CORRESPONDENCE: LETTER TO THE EDITOR
Reply
Brian Olshansky, MD, FACC*,
Lynda E. Rosenfeld, MD, FACC,
Alberta L. Warner, MD, FACC,
Allen J. Solomon, MD, FACC,
Gearoid O’Neill, MD, FACC,
Arjun Sharma, MD, FACC,
Edward Platia, MD, FACC,
Gregory K. Feld, MD, FACC,
Toshio Akiyama, MD, FACC,
Michael A. Brodsky, MD, FACC,
H. Leon Greene, MD, FACC and the AFFIRM Investigators
* Cardiac Electrophysiology, University of Iowa Hospitals, 4426A JCP, 200 Hawkins Drive, Iowa City, IA 52242 (Email: brian-olshansky{at}uiowa.edu).
We appreciate the interest of Drs. Veloso and de Paola and their comments about our study (1).
We did not specifically recommend beta-blockers as the first-line approach to rate control of atrial fibrillation in all patients. Other therapeutic options, such as digoxin, may indeed be a more appropriate first step in individual circumstances.
In the Atrial Fibrillation Follow-up Investigation of Rhythm Management (AFFIRM) trial, more patients were switched to beta-blockers than to other drug classes. Often, combination therapy was needed. The question "is there one best approach?'' cannot be answered definitively from our data for several reasons:
- 1 Rate control can be difficult. Drugs had to be changed in about one-third of patients in the AFFIRM study. Effective rate control may require open-mindedness to all rate-control options; there may be no one best approach for all patients.
- 2 Our study did not randomize the rate-control strategies. Some patients required a beta-blocker or digoxin for other clinical reasons. Beta-blockers may be necessary if the patient has certain conditions, such as coronary artery disease, whereas digoxin may be a first-line alternative when congestive heart failure and left ventricular systolic dysfunction are present.
- 3 Rate control is difficult to define. The need for a specific rate may vary by patient, by disease, and by drug. It is possible that AFFIRM’s approach to rate control was too stringent or was not targeting the correct rate.
- 4 Rate control might not be the only important end point in managing atrial fibrillation with rate-controlling drugs. These drugs may increase or decrease symptoms despite proper rate control, influence mortality, affect total costs, influence hospitalization rates, or influence the return to sinus rhythm. These factors, not explored in our report, must be considered for any patient requiring therapy for rate control, and drug classes may differ in this regard.
- 5 We could not analyze the combination of beta-blockers and digoxin because start and stop dates for drug use were not recorded in the AFFIRM study. Although it was possible to determine whether neither drug was used, it was not possible to determine whether both drugs were used concurrently.
The success of achieving rate control in the AFFIRM study may have hinged on the flexibility of the investigators to use more than one drug class. Over the long run, more patients were switched to beta-blockers than to the other drug classes. Beta-blockers tended to be used more commonly over time, and fewer patients abandoned this drug class. Of importance, rate control was possible for the majority of patients without the need for atrioventricular junctional ablation and a pacemaker, and rate control appeared to improve over time.
We do not necessarily advocate a beta-blocker as first-line therapy for rate control for all patients. Digoxin may be reasonable as first-line therapy in some patients, especially sedentary elderly patients.
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References
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- Olshansky B, Rosenfeld LE, Warner AL, et al. The Atrial Fibrillation Follow-up Investigation of Rhythm Management (AFFIRM) studyapproaches to control rate in atrial fibrillation. J Am Coll Cardiol 2004;43:1201-1208.[Abstract/Free Full Text]
Related Article
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Beta-Blockers Versus Digoxin to Control Ventricular Rate During Atrial Fibrillation
- Henrique H. Veloso and Angelo A.V. de Paola
J. Am. Coll. Cardiol. 2005 45: 1905-1906.
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