Nancy M Allen LaPointe, Yuliya Lokhnygina, Gillian Sanders, Eric Peterson, and Sana Al-Khatib

Is Selection of Antiarrhythmic Drugs for Atrial Fibrillation Consistent with Guideline Recommendations: Results from a Large Contemporary Community Cohort

Background

Two general treatment strategies for atrial fibrillation – rate vs. rhythm control

In the rhythm control strategy, guidelines recommend antiarrhythmic drug (AAD) selection based upon presence of concomitant heart disease – HF, CAD, HTN, or none of the above

The degree to which clinical practice adheres to the guidelines is largely unknown Especially in younger patients with atrial

fibrillation

Objective

In a large, contemporary, community cohort consisting of AF patients < 65 years of age, assess: Proportion receiving AADs (rhythm control

strategy) Proportion within guideline specified subgroups Antiarrhythmic drug use overall and within

guideline designated subgroups

Methods: Data Source

Thomas Reuters Marketscan® Commercial Claims and Encounters Database Inpatient, outpatient, and prescription claims

database from employers and health plans in the US

Includes covered employees and their spouses and dependents

Does not include any Medicare claims dataAll patients < 65 years of age

Claims data obtained from 1/1/06 through 12/31/10

Methods: Overall Study Cohort

Inpatient or outpatient encounter with an AF diagnosis (427.31) First AF encounter identified as index AF

encounter Age > 30 years No ventricular arrhythmia diagnosis at any point in

time No cardiothoracic (CT) surgery within 30 days of

index AF encounter Subsequent AF encounter w/o CT surgery could

be selected as index AF encounter

Methods: Subgroups

Patients were then categorized into one of the four subgroups Heart failure or Cardiomyopathy. Coronary Artery Disease Hypertension None of these

Category determined by an inpatient or outpatient diagnosis In order presented above

Methods: Antiarrhythmic Drugs and Analysis

NDC codes used to identify all oral Class Ia, Ic, and III AAD

Prescription claim for > 30 days supply following index date considered AAD use

Analysis Describe AAD use with focus on use in

subgroupsAssess consistency between use in clinical practice and guideline recommendations

Results: Characteristics of Overall Study CohortCharacteristic No AAD

n=252, 397 (76%)AAD

n=78,877 (24%)

Age, median (IQR) 56 (50,61) 57 (52,61)

Men 62% 69%

Region Northeast North Central South West Unknown

17%28%38%16%2%

11%30%41%16%2%

Type of Health Plan HMO PPO POS Other

17%64%9%11%

15%66%9%

10%

Index AF encounter Inpatient Outpatient

17%83%

20%80%

Results: Proportion of index AF encounters with subsequent AAD Use by Year (i.e. “new starts”)

Results: Period Prevalence of AAD Use (Quarter)

Guideline Recommendations

Fuster V et al. Circulation 2011;123:e269-e367

Copyright © American Heart Association

Results: Proportion of AF patients in each subgroup with AAD Use by Year (i.e. “new starts”)

Incidence of AAD Use by Year of AF index event (i.e. “new starts”)

AFib

study Population

(n= 331,274)

No Heart Disease Subgroup

n=81,891 (25% )

Patients with AAD n=15,461 (19%)

17,326 AADs

Flecainide (33%)

Propafenone (22%)

sotalol (20%)

Amiodarone (14%)

Dronedarone (6%)

Dofetilide (3%)

HTN Subgroup

n=110,752 (33%)

Patients with AAD

n= 24,527 (22%)

28,317 AADs

Flecainide (26%)

Sotalol (22%)

Propafenone (21%)

Amiodarone (19%)

Dronedarone (8%)

Dofetilide (3%)

CAD Subgroup

n= 77,782 (23%)

Patients with AAD n=20,551 (26%)

24,678 AADs

Amiodarone (28%)

Sotalol (27%)

Propafenone (16%)

Flecainide (16%)

Dronedarone (9%)

Dofetilide (4%)

HF Subgroup

n=60,849 (18%)

Patients with AAD

n= 18,338 (30%)

22,266 AADs

Amiodarone (48%)

Sotalol (19%)

Propafenone (10%)

Dronedarone (9%)

Flecainide (9%)

Dofetiide (5%)

Green=First line Recommendation; Yellow=Second line; Red=Contraindicated

Results: Consistency between practice and guidelines

HF: Only 53% of AADs used were consistent with guideline recommendations Between 28% - 47% of AADs were

“contraindicated” CAD: Only 31% of AADs used were considered 1st

line and 28% were 2nd line 32% considered contraindicated

HTN and No heart disease subgroups: All AADs used were 1st or 2nd line with exception

of dronedarone (still not clearly incorporated into US guidelines)

Main Limitations

Study cohort included only insured patients from participating health plans Results may not be generalizable to uninsured

patients or patients from non-participating health plans

AAD use was determined by prescription claims Some patients may not have actually taken the

prescribed medication Study relies on the accuracy and completeness of

the submitted diagnoses codes

Summary

AAD use is not the dominant strategy in this cohort of patients < 65 years of age

Decreasing incidence of AAD use overall and within subgroups from 2006-2010

Increasing prevalence of AAD use overall and within subgroups from 2006-2010 Flecainide followed by sotalol had highest

prevalence in the overall cohort Numerous inconsistencies with guideline

recommendations Opportunities for targeted education/awareness Additional research