LETTER TO THE EDITOR
Left atrial appendectomy and maze
Gianluca Bonanomi, MD*,*,
Marco A. Zenati, MD* and
David Schwartzman, MD, FACC*
* Division of Cardiothoracic Surgery, Atrial Arrhythmia Center, University of Pittsburgh Medical Center, 200 Lothrop Street, Suite C-700, Pittsburgh, Pennsylvania 15213, USA
* Reprint requests and correspondence: Dr. Gianluca Bonanomi, Division of Cardiothoracic Surgery, Atrial Arrhythmia Center, University of Pittsburgh Medical Center, 200 Lothrop Street, Suite C-700, Pittsburgh, Pennsylvania 15213, USA.
bonanomig{at}msx.upmc.edu
The feasibility and effectiveness of specific linear left atrial (LA) lesions to treat atrial fibrillation (AF) were addressed by Kottkamp et al. (1) in a recent issue of the Journal. Interestingly, linear lesions confined to the left atrium were able to cure AF in more than 90% of cases, and the technique was feasible with a minimally invasive right mini-thoracotomy approach. Although the main objective of AF cure is the restoration of sinus rhythm, it should be emphasized that the most dreadful consequence of the disease is embolic cerebrovascular accidents (CVA). Atrial fibrillation is responsible for 20% of all strokes, and the risk of stroke is increased fivefold in nonrheumatic AF and 17-fold in patients with mitral stenosis and AF (2).
The efficacy of systemic anticoagulation with warfarin to reduce the incidence of stroke has been demonstrated in randomized clinical trials, and the left atrial appendage (LAA) has been recognized as the source of more than 90% of emboli leading to CVA (3,4). Fifty percent of AF patients are age 75 or older, and it has been estimated that at least 20% have a contraindication to warfarin treatment (5). We believe that the importance of the LAA in the generation of embolic strokes should be addressed when a surgical approach to AF is contemplated and, therefore, we are concerned that the procedure proposed by Kottkamp et al. (1) may result in higher rate of CVA as compared to the classic maze approach, which includes LA appendectomy (6,7). It has been demonstrated that the maze procedure is associated with three-year 100% freedom from thromboembolic complications as compared to 83% in the non-maze group (8). In the study by Kottkamp et al. (1) surgical ablation was associated with restoration of sinus rhythm and an increase in LAA flow velocity that could potentially release occult clots into the systemic circulation. Moreover, oral anticoagulant therapy was prescribed for at least 3 months, the mean follow-up limited to 18 months and the incidence of CVA not mentioned.
Consequently, we would like the investigators to share their long-term results on freedom from thromboembolism associated with the innovative approach proposed. A minimally invasive method for removing and/or occluding the LAA would provide a valuable strategy for preventing stroke in patients with AF. Both percutaneous LAA occlusion and thoracoscopic LAA amputation have been recently developed, although further studies are needed to confirm the safety and efficacy of these approaches (7,9). Additional investigation is needed to determine whether LAA obliteration, which might have a potential clinical impact similar to carotid endarterectomy, is effective in preventing thromboembolism and whether it can be advocated as a "must" in the treatment of a selected population of patients with AF.
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References
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1. Kottkamp H, Hindricks G, Autschbach R, et al. Specific linear left atrial lesions in atrial fibrillation: intraoperative radiofrequency ablation using minimally invasive surgical techniques. J Am Coll Cardiol. 2002;40:475–480[Abstract/Free Full Text]
2. Wolf PA, Dawber TR, Thomas HE, Kannel WB. Epidemiologic assessment of chronic atrial fibrillation and risk of stroke: the Framingham study. Neurology. 1978;28:973–977[Abstract/Free Full Text]
3. 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
4. Transesophageal echocardiographic correlates of thromboembolism in high-risk patients with nonvalvular atrial fibrillation: Stroke Prevention in Atrial Fibrillation Investigators Committee on Echocardiography. Ann Intern Med 1998;128:639–47
5. Gottlieb LK, Salem-Schatz S. Anticoagulation in atrial fibrillation: does efficacy in clinical trials translate into effectiveness in practice? Arch Intern Med. 1994;154:1945–1953[Abstract/Free Full Text]
6. Cox JL, Jaquiss RD, Schuessler RB, et al. Modification of the maze procedure for atrial flutter and atrial fibrillation. II. Surgical technique of the maze III procedure. J Thorac Cardiovasc Surg. 1995;110:485–495[Abstract/Free Full Text]
7. Johnson WD, Ganjoo AK, Stone CD, Srivyas RC, Howard M. The left atrial appendage: our most lethal human attachment: surgical implications. Eur J Cardiothorac Surg. 2000;17:718–722[Abstract/Free Full Text]
8. Raanani E, Albage A, David TE, Yau TM, Armstrong S. The efficacy of the Cox/maze procedure combined with mitral valve surgery: a matched control study. Eur J Cardiothorac Surg. 2001;19:438–442[Abstract/Free Full Text]
9. Sievert H, Lesh MD, Trepels T, et al. Percutaneous left atrial appendage transcatheter occlusion to prevent stroke in high-risk patients with atrial fibrillation: early clinical experience. Circulation. 2002;105:1887–1889[Abstract/Free Full Text]
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