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

Prescription of oral anticoagulation in geriatric patients with atrial fibrillation

Objective

To determine the prevalence of prescription of oral anticoagulation in patients aged > 60 years with nonvalvular atrial fibrillation (NVAF).

Methods

Observational, cross-sectional, retrospective study based on a review of the clinical ­histories of patients aged >60 years diagnosed with NVAF from July 1 to September 30, 2019 and seen at the outpatient clinic (cardiology, internal medicine, geriatrics) of a secondary-level hospital in Queretaro, Mexico. Clinical profile and oral anticoagulant treatment were analyzed.

Results

The study population comprised 300 patients (mean age, 77.2±8.3 years; 53.3% women; 81% attended in cardiology). Of these, 91% had a high thromboembolic risk, 22.7% a high bleeding risk, and 1.7% contraindications for anticoagulation. Comorbidity was frequent. As for therapy, 82.7% were taking direct oral anticoagulants (DOAC), 11.0% vitamin K antagonists (VKA), and 6.3% no anticoagulant treatment. Anticoagulant therapy was inappropriate in 29.3% of patients, mainly because DOAC were prescribed without adjusting for age, weight, or serum creatinine and administered without indication according to thromboembolic risk. Only 39.4% of patients taking VKA were within the therapeutic range. Of all patients receiving DOAC, 48.0% were taking rivaroxaban, mainly at 20 mg/d (73.1%).

Conclusions

Thromboembolic risk is high in geriatric patients with NVAF. Anticoagulation is contraindicated in <2% of patients. Oral anticoagulants are prescribed inappropriately in three out of ten patients.

Direct Oral Anticoagulants versus Vitamin K Antagonists in Patients Aged 80 Years and Older

The effectiveness of direct oral anticoagulants (DOAC) is non-inferior to vitamin K antagonists (VKA) to treat atrial fibrillation and venous thromboembolism (VTE). In this cross-sectional study, we compared older persons taking DOACs to those taking VKAs. We included ambulatory individuals ≥80 years, affiliated to Mutualité Sociale Agricole of Burgundy, who were refunded for a medical prescription in September 2017. The demographic conditions, registered chronic diseases (RCD), and number and types of prescribed drugs were compared in the DOAC group and VKA group. Of the 3190 included individuals, 1279 (40%) were prescribed DOACs and 1911 (60%) VKAs. Individuals taking VKAs were older than those taking DOACs (87.11 vs. 86.35 years). In the DOAC group, there were more women (51.92% vs. 48.25%) (p = 0.043), less RCD (89.60% vs. 92.73%) (p = 0.002), less VTE (1.80% vs. 6.59%), less severe heart failure (58.09% vs. 67.87%), less severe hypertension (18.22% vs. 23.60%), less severe kidney diseases (1.49% vs. 3.82%), and fewer drugs per prescription (6.15 vs. 6.66) (p < 0.01 for all). The DOAC group were also less likely to be taking angiotensin receptor blockers (10.79% vs. 13.97%), furosemide (40.81% vs. 49.66%) or digoxin (10.32% vs. 13.66%) than the VKA group (p = 0.009, p < 0.001, and p = 0.005). DOACs were less prescribed than VKAs. Individuals taking VKAs were older and had more severe comorbidities and more drugs per prescription than those taking DOACs.

The Prescription of Vitamin K Antagonists in a Very Old Population: A Cross-Sectional Study of 8696 Ambulatory Subjects Aged Over 85 Years

We compared very elderly people taking vitamin K antagonists (VKA) and those not taking VKA (noVKA). Individuals were included in the noVKA group if there was no VKA on their reimbursed prescriptions during the study period. We also compared three subgroups, constituted by VKA type (fluindione, warfarin, or acenocoumarol). We included individuals aged over 85 years, affiliated to Mutualité Sociale Agricole of Burgundy, who were refunded for prescribed VKA in September 2017. The VKA and noVKA groups were compared in terms of demographic conditions, registered chronic diseases (RCD), number of drugs per prescription and cardiovascular medications. The three VKA subgroups were compared for the same items plus laboratory monitoring, novel and refill VKA prescriptions, and prescriber specialty. Of the 8696 included individuals, 1157 (13.30%) were prescribed VKA. Mean age was 90 years. The noVKA group had fewer women (53.67 vs 66.08%), more RCD (93.43 vs. 71.96%) and more drugs per prescription (6.65 vs. 5.18) than the VKA group (all p < 0.01). Except for direct oral anticoagulants and platelet aggregation inhibitors, the VKA group took significantly more cardiovascular medications. The most commonly prescribed VKA was fluindione (59.46%). Mean age was higher in the warfarin (90.42) than in the acenocoumarol (89.83) or fluindione (89.71) subgroups (p < 0.01). No differences were observed for sex (women were predominant) or RCD. 13% of subjects in this population had a VKA prescription. Fluindione was the most commonly prescribed VKA.

The Relationships Between Vitamin K and Cognition: A Review of Current Evidence

Vitamin K is a fat-soluble nutrient discovered in 1935 and its role in blood coagulation has been thoroughly explored. In recent years, studies conducted in vitro and on animals highlighted vitamin K involvement in brain cells development and survival. In particular, vitamin K seems to have an antiapoptotic and anti-inflammatory effect mediated by the activation of Growth Arrest Specific Gene 6 and Protein S. Moreover, this vitamin is involved in sphingolipids metabolism, a class of lipids that participate in the proliferation, differentiation, and survival of brain cells. An altered expression in sphingolipids profile has been related to neuroinflammation and neurodegeneration. This review stems from a growing interest in the role of vitamin K in brain functions, especially in cognition, also in view of an expected increase of prevalence of Alzheimer's disease and other forms of dementia. It collects recent researches that show interesting, even though not definitive, evidence of a direct correlation between vitamin K levels and cognitive performance. Moreover, vitamin K antagonists, used worldwide as oral anticoagulants, according to recent studies may have a negative influence on cognitive domains such as visual memory, verbal fluency and brain volume. The aim of this review is to analyze the evidence of clinical studies carried out up to date on the relationship between vitamin K intake and cognitive performances. The involvement of vitamin K antagonists (VKAs) in declining cognitive performances is also addressed separately.