Physician's Weekly Article - New Performance Measures for Atrial Fibrillation

       New performance measures for the treatment of non-valvular atrial fibrillation and atrial flutter have been released, stressing the need for assessing thromboembolic risk factors and for appropriate anticoagulant therapy.

      In February 2008, the American College of Cardiology (ACC) and the American Heart Association (AHA) developed new performance measures for nonvalvular atrial fibrillation (AF) to facilitate the translation of scientific evidence into clinical practice. “We extracted what we consider to be three measures best supported by evidence from the new guidelines for the treatment of AF,” says N.A. Mark Estes III, MD, FACC, FAHA, FHRS, who chaired the writing committee. “These measures include the stratification of patients according to risk, the employment of warfarin therapy, and the strict monitoring of the international normalized ratio [INR]. Physicians should view these performance measures as an earnest attempt by professional societies to help physicians assess their performance as related to what’s considered the best recommendations for AF, not as bureaucratic burden.”

      Assessing Three Key Measures

      In addition to prior stroke or transient ischemic attack—two of the most powerful independent predictors of stroke—heart failure, impaired left ventricular systolic function, hypertension, advanced age, and diabetes have consistently emerged as risk factors for AF. “Overwhelming evidence shows that anticoagulation therapy, particularly warfarin, appears to reduce the risk of stroke in selected groups of patients,” says Dr. Estes. “As a result, the first performance measure we focused on was the assessment of thromboembolic risk. Risk stratification is an important part of good quality clinical care. When patients present, clinicians should stratify AF risk based on CHADS₂ scores [Table 1], a clinical prediction rule for estimating the risk of stroke in AF patients. The CHADS₂ index stands for cardiac failure, hypertension, age, diabetes, and stroke; the stroke risk has a subscripted two to represent that it is weighed twice as high as the other factors. Based on the available evidence, anticoagulation therapy should be considered for patients if they have a CHADS₂ score of 2.0 or greater. However, there are important exclusion criteria to consider [Table 2].”

      The second performance measure relates to the assessment of an individual patient for anticoagulation therapy. “Anticoagulation therapy with warfarin—a vitamin K antagonist—is recommended for patients with more than one moderate risk factor unless otherwise contraindicated,” says Dr. Estes (Table 3). “However, the decision to initiate warfarin should be determined by physicians based on the benefits and risks of anticoagulation therapy for each individual patient. If the benefits for anticoagulation therapy outweigh the risks, physicians should elect to start patients on warfarin.”

      The third performance measure is to monitor AF patients on warfarin with a monthly assessment of INR once anticoagulation is stable. The 2008 ACC/AHA performance measures note that frequent monitoring of INR levels is essential to directing warfarin dose adjustments to maintain anticoagulation intensity in the target range. “Physicians should aim to maintain INR scores between 2.0 and 3.0,” says Dr. Estes, “and more frequent monitoring may be required during the initiation of warfarin therapy.”

      Tracking Physician Performance

      Dr. Estes emphasizes that while the performance measures focus on AF, they should also be applied to atrial flutter because this condition has been associated with the same risk factors as AF. In addition, the ACC/AHA performance measures also contain paper-based specifications and assessment tools (also available online at www.acc.org) that may aid doctors as they manage patients with AF. “These performance measures are meant to be a practical and useful tool to help physicians assess their performance on a patient-by-patient basis,” Dr. Estes notes. “They can easily be incorporated into routine evaluations by ancillary staff, the patients themselves, and ultimately by electronic medical records that prompt medical personnel to determine AF and atrial flutter risk factors.”

      According to Dr. Estes, the writing committee and task force associated with the performance measures anticipate that their document will be used to direct reimbursement for pay-for-performance initiatives in the future. “Like all performance measures, the question is whether or not the document will help clinicians reduce the risk of stroke from AF or atrial flutter. Our next step is to demonstrate that these measures can improve patient outcomes as well as make the practice of medicine easier for physicians who treat these patients.”

      N.A. Mark Estes III, MD, FACC, FAHA, FHRS, has indicated to Physician’s Weekly that he has or has had the following financial interest: Boston Scientific, Medtronic, and St. Jude Medical.