Efficacy and Safety of Direct Oral Anticoagulants Compared to Warfarin in Prevention of Thromboembolic Events Among Elderly Patients with Atrial Fibrillation

Risks of oral anticoagulants: Analysis of adverse drug reactions reported to the Portuguese National Pharmacovigilance System

Cardiovascular diseases are the leading cause of death globally, making the use of oral anticoagulants for prevention increasingly important. Historically, warfarin has played a significant role in this context. In recent years, introduction of new oral anticoagulants, such as rivaroxaban, apixaban, dabigatran, and edoxaban, has been seen. This study evaluates the risk associated with the use of oral anticoagulants by analyzing spontaneous adverse drug reactions reported to the Portuguese Pharmacovigilance System from 2012 to 2021. The study includes 951 adverse drug reactions reports, with the majority (n = 770; 80.97%) classified as serious. Of the 770 serious adverse drug reactions reports, the most commonly reported seriousness criterion was "Clinically Important" (n = 350; 45.45%). In terms of demographics, there was a higher reporting rate among the elderly population, with a greater prevalence of females. The System Organ Class group with the highest number of adverse drug reactions was "Gastrointestinal disorders," with the most commonly reported Preferred Term being "Gastrointestinal hemorrhage," and dabigatran was the most frequently reported drug. In summary, oral anticoagulants have adverse drug reactions that require continuous monitoring. Accurate identification and monitorization of adverse drug reactions is an important starting point to improve drug safety in population.

Direct Oral Anticoagulants versus Warfarin in Octogenarians with Nonvalvular Atrial Fibrillation: A Systematic Review and Meta-Analysis

Direct oral anticoagulants (DOACs) have been demonstrated to be more effective and safer than vitamin-K antagonist (VKA) for stroke prevention in patients with nonvalvular atrial fibrillation (AF). This meta-analysis aims to assess the effect of DOACS vs. VKA in patients ≥ 80 and AF. Primary endpoints were stroke or systemic embolism and all-cause death. Secondary endpoints included major bleeding, intracranial bleeding, and gastrointestinal bleeding. A random-effects model was selected due to significant heterogeneity. A total of 147,067 patients from 16 studies were included, 71,913 (48.90%) treated with DOACs and 75,154 with VKA (51.10%). The stroke rate was significantly lower in DOACs group compared with warfarin group (Relative risk (RR): 0.72; 95% confidence interval (CI): 0.63-0.82; p < 0.001). All-cause mortality was significantly lower in DOACs group compared with warfarin group (RR: 0.82; 95% CI: 0.70-0.96; p = 0.012). Compared to warfarin, DOACs were not associated with reductions in major bleeding (RR: 0.85, 95% CI 0.69-1.04; p = 0.108) or gastrointestinal bleeding risk (RR: 1.08, 95% CI 0.76-1.53; p = 0.678) but a 43% reduction of intracranial bleeding (RR: 0.47, IC 95% 0.36-0.60; p < 0.001) was observed. Our meta-analysis demonstrates that DOACs are effective and safe with statistical superiority when compared with warfarin in octogenarians with AF.

Elderly people are inherently sensitive to the pharmacological activity of rivaroxaban: implications for DOAC prescribing

According to both trial and clinical data on direct oral anticoagulants (DOACs) elderly patients are at greatest risk of bleeding. It is unclear whether age intrinsically affects anticoagulation response. To investigate the age-related sensitivity to DOACs, we compared the pharmacological activity of the direct factor Xa inhibitor, rivaroxaban, between young and elderly subjects ex-vivo. 36 fit elderly and 30 fit young subjects [median (IQR) age: 83(75–87) vs 30(26–38) years] provided a blood sample. Clotting parameters were measured in the resultant plasma samples incubated with rivaroxaban (100–500 ng/ml). Parametric, non-parametric tests and regression lines adjusted for rivaroxaban concentration and baseline values were used to compare data. Rivaroxaban produced a greater prolongation of both Prothrombin Time (PT) and modified Prothrombin Time (mPT) (both p < 0.001) in the elderly compared to young subjects (with difference in mean PT increasing from 1.6 to 6.1s and for mPT from 23.5 to 71.1s at 100 ng/ml and 500 ng/ml plasma rivaroxaban concentration, respectively). Factor X and factor II activity was significantly lower in the elderly in the presence of rivaroxaban (p < 0.001 for both). Rivaroxaban prolonged time-based parameters and suppressed the amount of thrombin generation to a significantly greater extent in the elderly compared to young subjects [%change from baseline for Endogenous Thrombin Potential (ETP): − 35.0 ± 4.4 vs − 29.8 ± 7.4 nM*min; p = 0.002]. The use of validated DOAC assays will be of considerable benefit for monitoring elderly patients who, because of their increased sensitivity to rivaroxaban, may require lower doses of the drug for therapeutic anticoagulation.

Treatment preferences as basis for decision making in patients using direct oral anticoagulants in Spain

Treatment preferences are considered a relevant decision-making driver by the main atrial fibrillation (AF) guidelines. Direct Oral Anticoagulants (DOACs), considered as similar clinically, have administration differences useful for treatment individualization. Preferences, priorities and satisfaction of DOAC users were assessed through an observational, multicentric (25 hospitals), cross-sectional study including adult AF-patients (and/or caregivers) in Spain. Three study groups were considered according to DOAC posology preferences: (A) once-daily, with water; (B) once-daily, with food; (C) twice-daily. Overall, 332 patients and 55 caregivers were included. Mean (SD) age was 73.7 (10.7) years [58.7 (13.9) for caregivers]; 51.5% women [69.1% for caregivers]; 80.7% showed comorbidities and poly-pharmacy [6.6 (3.3) drugs/day]. No statistically significant differences were shown among study groups. Once-daily administration was preferred by 274 patients (82.5%) [60.8% (Group A); 21.7% (Group B); 17.5% (Group C)], and 47 caregivers (85.5%) [58.2% (Group A); 27.3% (Group B); 14.5% (Group C)]. Once-daily DOACs were prescribed in 42.8% of the patients. Bleeding risk was the main concern for both, patients and caregivers, followed by DOAC posology and interactions. Although treatment satisfaction (patients and caregivers) was high (9.0 and 9.1 points, respectively), match between individual treatment preferences and real prescriptions was only shown in 41.0% of AF-patients, evidencing a need for patient involvement on treatment decision-making. There is not a patient profile linked to treatment preferences, and clinical criteria must be the main driver for decision-making. However, for most AF-patients (elderly patients), aged, with comorbidity, poly-pharmacy and high cardiovascular risk, once-daily DOACs would be the preferred option.

Reduced Stroke Risk among Patients with Atrial Fibrillation Receiving Chinese Herbal Medicines Treatment: Analysis of Domestic Data in Taiwan

Background and objectives: Patients with atrial fibrillation (AF) reportedly have a much higher risk of death due to stroke. Faced with this heavy burden, it remains unclear if the Chinese herbal medicines (CHMs), the most common form complementary and alternative medicine, can lower the risk of stroke for them. This study aimed to evaluate the association of CHMs use with stroke risk among them. Materials and Methods: From a nationwide database, 11,456 AF patients aged ≧ 20 years between 1998 and 2007 were identified. Afterwards, we enrolled 2670 CHMs users and randomly selected 2670 non-CHMs users using the propensity score method. The occurrence of stroke was recorded until the end of 2012. Results: Within the follow-up period, 671 CHMs users and 900 non-CHMs users developed stroke, with incidence rates of 33.02 and 45.46 per 1000 person-years, respectively. CHMs use was associated with a 30% lower stroke risk, especially for those receiving CHMs for over two years. Conclusions: The findings of the present study suggest that adding CHMs to conventional therapy could decrease subsequent stroke risk for AF patients. It is also suggested that prospective randomized trials are needed to further clarify if the detected association revealed in this study supports a causal link, and to identify the specific CHMs that may be beneficial to AF patients.

Non-vitamin K antagonist oral anticoagulants in patients with atrial fibrillation in secondary stroke and systemic embolism prevention

BACKGROUND

Oral anticoagulants (OAC) are recommended in all patients with atrial fibrillation (AF) after thromboembolic events without contraindications. It is hypothesized herein, that the majority of patients with AF after thromboembolic events receive OAC and the presence of specific factors, predisposes the use of non-vitamin K antagonist oral anticoagulants (NOACs).

METHODS

This is a retrospective study, encompassing patients with AF hospitalized in a reference cardiology center over the years 2014-2017. Thromboembolic events were defined as: ischemic stroke, transient ischemic attack and systemic embolism. Inclusion criteria were the following: diagnosis of non-valvular AF at discharge from hospital, hospitalization not resulting in death.

RESULTS

Among 2834 hospitalized patients with AF, a history of thromboembolic events was identified in 347 (12.2%) patients. In the group studied, of 347 patients with AF after a thromboembolic event, 322 (92.8%) received OAC, including 133 patients on vitamin K antagonist (41.3% of patients on OAC) and 189 patients on NOACs (58.7% of patients on OAC). Among patients treated with NOACs the majority were on dabigatran (116 patients, 61.4%), followed by rivaroxaban (54 patients, 28.6%), and apixaban (19 patients, 10%). Multivariate logistic regression analysis demonstrated that the presence of arterial hypertension reduced the chance for NOACs use (odds ratio [OR] 0.4, 95% confidence interval [CI] 0.2-0.9, p = 0.04) and left atrial size ≤ 40 mm was a factor increasing the chance for the use of NOACs (OR 2.5, 95% CI 1.1-5.8, p = 0.03).

CONCLUSIONS

Nearly all hospitalized patients with AF received OAC in the secondary prevention of thromboembolic complications. NOACs were used for secondary prevention of stroke among patients with AF in patients with fewer comorbidities.

The impact of warfarin on operative delay and 1-year mortality in elderly patients with hip fracture: a retrospective observational study

Background

Guidelines underline the importance of early surgery in elderly patients with proximal femoral fractures. However, most of these patients present a high number of comorbidities, some of which require the use of warfarin. Waiting for INR decrease is a cause of surgical delay, and this influences negatively their outcome.

Methods

We retrospectively reviewed all patients with proximal femoral fracture admitted to our unit from March 2013 to March 2017 to determine whether warfarin therapy is associated with reduction of survival, delay of surgery, and increased blood loss. From 1706 patient, a total of 1292 fulfilled the eligibility criteria and were included. Data regarding general information (type of fracture according to AO/OTA classification), pharmacological history regarding anticoagulant therapy pre-admission, surgery (type of surgery and time to surgery), clinical findings (blood loss), and date of exitus were collected.

Results

We identified 157 patients with warfarin, 442 with antiplatelet agents (aspirin, clopidogrel, ticlopidin), and 693 in the control group. We observed a significant difference in the warfarin group regarding an increased ASA score, Charlson Comorbidity Index, and blood loss. Patients taking warfarin experience delay to the theater significantly more than the other groups. Patients in warfarin therapy have a 42% higher risk of death within 1 year from their surgery. Patients who underwent surgery after 48 h have 1.5 times higher risk of mortality with respect to the patients who underwent surgery within 48 h.

Conclusion

Warfarin therapy at the time of proximal femoral fractures is associated with increased time to surgery, blood loss, and mortality.

Successful resolution with apixaban of a massive left atrial appendage thrombus due to nonrheumatic atrial fibrillation: A case report and review

A 32-year-old woman with a past medical history of paroxysmal atrial fibrillation, long QT syndrome, and implantation of an automatic iimplantable cardioverter-defibrillator (AICD) following cardiac arrest presented with disabling symptoms of paroxysmal atrial fibrillation due to recurrent AICD shocks. Before curative ablation, transesophageal echocardiography was performed to assess for existing thrombi. This is a rare case of successful resolution with apixaban of a massive left atrial appendage thrombus due to non-rheumatic atrial fibrillation that was successfully treated with apixaban.

Clinical characteristics and type of antithrombotic treatment in a Spanish cohort of elderly patients with atrial fibrillation according to dependency, frailty and cognitive impairment

BACKGROUND

Available data regarding clinical profile and management of elderly patients with atrial fibrillation (AF) according to dependency, fragility and cognitive impairment are scarce. The objective of the study was to analyze the biodemographic data, clinical profile and antithrombotic treatment according to dependency, fragility and cognitive impairment in elderly AF patients.

METHODS

Cross-sectional and multi-center study performed in consecutive AF patients ≥ 75 years treated with oral anticoagulants ≥ 3 months attended in Internal Medicine Departments in Spain.

RESULTS

A total of 837 patients (83.0 ± 5.0 years; CHA2DS2-VASc: 5.0 ± 1.4; HAS-BLED: 2.1 ± 0.9) were included. 44.4% of patients had some degree of dependency, 43.3% were fragile, and 32.3% had cognitive impairment. Patients with any of these conditions were older, had a worse clinical profile, with more comorbidities and higher risks of thromboembolic and bleeding events. All these conditions were independently associated among them. Overall, 70.8% of patients were taking vitamin K antagonists, the remaining 29.2% direct oral anticoagulants and 9.7% oral antiplatelets. This distribution was independent of the presence of dependency or fragility, but there was a trend to a higher prescription of vitamin K antagonists in those patients with cognitive impairment (75.2% vs. 68.8%; P = 0.05).

CONCLUSIONS

Approximately 32%-44% of elderly anticoagulated AF patients attended have some degree of dependency, fragility and/or cognitive impairment. Patients with any of these conditions are older and have a worse clinical profile. Approximately 71% of patients are taking vitamin K antagonists, regardless dependency or frailty, but with a trend to higher prescription in patients with cognitive impairment.