More than one-third of the antiarrhythmic drugs used to treat some cardiac patients aren’t being used according to guideline recommendations, say researchers from Duke Clinical Research Institute in Durham, North Carolina.
The researchers used commercial health claims to identify and categorize patients into guideline-established groups based on their most serious concurrent heart disease: heart failure (HF), coronary artery disease (CAD), hypertension (HTN), and no heart disease.
Of 78,877 patients with a prescription for ≥ 1 antiarrhythmic drug (AAD), most received 1 AAD, 12% received 2 AADs, and 2% received ≥ 3 AADs. The median time from the first inpatient or outpatient encounter for the diagnosis of atrial fibrillation (AFib) to the first prescription claim for an AAD was 29 days (range, 9-89 days).
In the patients with HF and CAD, 45% and 31% of AADs were inconsistent with first- or second-line recommendations, respectively. Only 55% of AAD use (amiodarone and dofetilide) in patients with AFib and HF conformed to recommendations. The use of sotalol, dronedarone, propafenone, and flecainide did not conform. Among patients with AFib and CAD, only 40% of AAD use (sotalol, dronedarone and dofetilide) conformed to first-line recommendations. Propafenone and flecainide, which are not recommended for patients with CAD, accounted for 31% of AAD use, the researchers found.
Among patients with AFib and HTN, all the high-use AADs were consistent with guidelines. Of the 81,891 patients with AF who did not have HF, CAD, or HTN, 19% received AADs, usually flecainide, propafenone, and sotalol, which are all acceptable according to clinical practice guidelines.
This study raises several concerns, the researchers say, such as the high use of dronedarone. As the first study to address how dronedarone, introduced in 2009, is being used in the U.S., it provides an early picture of a drug that has since been reported to have safety issues. Although dronedarone was only available for less than one-third of the study period, it accounted for 9% of all AAD use in patients with HF or CAD, 8% in patients with HTN, and 6% in patients without the selected cardiac diseases.
Although the study provides only a “snapshot” of AAD use based on claims data, the high rate of nonconformity is concerning, the researchers say. They note that much of the recent focus has been on evaluating and comparing a rate- vs rhythm-control strategy, with relatively little attention given to evaluating or comparing the specific drugs used in those strategies. The “extensive use of potentially inappropriate AADs highlights the need for more detailed analyses of AAD drug selection,” they conclude, especially for patients with concomitant HF and CAD.
Source
LaPointe NMA, Lokhnygina Y, Sanders GD, Peterson ED, Al-Khatib SM. Am Heart J. 2013;166(5):871-878.
doi: 10.1016/j.ahj.2013.08.010.