South Asia Perspective
According to data from the Indian atrial fibrillation (AF) registries and multinational trials, AF in South Asia strikes at a younger age than in other parts of the world; has both valvular and nonvalvular preponderance; is more frequently associated with comorbidities such as rheumatic heart disease, hypertension, diabetes mellitus, coronary artery disease, or heart failure; and is persistent in about two-thirds of patients. Anticoagulants are grossly underprescribed to reduce cardioembolic stroke and mortality in AF and, contrary to guidelines, antiplatelets alone are still preferred in a sizeable eligible population here. The other major indications for anticoagulation—venous thromboembolism and pulmonary embolism—are underreported and not optimally treated. It is too early to comment on novel emerging indications such as chronic vascular disease or acute coronary syndrome.
India-specific data on injectable anticoagulants such as heparin (including low-molecular-weight heparin) and fondaparinux are scarce and possibly their safety and efficacy are the same as elsewhere. Among oral anticoagulants, vitamin K antagonists (VKAs), warfarin, and acenocoumarol are the preferred drugs due to years of familiarity, cost effectiveness, reliable titration, and lack of alternatives in patients with AF and valvular heart disease. Inadequate monitoring, poor dose adjustment, and underdosing continue to dodge effective utilization. High consumption of green leafy vegetables and poor health-care infrastructure in rural areas compound the problem. Drugs (anti-inflammatory agents, antibiotics, antitubercular agents) and herbs are used in a significant number of patients, leading to harmful drug interactions. The preference for direct oral anticoagulants (DOACs) has been gradually growing over the last decade in South Asia, especially in nonvalvular AF, with comparable efficacy and bleeding risk.
Future challenges include changing age-old practices, combining antiplatelets and oral anticoagulants (lower doses) in different permutations, and convincing the sizable eligible population to accept oral anticoagulation, particularly DOACs, to mitigate stroke incidence and mortality.
