Non-vitamin K antagonist oral anticoagulants versus warfarin in AF patients ≥ 85 years

Protein S contributes to the paradoxical increase in thrombin generation by low-dose dabigatran in the presence of thrombomodulin

Low dose of dabigatran paradoxically increased thrombin generation through inhibition of protein C activation. Protein S is a co-factor in the activation of protein C. However, the role of protein S in the enhancement of thrombin generation has not been addressed. Firstly, we measured thrombin generation by calibrated automated thrombinography (CAT) and prothrombin fragments 1+2 (F1+2) assays. Secondly, we assessed activated protein C (APC) formation in normal or protein S-deficient plasma spiking with dabigatran. Then, protein C activation was measured. Finally, heavy chain of factor Va (FVa) and its degradation products were detected by western blot. CAT assay showed that 70-141 ng/ml dabigatran paradoxically increased thrombin generation in normal plasma. However, higher concentrations of dabigatran (283 ng/ml) suppressed the level of ETP. F1+2 assay showed the similar results. In protein S-deficient or protein C-deficient plasma, the paradoxical increase in thrombin generation was absent. Level of generated APC was to a similar extent inhibited by dabigatran in normal and protein S-deficient plasma. Low-dose dabigatran inhibited the protein S-dependent inactivation of factor Va. Protein S participated in the paradoxical enhancement of thrombin generation in normal plasma spiking with low concentrations of dabigatran. Increased thrombin generation at low dabigatran can be explained by reduced thrombin-thrombomodulin mediated APC formation and subsequent reduced FVa inactivation that is protein S-dependent.

Association between antithrombotic drug regimen changes and clinical outcomes after stroke in atrial fibrillation

BACKGROUND

The impact of post-stroke antithrombotic regimen in atrial fibrillation is uncertain.

OBJECTIVE

This study aimed to describe antithrombotic therapy prescribing patterns after ischemic stroke and the impact on outcomes.

METHODS

A total of 23,165 patients with atrial fibrillation experiencing ischemic stroke were identified. Subsequent post-stroke events included recurrent ischemic stroke, intracranial hemorrhage, major bleeding, mortality, and composite outcomes.

RESULTS

Of those who were nonanticoagulated before a stroke, 33.5% remained nonanticoagulated and 39.2% were prescribed only antiplatelet agents (APs) after a stroke. Compared with non-vitamin K antagonist oral anticoagulants (NOACs) after stroke, there was a significant increase in ischemic stroke and mortality in nonanticoagulated patients (adjusted hazard ratio [aHR], 2.09 and 3.92) and AP users (aHR, 1.32 and 1.28). Post-stroke warfarin was associated with a significantly increased risk of major bleeding compared with NOACs (aHR, 1.23). Of 769 patients receiving NOACs before stroke and continuing NOACs after stroke, those switching to a different NOAC were associated with significantly higher risk of ischemic stroke (aHR, 2.07) and composite outcomes (aHR, 1.36-1.85) with no difference in intracranial hemorrhage, major bleeding, or mortality compared with those receiving the same NOAC after stroke. Of patients receiving NOACs before stroke, the risks of clinical events were similar between patients taking NOACs alone and those taking NOAC plus AP after stroke.

CONCLUSION

NOAC alone after stroke was associated with a better clinical outcome compared with nonanticoagulation, AP, or warfarin. Of patients already taking NOACs before stroke, the addition of AP did not confer additional benefits compared with NOACs alone. A change of NOAC types after stroke was associated with a 2-fold higher risk of ischemic stroke and composite outcomes.

Optimal Dose of Edoxaban for Very Elderly Atrial Fibrillation Patients at High Risk of Bleeding: The LEDIOS Registry

BACKGROUND AND OBJECTIVES

Optimal anticoagulation in very elderly patients is challenging due to the high risk of anticoagulant-induced bleeding. The aim of this study was to assess outcomes of on-label reduced-dose edoxaban (30 mg) in very elderly patients who had additional risk factors for bleeding.

METHODS

This was a multi-center, prospective, non-interventional observational study to evaluate the efficacy and safety of on-label reduced-dose edoxaban in atrial fibrillation (AF) patients 80 years of age or older and who had more than 1 risk factor for bleeding.

RESULTS

A total of 2448 patients (mean age 75.0±8.3 years, 801 [32.7%] males) was included in the present study, and 586 (23.9%) were 80 years of age or older with additional risk factors for bleeding. Major bleeding events occurred frequently among very elderly AF patients who had additional bleeding risk factors compared to other patients (unadjusted hazard ratio [HR], 2.16; 95% confidence interval [CI], 1.16-4.02); however, there were no significant differences in stroke incidence (HR, 1.86; 95% CI, 0.98-3.55). There were no significant differences for either factor after adjusting for age and sex (adjusted HR, 1.65; 95% CI, 0.75-3.62 for major bleeding; adjusted HR, 1.13; 95% CI, 0.51-2.50 for stroke).

CONCLUSIONS

In very elderly AF patients with comorbidities associated with greater risk of bleeding, the incidence of major bleeding events was significantly increased. In addition, risk of stroke showed tendency to increase in same population. Effective anticoagulation therapy might be important in these high-risk population, and close observation of bleeding events might also be required.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03554837.

Managing older people with atrial fibrillation and preventing stroke: a review of anticoagulation approaches

INTRODUCTION

Oral anticoagulants (OACs) are the cornerstone of stroke prevention in atrial fibrillation (AF), but prescribing decisions in older people are complicated. Clinicians must assess the net clinical benefit of OAC in the context of multiple chronic conditions, polypharmacy, frailty and life expectancy. The under-representation of high-risk, older adult sub-populations in clinical trials presents the challenge of choosing the right OAC, where a 'one-size-fits-all' approach cannot be taken.

AREAS COVERED

This review discusses OAC approaches for stroke prevention in older people with AF and presents a prescribing aid to support clinicians' decision-making. High-risk older adults with multiple chronic conditions, specifically chronic kidney disease, dementia/cognitive impairment, previous stroke/transient ischemic attack or intracranial hemorrhage, polypharmacy, frailty, low body weight, high falls risk, and those aged ≥75 years are considered.

EXPERT OPINION

Non-vitamin K antagonist OACs are the preferred first-line OAC in older adults with AF, including high-risk subpopulations, after individual assessment of stroke and bleeding risk, except those with mechanical heart valves and moderate-to-severe mitral stenosis. Head-to-head comparisons of NOACs are not available, therefore the choice of drug (and dose) should be based on an individual's risk (stroke and bleeding) and incorporate their treatment preferences. Treatment decisions must be person-centered and principles of shared decision-making applied.

Secondary prevention after intracerebral haemorrhage

BACKGROUND

Intracerebral haemorrhage (ICH) has high mortality in the acute phase and poor functional outcome in the majority of survivors. ICH recurrence is a major determinant of long-term prognosis and is the most feared complication of antithrombotic treatment. On the other hand, ICH patients are at high risk of future ischaemic vascular events.

METHODS

This narrative review provides a critical analysis of the current knowledge on the topic. We performed a Pubmed search with the following terms 'intracerebral haemorrhage', 'stroke', 'outcome', 'secondary prevention', 'anticoagulation' and 'atrial fibrillation', including only English written studies with no time restrictions.

RESULTS

Blood pressure management is the cornerstone of secondary ICH prevention, regardless of ICH location or underlying cerebral small vessel disease. Resumption of antiplatelet and anticoagulation therapy is often challenging, with limited evidence from randomized trials. Clinical and imaging predictors can inform the stratification of ICH recurrence risk and might identify patients at very high probability of future haemorrhagic events. This narrative review provides a summary of the main diagnostic tools and therapeutic strategies available for secondary prevention in ICH survivors.

CONCLUSION

Appropriate recognition and treatment of modifiable risk factors for ICH recurrence might improve outcomes in ICH survivors. Ongoing randomized trials might provide novel insights and improve long-term management.

Diabetes-Related Complications and Mortality in Patients With Atrial Fibrillation Receiving Different Oral Anticoagulants : A Nationwide Analysis

BACKGROUND

Evidence about the association between types of oral anticoagulants and hazards of diabetes complications is limited in patients with atrial fibrillation (AF) and diabetes mellitus (DM).

OBJECTIVE

To compare the hazards of diabetes complications and mortality between patients with AF and DM receiving non-vitamin K antagonist oral anticoagulants (NOACs) and those receiving warfarin.

DESIGN

A retrospective cohort study.

SETTING

Nationwide data obtained from Taiwan's National Health Insurance Research Database.

PATIENTS

Patients with AF and DM receiving NOACs or warfarin between 2012 and 2017 in Taiwan were enrolled. Treatment groups were determined by patients' first initiation of oral anticoagulants.

MEASUREMENTS

Hazards of diabetes complications (macrovascular complications, microvascular complications, and glycemic emergency) and mortality in the NOAC and warfarin users were investigated with a target trial design. Cause-specific Cox proportional hazards models were used to estimate hazard ratios (HRs). Propensity score methods with stabilized inverse probability of treatment weighting were applied to balance potential confounders between treatment groups.

RESULTS

In total, 19 909 NOAC users and 10 300 warfarin users were included. Patients receiving NOACs had significantly lower hazards of developing macrovascular complications (HR, 0.84 [95% CI, 0.78 to 0.91]; P < 0.001), microvascular complications (HR, 0.79 [CI, 0.73 to 0.85]; P < 0.001), glycemic emergency (HR, 0.91 [CI, 0.83 to 0.99]; P = 0.043), and mortality (HR, 0.78 [CI, 0.75 to 0.82]; P < 0.001) than those receiving warfarin. Analyses with propensity score matching showed similar results. Several sensitivity analyses further supported the robustness of our findings.

LIMITATION

The claims-based data did not allow for detailed data on patients' lifestyles and laboratory examinations to be obtained.

CONCLUSION

Non-vitamin K antagonist oral anticoagulants were associated with lower hazards of diabetes complications and mortality than warfarin in patients with AF and DM.

PRIMARY FUNDING SOURCE

Hualien Tzu Chi Hospital.

Modified Taiwan Atrial Fibrillation Score for the Prediction of Incident Atrial Fibrillation

Background

We have proposed the Taiwan AF score consisting of age, male sex, hypertension, heart failure, coronary artery disease, end-stage renal disease, and alcoholism to predict incident atrial fibrillation (AF) in Asian population. We hypothesized that the modified Taiwan AF score (mTaiwan AF score) excluding alcoholism remained useful for predicting new onset AF.

Methods

A total of 7,220,654 subjects aged ≥ 40 years without a past history of cardiac arrhythmia were identified from a national cohort, and 438,930 incident AF occurred during a 16-year follow-up with an incidence of 0.42 per 100 person-years. The mTaiwan AF score ranging between −2 and 14 and its predictive accuracy of incident AF was analyzed.

Results

The areas under the receiver operating characteristic curve (AUCs) of the mTaiwan AF scores in predicting AF are 0.861 for 1-year follow-up, 0.829 for 5-year follow-up, 0.795 for 10-year follow-up, and 0.751 for 16-year follow-up. The risk of incident AF increased from 0.05%/year for patients with a score of −2 to 6.98%/year for those having a score of 14. Patients were classified into three groups based on the tertile values of the mTaiwan AF scores—group 1 (score −2-3), group 2 (score 4-9) and group 3 (score 10-14). The annual risks of incident AF were 0.20, 1.33, and 3.36% for group 1, 2, and 3, respectively. Compared to patients in group 1, the hazard ratios of incident AF were 5.79 [95% confidence interval (CI) 3.75-7.75] for group 2 and 8.93 (95% CI 6.47-10.80) for group 3.

Conclusions

We demonstrated that the mTaiwan AF score based on age and clinical comorbidities could be used to predict incident AF in Asian population.

2021 Focused update of the 2017 consensus guidelines of the Asia Pacific Heart Rhythm Society (APHRS) on stroke prevention in atrial fibrillation

The consensus of the Asia Pacific Heart Rhythm Society (APHRS) on stroke prevention in atrial fibrillation (AF) has been published in 2017 which provided useful clinical guidance for cardiologists, neurologists, geriatricians, and general practitioners in Asia-Pacific region. In these years, many important new data regarding stroke prevention in AF were reported. The Practice Guidelines subcommittee members comprehensively reviewed updated information on stroke prevention in AF, and summarized them in this 2021 focused update of the 2017 consensus guidelines of the APHRS on stroke prevention in AF. We highlighted and focused on several issues, including the importance of AF Better Care (ABC) pathway, the advantages of non-vitamin K antagonist oral anticoagulants (NOACs) for Asians, the considerations of use of NOACs for Asian patients with AF with single 1 stroke risk factor beyond gender, the role of lifestyle factors on stroke risk, the use of oral anticoagulants during the "coronavirus disease 2019" (COVID-19) pandemic, etc. We fully realize that there are gaps, unaddressed questions, and many areas of uncertainty and debate in the current knowledge of AF, and the physician's decision remains the most important factor in the management of AF.

[Atrial fibrillation in old age: risk management and features of the use of direct oral anticoagulants]

Senile patients with atrial fibrillation (AF) are at a higher risk of thromboembolism and hemorrhage than younger patients. Three direct oral anticoagulants (DOAC), apixaban, dabigatran, and rivaroxaban, are registered in the Russian Federation and are extensively used for prevention of stroke in patients with AF. The DOAC treatment of older patients requires considering peculiarities of these patients, clinical situation and properties of individual drugs to achieve the balance of efficiency and safety and a comprehensive protection. According to studies of real clinical practice DOAC may have advantages over warfarin (reduced risk of fractures, diabetes mellitus, and dementia). Compliance with and constancy of the DOAC treatment are important for its efficiency, particularly in senile age. Results of clinical trials and real clinical practice studies have confirmed that rivaroxaban may provide a comprehensive protection for a senile patient with AF due to favorable indexes of efficiency and safety, beneficial effect on the risk of coronary events and impairment оf renal function, whereas once a day dosing of rivaroxaban improves the compliance with this treatment and its constancy.

Characteristics and Treatment of Atrial Fibrillation with Respect to the Presence or Absence of Heart Failure. Insights from the Multicenter Polish Atrial Fibrillation (POL-AF) Registry

Background: We aimed to assess characteristics and treatment of AF patients with and without heart failure (HF). Methods: The prospective, observational Polish Atrial Fibrillation (POL-AF) Registry included consecutive patients with AF hospitalized in 10 Polish cardiology centers in 2019–2020. Results: Among 3999 AF patients, 2822 (71%) had HF (AF/HF group). Half of AF/HF patients had preserved ejection fraction (HFpEF). Compared to patients without HF (AF/non–HF), AF/HF patients were older, more often male, more often had permanent AF, and had more comorbidities. Of AF/HF patients, 98% had class I indications to oral anticoagulation (OAC). Still, 16% of patients were not treated with OAC at hospital admission, and 9%—at discharge (regardless of the presence of HF and its subtypes). Of patients not receiving OAC upon admission, 61% were prescribed OAC (most often apixaban) at discharge. AF/non–HF patients more often converted from AF at admission to sinus rhythm at discharge compared to AF/HF patients (55% vs. 30%), despite cardioversion performed as often in both groups. Class I antiarrhythmics were more often prescribed in AF/non–HF than in AF/HF group (13% vs. 8%), but still as many as 15% of HFpEF patients received them. Conclusions: Over 70% of hospitalized AF patients have coexisting HF. A significant number of AF patients does not receive the recommended OAC.