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Atrial Fibrillation SurgeryAtrial Fibrillation SurgeryThe Blackpool ExperienceThe Blackpool Experience
Augustine TangAugustine TangBMedSc(Hon) DM FRCS(C‐Th) FETCS
Consultant Cardiothoracic Surgeon
AF ‐ Pathophysiology• Structural heart disease
• ↑BP, CCF• Autoimmune: anti‐MHC
• Genetic ‐ lamin AC gene
• RAAS, MMP, disintegrin
• Conduction system
• Sick sinus syndromeHenry WL, Morganroth J, Pearlman AS, et al. Relation betweenechocardiographically determined left atrial size and atrial fibrillation.Circulation. 1976;53:273-9.Bailey GWH, Braniff BA, Hancock EW, Cohn KE. Relation of leftatrial pathology to atrial fibrillation in mitral valvular disease. AnnIntern Med. 1968;69:13-20.Davies MJ, Pomerance A. Pathology of atrial fibrillation in man. BrHeart J. 1972;34:520-5.Sanfilippo AJ, Abascal VM, Sheehan M, et al. Atrial enlargement as aconsequence of atrial fibrillation. A prospective echocardiographicstudy. Circulation. 1990;82:792-7.
AF Surgery – Why do it?• Restoration of sinus rhythm would
– Improve quality of life, reduce symptoms & increase exercise tolerance
– Offer freedom from long‐term anti‐arrhythmic drugs
– Offer freedom from long‐term anticoagulation
– Reduce thromboembolism & stroke ?
– Reduce long‐term mortality ?
• Removal of left atrial appendage would– Minimize thromboembolic stroke
– Offer freedom from long‐term anticoagulation
AF Surgery – Basis• Macro‐reentry circuits in
atrial walls• Ectopic ‘triggers’ sited in
Pulmonary veins• Substrate remodelling• Perceived invasiveness:
CPB duration & technical demands
• Postoperative morbidities: bleeding, arrhythmias & LA function
AF Surgery ‐ Evolution
• Cox‐Maze procedures
• Version III 1988
• Modified CM III/CM IV
• (Cryothermy 2000; Bipolar RF 2003)
AF Surgery – Muddy Waters• Gold Standard – CM III
Freedom from AF
96.6% at 6yr FU
95% at 10yr FU
93% at 14yr FU
• Emerging fore‐runner –CM IV (n=282)
89% free from AF at 1yr
78% free from AF & drugs(Damiano, RJ et. al. J Thorac Cardiovasc Surg 2011;141:113‐
121)
But what about...............
• Patient factors?– Paroxysmal v. Persistent
– AF duration
– Lone v. Concomitant
– Preop atrial size
• Technical factors?– Lesion pattern
– Energy source & design
– Exit block test for PVI
– Concomitant procedures
Atrial Fibrillation
Left atrial size
Atrial fibrillation
AF & Atrial size• Very large left atria provide the substrate for atrial fibrillation [Kopecky S, Gersh B, McGoon M, Whisnant JP, Holmes Jr DR, Ilstrup DM, Frye RL. The natural history of
lone atrial fibrillation: A population based study over three decades. N Engl J Med 1987;317:669—74]
• LA with diameter >60 mm is a substrate for development and maintenance of AF [Henry W, Morganroth J,
Pearlman A, Clark CE, Redwood DR, Itscoitz SB, Epstein SE. Relation between echocardiographically determined LA size and AF. Circulation 1976;53:273—9]
• Ravelli F, Allessie M. Effects of atrial fibrillation on refractory period and vulnerability to atrial fibrillation the isolated Langendorff‐perfused rabbit heart. Circulation 1997;96:1686‐95
– acute dilatation of the atria by volume load in isolated perfused rabbit hearts
– measured the right and left effective refractory periods, as well as the generation of atrial fibrillation by simple premature stimuli
– a decrease in threshold and an increase in the ability to induce AF from 0% to 100% (drastic shortening of atrial effective refractory period)
– the induced atrial fibrillation in a dilated left atrium contributes to further atrial dilatation
RF Catheter AF ablation & LA
Jeevanantham V, Ntim W, Navaneethan SD, Shah S, Johnson AC, Hall B, Shah A, Hundley WG, Daubert JP, Fitzgerald D. Meta‐analysis of the effect of radiofrequency catheter ablation on left atrial size, volumes and function in patients with atrial fibrillation. Am J Cardiol. 2010 May 1;105(9):1317‐26
• Systematically review relevant studies through April 2009 for the effects of RFCA on LA size, volumes, and function in patients with AF
• Weighted mean differences for changes in LA diameter, LA max volume, LA min volume, LA ejection fraction, and LA active emptying fraction were estimated using fixed‐ and random‐effects meta‐analyses
• Seventeen (869 patients) among 192 studies were analyzed
• Compared to baseline, overall LA diameter and volume ↓ significantly after ablation
• LA ejection fraction & active emptying fraction remain unchanged after ablation
• These changes were not observed in those with recurrent AF after ablation
• Successful RFCA in patients with AF significantly decreases LA size and volume and does not seem to adversely affect LA function
Effect of AF surgery on LA size• It has been reported that atrial size remained unchanged after an isolated maze procedure Jessurun ER, van Hemel NM, Kelder JC, et al. The effect of maze operations on atrial volume. Ann Thorac Surg 2003;75:51–6
• Choo et al. compared GLA patients to those with LA diameter <65 mm who underwent the maze procedure. LA size was reduced in both groups early postoperatively, but no further reduction was observed for the next 2 years follow‐up Choo S, Park N, Lee S, Kim JW,
Song JK, Song H, Song MG, Lee JW. Excellent results for atrial fibrillation surgery in the presence of giant left atrium and mitral valve disease. Eur J Cardiothorac Surg 2004;26:336—41
• Among 30 GLA patients, LA diameter ↓ significantly from 69.0±8.5 mm to 53.7±9.1 mm shortly after surgery and maintained at 5 years of follow‐up Hagihara H, Kitamura S, Kawachi K, Morita R, Taniguchi S, Fukutomi M, Kawata T, Hasegawa J, Yoshida Y. Left atrial plication combined with mitral valve surgery in patients with a giant left atrium. Surg Today 1995;25:338—42
Cox‐maze for AF & Atrial size
DOES SIZE MATTER?
Cox‐maze & atrial morphology • Multiple trans‐mural lesions to interrupt macro re‐entry circuits
• Excision/exclusion of left atrial appendage
• Left atriotomy• Right atriotomy• RA appendage access incision
Cox‐maze in Giant atria• The ability of the left atrium to fibrillate is determined by the
relation between the effective refractory period of the atrial myocardium and the atrial area available for the macroreentrant circuit. This fact—that a critical area of atrial tissue is needed to support or sustain atrial fibrillation—would therefore suggest the importance of reducing the size of the atrium to eliminate AF. Furthermore, by Laplace’s law, decreasing the size of the atrium will ultimately decrease the wall stress of the chamber and may reduce a primary stimulus for fibrillation Matthew A. Romano, David S. Bach, Francis D. Pagani, Richard L. Prager, G. Michael Deeb and Steven F. Bolling. Atrial reduction plasty Cox maze procedure: extended indications for atrial fibrillation surgery Ann Thorac Surg 2004;77:1282‐1287
• “The maze itself depends on placing the incisions close enough topreclude the development of macro re‐entrant circuits in the atrium. A maze can be performed absolutely perfectly in a huge atrium, but if the resultant lesions are far enough away from one another that macro re‐entrant circuits can form between them, then the operation will fail and the atrial fibrillation will persist.”James L Cox STS 2004
Recurrent AF after Cox‐maze• Mean LA size 5.8cm preop (N=263)
• Larger LA diameter ↑ the prevalence of AF in both the late & constant time phases
• At 5 yr FU, the predicted prevalence of AF was 5% with a 4‐cm LA but 15% with a 6‐cm left atrium
• There is no clear cut‐off value beyond which restoration of sinus rhythm is impossible
• Earlier operation and left atrial size reduction should be considered
Gillinov AM, Sirak J, Blackstone EH, McCarthy PM, Rajeswaran J, Pettersson G, et al. The Cox Maze procedure in mitral valve disease: predictors of recurrent atrial fibrillation. J Thorac Cardiovasc Surg 2005;130:1653‐60.
LA reduction in Cox‐mazeConcomitant LA reduction:•facilitate SR restoration (85% v. 68% p<0.05)•improve LA mechanics & function (↑Booster pump & reservoir function)•promote LA reverse remodelling
LA reduction in Cox‐maze
In the present study, patients who did not undergo LA volume reduction surgery did not have reduced LA volume despite successful sinus rhythm recovery, most likely because prolonged atrial overload before the surgery may have caused irreversible structural damage to the LA myocardium, or because the higher wall stress of the enlarged left atrium compared with the reduced left atrium might prevent the reverse remodeling.
BUT non‐randomized with only 1‐yr FU and limitations of MRI gating in AF
Isolated LA reduction for AFImpact of Left Atrial Size Reduction on Chronic Atrial
Fibrillation in Mitral Valve SurgeryMirela Scherer MD, Omer Dzemali MD, Tayfun Aybek MD, Gerhard Wimmer‐
Greinecker MD, Anton Moritz MD Department of Thoracic and Cardiovascular Surgery, J. W. Goethe University, Frankfurt am Main, Germany
The Journal of Heart Valve Disease 2003;12:469‐474
Background and aim of the study: Left atrial enlargement is a risk factor for the development of atrial fibrillation (AF). Large atrial size increases thromboembolic risk and reduces the success rate of cardioversion. The study aim was to evaluate if left atrial size reduction affects cardiac rhythm in patients with chronic AF undergoing mitral valve surgery. Methods: Twenty‐seven patients were analyzed prospectively. The left atrial incision was extended to the left inferior pulmonary vein. Left atrial size reduction was achieved by closure of the left atrial appendage from inside with a double running suture. The same suture plicated the left lateral atrial wall to the roof of the left pulmonary vein inflow and the inferior atrial wall. The atrial septum was plicated by placing stitches of the closing suture line across the fossa ovalis. Rhythm, neurological complications, cardioversion, anticoagulation and anti‐arrhythmic medication were evaluated at one year postoperatively and at recent follow up (mean 40 ± 15 months). Results: At discharge, five patients (19%) were in sinus rhythm (SR). At one year postoperatively, SR was restored in 17 patients (63%), but five (19%) reported episodes of arrhythmia and AF persisted in 10 (37%). At recent follow up, four patients had died and three were lost to follow up. Among 20 patients examined, 13 (65%) had SR but six reported episodes of arrhythmia and AF persisted in seven (35%). LA diameter was significantly reduced, from 60.2 ± 9.8 mm preoperatively to 44.5 ± 7.0 mm at one year after surgery. Conclusion: The addition of left atrial size reduction to mitral valve surgery is technically simple, and was effective in 63% of patients with chronic AF, restoring predominant SR. In order to influence pathogenetic factors other than size, additional ablative steps may further increase the SR conversion rate. Size reduction may also improve the outcome of other ablative approaches.
Isolated LA reduction for AF
Hornero F, Rodriguez I, Buendía J, Bueno M, Dalmau MJ, Canovas S, Gil O, Garcia R, Montero JA. Atrial remodeling after mitral valve surgery in patients with permanent atrial fibrillation. J Card Surg. 2004 Sep‐Oct;19(5):376‐82.
• PRCT (N=50) Permanent AF & ↑ LA • Randomized to isolated MVS or concomitant LA reduction
• LAR group has ↑ SR (46% v. 18%), ↓ LA volume & ↑ LA remodeling (p<0.05 for both)
LA reduction – Surgical technique
LA reduction – Surgical technique
LA reduction – Surgical technique
LA reduction – Surgical technique
LA reduction – Surgical technique
LA reduction – Surgical technique
LA reduction – Surgical techniquePartial auto‐transplantation
Pros: Significant atrial reduction; good access to mitral/tricuspid valves; excellent PV isolation
Cons: Prolonged ischaemic time; involvement of non‐affected structures (PA, aorta, SVC, IVC); ↑ complication from a complex approach
LA reduction + Cox‐maze = Holy Grail?
• Clinical series show sustained SR at 12 months ∼ 75 – 85%
• Sick atrial substrate with LA diameter/volume as a surrogate marker?
• Long‐term anti‐arrhythmic agents postoperatively?
• Subgroup ‘too late’ to respond?
CoxCox‐‐maze IV maze IV –– Blackpool Experience Blackpool Experience
• Concomitant vs stand‐alone AF surgery
• Referred for surgery with structural heart disease/ischaemic heart disease/aortic disease – surgical OP assessment
• Arrhythmias MDT meeting
• Screened for eligibility for the AMAZE trial
• Surgery with EP input: confirm PVI exit block
• EP follow‐up after surgical OP discharge
CoxCox‐‐maze IV maze IV –– Blackpool Experience Blackpool Experience
• Total in series = 27– 1 in 2009
– 8 in 2010
– 15 in 2011
– 3 in Jan 2012 (?>30)
• 22 valve +/‐ CABG surgery, 5 CABG; 1 redo, 1 ASD
• Full hybrid lesion set in 24, left atrial lesions for flutter in 3, atrial reduction since 2011
CoxCox‐‐maze IV maze IV –– Blackpool Experience Blackpool Experience
• M:F = 16:11
• Mean age = 72 (range 57 – 86)
• 1 in‐hospital death, 1 ischaemic stroke, 1 PPM
• 1 late death
• Freedom from AF at latest FU = 24/25 (96%)
• Freedom from AF at 12m FU = 7/8 (88%)
• Symptomatic improvement = 24/25 (96%)
• Warfarin withdrawal – CHAD VASC score
CoxCox‐‐maze IV maze IV –– Blackpool Experience Blackpool Experience
THANK YOU!ANY QUESTIONS
PLEASE?
