HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Abstract Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Add to Personal Folders Download to citation manager Permission Requests Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Siebert, J. Articles by Narkiewicz, M. Search for Related Content PubMed PubMed Citation Articles by Siebert, J. Articles by Narkiewicz, M. Related Collections Coronary disease Electrophysiology - arrhythmias

Eur J Cardiothorac Surg 2001;19:455-459
© 2001 Elsevier Science NL

Atrial fibrillation after coronary artery bypass grafting: does the type of procedure influence the early postoperative incidence?

^a Department of Cardiac Surgery and Cardiology, Institute of Cardiology, Medical University of Gdansk, Debinki 7, 80-211 Gdansk, Poland
^b Department of Anaesthesiology and Intensive Therapy, Medical University of Gdansk, Debinki 7, 80-211 Gdansk, Poland

Received 5 October 2000; received in revised form 11 February 2001; accepted 14 February 2001.

Corresponding author. Tel./fax: +48-58-341-7669
e-mail: jsiebert{at}amg.gda.pl

	Abstract

Top Abstract 1. Introduction 2. Materials and methods 3. Results 4. Discussion 5. Conclusions Appendix A. Conference... References

 
Objective: Atrial fibrillation (AF), the common postoperative complication, has been observed after coronary artery bypass grafting (CABG) in 7–40% of patients. Cardiopulmonary bypass (CPB), eliminated in off-pump operations (OPCABG) may decrease the incidence of AF, whereas the combination of CABG with heart valve replacement may result in more frequent postoperative atrial fibrillation. The aim of our study was to compare the early postoperative AF incidence rate during ICU stay in three groups of patients: after CABG, OPCABG, and CABG combined with valve replacement. Material and methods: A prospective study of 906 consecutive patients was carried out between January 1999 and January 2000. Clinical profile of 906 patients, including factors having potential influence on postoperative AF did not showed any significant differences between the groups. The presence of arrhythmia history was the reason of excluding 85 patients from the statistical analysis. The observation was performed in each case during ICU-stay, using a HP system for continuos automated arrhythmia analysis. Early postoperative incidence of AF was recorded and compared between three groups of patients: 650 after conventional CABG, 118 after OPCABG, and 53 after CABG combined with valve replacement. Chi-square and a Mann–Whitney tests, Statistica 5.0 PL were used for the statistical analysis. Results: Atrial fibrillation occurred during the postoperative ICU stay in 9.8% of patients after CABG, in 10.2% after OPCABG, and in 21% after CABG combined with valve replacement. There was no significant difference between CABG and OPCABG groups (P=0.965). The confidence interval of the odds ratio ranges from 0.5 to 1.85. Consequently, an increased risk would be possible for both methods. We observed a statistically significant increase of the early postoperative atrial fibrillation incidence rate in patients after CABG combined with valve replacement, when compared with both CABG + OPCABG groups (P=0.005). Conclusions: (1) Atrial fibrillation is a common postoperative complication after myocardial revascularization procedures which prolongs ICU stay. (2) The study did not show that the incidence of postoperative AF is influenced by the technique of coronary artery bypass grafting: with or without CPB. (3) The prevalence of postoperative AF increase when CABG is combined with valve replacement.

Key Words: Atrial fibrillation • Coronary artery bypass graft • Off-pump coronary artery bypass graft • Myocardial revascularization and valve replacement

	1. Introduction

Top Abstract 1. Introduction 2. Materials and methods 3. Results 4. Discussion 5. Conclusions Appendix A. Conference... References

 
Coronary artery bypass graft (CABG) surgery is an effective form of treatment for patients with ischemic heart disease. This method is well tolerated by majority of patients, however it can cause some complications. The early postoperative atrial fibrillation (AF) is among the most common ones.

Occurrence rate of postoperative AF varies from 5 to over 40% according to definition of the arrhythmia, patients characteristics, type of operation and method of heart rhythm monitoring.

Some investigators consider postoperative AF to be a benign and self-limited arrhythmia. It rarely has a fatal outcome, however may lead to instability of the patient, prolongs hospital stay and increases costs [1,2]. In some cases AF can be the reason of perioperative myocardial infarction, stroke, and persistent congestive heart failure [3]. The use of cardiopulmonary bypass (CPB), the influence of cardioplegia and myocardial ischemia are possible factors responsible for postoperative occurrence of AF.

For last few years less-invasive CABG procedures on the beating heart, without cardiopulmonary bypass have become very popular. Rapid development of surgical instrumentation, especially stabilising devices, have enabled approach to almost all surfaces of the beating heart.

Myocardial revascularization without CPB, usually performed by the standard median sternotomy approach (off-pump coronary artery bypass grafting, OPCABG) has excellent short-term results, however is not completely free from complications. The problem of the postoperative arrhythmia in patients after beating heart surgery appears to be controversial. One should expect lower incidence of postoperative arrhythmia, when the operations are made without the use of CPB.

In our preliminary report we found no statistically significant difference between incidence rate of AF occurring after myocardial revascularization performed with or without CPB [4].

The aim of this study was to confirm that finding, by analysing the early postoperative incidence of AF during ICU stay on a large group of patients after coronary artery bypass grafting operations.

	2. Materials and methods

Top Abstract 1. Introduction 2. Materials and methods 3. Results 4. Discussion 5. Conclusions Appendix A. Conference... References

 
A prospective study was carried out in 906 consecutive patients with coronary artery disease (CAD), who were operated on at our institute in the period between January 1999 and January 2000. The 703 patients underwent standard CABG using CPB, 135 patients were operated on without CPB using OPCABG (off-pump CABG) technique, and 68 patients underwent combined procedures: CABG and aortic valve replacement (CABG+AVR) or CABG and mitral valve replacement (CABG+MVR).

Clinical data are shown in Table 1. Some of the AF risk factors, known from the literature, were found in the analysed groups [5–8]. The 85 patients, who had a history of preoperative heart rhythm disturbances, were excluded from further statistical analysis. The anaestetic management was identical in all groups.

	3. Results

Top Abstract 1. Introduction 2. Materials and methods 3. Results 4. Discussion 5. Conclusions Appendix A. Conference... References

 
The analysis, designed to compare the early postoperative incidence of AF, included 811 patients without arrhythmia history, divided into three main groups of patients: CABG (650), OPCABG (118), and CABG combined with valve replacement (53, with 36 AVR and 17 MVR). The mean period of observation during ICU stay was 2.03 days for CABG group, 1.82 days for OPCABG group, and 2.79 days for CABG + valve group.

The comparison of the early postoperative AF incidence between groups is displayed in Table 2.

Much more frequent occurrence of AF was noticed after CABG combined with valve replacement. The comparison between the subgroups showed higher AF incidence after CABG+AVR (nine of 36), then after CABG+MVR procedures (three of 17), however the difference was not statistically significant (P=0.6).

The most expressed difference in the early postoperative AF incidence rate was presented by comparison between the cumulated groups: CABG+OPCABG – 76 of 768 patients (10%), and CABG+AVR or MVR – 11 of 53 patients (21%). This difference was statistically significant (P=0.005, odds ratio = 2.66, 95% confidence interval 1.34–5.29).

Perioperative complications are presented in Table 3. Standard CABG with CPB use was related to the largest frequency of low cardiac output situations with the necessity of intraaortic balloon pump support. This has resulted in the highest mortality rate. Excessive postoperative bleeding had occurred most frequently after CABG combined with valve replacement. The elevation of cardiac enzymes was most frequent after OPCABG procedures, but only in one case the diagnosis of myocardial infarction was confirmed.

	4. Discussion

Top Abstract 1. Introduction 2. Materials and methods 3. Results 4. Discussion 5. Conclusions Appendix A. Conference... References

A pathomechanism of postoperative AF is still not well defined. The best documented, independent risk factor for postoperative AF development is patients age and related to it structural changes in atrium, i.e. dilatation, focal fibrosis and muscle atrophy [13,14]. These factors create changes in local atrial refractory periods, called ‘dispersion of refractoriness’ [15]. This lack of uniformity, in presence of triggering factors, may exhibit AF [16].

Our study has shown a slight increase of AF after OPCABG in comparison to conventional CABG, however this difference did not reach statistical significance. Almost equal incidence rate of AF in these two groups was also found in our previous study [4]. One of possible explanations may be proposed after analysing other postoperative complications, summarised in Table 3.

We have noted a relatively high incidence rate of perioperative cardiac enzyme elevation in off-pump group – 4.4%. This was most probably due to transient intraoperative regional myocardial ischemia, which always accompanies the construction of coronary artery – graft anastomosis on beating heart. All but one patient were symptom – free, without ECG evidence of myocardial infarction. Transient regional ischemia, in some cases even leading to MI, could increase dispersion of refractoriness, eventually resulting in relatively high incidence of AF in the OPCABG group.

CABG combined with valve replacement was related to statistically significant higher number of postoperative AF, which corresponds to data known from literature [3,9]. Similarly to coronary artery surgery, application of less-invasive procedures in isolated valvular surgery did not diminish the incidence of AF [17].

Although atrial fibrillation appears usually between 2nd and 3rd postoperative day, and quite frequently later, and our observation time was limited to the patients ICU-stay, the study reflect complications occurring early after operation, in the period which is the most dangerous for a patient. The most frustrating thing about postoperative AF is that over 5% of patients undergoing any type of cardiac or other major surgical procedure will develop the arrhythmia independently of currently used prophylaxis [15].

The risk factors for the development of AF after beating heart surgery seem to be similar to those after on-pump procedures, and we hope, that further prospective investigations may provide an answer how to effectively prevent the occurrence of postoperative arrhythmia.

	5. Conclusions

Top Abstract 1. Introduction 2. Materials and methods 3. Results 4. Discussion 5. Conclusions Appendix A. Conference... References

 

1. Atrial fibrillation is a common postoperative complication after myocardial revascularization procedures which prolongs the ICU stay.
   
2. The study did not show that the incidence of postoperative AF is influenced by the technique of coronary artery bypass grafting: with or without CPB.
   
3. The prevalence of early postoperative atrial fibrillation increases, when CABG is combined with heart valve replacement.
   

	Footnotes

 
Presented at the 14th Annual Meeting of the European Association for Cardio-thoracic Surgery, Frankfurt, Germany, October 7–11 2000.

	Appendix A. Conference discussion

Top Abstract 1. Introduction 2. Materials and methods 3. Results 4. Discussion 5. Conclusions Appendix A. Conference... References

 
Dr X. Mueller (Lausanne, Switzerland): You know that atrial fibrillation occurs mainly during the 3 first postoperative days. Your observation period is rather short, shorter than this period, and the standard deviation of your observation period is quite large. Moreover, taking into account that the number of patients per group is quite different, with lower patients in the OPCAB group, I think this would preclude any definitive conclusion. Your comment about that?

Dr Anisimowicz: This is a very good statement, and in fact we would like to look much closer at the subset of patients with different types of operations as well as extend observation for a longer period, but I think we need a much larger population to divide them into more subgroups.

Dr C. Yankah (Berlin, Germany): We also experience quite a number of atrial fibrillation in the CABG patients; it is about 10 to 15%. I would like to ask you a question, that is, these coronary patients have usually preoperatively a beta blocker, and I would like to know whether your patients had a beta blocker and when did you start giving them the beta blocker after surgery and whether you can differentiate the beta blocker group from the non-beta blocker group with regard to development of atrial fibrillation.

Dr Anisimowicz: All of the patients who received beta blocker therapy before the operations were also followed with the same therapy in the perioperative period, and the comparison between different treatment groups of patients will probably be carried out, but, again, this division makes these groups inadequate to make any statistical analysis yet.

Dr S. Akhmedov (Tomsk, Russia): Did you investigate the electrophysiologic changes of the atrium before and after CABG procedure, because, as you know, one of the theories of atrial fibrillation is atrial denervation response to removal of fat tissue onto the anterior surface of the ascending aorta for aortic cross clamping and proximal anastomosis sewing? Do you understand?

Dr Anisimowicz: Yes. We didn't do any electrophysiological examination in the operation period or after. This probably could support the many theories which deal with atrial fibrillation, a phenomenon which, as we all know, is not completely understood.

We were a little bit astonished with the discovery that the incidence of atrial fibrillation after off-pump surgery is the same and even a little bit higher than after conventional surgery, and, we can only give suppositions that there may be some factors which create more triggering situations in off-pump procedure, namely, the mechanical distension of the heart, which sometimes is probably more stressed from both the displacement of the heart and also from the changing volumes of the heart during off-pump procedure. This is one factor.

Another may be that the electrical activity is completely gone during cardioplegia, but during off-pump procedures with electrical activity we provoke some focal ischemia during constructions of the grafts on the heart.

Dr G.-W. He (Hong Kong, China): We agree with you that atrial fibrillation is a common complication after coronary artery bypass surgery that happens in about 15 to 20% of patients of ours. And we recently did a clinical trial using biatrial pacing to overcome this problem. We put one pacing wire on the right atrium, the other one on the left atrium, on the top, and we tried to overdrive pacing the patients immediately after coronary bypass surgery for about 2 or 3 days, sometimes less, and we find that this may reduce the incidence of atrial fibrillation after CABG, and we published this data in Circulation in the last issue.

Would you like to comment on this method or would you like it in your patients?

Dr Anisimowicz: This is indeed a very interesting method, but we didn't try it and we didn't use it in our patients, but maybe this is really promising and we will try this.

Mr T. Treasure (London, UK): A couple of comments in addition. You can see why I called it an old chestnut because we have worked and worked away at this over the years. In fact, this point about atrial pacing, in Dr. Kirklin's department in Alabama when I was his research fellow, which is a long time ago, the cardiologist, Dr. Waldo, and he had a protocol along those lines. So if you are interested in doing that, you should at least go back and look at that policy. We didn't pursue it.

The other thing that is interesting is in our own studies years ago we found that age and obesity – and presumably obesity is a surrogate for hypoxemia – were the two unifying factors. So I am very interested now that although there will be some debate about it, that OPCAB doesn't make it all go away. There are other factors that keep atrial fibrillation as part of our problem.

Dr P. Sergeant (Leuven, Belgium): If you allow me to continue on Professor Treasurer's comments, indeed, with our experience in off-pump surgery, there is a definite reduction in atrial fibrillation, but as you might have noticed in the data samples of this presentation, the age is an average age of 60. So it is a fairly young data set, and, as Tom Treasure just pointed out, age is very much related to this event. So if you are bringing in risk, there is a higher chance of reducing the risk. Here the observation periods were short, so the chances of observing a reduction were much less.

	References

Top Abstract 1. Introduction 2. Materials and methods 3. Results 4. Discussion 5. Conclusions Appendix A. Conference... References

 

1. Aranki S.F., Shaw D.P., Adams D.H., Rizzo J.R., Couper S.G., Vilet M.V., Collins J.J., Cohn L.H., Burstin R.H. Predictors of atrial fibrillation after coronary artery surgery. Current trends and impact on the hospital resources. Circulation 1996;94:390-397.[Abstract/Free Full Text]
2. Borzak S., Tisdale J.E., Amin N.B., Goldberg A.D., Frank D., Pohdi D., Higgins S.R. Atrial fibrillation after bypass surgery. Chest 1998;113:1489-1491.[Abstract/Free Full Text]
3. Almassi G.H., Schowalter T., Nikolosi A.C., Aggarwal A., Moritz T.E., Henderson W.G., Tarazi R., Shroyer I., Sethi G.K., Grover F.L., Hammermeister K.E. Atrial fibrillation after cardiac surgery - a major morbid event ?. Ann Surg 1997;226(4):501-513.[Medline]
4. Siebert J., Rogowski J., Jagielak D., Anisimowicz L., Lango R., Narkiewicz M. Atrial fibrillation after coronary artery bypass grafting without cardiopulmonary bypass. Eur J Cardio-thorac Surg 2000;17:520-523.[Abstract/Free Full Text]
5. Ducceschi V., D'Andrea A., Liccardo B., Alfieri A., Sarubbi B., De Feo M., Santangelo L., Cotrufo M. Perioperative clinical predictors of atrial fibrillation occurrence following coronary artery surgery. Eur J Cardio-thorac Surg 1999;16:435-439.[Abstract/Free Full Text]
6. Hogue C.H.W., Hyder M.L. Atrial fibrillation after cardiac operation: risks. mechanisms, and treatment. Ann Thorac Surg 2000;69:300-306.[Abstract/Free Full Text]
7. Pires L.A., Wagshal A.B., Lancey R., Huang S.K. Arrhythmias and conduction disturbances after coronary artery bypass surgery: epidemiology, management, and prognosis. Am Heart J 1995;129(4):799-808.[Medline]
8. Asher C.R., Miller D.P., Grimm R.A., Cosgrove D.M., Chung M.K. Analysis of risk factors for development of atrial fibrillation early after cardiac valvular surgery. Am J Cardiol 1998;82:892-895.[Medline]
9. Stamou S.C., Dangas G., Hill P.C., Pfister A.J., Dullum M.K.C., Boyce S.W., Bafi A.S., Garcia J.M., Corso P.J. Atrial fibrillation after beating heart surgery. Am J Cardiol 2000;86:64-67.[Medline]
10. Allen K.B., Matheny R.G., Robison R.J., Heimansohn D.A., Shaar C.J. Minimally invasive versus conventional reoperative coronary artery bypass. Ann Thorac Surg 1997;64:616-622.[Abstract/Free Full Text]
11. Boyd W.D., Desai N.D., Del Rizzo D.F., Novick R.J., McKenzie F.N., Menkis A.H. Off-pump surgery decreases postoperative complications and resource utilization in the elderly. Ann Thorac Surg 1999;68:1490-1493.[Abstract/Free Full Text]
12. Sutandar A., Tamis J.C., Narula D., Gemayel C.G., Vloka M.E., Steinberg J.S. Atrial fibrillation after minimally invasive bypass surgery is not less frequent than after CABG. PACE 1999;22(II):719 (abstract).
13. Kitzman D.W., Edwards W.D. Age-related changes in the anatomy of the normal human heart. J Gerontol 1990;45:M33-M39.[Abstract]
14. Lie J.T., Hammond P.I. Pathology of the senescent heart: anatomic observations on 237 autopsy studies of patients of 90 to 105 years old. Mayo Clin Proc 1988;63:552-564.[Medline]
15. Cox J.L. A perspective of postoperative atrial fibrillation in cardiac operations. Ann Thorac Surg 1993;56:405-409.[Medline]
16. Jideus L., Blomstrom P., Nilsson L., Stridsberg M., Hansell P., Blomstrom-Lundqvist C. Tachyarrhythmias and triggering factors for atrial fibrillation after coronary artery bypass operations. Ann Thorac Surg 2000;69:1064-1069.[Abstract/Free Full Text]
17. Asher C.R., DiMengo M., Arheart K.L., Weber M.M., Grimm R.A., Blackstone E.H., Cosgrove D.M., Chung M.K. Atrial fibrillation early postoperatively following minimally invasive cardiac valvular surgery. Am J Cardiol 1999;84(15):744-747.[Medline]

This article has been cited by other articles:

				A. Sezai, M. Hata, T. Niino, Y. Kasamaki, T. Nakai, A. Hirayama, and K. Minami Study of the factors related to atrial fibrillation after coronary artery bypass grafting: A search for a marker to predict the occurrence of atrial fibrillation before surgical intervention J. Thorac. Cardiovasc. Surg., April 1, 2009; 137(4): 895 - 900. [Abstract] [Full Text] [PDF]

				D. Kisner, M. J. Wilhelm, M. S. Messerli, G. Zund, and M. Genoni Reduced incidence of atrial fibrillation after cardiac surgery by continuous wireless monitoring of oxygen saturation on the normal ward and resultant oxygen therapy for hypoxia Eur. J. Cardiothorac. Surg., January 1, 2009; 35(1): 111 - 115. [Abstract] [Full Text] [PDF]

				F. Bakhtiary, P. Therapidis, O. Dzemali, K. Ak, H. Ackermann, D. Meininger, P. Kessler, P. Kleine, A. Moritz, T. Aybek, et al. Impact of high thoracic epidural anesthesia on incidence of perioperative atrial fibrillation in off-pump coronary bypass grafting: A prospective randomized study J. Thorac. Cardiovasc. Surg., August 1, 2007; 134(2): 460 - 464. [Abstract] [Full Text] [PDF]

				G. J. Padfield, N. M. Hawkins, and M. R. MacDonald Letter by Padfield et al Regarding Article, "Randomized Trial of Atorvastatin for Reduction of Postoperative Atrial Fibrillation in Patients Undergoing Cardiac Surgery: Results of the ARMYDA-3 (Atorvastatin for Reduction of Myocardial Dysrhythmia After Cardiac Surgery) Study" Circulation, April 17, 2007; 115(15): e403 - e403. [Full Text] [PDF]

				C. G. Koch, L. Li, D. R. Van Wagoner, A. I. Duncan, A. M. Gillinov, and E. H. Blackstone Red Cell Transfusion is Associated With an Increased Risk for Postoperative Atrial Fibrillation Ann. Thorac. Surg., November 1, 2006; 82(5): 1747 - 1756. [Abstract] [Full Text] [PDF]

				M. L. Fontes, J. P. Mathew, H. M. Rinder, D. Zelterman, B. R. Smith, C. S. Rinder, and the Multicenter Study of Perioperative Ischemia (M Atrial Fibrillation After Cardiac Surgery/Cardiopulmonary Bypass Is Associated with Monocyte Activation Anesth. Analg., July 1, 2005; 101(1): 17 - 23. [Abstract] [Full Text] [PDF]

				E. A Black, S. Ghosh, K. Sin, T. Spyt, and R. Pillai Off-Pump Coronary Artery Bypass Surgery Asian Cardiovasc Thorac Ann, December 1, 2004; 12(4): 379 - 386. [Abstract] [Full Text] [PDF]

				J. E. Cummings, I. Gill, R. Akhrass, M. Dery, L. A. Biblo, and K. J. Quan Preservation of the anterior fat pad paradoxically decreases the incidence of postoperative atrial fibrillation in humans J. Am. Coll. Cardiol., March 17, 2004; 43(6): 994 - 1000. [Abstract] [Full Text] [PDF]

				J. Melo, P. Voigt, B. Sonmez, M. Ferreira, M. Abecasis, M. Rebocho, A. Timoteo, C. Aguiar, S. Tansal, H. Arbatli, et al. Ventral cardiac denervation reduces the incidence of atrial fibrillation after coronary artery bypass grafting J. Thorac. Cardiovasc. Surg., February 1, 2004; 127(2): 511 - 516. [Abstract] [Full Text] [PDF]

				A. H Olivencia-Yurvati, N. Wallace, S. Ford, and R. T Mallet Leukocyte filtration and aprotinin: synergistic anti-inflammatory protection Perfusion, January 1, 2004; 19(1_suppl): S13 - S19. [Abstract] [PDF]

				R A Archbold and N P Curzen Off-pump coronary artery bypass graft surgery: the incidence of postoperative atrial fibrillation Heart, October 1, 2003; 89(10): 1134 - 1137. [Abstract] [Full Text] [PDF]

				H. Shin, K. Hashizume, Y. Iino, K. Koizumi, T. Matayoshi, and R. Yozu Effects of atrial fibrillation on coronary artery bypass graft flow Eur. J. Cardiothorac. Surg., February 1, 2003; 23(2): 175 - 178. [Abstract] [Full Text] [PDF]

				P. Totaro, R. Lorusso, and G. Minzioni Postoperative atrial fibrillation after coronary surgery and prolonged intensive care unit stay: a coin with two sides Eur. J. Cardiothorac. Surg., January 1, 2002; 21(1): 159 - 159. [Full Text] [PDF]

				J. Siebert, L. Anisimowicz, R. Pawlaczyk, and M. Narkiewicz Reply to Totaro et al. Eur. J. Cardiothorac. Surg., January 1, 2002; 21(1): 159 - 160. [Full Text] [PDF]

This Article Abstract Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Add to Personal Folders Download to citation manager Permission Requests Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Siebert, J. Articles by Narkiewicz, M. Search for Related Content PubMed PubMed Citation Articles by Siebert, J. Articles by Narkiewicz, M. Related Collections Coronary disease Electrophysiology - arrhythmias