Abstract 16336: Calcium Channel Blockers Improve Exercise Capacity and Lower NT-proBNP Levels Compared to Beta Blockers in Patients with Permanent Atrial Fibrillation
Introduction Rate control of atrial fibrillation (AF) is a main treatment modality, but there is still a lack of data regarding the effects of the different rate reducing drugs. Hypothesis We hypothesized that calcium channel blockers may have more favourable effects than beta blockers on exercise capacity and NT-proBNP levels in patients with permanent AF.
Methods We included 60 patients (mean age 71±9 years, 18 women) with permanent AF and normal left ventricular function in a cross-over, investigator-blinded study. Diltiazem 360 mg, verapamil 240 mg, metoprolol 100 mg and carvedilol 25 mg were administered o.d. for three weeks, in a randomized sequence. At baseline and on the last day of each treatment period, the patients underwent a maximal cardiopulmonary exercise test on a bicycle ergometer. Blood samples for NT-proBNP analyses were obtained at rest and at peak exercise.
Results The VO2 peak was significantly lower during treatment with metoprolol and carvedilol compared to baseline or treatment with diltiazem and verapamil (p<0.001 for all). Compared to baseline, treatment with diltiazem and verapamil significantly reduced the NT-proBNP levels both at rest and at peak exercise, whereas treatment with metoprolol and carvedilol increased the levels (p< 0.05 for all). See table.
Conclusion In conclusion, rate reducing treatment with diltiazem and verapamil preserved exercise capacity and reduced levels of NT-proBNP compared to baseline whereas treatment with metoprolol and carvedilol had the opposite effect. Calcium channel blockers should hence be considered more often for rate control in AF patients without comorbidities that mandate the use of beta blockers.
- © 2012 by American Heart Association, Inc.