Ann Thorac Surg 2008;85:32-33. doi:10.1016/j.athoracsur.2007.09.013
© 2008 The Society of Thoracic Surgeons
Original Articles: Cardiovascular
Invited commentary
Adrian William Pick
Cardiothoracic Surgery, Alfred Hospital, 660 Orrong Rd Toorak, Melbourne VI 3142, Australia
(Email: apick{at}optusnet.com.au).
Atrial fibrillation remains the most common complication after cardiac surgery. Despite this, very few centers commit resources to prophylaxis. Several well-constructed, randomized control trials have demonstrated efficacy for the use of oral amiodarone administered prior to planned elective surgery. It is also well established that beta blockers administered preoperatively must be reinstated early in the postoperative period to prevent increased sympathomimetic activity, which is a clear precursor to atrial fibrillation development.
Unfortunately, the literature is also replete with poorly constructed trials and nonrandomized studies advocating an exhaustive list of anti-arrhythmics in varying doses over varying time periods and on occasions, invalidating their use. This has lead to confusion regarding the need to commit resources to the management of this condition and a very common clinical philosophy that defaults to managing only the subgroup that develop postoperative atrial fibrillation.
Zebis and colleagues [1] bring a refreshing perspective to this clinical problem. They have conducted a randomized double-blind controlled trial. Importantly, they have eliminated the need for preoperative dosing by commencing a very practicable solution on the day of surgery, given the high volume of urgent or unstable patients in which surgery cannot be deferred. They also take advantage of the delayed onset of atrial fibrillation (between 3 to 5 days postoperatively) to administer 4 to 5 grams of agent. The long half-life of amiodarone also allows it to be discontinued on hospital dismissal, but it still remains effective for the 4 to 6 weeks during which the patient remains dysrhythmogenic, and this short dose interval obviates side effects associated with long-term therapy.
This article also undertakes an economic analysis. However, some calculations seem to be center specific (ie, costs calculated for nursing attendances, which in many institutions are not calculated on a per patient basis). For delayed onset atrial fibrillation, the costs of readmission are also difficult to calculate as they may occur outside the original institution. Adjusting for these caveats, the cost savings could arguably be greater.
A reduction in atrial fibrillation from 26% to 11% is a very powerful treatment effect; and in larger series with longer follow-up, one would anticipate this being translated to a significant reduction in length of hospitalization as well as the incidence of secondary complications, including stroke.
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References
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- Zebis LR, Christensen TD, Kristiansen IS, Hjortdal VE. Amiodarone cost effectiveness in preventing atrial fibrillation after coronary artery bypass graft surgery Ann Thorac Surg 2008;85:28-33.[Abstract/Free Full Text]
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