CORRESPONDENCE: LETTERS TO THE EDITOR
Preservation of the anterior fat pad and incidence of postoperative atrial fibrillation following coronary surgery
Gianluigi Bisleri, MD*,
Tomaso Bottio, MD, PhD,
Jeffrey A. Morgan, MD and
Claudio Muneretto, MD
* UDA Cardiochirurgia-Spedali Civili, P.le Spedali Civili, 1, 25123 Brescia, Italy (Email: gianluigi_bisleri{at}katamail.com).
We read with interest the recent contribution by Cummings et al. (1) about the reduced incidence of postoperative atrial fibrillation (AF) in patients with preservation of the anterior fat pad (FP). The investigators performed an elegant evaluation of parasympathetic tone influence in a group of 55 patients undergoing myocardial revascularization on-pump and randomized either to group A (26 patients with anterior FP preservation) or group B (29 patients with dissection of the anterior FP). The incidence of postoperative AF was significantly less in group A (group A = 7% vs. groupB = 37%; p < 0.01); the researchers conclude that anterior FP preservation decreases the incidence of postoperative AF (1).
Besides the limitation of the study represented by the small sample size of patients randomized either to anterior FP preservation or removal, the study method holds additional limitations to the ones depicted by the investigators. First, despite patient use of class I or III antiarrhythmic medications being considered as an exclusion criteria, patients taking class II and IV antiarrhythmic drugs were not excluded from the study. In particular, patients with preoperative oral intake of beta-blockers did not withdraw their medications, as depicted in Table 1. It is questionable whether this fact may bias the results of the study as previous reports demonstrated that the perioperative withdrawal of beta-blockers may hamper efforts to reduce the incidence of postoperative AF. In particular, Salamon et al. (2) demonstrated that off-pump surgery alone was not effective in reducing postoperative AF without concomitant beta-blocker administration. Additionally, the use of different techniques for myocardial protection (i.e., cold blood oxygenated or crystalloid cardioplegia) may add another bias to the entire study; conversely, avoidance of cardiopulmonary bypass at all would have reduced a well-known risk of developing AF (3).
Finally, Cummings et al. (1) report a prevalence of diabetes in a relatively high percentage of patients (about 35% in both groups of the study population). Because autonomic neuropathy with partial denervation commonly occurs in diabetic patients (4), the real effectiveness of anterior FP preservation in this population may be questionable, and this fact would therefore raise additional concerns about the final validation of the study.
 |
References
|
|---|
- Cummings JE, Gill I, Akhrass R, Dery MA, Biblo LA, Quan KJ. Preservation of the anterior fat pad paradoxically decreases the incidence of postoperative atrial fibrillation in humans J Am Coll Cardiol 2004;43:994-1000.[Abstract/Free Full Text]
- Salamon T, Michler RE, Knott KM, Brown DA. Off-pump coronary artery bypass grafting does not decrease the incidence of atrial fibrillation Ann Thorac Surg 2003;75:505-507.[Abstract/Free Full Text]
- Ascione R, Caputo M, Calori G, Lloyd CT, Underwood MJ, Angelici GD. Predictors of atrial fibrillation after conventional and beating heart coronary surgery Circulation 2000;102:1530-1535.[Abstract/Free Full Text]
- Vinik Al, Freeman R, Erbas T. Diabetic autonomic neuropathy Semin Neurol 2003;23:365-372.[CrossRef][ISI][Medline]
Related Article
-
Reply
- Jennifer E. Cummings, Inderjit Gill, Rami Akhrass, MarkAlain Dery, Lee A. Biblo, and Kara J. Quan
J. Am. Coll. Cardiol. 2005 45: 1308-1309.
[Full Text]
[PDF]
|
Top
References