Research from the ACC’s PINNACLE Registry® indicates that in the U.S. anticoagulation therapy for eligible patients with atrial fibrillation (AF) is suboptimal and varies widely from practice to practice1. Less well understood are global anticoagulation patterns, especially in emerging markets. Even in developed countries, understanding the perceptual and systemic issues underlying suboptimal anticoagulation rates requires further investigation.

Level of Control Over Anticoagulation Options by CountryTo develop a broader understanding of the causes of gaps in anticoagulation for eligible patients, the ACC launched Project TREAT-RISK (Transnational Evaluation of AF Therapy for the Reduction of Ischemic Stroke). Results from TREAT-RISK will help inform the ACC’s AF-focused quality improvement programs, including awareness building, educational programs and tools.

The first stage of TREAT-RISK included a major transnational survey of AF treatment patterns from June to July 2012. A total of 1,134 cardiologists responded and were based in the U.S. (232), Brazil (261), China (145), Germany (125), India (218) and the United Kingdom (U.K.) (153).

The survey showed that AF treatment is a global concern for practicing cardiologists, as nearly all cardiologists surveyed currently treat patients with AF: 99% in the U.K., 97% in the U.S., 96% in Germany, and 95% in Brazil, China and India. AF patient prevalence was consistent across country, practice setting and gender.

Cardiologists in all six countries report that they prescribe warfarin or another anticoagulant for the majority of their eligible AF patients, with the highest mean rate in the U.S. (82%) and the lowest in China (58%). Furthermore, in the U.S. and U.K., 27% and 24% of cardiologists respectively stated that they prescribe an anticoagulant for 100% of their eligible patients.

In all countries, a strong majority of providers stated that balancing stroke prevention and bleeding is their primary objective when contemplating an anticoagulation strategy, though considerable minorities in Germany (27%), Brazil (20%), and the U.S. (16%) replied that ischemic stroke prevention is the primary objective.

Cardiologists in India and China were least likely to prescribe an anticoagulant for patients over age 75, with only 47% and 43%, respectively, reporting that they “always” or “frequently” anticoagulate these patients. Cardiologists in Germany (93%), the U.K. (92%), and the U.S. (88%) were far more likely to always or frequently anticoagulate patients over age 75, followed by cardiologists in Brazil (65%).

Anticoagulation With Older PatientsAcross all countries, most cardiologists (72%) would consider switching patients from warfarin to a novel oral anticoagulant. Stroke prevention efficacy (57%) and bleeding risk (52%) were selected as two of the “most important” factors considered when switching patients from warfarin to a novel oral anticoagulant, followed by ease of use (39%). Stroke prevention efficacy was most important to cardiologists in the U.S. and U.K. Many of the issues with anticoagulation using warfarin are at least generally understood: safety, bleed risk, patient preference, and stroke prevention efficacy. The introduction of novel oral anticoagulants has added cost as a further consideration.

Willingness to prescribe a novel oral anticoagulant drops considerably, across all countries – from 72% when cost is not a factor to 17% when cost is considered. Cost is a more central concern in India, Brazil, and the U.S. These findings may be expected, as cardiologists report that patients in India and Brazil are most likely to pay out of pocket for an anticoagulation treatment while the government is the primary payer in Germany and the U.K. Patients in the U.S. and China typically pay for treatment themselves, in conjunction with government and private payers.

Control over anticoagulation options in the care setting is another factor impacting the introduction of new anticoagulants. Nearly all cardiologists (87%) have some level of control over anticoagulation options and nearly half (47%) report a “high level” control.

The ACC will continue to analyze and release findings from the TREAT-RISK Project in the months ahead. Issues of balancing stroke risk against bleeding risk, perceptions of bleeding risk, and the impact of comorbidities and other attendant medication therapies also surfaced in the survey findings and should prove a rich vein for continued investigation. In addition, the College is currently in the early stages of developing a comprehensive initiative to address gaps in treatment of anticoagulation therapy and to encourage compliance with guideline-recommended care.


  1. Chan PS, Maddox TM, Tang F, Spinler S, Spertus JA. Practice-level variation in warfarin use among outpatients with atrial fibrillation (from NCDR PINNACLE Program). American Journal of Cardiology. 2011; 108:1136-1140