Ann Thorac Surg 2005;79:521-525
© 2005 The Society of Thoracic Surgeons
Original article: Cardiovascular
Midterm Results of Pulmonary Vein Isolation for the Elimination of Chronic Atrial Fibrillation
Taijiro Sueda, MD*,
Katsuhiko Imai, MD,
Kazumasa Orihashi, MD,
Kenji Okada, MD,
Kouji Ban, MD,
Masaki Hamamoto, MD
Department of Cardiovascular Surgery, Hiroshima University, Graduate School of Medical Sciences, Hiroshima, Japan
Accepted for publication August 3, 2004.
* Address reprint requests to Dr Sueda, Department of Cardiovascular Surgery, Hiroshima University, Graduate School of Medical Sciences, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8551, Japan; (E-mail: sueda{at}hiroshima-u.ac.jp).
 |
Abstract
|
|---|
BACKGROUND: This study aims to clarify midterm results of chronic atrial fibrillation elimination after pulmonary vein isolation and provides an evaluation of factors influencing results.
METHODS: Forty-nine patients were enrolled in this study. We performed a simple pulmonary vein isolation with the aid of cryoablation or radiofrequency ablation directed towards the left posterior remnant of the posterior left atrium. Results were evaluated using elimination rates of atrial fibrillation during the postoperative follow-up for > 12 months.We also examined factors influencing the recurrence of atrial fibrillation.
RESULTS: There were no hospital deaths or serious complications among the 49 patients. The total follow-up duration was 137.2 patient years. Forty-seven patients (96%) were followed with serial consultations, but 2 patients were dropped from this study because of changes in residence. Thirty-five of 49 patients (71.4%) showed regular sinus or nodal rhythms at discharge. In 4 patients atrial fibrillation recurred during the follow-up period, whereas in another 4 patients sinus rhythm was restored, although they showed atrial fibrillation at discharge. The cumulative elimination rate was 70.2% (33 of 47 patients), which was determined at the last follow-up period. Large left atrial diameters, a long history of atrial fibrillation, and low-voltage fibrillatory waves in V1 leads were preoperative indicators of recurrence of atrial fibrillation.
CONCLUSIONS: Pulmonary vein isolations were effective in the treatment of chronic atrial fibrillation patients and sinus rhythms were restored within the follow-up period.
|
Introduction
|
|---|
Atrial fibrillation (AF) is the most prevalent arrhythmia in patients with mitral valve disease [1]. Several surgical procedures have been attempted for chronic AF elimination. Among them, the Maze procedure was believed to be the most effective procedure for eliminating all kinds of AF [2, 3]. Although the Maze procedure was devised for eliminating idiopathic AF, it could also reverse chronic AF associated with mitral valve disease to sinus rhythm in many cases [4]. However, we hypothesized that chronic AF was caused by a distended left atrium in instances of mitral valve disease and was maintained by the distended left atrium [5]. We then performed a simple surgical procedure on the left atrium and proved the efficacy of this procedure in eliminating chronic AF associated with mitral valve disease [6]. Recently, Haissaguerre and coworkers [7] reported a focal source of paroxysmal AF originating from pulmonary veins, which they suggested to be a source of AF in many cases with paroxysmal and persistent AF. On the basis of recent observations by Haissaguerre and coworkers [7], we modified our previous simple left atrial procedure and performed surgical isolation of pulmonary vein orifices to eliminate chronic AF during cardiac surgery [8, 9]. In this study, we evaluate the mid-term follow-up results of pulmonary vein isolation for the elimination of chronic AF for at least a 1-year follow-up period.
|
Patients and Methods
|
|---|
Patient Population
Since February 1999, we performed the simple isolation of whole pulmonary vein orifices for the elimination of chronic persistent AF in 49 patients. All patients had chronic persistent AF with duration ranging from 13 to 216 months (82 ± 75 months). They were 27 males and 22 females whose ages ranged from 24 to 83 years old (mean age, 66 years old). Underlying cardiac diseases consisted of mitral valvular disease (41 patients), idiopathic atrial fibrillation with left atrial thrombus (4 patients), atrial septal defects (2 patients), chronic constrictive pericarditis (1 patients), and ischemic heart disease (1 patient) (Table 1). We performed concomitant surgeries, including 41 valvular surgeries (mitral valve replacement or plasty in 33 patients, mitral valve replacement plus tricuspid valve annuloplasty in 6 patients, mitral and aortic valve replacement in 2 patients), 2 closures of atrial septal defect, 4 embolectomies of the left atrial thrombi, 1 coronary arterial bypass graft, and 1 pericardiotomy.
Postoperative follow-up for longer than 1 year was available in 47 of 49 patients. The remaining 2 patients dropped out of the serial follow-up studies due to residential changes. The other 47 patients serially consulted with us at the hospital every 3 to 6 months.
Surgical Procedures
After the initiation of a cardiopulmonary bypass, body temperature was maintained at 34°C. The aorta was clamped, and cold blood cardioplegia was infused for myocardial protection. A right-sided vertical incision in the left atrium was extended towards the left margin of both left pulmonary vein orifices. Complementary cryoablation at –60°C for 120 seconds or radiofrequency ablation at 80°C for 90 seconds (Cobra monopolar catheter [Boston Scientific, Natick, MA]) was then applied to the remnant of the circular incision between the left upper pulmonary vein orifice and the left lower pulmonary vein orifice, instead of the entire surgical circular incision. In patients who had a mural thrombus in the left atrial appendage, the mural thrombus was excised and the orifice of the left atrial appendage was closed with a running suture (Fig 1). Further atriotomy procedures were not performed on the atrial septum or the right atrium, except for vertical right atriotomies for tricuspid valve annuloplasties. After the completion of this procedure, mitral valve surgery with or without other cardiac procedures was performed, and the isolated left atrium around the pulmonary vein orifices was sutured using running sutures.
View larger version (41K):
[in this window]
[in a new window]
|
Fig 1. The pulmonary vein orifice isolation procedure. A right-sided vertical incision in the left atrium was extended to the left margin of both left pulmonary vein orifices. Complementary cryoablation or radiofrequency ablation was then applied to the remnant of the circular incision between the left upper pulmonary vein orifice and the left lower pulmonary vein orifice (dotted line), instead of to the entire surgical circular incision. Dotted line = cryoablation or radiofrequency ablation. (IVC = inferior vena cava; LAA = left atrial appendage; MV = mitral valve; PVs = pulmonary veins; rt. = right; SVC = superior vena cava.)
|
|
Data Acquisition and Follow-Up
The length of preoperative AF was confirmed by medical histories or past electrocardiograms. Antiarrhythmic drugs (digoxin 0.25 mg/d and disopyramide 300 mg/d) were administered to all patients after surgery and were discontinued 3 months after surgery. The disappearance of AF was defined as no detectable AF on electrocardiograms and Holter electrocardiograms at discharge. After discharge, all patients were followed-up every 3 to 6 months, and we examined the disappearance of AF using electrocardiograms. Although patients complained of palpitation in spite of regular cardiac rhythm on electrocardiograms, Holter electrocardiograms were taken, and the possibility of paroxysmal AF was examined. The patients were divided into a sinus rhythm group and a recurrent AF group based on cardiac rhythms obtained at each follow-up period. The sinus rhythm group was without AF and regained sinus rhythm postoperatively. The AF group had recurrent AF postoperatively or during the follow-up period. Dual chamber pacemakers were implanted in patients with sinus bradycardia. Between these two groups, preoperative profiles and intraoperative variables were compared. Preoperative variables were gender, duration of AF, amplitude of f-waves at lead V1, cardiothoracic ratio, ejection fraction, diastolic diameter of the left ventricle, and left atrial dimensions. Intraoperative variables were duration of extracorporeal circulation and aortic cross clamping, associated valve interventions, cryoablation, or radiofrequency ablation.
Informed Consent and Statistical Analysis
Informed consent forms for this surgical procedure and postoperative follow-up studies were obtained from each patient and approved by the Institutional Review Board for human studies. All values were expressed as means ± standard deviation. All collected data were entered into a database. Continuous variables were compared using the nonparametric Mann-Whitney U test. Proportions were compared with Fisher's exact test. A p value < 0.05 was considered to be statistically significant.
|
Results
|
|---|
Operative Mortality and Morbidity
Simple isolation of pulmonary vein orifices was completed in every patient. The duration of cardiac arrest ranged from 61 to 157 minutes (mean, 112 ± 28 min), and the duration of cardiopulmonary bypass ranged from 110 to 240 minutes (mean, 178 ± 34 min). It took an additional 15 to 20 minutes to isolate whole pulmonary vein orifices and suture posterior left atrial walls. No patient required postoperative circulatory support, such as intraaortic balloon pumping, and there was no re-exploration for postoperative hemostasis. There was no postoperative mortality. All patients were discharged without any serious complication. The follow-up period ranged from 13 to 48 months (mean, 28.6 ± 15.1 month) with a total of 137.2 patient-years. None of the patients experienced any postoperative cerebral thromboembolic complications.
Recurrence of Atrial Fibrillation
In 44 of 49 patients (89.8%), AF ceased after surgery, but 9 experienced AF recurrence during their hospital stay. Thirty-five of 49 patients were discharged with sinus rhythms or regular nodal rhythms (71.4%). During the follow-up period, 2 patients dropped out of the study because of a change in residence; both were sinus rhythm patients. The other 47 patients were followed-up by serial hospital consultations. Among them, 4 of the AF patients (4 of 13; 30.8%) recovered their sinus rhythm without any intervention and 4 of the sinus rhythm patients (4 of 34; 11.8%) experienced AF relapse. At the final follow-up, 33 of 47 patients (70.2%) remained free of chronic AF (Fig 2).
Preoperative and Intraoperative Variables in Relation to Postoperative Status
Comparisons of preoperative and intraoperative variables between the sinus rhythm and AF groups are shown in Table 2. Among preoperative variables, a large left atrial diameter and large left ventricular endodiastolic dimensions were predisposing factors for postoperative persistence of AF. At each follow-up, AF duration and the amplitude of V1 f-waves were also factors influencing AF recurrence. We determined the duration of AF by checking the actual electrocardiographic data in the medical records. Atrial fibrillation duration ranged from 13 to 123 months (54 ± 63 months) in the sinus rhythm group and from 42 to 216 months (129 ± 87 months) in the AF group. The AF duration was significantly shorter in the sinus rhythm group (Table 2). Intraoperative variables, such as aortic cross-clamping times, extracorporeal circulation times, and associated valve surgeries did not influence postoperative AF elimination. Cryoablation was used in 34 patients and surgical radiofrequency (RF) catheters were used in 15 patients. Atrial fibrillation elimination rates were 24 of 34 patients (70.6%) for cryoablation and 11 of 15 (73.3%) for RF catheters at discharge. At the final follow-up, the AF eliminating ratios were 23 of 33 patients (69.7%) for cryoablations and 10 of 14 (71.4%) for RF ablations. Operative modalities including cryoablations and radiofrequency catheters did not affect AF elimination (Fig 3).
View larger version (22K):
[in this window]
[in a new window]
|
Fig 3. Results influenced by intraoperative modalities. (AF = atrial fibrillation; ns = not significant; RF = radiofrequency ablation.)
|
|
Postoperative Supraventricular Arrhythmia and Sinus Node Dysfunction
Two of 33 patients (6.1%) without AF recurrence showed other sustained atrial tachycardias during the follow-up period; one patient had a common atrial flutter and the other had an incisional tachycardia around the right atriotomy for tricuspid annuloplasty. The atrial flutter was treated by radiofrequency ablation toward the tricuspid isthmus between the tricuspid valve and coronary sinus orifice. The right atrial incisional tachycardia was also treated by linear ablation between the incisional scar and the inferior vena cava. These patients regained their sinus rhythms after radiofrequency catheter ablation. Four of 33 patients (12%) without AF recurrence received pacemaker implantations because of sinus bradycardia (< 60 beats/min) or sinus arrest with slow nodal rhythms. Dual-chamber pacemakers were implanted in these patients (Table 3).
Postoperative Medication
Digitalis was administered to 10 patients (30.3%) and antiarrhythmic agents of Vaughan Williams class I to 13 patients (39.4%) in the sinus rhythm group at the last follow-up. Twenty of 33 patients (60.6%) maintained their sinus rhythm without any antiarrhythmic agents. Warfarin was administered to every patient with a mechanical valve replacement, and to none of the patients who underwent valve repair procedures (7 patients) at the last follow-up.
|
Comment
|
|---|
Chronic AF associated with mitral valve disease often persists despite the proper repair of the cardiac defects [10, 11]. The Maze procedure has been used for the surgical ablation of AF in patients with mitral valve disease and has proven to be effective in conversion to a sinus rhythm [4]. Although various concepts involving reentry and ectopic foci have been proposed to explain the mechanism underlying AF [12, 13], the real mechanism underlying chronic AF associated with mitral valve disease remains unknown. Harada and colleagues [14] reported regular atrial activation of the left atrium during chronic AF in patients with isolated mitral valve disease. Our previous study also demonstrated regular and repetitive activation of the left atrium in 7 of 11 patients with mitral valve disease [5]. Recently Haissaguerre and coworkers [7] reported the spontaneous initiation of AF due to ectopic beats originating from pulmonary veins, and they reported successful application of radiofrequency ablation at these focal sources [15]. We also observed repetitive and regular activation originating from the left pulmonary vein during chronic AF associated with mitral valve disease [16]. In addition, the shortest atrial fibrillation cycle was recorded in the posterior left atrium in most patients [9]. Then we believed that these regular activations may originate from the pulmonary veins, similar to the activation in patients with paroxysmal AF reported by Haissaguerre and coworkers [7]. Therefore we simplified our previous left atrial Maze procedure [6] and performed simple pulmonary vein orifice isolation for the treatment of chronic AF associated with mitral valve disease [9].
Chronic AF was effectively eliminated in 70% of patients during the mid-term follow-up period. These surgical results are inferior to those reported for Maze procedures performed at several institutions [4, 17, 18], but there was no statistical difference in surgical results between pulmonary vein orifice isolation and the Maze procedure at our institution. Successfully treated patients showed regular sinus rhythms after surgery and restored left atrial contraction. This simple procedure has numerous advantages, such as a short surgical time and reduced risk of coronary artery injuries as compared with the Maze procedure. Extracorporeal circulation and aortic cross-clamping times of this procedure were shorter than those of the Maze procedure. In addition, postoperative supraventricular arrhythmias and the requirements for a pacemaker were less frequent with this procedure. A common atrial flutter was observed in 1 patient (2%) and atrial tachycardia of the right atrium was also observed in another (2%). A pacemaker was required rather frequently in our series. We positively implanted dual-chamber pacemakers in patients with sinus bradycardia (< 60 beats/min) because dual-chamber high-rate pacing (80 beats/min) increased their cardiac output significantly. The choice of operative modalities including the use of cryoablations and RF catheters had no impact on AF elimination.
Several reports cite esophageal injuries after surgical RF ablation [19, 20]. We did not experience these complications because we extended the left vertical atriotomy toward the superior and inferior orifices of the left pulmonary veins, and we performed RF ablation onto the left atrial remnants between the superior and inferior left pulmonary veins where the esophagus is not present.
A limitation of this study is the small sample size and 70% efficacy of the procedure. Although the surgical correction of mitral valve lesions reduces the left atrial size and improves the hemodynamic status once chronic AF has developed, the mitral valve operation itself rarely stops the arrhythmia [10]. Our previous data revealed that the rate of recovery of a sinus rhythm was much higher in those patients who underwent an AF operation than in those who did not (ie, AF disappearance rate was 27% with conventional valve surgeries) [6]. Our clinical experience suggests that the pulmonary vein remains afflicted with chronic AF in most patients and that the isolation of pulmonary vein orifices alone is adequate as a less-invasive procedure for AF elimination during concomitant valvular surgery. This procedure can eliminate AF in 70% of patients with chronic AF and organic cardiac disease for long periods of time.
Further examinations and experiences with new surgical modalities will improve the procedure for eliminating chronic AF and help to elucidate the exact mechanism of chronic AF associated with organic cardiac disease.
|
References
|
|---|
- Hirosawa K, Sekiguchi M, Kasanuki H. Natural history of atrial fibrillation Heart Vessels 1987;2(Suppl):14.
- Cox JL, Canavan TE, Schessler RB, et al. The surgical treatment of atrial fibrillationII. Intraoperative electrophysiological mapping and description of the electrophysiologic basis of atrial flutter and atrial fibrillation. J Thorac Cardiovasc Surg 1991;101:406-426.[Abstract]
- Cox JL, Schuessler RB, D'Agostino HJ, et al. The surgical treatment of atrial fibrillation. III. Development of a definitive surgical procedure J Thorac Cardiovasc Surg 1991;101:569-583.[Abstract]
- Kosakai Y, Kawaguchi A, Isobe F, et al. Cox maze procedure for chronic atrial fibrillation associated with mitral valve disease J Thorac Cardiovasc Surg 1994;108:1049-1055.[Abstract/Free Full Text]
- Sueda T, Nagata T, Shikata H, et al. Simple left atrial procedure for chronic atrial fibrillation associated with mitral valve disease Ann Thorac Surg 1996;62:1796-1800.[Abstract/Free Full Text]
- Sueda T, Nagata T, Orihashi K, et al. Efficacy of a simple left atrial procedure for chronic atrial fibrillation in mitral valve operations Ann Thorac Surg 1997;63:1070-1075.[Abstract/Free Full Text]
- Haissaguerre M, Jais P, Shah DC, et al. Spontaneous initiation of atrial fibrillation by ectopic beats originating in the pulmonary veins New Engl J Med 1998;339:659-666.[Abstract/Free Full Text]
- Sueda T, Imai K, Orihashi K, Watari M, Okada K. Pulmonary vein orifice isolation for elimination of chronic atrial fibrillation Ann Thorac Surg 2001;71:708-710.[Abstract/Free Full Text]
- Sueda T, Imai K, Ishii O, Orihashi K, Watari M, Okada K. Efficacy of pulmonary vein isolation for the elimination of chronic atrial fibrillation in cardiac valvular surgery Ann Thorac Surg 2001;71:1189-1193.[Abstract/Free Full Text]
- Sato S, Kawashima Y, Hirose H, et al. Long-term results of direct-current cardioversion for atrial fibrillation in open mitral commissurotomy for mitral stenosis Am J Cardiol 1986;57:629-633.[Medline]
- Flugelman MY, Hasin Y, Katznelson N, Kriwiwsky M, Shefer A, Gotsman MS. Restoration and maintenance of sinus rhythm after mitral valve surgery for mitral stenosis Am J Cardiol 1984;54:17-27.
- Ten Eick RE, Singer DH. Electrophysiological properties of diseased human atrium. I. Low diastolic potential and altered cellular response to potassium Cir Res 1979;44:545-557.[Free Full Text]
- Cosio FG, Palacio J, Vidal JM, Cocina EG, Gomez-Sanchez MA, Tamarogo L. Electrophysiological studies in atrial fibrillationSlow conduction of premature impulses: a possible manifestation of the background for re-entry. Am J Cardiol 1983;51:122-130.[Medline]
- Harada A, Sasaki K, Fukushima T, et al. Atrial activation during chronic atrial fibrillation in patients with isolated mitral valve disease Ann Thorac Surg 1996;61:104-112.[Abstract/Free Full Text]
- Jais P, Haissaguere M, Shah DC, Chouairi S, Gencel L, Hocini M. A focal source of atrial fibrillation treated by discrete radiofrequency ablation Circulation 1997;95:572-576.[Abstract/Free Full Text]
- Sueda T, Imai K, Watari M, Orihahsi K, Shikata H, Matsuura Y. Possibility of focal activation around the left upper pulmonary vein during chronic atrial fibrillation with mitral valve disease Ann Thorac Cardiovasc Surg 1999;5:116-120.[Medline]
- Handa N, Schaff HV, Morris JJ, Anderson BJ, Kopecky SL, Enriquez-Sarano M. Outcome of valve repair and the Cox maze procedure for mitral regurgitation and associated atrial fibrillation J Thorac Cardiovasc Surg 1999;118:628-635.[Abstract/Free Full Text]
- Gillinov AM, Blackstone EH, McCarthy PM. Atrial fibrillation: current surgical options and their assessment Ann Thorac Surg 2002;74:2210-2217.[Abstract/Free Full Text]
- Sonmez B, Demirsoy E, Yagan N, et al. A fatal complication due to radiofrequency ablation for atrial fibrillation: atrio-esophageal fistula Ann Thorac Surg 2003;76:281-283.[Abstract/Free Full Text]
- Doll N, Borger MA, Fabricius A, et al. Esophageal perforation during left atrial radiofrequency ablation: Is the risk too high? J Thorac Cardiovasc Surg 2003;125:836-842.[Abstract/Free Full Text]
This article has been cited by other articles:
|
|
|
|
 
D. Tamborero, L. Mont, A. Berruezo, M. Matiello, B. Benito, M. Sitges, B. Vidal, T. M. de Caralt, R. J. Perea, R. Vatasescu, et al.
Left Atrial Posterior Wall Isolation Does Not Improve the Outcome of Circumferential Pulmonary Vein Ablation for Atrial Fibrillation: A Prospective Randomized Study
Circ Arrhythm Electrophysiol,
February 1, 2009;
2(1):
35 - 40.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
P. B. Rahmanian, J. G. Castillo, D. Mehta, D. H. Adams, and F. Filsoufi
Epicardial Pulmonary Vein Isolation: A Long-Term Histologic and Imaging Animal Study Comparing Cryothermy Versus Radiofrequency
Ann. Thorac. Surg.,
September 1, 2008;
86(3):
849 - 856.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
J. Chen, M. K. Off, E. Solheim, P. Schuster, P. I. Hoff, and O.-J. Ohm
Treatment of atrial fibrillation by silencing electrical activity in the posterior inter-pulmonary-vein atrium
Europace,
March 1, 2008;
10(3):
265 - 272.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
C. Blomstrom-Lundqvist, B. Johansson, E. Berglin, L. Nilsson, S. M. Jensen, S. Thelin, A. Holmgren, N. Edvardsson, G. Kallner, and P. Blomstrom
A randomized double-blind study of epicardial left atrial cryoablation for permanent atrial fibrillation in patients undergoing mitral valve surgery: the SWEDish Multicentre Atrial Fibrillation study (SWEDMAF)
Eur. Heart J.,
December 1, 2007;
28(23):
2902 - 2908.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
P. Sanders, M. Hocini, P. Jais, F. Sacher, L.-F. Hsu, Y. Takahashi, M. Rotter, T. Rostock, C. J. Nalliah, J. Clementy, et al.
Complete isolation of the pulmonary veins and posterior left atrium in chronic atrial fibrillation. Long-term clinical outcome
Eur. Heart J.,
August 1, 2007;
28(15):
1862 - 1871.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
A. Marui, T. Nishina, K. Tambara, Y. Saji, T. Shimamoto, M. Nishioka, T. Ikeda, and M. Komeda
A novel atrial volume reduction technique to enhance the Cox maze procedure: initial results.
J. Thorac. Cardiovasc. Surg.,
November 1, 2006;
132(5):
1047 - 1053.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
S. D. Barnett and N. Ad
Surgical ablation as treatment for the elimination of atrial fibrillation: A meta-analysis
J. Thorac. Cardiovasc. Surg.,
May 1, 2006;
131(5):
1029 - 1035.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
B. Akpinar, I. Sanisoglu, M. Guden, E. Sagbas, B. Caynak, and Z. Bayramoglu
Combined Off-Pump Coronary Artery Bypass Grafting Surgery and Ablative Therapy for Atrial Fibrillation: Early and Mid-Term Results
Ann. Thorac. Surg.,
April 1, 2006;
81(4):
1332 - 1337.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
S. Benussi and O. Alfieri
Concomitant ablation of atrial fibrillation during mitral surgery
MMCTS,
November 29, 2005;
2005(1129):
1081.
[Abstract]
[Full Text]
[PDF]
|
|
|
Top
Abstract
Introduction
