Update on anti-coagulation in atrial fibrillation

Abstract

Atrial fibrillation (AF), the most common clinically relevant arrhythmia, affects 2.2 million individuals in the USA and 4.5 million in Europe, resulting in significant morbidity and mortality. Pharmacotherapy aimed at controlling both heart rate and rhythm is employed to relieve AF symptoms, though debate continues about which approach is preferable. AF prevalence rises with age from 0.4% to 1% in the general population to 11% in those aged >70 years. AF is associated with a pro-thrombotic state and other comorbidities; age, hypertension, heart failure and diabetes mellitus all play a key role in AF pathogenesis. Anti-coagulation is essential for stroke prevention in patients with AF and is recommended for patients with one or more risk factors for stroke. Used within the recommended therapeutic range, warfarin and other vitamin K antagonists decrease the incidence of stroke and mortality in AF patients. Warfarin remains under-used, however, because of the perceived high risk of haemorrhage, narrow therapeutic window and need for regular monitoring. Several novel anti-coagulants show promise in AF-related stroke prevention. In particular, the novel, oral, direct thrombin inhibitor, dabigatran etexilate, recently licensed by the US Food and Drug Administration (FDA) and Health Canada has shown improved efficacy and safety compared with warfarin for stroke prevention in AF, and has the potential to replace warfarin in this indication. The increasing number of new therapeutic options, including improved anti-arrhythmic agents, novel anti-coagulants and more accessible ablation techniques, are likely to deliver better care for AF patients in the near future.

Clinical Characteristics of Atrial Fibrillation in Saudi Women Cohort and Its Clinical Impact in a Tertiary University Hospital

“…The importance of anticoagulation cannot be understated, as shown in many studies, the ability of warfarin use to save up to 26% of lives and prevent 67% of strokes in patients with atrial fi brillation, adding to all the risks for women as mentioned [18][19][20][21] .…”

Analysis of Novel Anticoagulants for Atrial Fibrillation – Pharmacokinetics and Pharmacological Considerations

“…As the population ages, the incidence of AF is projected to increase by 2.5 fold in the next 50 years [2]. It is responsible for one-third of the hospitalizations for cardiac rhythm disturbances and is associated with significant morbidity and mortality, including a 4-fold to 5-fold increased risk of stroke and 3-fold increased risk of heart failure, resulting in significant effects on quality of life (QoL) [3]. Stroke is the third leading cause of death and the principal cause of serious, long-term disability in the United States, therefore exerting a high socioeconomic burden [4].…”

A Study of Elderly Adults Taking Warfarin Admitted with Prolonged International Normalized Ratio: A Community Hospital's Experience

“…Additional indications include the prophylaxis of recurrent thromboembolic events in individuals with venous thromboembolism and in those with prosthetic mechanical valves. Using the CHADS 2 (Congestive heart failure, Hypertension, Aged ≥75, Diabetes mellitus, Stroke or transient ischemic attack) score in treating elderly adults with atrial fibrillation has shown that they benefit from oral anticoagulant treatment for the prevention of ischemic cerebrovascular events . The benefits of oral anticoagulant treatment must always be weighed against the risk of major bleeding, especially in elderly adults .…”

“…It also requires regular INR tests and a dedicated family physician. In clinical practice, individuals have been shown to remain within the therapeutic range for less than 45% of the time . The recommended INR for most indications, such as atrial fibrillation and venous thromboembolism, is 2 to 3.…”