Guidelines say “no” to anticoagulation for young, otherwise healthy persons with atrial fibrillation. New research finds that clinical practice looks quite different.
Hsu JC, Chan PS, Tang F, Maddox TM, Marcus GM. Oral Anticoagulant Prescription in Patients With Atrial Fibrillation and a Low Risk of Thromboembolism: Insights From the NCDR PINNACLE Registry. JAMA Intern Med. Published online April 13, 2015. doi:10.1001/jamainternmed.2015.0920Access publication, here.
Use of oral anticoagulation (OAC) in patients with non-valvular atrial fibrillation (AF) at high risk for stroke or systemic embolism is known to reduce morbidity and mortality but must be weighed against risk of bleeding. Real-world practice patterns are highly variable and it is uncertain how often these agents are used in those who are the lowest risk for stroke. Study Goal: To characterize the use of oral anticoagulation and clinical predictors of use in low risk patients with AF (CHADS2=0 and CHA2DS2-VASc=0) in PINNACLE, a real-world clinical outpatient registry of the American College of Cardiology. (ACC).
1.7 million patients in PINNACLE, the largest U.S. registry of outpatient cardiology visits: 21% (359,315) identified with AF from 76 different practices in 33 states.-CHADS2=0 (n=10,995); CHA2DS2-VASc = 0 (n=6730). Hierarchical Poisson regression models adjusted for patient demographics and clinical characteristics.
Mean age ~51 years. Low risk patients prescribed anticoagulation were: more frequently older and insured by Medicare or uninsured; less likely to have paroxysmal AF or be smokers; had higher BMI; more likely to be from the Northeast and West.
Those with CHADS2=0 (n= 2561, 23.3%) were: more likely to be male; more likely to have dyslipidemia. In a multivariate model, the clinical predictors of anticoagulant use were: older age (adjusted RR 1.48 per 10 years, 95% CI 1.41-1.56; higher BMI (adjusted RR, 1.18 per 5 kg/m2; 95% CI, 1.14-1.22); Medicare c/w private insurance (adjusted RR, 1.32; 95% CI, 1.17-1.49); geographical location: South vs. Northeast U.S. (adjusted RR 0.69; 95% CI, 0.49-0.98).
There were 1787 (26.6%) patients with CHA2DS2-VASc=0. In a multivariate model, the clinical predictors of anticoagulant use in this population were similar to those with CHADS2=0: older age (adjusted RR, 1.44/10 years; 95% CI, 1.36-1.54); higher body mass index (adjusted RR, 1.19/5 kg/m2; 95% CI, 1.15-1.23); Medicare c/w private insurance (adjusted RR, 1.29; 95% CI, 1.13-1.47); No insurance c/w private insurance (adjusted RR, 1.19; 95% CI, 1.03-1.37); Geographic location: South vs Northeast US (adjusted RR, 0.67; 95% CI, 0.47-0.96).
CHA2DS2-VASc=0 carries a very low risk of stroke (0.47/100 person years) at one year (Lip et al, JACC). Despite being very low risk for stroke by CHADS2 or CHA2DS2-VASc scoring and young (mean age ~51y), ~25% of outpatients with AF received oral anticoagulation. Clinical predictors of anticoagulant use were older age, higher BMI, insurance status; lower anticoagulant use was seen in the Southern states. Study strength: Large “real world” registry that captures a diverse geographic and demographic population of cardiology outpatients.
Caveats: PINNACLE did not capture whether other indications for anticoagulation (eg, DVT, PE) may have been present that could explain these results. These practice patterns may have been altered/affected by the recent approval of multiple novel OACs for use in AF and the 2014 update to the ACC/AHA/HRS guidelines, which recommended the use of CHA2DS2-VASc over CHADS2 score and may lead to an increase in the number of low risk patients being given anticoagulation. This was not parsed out well in this study.
Clinical Pearls: No risk score is perfect and fully captures risk of stroke or bleeding so individualized risk assessment and informed discussion with the patient is critical prior to initiating oral anti-coagulation. Identifying these clinical predictors of stroke risk may raise awareness amongst physicians and improve the ability to prescribe oral anticoagulation more sparingly in such low risk individuals.
Patients with atrial fibrillation (AF) who are at low risk for thromboembolism are poor candidates for oral anticoagulation (OAC) because the bleeding risk outweighs any potential benefit. In fact, guidelines recommend against OAC in AF patients younger than 60 years and in AF patients who have no other risk factor for stroke.An analysis of AF patients in the National Cardiovascular Data Registry’s (NCDR) Practice Innovation and Clinical Excellence (PINNACLE) Registry found that theory, even when evidence-based, does not always translate into clinical practice. The slides above summarize insights from the analysis, including the prevalence of OAC prescribing for young healthy patients with AF and clinical predictors of the practice.Â References Hsu JC, Chan PS, Tang F, et al. Oral anticoagulant prescription in patients with atrial fibrillation and a low lisk of thromboembolism: Insights From the NCDR PINNACLE Registry. JAMA Intern Med. Published online April 13, 2015. doi:10.1001/jamainternmed.2015.0920.January CT, Wann LS, Alpert JS, et al. 2014 AHA/ACC/HRS guideline for the management of patients with atrial fibrillation: executive summary: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines and the Heart Rhythm Society.Â Circulation. 2014;130:2071-2104.Â Lip GH, SkjÃ¸th F, Rasmussen L, Larsen T. Oral anticoagulation, aspirin, or no therapy in patients with nonvalvular AF with 0 or 1 stroke risk factor based on the CHA2DS2-VASc Score. J Am Coll Cardiol. 2015;65:1385-1394. doi:10.1016/j.jacc.2015.01.044.