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AHRQ Submitted Comments on Key Questions for Stroke Prevention in Atrial Fibrillation–2012

Published September 28, 2012

September 28, 2012

Agency for Health Research and Quality
Effective Health Care Program
Scientific Resource Center, Oregon EPC Mail code: BICC 3181 S.W. Sam Jackson Park Road Portland, Oregon 97239-3098
Re: Draft Report on Comparative Effectiveness Review (CER) of Stroke Prevention in Atrial Fibrillation

Dear Sir or Madam,

Because of the growing impact atrial fibrillation (AFib) is having on our aging population, the AFib Optimal Treatment Task Force, comprised of 12 leading organizations in the thrombosis space, was formed in 2011 to raise awareness of the impact of the disease and to explore issues related to the process used by healthcare providers to assess stroke and bleeding risk in making decisions about anticoagulation therapy for older patients with AFib. We submitted comments to the Agency for Health Research and Quality (AHRQ) in October of 2011 on the importance of reviewing both stroke and bleeding risk assessment tools in the Effective Health Care Program’s comparative effectiveness study of stroke prevention in AFib, and we appreciate the opportunity to provide additional comments on the findings included in the draft report.

General Comments

We agree with AHRQ’s finding that stroke prevention in patients with AFib in clinical practice is complex and challenging but critically important given the morbidity and mortality associated with stroke events. AFib is associated with an approximate doubling of mortality risk, in large part due to the increased risk of stroke1. There are currently conflicting clinical guidelines and educational efforts, which leads to confusion about how healthcare providers should determine stroke risk and bleeding risk in patients with AFib, what tools should be used, and how best to incorporate scores from these tools into treatment decision making with their patients. The result is commonly the underutilization of anticoagulants, particularly in older patients who are often at a perceived higher risk of bleeding. This is a major obstacle to effective care that reduces morbidity and mortality for this condition.

We were pleased that AHRQ included a key question in this review on the strength of evidence to support the validity of current bleeding risk assessment tools in addition to tools available to determine a patient’s risk of stroke. Bleeding risk assessment is not only important because it can uncover risk factors for serious bleeding such as intracranial hemorrhage, but also because it can identify modifiable risk factors that can be addressed before a patient receives anticoagulation therapy.

Supporting Consensus

The AFib Optimal Treatment Task Force convened a roundtable of experts in cardiology, neurology and other related fields on January 18, 2012 to forge consensus on the best practices for assessing stroke and bleeding risk in anticoagulation decision-making using available risk assessment tools. These experts subsequently developed a consensus statement (see Appendix A) to provide guidance to health care providers on evaluating patients with AFib. This consensus statement aligns with and supports the AHRQ recommendations.

In the consensus statement, the experts recommend a three-step approach:

  • First, a patient’s stroke risk should be assessed and recorded no less than annually using an established scoring tool. Those identified as intermediate or high risk should be put on an anticoagulant—warfarin or a direct thrombin inhibitor or a factor Xa inhibitor. Aspirin is not recommended for stroke prophylaxis in AFib.
  • Second, if the patient is at high enough risk to require anticoagulation therapy, the patient’s bleeding risk should then be evaluated to estimate the net clinical benefit of an anticoagulant Risk factors for intracranial hemorrhage should be considered although routine screening for these risk factors is not currently indicated. For the majority of patients, the net benefit of stroke prophylaxis supersedes the “net harm” of serious bleeding events—even in older patients.
  • Third, the decision to undergo anticoagulation therapy must reflect patient preferences and values. The patient must also understand the relative benefits and risks involved in the discussion and decision surrounding the clinical net benefit of anticoagulation therapy.

In addition to this recommended approach, our roundtable experts agreed that priority should be given to collecting and analyzing real-world data on new anticoagulants to identify which patients are best suited for specific agents. The experts identified needed health care professional and patient education materials and tools to support both risk assessment and implementation of new anticoagulation therapies. They also highlighted areas requiring additional research.

Supporting AHRQ’s identified research gaps in the areas of risk stratification for thromboembolic and bleeding risk, our roundtable experts concluded that more research is needed into specific risks associated with intracranial hemorrhage, including the biological (versus chronological) age, frailty and specific findings on brain imaging. The roundtable experts also suggest that further refinement of stroke risk stratification could result in identifying patients who are truly at low risk for a stroke and who
presumably have a low net clinical benefit from anticoagulation. Such refinement could improve the predictive value of risk stratification tools, however there will still be the need for additional healthcare provider education on the risks and benefits of new and existing treatments for stroke prevention in AFib and facilitating a dialogue with patients about their individual risk of stroke and the benefit of treatment.


The AFib Optimal Treatment Task Force applauds AHRQ’s efforts to undertake a review of stroke prevention in AFib. The Task Force consensus statement supports many of the findings in the draft CER report and we agree that additional research on risk assessment and prediction tools may lead to a more accurate stratification of AFib patients according to their stroke and bleeding risk. With as many as 1 in 10 Americans afflicted with AFib by age 802, this disease is a pressing problem for our health care system, making this stratification and how it affects decision making on anticoagulation therapy critically important. If you have any questions or require additional information, please contact Cynthia Bens, Director of Public Policy at the Alliance for Aging Research at [email protected] or 202-293-2856.

Alliance for Aging Research
Anticoagulation Forum
Atrial Fibrillation Association
Heart Rhythm Society
Mended Hearts
Men’s Health Network
Preventive Cardiovascular Nurses Association
Society for Women’s Health Research

1 Benjamin, E, P Wolf, R D’Agostino, H Silbershatz, W Kannel, and D Levy. 1998. Impact of atrial fibrillation on the risk of death: The Framingham Heart Study. Circ 98(10):946-52.
2 Go, AS, EM Hylek, KA Phillips, Y Chang, LE Henault, JV Selby, and DE Singer. 2001. Prevalence of Diagnosed Atrial Fibrillation in Adults: National implications for rhythm management and stroke prevention—the AnTicoagulation and Risk Factors In Atrial Fibrillation (ATRIA) Study. JAMA. 285(18):2370-5.