Long-term oral anticoagulation for atrial fibrillation in low and middle income countries

Abstract

With increasing life-expectancy and changing demographics, non-valvular atrial fibrillation (AF) is currently the most common indication for long-term oral anticoagulation (OAC) in low and middle income countries (LMICs). Due to a decreasing trend in the prevalence of rheumatic heart disease (RHD), valve disease as a primary cause of AF now constitutes a small fraction of all people with AF. Moreover, emerging data also indicate that, patients with significant valve disease and AF may have a risk of stroke similar to, if not lower than, those with non-valvular AF. Previous trials of anticoagulation for AF excluded people from LMICs partly because valvular AF constituted a large proportion of those with AF, and it was thought to confer a prohibitively high risk of stroke. Trialists should therefore be less reluctant to include patients with AF from LMICs in general, and those with valve disease in particular, in future trials of anticoagulation. The quality of vitamin K antagonist based oral anticoagulation remains poor in LMICs to a large extent because of poor monitoring. The widespread use of the direct oral anticoagulants (DOAC) presents a practical approach to improve anticoagulation quality. Randomised trials of DOACs in valvular AF are particularlycriticalto bridge the knowledge gap in this area. Discussions regarding oral anticoagulation (OAC) use in low and middle income countries (LMICs) have historicallybeendominated by severallong-held beliefs. The first is that the quality of vitamin K antagonist (VKA) based anticoagulation is poor in these countries. The veracity of this assumption is supported by a large number of studies documenting both lower prescription of OACs, and a lower proportion of international normalised ratio (INR) values in the therapeutic range. 1 The second is that a large proportion of patients receiving OAC in LMICs have atrial fibrillation (AF) related to valvular heart disease, and rheumatic mitral stenosis in particular. This assumption, perhaps valid several decades ago, is no longer supported by the data. Finally, patients with valvular heart disease and AF (specifically those with moderate or severe valve lesions), are thought to be at prohibitively high thromboembolic risk. 2 However, recent evidence suggests that this risk may have been overestimated. 3 4 Nevertheless, the aforementioned assumptions continue to contribute to the underrepresentation of patients from LMICs in clinical trials of oral anticoagulation. Knowledge of the characteristics of contemporary patients in LMICs who are eligible for long-term OAC, estimates of their stroke risk, and a better understanding of the drivers of poor anticoagulation quality, may help guide research and clinical practice. In this review, we seek to provide an evidence-based perspective on OAC use in patients with AF living in LMICs and China.

Global Oral Anticoagulation Use Varies by Region in Patients With Recent Diagnosis of Atrial Fibrillation: The GLORIA‐AF Phase III Registry

“…Differences seen might result from systemwide differences in management among regions because pf local AF guidelines, health care systems, or socioeconomic factors. 12 , 13 , 21 The high use of antiplatelet drugs in patients from Asia was previously reported. 22 , 23 , 24 , 25 Reasons are likely multifactorial.…”

Stroke in Sierra Leone: Case fatality rate and functional outcome after stroke in Freetown

“…Atrial fibrillation detection should be increased through use of cardiac holters or wearable smart devices with proven diagnostic accuracy 39 . Atrial fibrillation diagnosis and management remains challenging in our setting, with the prohibitive costs of direct oral anticoagulants 40 , and low levels of access to affordable and reliable International Normalized Ratio (INR) monitoring to allow safe and effective warfarin prescription 41,42 . In hospital complications were associated with fatality and worse functional outcome, demonstrating the need to implement evidence based stroke care, such as stroke unit based care, inclusive of swallow screening for the prevention of aspiration pneumonia 15 .…”

“…38 Atrial fibrillation diagnosis and management remains challenging in our setting, with the prohibitive costs of direct oral anticoagulants, 39 and low levels of access to affordable and reliable International Normalized Ratio (INR) monitoring to allow safe and effective warfarin prescription. 40,41 In-hospital complications were associated with fatality and worse functional outcome, demonstrating the need to implement evidence-based stroke care, such as stroke unitbased care, inclusive of swallow screening for the prevention of aspiration pneumonia. 14 Our previous study found male sex to be associated with in-hospital fatality 14 ; we demonstrate this finding again for long-term fatality (HR: 1.28 (1.05-1.56)).…”

Global burden of atrial fibrillation/flutter due to high systolic blood pressure from 1990 to 2019: estimates from the global burden of disease study 2019

“…The inequalities in disease burden can partially be attributable to the treatment conditions, such as the use of new oral anticoagulants, left atrial appendage occlusion, and catheter or cryogenic balloon ablation, which are distributed unequally in different socioeconomic regions. 22,23 It is reported that patients living in the most deprived areas were 15% less likely to receive oral anticoagulation, compared to patients living in the least deprived areas. 24 In addition, population aging as well as some metabolic and behavioral risk factors, including diabetes, obesity, tobacco use, and sedentary lifestyle, tend to increase with development.…”

“…The AF/AFL burden was associated with the socioeconomic development and skewed more toward middle, low‐middle, and low‐SDI countries. The inequalities in disease burden can partially be attributable to the treatment conditions, such as the use of new oral anticoagulants, left atrial appendage occlusion, and catheter or cryogenic balloon ablation, which are distributed unequally in different socioeconomic regions 22,23 . It is reported that patients living in the most deprived areas were 15% less likely to receive oral anticoagulation, compared to patients living in the least deprived areas 24 .…”