Current issues of ACP Journal Club are published in Annals of Internal Medicine


Economics

Cardioversion followed by aspirin alone or with amiodarone was cost-effective for nonvalvular atrial fibrillation

ACP J Club. 1999 Jan-Feb;130:24. doi:10.7326/ACPJC-1999-130-1-024


Source Citation

Eckman MH, Falk RH, Pauker SG. Cost-effectiveness of therapies for patients with nonvalvular atrial fibrillation. Arch Intern Med. 1998 Aug 10/24;158:1669-77.


Abstract

Question

How cost-effective are antiarrhythmic and antithrombotic therapy strategies with and without cardioversion for patients with atrial fibrillation (AF)?

Design

Cost-effectiveness analysis with a Markov state-transition model.

Setting

United States.

Patient

Data were presented for a 65-year-old man with nonvalvular AF.

Intervention

19 strategies using cardioversion, antiarrhythmic agents (quinidine, sotalol, or amiodarone), and anticoagulant or antiplatelet agents (aspirin or warfarin). Strategies included allowing AF to continue with or without aspirin or warfarin; cardioversion with any of 4 antithrombotic therapies (warfarin if AF recurred, long-term aspirin regardless of occurrence, long-term aspirin for sinus rhythm with warfarin if AF recurred, and long-term warfarin regardless of AF recurrence); and cardioversion with the same antithrombotic therapies with the addition of quinidine, sotalol, or amiodarone. Warfarin was given 3 weeks before and after cardioversion. Antiarrhythmic therapy was discontinued if AF recurred. Quinidine, 324 mg 3 times/d, or sotalol, 80 mg twice/d (which was doubled as tolerated), was started immediately after cardioversion; amiodarone, 600 mg/d with a decrease to 400 mg/d after 7 to 10 days, was started 3 weeks before cardioversion. Assumptions were made for managing adverse events and recurrent AF. Discounting was 3%/y.

Main outcome measures

Cardiac rhythms, adverse effects of each treatment strategy, death, hemorrhage, embolic events, and quality of life. Adverse effects were classified as fatal, long-term, or short-term. Costs were in 1995 U.S. dollars and included inpatient and ambulatory costs.

Main results

Discounted effectiveness for the 19 strategies ranged from 8.4 quality-adjusted life-years (QALYs) for no treatment to 10.0 QALYs for the strategy of cardioversion with amiodarone and warfarin. Aspirin alone had the largest incremental gain, 1.2 QALYs, compared with no treatment. Only 2 strategies showed evidence of effectiveness and cost-effectiveness: cardioversion followed by long-term aspirin plus warfarin if AF recurred ($10 800/QALY) and cardioversion followed by amiodarone plus long-term aspirin or amiodarone plus warfarin if AF recurred ($33 700/QALY). Cardioversion with amiodarone and warfarin was more cost-effective but more expensive. Use of quinidine or sotalol after cardioversion was both more expensive and less effective than competing strategies.

Conclusion

For patients with nonvalvular AF, only 2 of 19 strategies were effective and cost-effective: cardioversion followed by long-term aspirin or warfarin if AF recurred and the same strategy with amiodarone added.

Sources of funding: In part, National Library of Medicine and Pfizer Inc.

For correspondence: Dr. M.H. Eckman, New England Medical Center, 750 Washington Street, Box 302, Boston, MA 02111, USA. E-mail: meckman@es.nemc.org.


Commentary

Anticoagulation or antiplatelet agents are effective for AF; cardioversion and antiarrhythmic therapy may also be appropriate. Eckman and colleagues used a decision model to show that, for a 65-year-old man, cardioversion followed by aspirin with or without amiodarone was effective and not very expensive. Cardioversion followed by warfarin and amiodarone was effective but more expensive. Hence, warfarin and amiodarone exceeded the threshold for what usually is considered economically attractive (1).

The efficacy of aspirin was set at 44%. A more conservative estimate has been proposed by others. If the benefit of aspirin is indeed lower, then cardioversion followed by warfarin and amiodarone is economically more attractive.

Propafenone, which was not considered, has similar cost and incidence of side effects as sotalol. Therefore, it is unlikely that propafenone would be more cost-effective than amiodarone.

Some patients have a higher-than-average chance of stroke. In a pooled analysis, the stroke rate was 8.1%/y in patients > 75 years of age who have ≥ 1 risk factor (2). Although such high-risk patients were not considered in this analysis, cardioversion followed by warfarin and amiodarone would be even more effective and cost-effective in this group.

Evidence will continue to evolve about the effectiveness of maintenance of sinus rhythm compared with rate control alone (3) or of transesophageal-guided cardioversion compared with empiric cardioversion (4). Until then, this analysis shows that cardioversion followed by long-term aspirin or warfarin if AF recurs, with or without amiodarone, is the treatment of choice.

Graham Nichol, MD
Loeb Health Research Institute
Martin S. Green, MD
Ottawa Heart InstituteOttawa, Ontario, Canada


References

1. Garber AM, Phelps CE. Economic foundations of cost-effectiveness analysis. J Health Economics. 1997;16:1-31.

2. Risk factors for stroke and efficacy of antithrombotic therapy in atrial fibrillation. Analysis of pooled data from five randomized controlled trials. Arch Intern Med. 1994;154:1449-57.

3. The Planning and Steering Committees of the AFFIRM Study for the NHLBI AFFIRM Investigators. Atrial fibrillation follow-up investigation of rhythm management—the AFFIRM study design. Am J Cardiol. 1997;79:1198-202.

4. Klein AL, Grimm RA, Black IW, et al. Cardioversion guided by transesophageal echocardiography: the ACUTE pilot study. A randomized controlled trial. Assessment of cardioversion using transesophageal echocardiography. Ann Intern Med. 1997;126:200-9.