore, Med-diet score (β -0.137, P<0.001) was predictive of log-LPS, with fruits (β -0.083, P=0.030) and legumes (β -0.120, P=0.002) negatively associated with log-LPS levels. Log-LPS and log-TxB2 were highly correlated (r=0.598, P<0.001). Log-LPS (β 0.574, P<0.001) and Med-diet score (β -0.218, P<0.001) were significantly associated with baseline urinary excretion of TxB2.

CONCLUSIONS

In this cohort of AF patients, LPS levels were predictive of MACE and negatively affected by high adherence to Med-diet. LPS may contribute to MACE incidence in AF by increasing platelet activation.