Novel oral anticoagulants for stroke prevention in atrial fibrillation: a focus on the older patient

Seasonal Variations in Stroke and a Comparison of the Predictors of Unfavorable Outcomes among Patients with Acute Ischemic Stroke and Cardioembolic Stroke

We investigated the seasonal variations in stroke in 4040 retrospectively enrolled patients with acute ischemic stroke (AIS) admitted between January 2011 and December 2022, particularly those with cardioembolic (CE) stroke, and compared predictors of unfavorable outcomes between AIS patients and CE stroke patients. The classification of stroke subtypes was based on the Trial of ORG 10172 in Acute Stroke Treatment. Stroke occurrence was stratified by seasons and weekdays or holidays. Of all AIS cases, 18% were of CE stroke. Of all five ischemic stroke subtypes, CE stroke patients were the oldest; received the most thrombolysis and thrombectomy; had the highest initial National Institutes of Stroke Scale (NIHSS) and discharge modified Rankin Scale (mRS) scores; and had the highest rate of in-hospital complications, unfavorable outcomes (mRS > 2), and mortality. The highest CE stroke prevalence was noted in patients aged ≥ 85 years (30.9%); moreover, CE stroke prevalence increased from 14.9% in summer to 23.0% in winter. The main predictors of death in patients with CE stroke were age > 86 years, heart rate > 79 beats/min, initial NIHSS score > 16, neutrophil-to-lymphocyte ratio (NLR) > 6.4, glucose > 159 mg/dL, cancer history, in-hospital complications, and neurological deterioration (ND). The three most dominant factors influencing death, noted in not only patients with AIS but also those with CE stroke, are high initial NIHSS score, ND, and high NLR. We selected the most significant factors to establish nomograms for predicting fatal outcomes. Effective heart rhythm monitoring, particularly in older patients and during winter, may help develop stroke prevention strategies and facilitate early AF detection.

Advances and Application of a Novel Oral Anticoagulant in Specific Populations: Dabigatran Etexilate

BACKGROUND

Dabigatran etexilate (DE) was approved by the FDA in 2010 to reduce the risk of stroke and systemic embolism in adults with Non-valvular Atrial Fibrillation (NVAF). Compared with warfarin, a traditional anticoagulant drug, DE exhibits a shorter half-life, improved dose-effect relationship, fewer food and drug interactions, and can be taken orally without monitoring the conventional coagulation index. DE can also prevent or reduce the severity of adverse events, such as attenuated drug efficacy or bleeding. It is convenient for patients to take DE due to low levels of individual variation. This review aims to application of Dabigatran etexilate in specific populations.

METHODS

Fifty-five papers were included in the review.

RESULTS

We review the pharmacological mechanisms, pharmacokinetics and drug interactions, as well as the application of DE for different clinical populations, and provide clinical guidelines.

CONCLUSION

When using DE, one should consider the risk of bleeding, age, renal function, drug interactions, and other factors.

Pharmacogenetic studies with oral anticoagulants. Genome-wide association studies in vitamin K antagonist and direct oral anticoagulants

Oral anticoagulants (OAs) are the recommended drugs to prevent cardiovascular events and recurrence in patients with atrial fibrillation (AF) and cardioembolic stroke. We conducted a literature search to review the current state of OAs pharmacogenomics, focusing on Genome Wide Association Studies (GWAs) in patients treated with vitamin K antagonists (VKAs) and direct oral anticoagulants (DOACs).

VKAs: Warfarin, acenocoumarol, fluindione and phenprocoumon have long been used, but their interindividual variability and narrow therapeutic/safety ratio makes their dosage difficult. GWAs have been useful in finding genetic variants associated with VKAs response. The main genes involved in VKAs pharmacogenetics are: VKORC1, CYP2C19 and CYP4F2. Variants in these genes have been included in pharmacogenetic algorithms to predict the VKAs dose individually in each patient depending on their genotype and clinical variables.

DOACs: Dabigatran, apixaban, rivaroxaban and edoxaban have been approved for patients with AF. They have stable pharmacokinetics and do not require routine blood checks, thus avoiding most of the drawbacks of VKAs. Except for a GWAs performed in patients treated with dabigatran, there is no Genome Wide pharmacogenomics data for DOACs. Pharmacogenomics could be useful to predict the better clinical response and avoid adverse events in patients treated with anticoagulants, identifying the most appropriate anticoagulant drug for each patient. Current pharmacogenomics data show that the polymorphisms affecting VKAs or DOACs are different, concluding that personalized medicine based on pharmacogenomics could be possible. However, more studies are required to implement personalized medicine in clinical practice with OA and based on pharmacogenetics of DOACs.

[Multidisciplinary meeting about the use of direct oral anticoagulants in nonvalvular atrial fibrillation]

Knowing the real impact of atrial fibrillation in the stroke, the Sociedad Mexicana of Electrofisiología y Estimulación Cardiaca (SOMEEC) had the initiative to develop a multidisciplinary meeting of experts the with the purpose to update the available scientific evidence from clinical practice guidelines, meta-analyses, controlled clinical trials, and complementing with the experience and views of a group of experts. To meet this goal, SOMEEC gathered a group of specialists in the area of cardiology, electrophysiology, neurology and hematology that given their experience in certain areas, they share the scientific evidence with the panel of experts to leave open a discussion about the information presented in this article. This document brings together the best scientific evidence available and aims to be a useful tool in the decision to use of new oral anticoagulants in nonvalvular atrial fibrillation and ischemic heart disease, or relating to the management of patients with stroke or renal failure, and even those that will be submitted to elective surgery and invasive procedures. In the same, they handled comparative schemes of follow-up and treatment which simplifies the decision making by the specialists participants.

Do NOACs Improve Antithrombotic Therapy in Secondary Stroke Prevention in Nonvalvular Atrial Fibrillation?

Guidelines recommended oral anticoagulant (OAC) for ischemic stroke patients related to atrial fibrillation (AF). But, underprescription or underdose of warfarin was observed worldwide. We aimed to explore if the use of antithrombotic therapy in nonvalvular AF (NVAF) ischemic stroke patients improved after novel oral anticoagulants (NOACs) became available. Between January 2011 to December 2013, 360 acute ischemic stroke patients related to NVAF were recruited. Patients were categorized into 2 groups based on the date (July 2012) of NOACs' availability. There were 184 patients recruited before July 2012, and whereas 176 patients after July 2012. Demographic data, interested factors, and the percentage of patient on OAC were compared. One month after discharge, percentage of OAC utilization was significantly higher (29% versus 41%; P = 0.022) as well as effective anticoagulation (22.2% versus 80.6%; P < 0.001); warfarin utilization was significantly less (28.3% versus 11%; P < 0.001) after NOACs became available. Antiplatelet agent utilization was high in 2 groups (57% versus 52%; P = 0.36). Age (odd ratios [OR] 0.947; 95% confidence intervals [CI] 0.912-0.984; P = 0.005), Barthel index (OR 1.012; 95% CI 1.000-1.025; P = 0.05), and NOACs' availability (OR 1.857; 95% CI 1.086-3.175; P = 0.024) were the significant factors affecting the use of OAC. A higher percentage of NVAF ischemic stroke patients returning for their 1-month follow-up were treated with NOACs than with warfarin. The use of antithrombotic therapy improved after NOACs became available. But, the majority of the patients were still received antiplatelet agent for emboli stroke prevention.

Efficacy and Harms of Direct Oral Anticoagulants in the Elderly for Stroke Prevention in Atrial Fibrillation and Secondary Prevention of Venous Thromboembolism: Systematic Review and Meta-Analysis

BACKGROUND

Evidence regarding the use of direct oral anticoagulants (DOACs) in the elderly, particularly bleeding risks, is unclear despite the presence of greater comorbidities, polypharmacy, and altered pharmacokinetics in this age group.

METHODS AND RESULTS

We performed a systematic review and meta-analysis of randomized trials of DOACs (dabigatran, apixaban, rivaroxaban, and edoxaban) for efficacy and bleeding outcomes in comparison with vitamin K antagonists (VKA) in elderly participants (aged ≥75 years) treated for acute venous thromboembolism or stroke prevention in atrial fibrillation. Nineteen studies were eligible for inclusion, but only 11 reported data specifically for elderly participants. The efficacy in managing thrombotic risks for each DOAC was similar or superior to VKA in elderly patients. A nonsignificantly higher risk of major bleeding than with VKA was observed with dabigatran 150 mg (odds ratio, 1.18; 95% confidence interval, 0.97-1.44) but not with the 110-mg dose. Significantly higher gastrointestinal bleeding risks with dabigatran 150 mg (1.78, 1.35-2.35) and dabigatran 110 mg (1.40, 1.04-1.90) and lower intracranial bleeding risks than VKA for dabigatran 150 mg (0.43, 0.26-0.72) and dabigatran 110 mg (0.36, 0.22-0.61) were also observed. A significantly lower major bleeding risk in comparison with VKA was observed for apixaban (0.63, 0.51-0.77), edoxaban 60 mg (0.81, 0.67-0.98), and 30 mg (0.46, 0.38-0.57), whereas rivaroxaban showed similar risks.

CONCLUSIONS

DOACs demonstrated at least equal efficacy to VKA in managing thrombotic risks in the elderly, but bleeding patterns were distinct. In particular, dabigatran was associated with a higher risk of gastrointestinal bleeding than VKA. Insufficient published data for apixaban, edoxaban, and rivaroxaban indicate that further work is needed to clarify the bleeding risks of these DOACs in the elderly.

SYSTEMATIC REVIEW REGISTRATION

http://www.crd.york.ac.uk/PROSPERO. Unique identifier: PROSPERO CRD42014007171/.

Cardioembolic stroke is the most serious problem in the aging society: Japan standard stroke registry study

BACKGROUND

Japan has the fastest aging society in the world. Older patients have a different stroke risk profile and different stroke features compared with younger patients. The aim of the present study was to examine the stroke subtypes, risk factor profiles, stroke severities, and functional outcomes in the different age groups.

METHODS

A total of 78,096 patients with acute ischemic stroke, including transient ischemic attacks, were included in a multicenter, hospital-based registration study based on a computerized database involving 95 Japanese institutes between 2000 and 2012.

RESULTS

The frequency of atrial fibrillation increased even after the age of 90 years; consequently, the proportion of patients experiencing cardioembolic stroke also increased in the same age group. Furthermore, more severe symptoms on arrival and worse functional outcomes were observed with increasing age. The frequency of hypertension increased with age, peaking in patients in their 70s, and decreasing slightly thereafter. The frequency of diabetes mellitus and hyperlipidemia peaked in patients in their 50s or 60s and gradually decreased thereafter.

CONCLUSION

The findings of the present study suggest that in the currently aging society, cardioembolic stroke is the most important stroke subtype. The roles of hypertension, diabetes mellitus, and hyperlipidemia are greatest in stroke patients in their 50s to 60s. In older patients, the role of atrial fibrillation is more significant.

Diagnosis and management of pulmonary embolism in the elderly

Elderly patients are a population not only at particularly high risk of venous thromboembolism including pulmonary embolism (PE), but also at high risk of adverse clinical outcomes and treatment-related complications. Major progresses have been achieved in the diagnosis and treatment of PE over the last two decades. Nevertheless, some of elderly patients' specificities still represent important challenges in the management of PE in this population, from its suspicion to its diagnosis and treatment, and are discussed in this review. Perspectives for the future are from a diagnostic point of view the potential implementation of age-adjusted d-dimer cut-offs that will allow ruling out PE in a greater proportion of elderly patients without the need for thoracic imaging. From a therapeutic point of view, acquisition of post-marketing clinical experience with the use of new oral anticoagulants is still necessary, and in the meantime, these drugs should be prescribed with great caution in thoroughly selected elderly patients.