DOACs for Atrial Fibrillation, Why Are So Many AF Patients NOT on Anticoagulation? David Garcia, MD April 2017
Disclosures for David Garcia Consultancy: Boehringer Ingelheim; Bristol-Meyers Squibb; Daiichi Sankyo; Incyte; Pfizer Research Funding: Daiichi Sankyo; Incyte; Janssen Speakers Bureau: None Promotional Presentations: None Discussion of off-label drug use: None
AC is historically underutilized in patients with AF Circulation. 2014;129:1568-1576 Oldgren et al. Circulation. 2014 Apr 15;129(15):1568-76
Why is AC Underutilized? Error of Omission vs. Commission AF is an asymptomatic risk factor AC is burdensome and/or expensive Risk-benefit decision is complex
CHADS 2 Score Correlates with Bleeding Risk in Elderly Poli et al. Thrombosis Research (2007) 121, 347 352
CHA 2 DS 2 VASc Score Correlates with Bleeding Risk Roldan et al. J Am Coll Cardiol. 2013 Dec 10;62(23):2199-204.
Can Doctors Predict Patients Preferences? Patients from 3 different primary care practices (none had AF) (n = 96) Internal medicine, family medicine, cardiology physicians (n = 96) Study set in Spain Various health states were described Major stroke, minor stroke, major bleeding and burden of treatment with warfarin
Probability Trade-off Scenario Alonso-Coello P, et al. Health Expectations, 18, pp.2318 2327
Who Participated Patients Physicians Alonso-Coello P, et al. Health Expectations, 18, pp.2318 2327
Number of GIBs acceptable in exchange for 3% reduction in stroke risk (per 100 pts over 2 years) Dark blue = patients Light blue = physicians Median acceptable # of GI Bleeds not different (10) Physicians whose pts had previously experienced a major bleed on warfarin or stroke without warfarin were willing to tolerate a higher number of bleeding events (15 16) Alonso-Coello P, et al. Health Expectations, 18, pp.2318 2327
ORBIT-AF : a U.S. Registry Data collected 2010 2011 174 ambulatory care sites Primary care, cardiology, electrophysiology practices 9,553 patients with AF prior intracranial hemorrhage, allergy, and pregnancy, excluded (n = 89)
Proportion Taking an Anticoagulant All patients (n=9553) On Oral AC Not on Oral AC 78% 22% CHA 2 DS 2 VASc 2 (n = 8786) 79% 21% Hess et al. Am J Med. 2016 Nov 23. pii: S0002-9343(16)31195-0 doi: 10.1016/j.amjmed.2016.11.001. [Epub ahead of print]
Factors Associated with OAC Non-use Atrial fibrillation type (reference = new-onset) paroxysmal OR 0.73 persistent OR 0.35 permanent OR 0.14 left atrial enlargement (reference = normal diameter) mild OR 0.80 moderate OR 0.58 severe OR 0.53 Less likely to take OAC Less likely to take OAC Age >80 years OR 1.04 (per 1-year increase) Hess et al. Am J Med. 2016 Nov 23. pii: S0002-9343(16)31195-0 doi: 10.1016/j.amjmed.2016.11.001. [Epub ahead of print]
Other Factors that Decreased OAC Use History of coronary artery disease Alcohol abuse Cancer Hess et al. Am J Med. 2016 Nov 23. pii: S0002-9343(16)31195-0 doi: 10.1016/j.amjmed.2016.11.001. [Epub ahead of print]
ORBIT-AF Interpretation Perhaps some of these decisions not to anti-coagulate are appropriate One-fifth of the patients not treated with OAC had CHA 2 DS 2 VASc = 0 1 Increasing # of co-morbidities correlated with less OAC use This study likely over-estimates the proportion of AF patients on OAC Included sites may not be representative of general practice Possible Hawthorne Effect
Are DOACs Increasing the Proportion of AF Patients on Treatment? 2008 2010 2011 2012 2013 2014 2013 2014 Alamneh et al. Am J Cardiovasc Drugs (2016) 16:183 200
Office Visits for AF with Anticoagulant Use Barnes et al. Am J Med. 2015 Dec; 128(12): 1300 1305.e2
Quarterly Office Visits by AC Type Barnes et al. Am J Med. 2015 Dec; 128(12): 1300 1305.e2
Conclusion In the United States, it appears that many (though certainly not all) AF patients who stand to benefit from AC are receiving it. The arrival of the DOACs may have increased the overall proportion of AF patients on AC. The reasons for AC non-use among AF patients are complex (and sometimes legitimate)