Author + information
- Eric D. Peterson, MD, MPH∗ ( and )
- Sean D. Pokorney, MD, MBA
- ↵∗Address for correspondence:
Dr. Eric D. Peterson, Duke Clinical Research Institute, Duke University Medical Center, 2400 Pratt Street, PO Box 17969, Durham, North Carolina 27705.
Atrial fibrillation (AF) is the most common cardiac arrhythmia, affecting >33 million patients worldwide (1). If not adequately treated, patients with AF face a high risk for ischemic stroke (1). Fortunately, oral anticoagulation (OAC) with vitamin K antagonists (VKAs) can reduce stroke risk in AF by more than two-thirds (2). Recently, clinical trials have found that several direct oral anticoagulants (DOACs) were equivalent or more effective than VKAs for AF stroke prevention (3).
Unfortunately, studies have demonstrated major gaps in the use of AF stroke prevention among eligible patients. A global registry in 46 countries found that only one-third (34%) of patients with guideline indications for OAC actually received them (4). Although use of OAC in AF patients was slightly better in the United States, treatment remained suboptimal (52%) (4). As a result, there are hundreds of thousands of preventable strokes worldwide each year.
Perceived barriers to the broader use of OAC in clinical practice include challenges with use of VKAs. Patients using VKAs face multiple dietary and drug interactions, and patients are required to have frequent blood draws for drug monitoring. When the DOAC medications, which are safer and easier to use than VKAs (3), received regulatory approval, many believed DOACs would be widely adopted and quickly become the dominant drugs used for AF stroke prevention. It was also hoped that the DOAC era would lead to a dramatic increase in the proportion of patients with AF receiving appropriate anticoagulation. In this issue of the Journal, Marzec et al. (5) show that neither of these rosy expectations have borne out.
Marzec et al. (5) investigated temporal trends in OAC use for stroke prevention among 655,000 AF patients treated at U.S. cardiology practices that volunteered to participate in the National Cardiovascular Data Registry (NCDR) Practice Innovation and Clinical Excellence (PINNACLE) registry. The investigators found that the adoption of DOACs in the United States has been slow and highly variable. As of 2014, VKAs remained the dominant OAC strategy for AF stroke prevention. Even more disturbing, the investigators found that over a nearly 7-year period, overall use of OAC increased only slightly from 52.4% to 60.7% among AF patients with a guideline indication for OAC. Said another way, up to 4 in 10 AF patients with elevated stroke risk still fail to receive effective stroke prophylaxis in contemporary clinical practice.
The study has many strengths, including the large number of sites and patients studied, the high quality of clinical data collected through the registry, and the study’s ability to specifically analyze those who met American College of Cardiology/American Heart Association guideline eligibility criteria (CHA2DS2-VASc score ≥2). The study also had some limitations. First, the PINNICLE registry was limited to cardiology practices that actively volunteer to participate in this national quality improvement registry, and results from PINNACLE might have overestimated adoption of DOACs and overall use of OAC in nonparticipating practices. Second, most data in PINNACLE was abstracted from electronic health records and might not have fully captured information on patient treatment preferences or contraindications to OAC. Third, the study lacked information on patient socioeconomic or pharmacy benefit status, which might affect use of the more costly DOACs.
These minor weaknesses aside, the current analysis provided a sobering message to clinicians. Even if the registry missed some patients with OAC contraindications or documented refusals, there is still likely a large gap between what is possible and what is actually being delivered for AF stroke prevention in contemporary clinical care. This is even more profound because the study only assessed overall prescriptions of OAC and not adequacy of dosing. Previous studies showed that up to 35% of the time, patients in community practice and treated with a VKA will not be in a therapeutic range (6). Similarly, those treated with DOACs often are underdosed relative to treatment recommendations (7). Combined, this likely means that a minority of AF patients are receiving effective stroke prophylaxis.
The PINNACLE Registry also begins to explore reasons why there has been such slow adoption of DOACs and why there is underutilization of OAC. The study found that use of P2Y12 receptor inhibitors was associated with a failure to receive OAC, in part reflecting clinicians concerns regarding bleeding risks when combining dual antiplatelet use with OAC. We hope that recent and ongoing trials that evaluate treatment regimens that drop aspirin will lead to higher treatment rates in patients requiring P2Y12 inhibitor therapy (8,9).
The study also found that patients’ providers were the strongest predictor of both use of OAC and adoption of DOACs. Some practices consistently used OAC in up to 70% of cases, whereas use in other practices was as low as 10%. Similarly, although some clinicians adopted DOAC use in nearly 40% of cases, others almost never used these agents. Thus, the problem may be amenable to focused change initiatives.
This study should incite an urgent call to action. The good news for our profession is that health care providers have faced and overcome similar quality challenges in the past. One example is the use of beta-blockers after an acute myocardial infarction (MI). In the 1990s, less than one-half of Medicare patients received beta-blockers post-MI, whereas a decade later, 96% of eligible MI patients received beta-blockers at discharge (10). A combination of initiatives drove this change. Several regional and national quality improvement projects targeted the issue. Each encouraged practices to consistently measure drug use, benchmark their performance relative to peers, implement local quality initiatives, and then re-measure to assure improvement (11–13). Further increases in beta-blocker use were seen when post-MI beta-blocker use was made a national performance measure used in public reporting and pay-for-performance metrics by the Centers for Medicare and Medicaid. Now, failure to give a beta-blocker to eligible MI patients has become so rare that some have questioned whether ongoing measurement is needed.
Stroke prevention for AF seems ideally suited for a similar national improvement campaign. Effective OAC use could substantially reduce morbidity and mortality associated with AF-related strokes, as well as have a marked effect on patient quality of life and overall health care costs. Moving forward, several important efforts are needed. First, there needs to be further evaluation of the underlying causes for underuse of OAC with AF, including detailed information from providers and patients. Second, the large degree of practice variation invites examination of “leading versus lagging” centers to identify practices and processes that result in more consistent evidence-based care. Third, registries such as PINNACLE and the American Heart Association’s Get With the Guidelines Atrial Fibrillation need to continue to monitor the quality of AF stroke prophylaxis as local, regional, and national quality improvement initiatives are conducted. Finally, use and appropriate dosing of OAC in AF need to become national performance measures, linked to public reporting and pay-for-performance.
Just as we did for MI care, we need a national, professional response to the underuse of evidence-based stroke prevention treatments in AF. Strong clinical trial evidence demonstrates the efficacy of VKAs and DOACs for stroke prevention, and efforts now need to be focused on bringing evidence to practice. Combined and united, our profession should find ways of bridging the gap in AF stroke prevention care and improving the quality of care delivered to AF patients.
↵∗ Editorials published in the Journal of the American College of Cardiology reflect the views of the authors and do not necessarily represent the views of JACC or the American College of Cardiology.
Dr. Peterson has received research grants from Eli Lilly & Company, Genentech Inc., Janssen Pharmaceuticals, Inc., and the American Heart Association; and has received consultant/advisory board support from Boehringer Ingelheim, Bristol-Myers Squibb, Janssen Pharmaceuticals, Inc., Pfizer, and Genentech Inc. Dr. Pokroney has received consulting support from Bristol-Myers Squibb, Boston Scientific, and Medtronic; and has received research support from Gilead, Boston Scientific, Bristol-Myers Squibb, Janssen Pharmaceuticals, and the Food and Drug Administration.
- 2017 American College of Cardiology Foundation
- January C.T.,
- Wann L.S.,
- Alpert J.S.,
- et al.
- Oldgren J.,
- Healey J.S.,
- Ezekowitz M.,
- et al.
- Marzec L.N.,
- Wang J.,
- Shah N.D.,
- et al.
- Steinberg B.A.,
- Shrader P.,
- Thomas L.,
- et al.
- Gibson C.M.,
- Mehran R.,
- Bode R.,
- et al.
- Eagle K.A.,
- Montoye C.K.,
- Riba A.L.,
- et al.
- Peterson E.D.,
- Roe M.T.,
- Rumsfeld J.S.,
- et al.