Trends in utilization for rate-control and rhythm-control drugs from 2001 to 2009: Results from the national ambulatory medical care survey

OBJECTIVES: Results from several clinical trials have showed that rhythm-control drugs, which have serious adverse events, have no survival advantage over ratecontrol drugs in patients with atrial fibrillation (AF). The objective of the study was to determine 1) the trends in utilization for rate-control and rhythm-control drugs from 2001 to 2009; and 2) if the utilization of rhythm-control drugs decreased over time. METHODS: The physician's-office and outpatient data components of the National Ambulatory Medical Care Survey (NAMCS) from 2001 to 2009 were used. Visits with AF were identified by ICD-9 diagnosis code, '427.31'. From these visits, visits with mentions of rate-control drugs, beta blockers (e.g. metoprolol, propranolol, carvedilol, etc.) and non-dihydropyridine calcium channel blockers (verapamil and diltiazem) and visits with mentions of rhythm-control drugs ( e.g. amiodarone, disopyramide, propafenone, etc.) were identified using drug codes provided by NAMCS. Trends in utilization were calculated as total number of visits with prescriptions divided by total number of visits with AF for each year. RESULTS: From 2001 to 2009, visits with AF rose from 6.83 million to 11.56 million. The prescription rate for rate-control drugs increased from 24.28% to 62.31% from 2001 to 2009. The prescription rate for rhythm-control drugs remained the same, 5.31% in 2001 and 5.14% in 2009. The prescription rate for any pharmacotherapy for AF increased from 29.32% to 67.44% from 2001 to 2009. CONCLUSIONS: The utilization of rhythm-control drugs remained constant while that of rate- control drugs increased from 2001 to 2009. Previously, the treatment approach for AF was to achieve normal sinus rhythm with rhythm-control drugs and direct current cardioversion, rather than use the rate-control drugs. Following the trials on ratecontrol and rhythm-control drugs, the use of rate-control strategy increased.