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RF Ablation of Atrial
Fibrillation in Valvular Heart
Surgery Patients
Željko Sutlić
DEPARTMENT OF CARDIAC SURGERY
Dubrava University Hospital
Zagreb, Croatia
www.kbd.hr
Introduction
The incidence of chronic atrial fibrilation (AF) is
age dependent:
1% of the general population
4% in pts > 60 years
7% in pts > 70 years
60-80 % in pts with significant mitral valve disease
Department of Cardiac Surgery
Dubrava University Hospital
Zagreb, Croatia www.kbd.hr/kardkir
AF - TYPES
paroxsismal AF
persistant AF
permanent AF
Department of Cardiac Surgery
Dubrava University Hospital
Zagreb, Croatia www.kbd.hr/kardkir
Criteria for Success
Sinus Rhythm
Absence of intermittent AF
Absence of atrial flutter
Atrial transport function
Restricted antiarrhythmic medication
Department of Cardiac Surgery
Dubrava University Hospital
Zagreb, Croatia www.kbd.hr/kardkir
Criteria
Indication for mitral valve repair/replacement or
coronary artery disease
Chronic atrial fibrillation (>6 months)
Electrocardiographical confirmation of diagnosed
chronic atrial fibrillation by 24 hour holter monitoring
EF > 30 %
Age: 18 – 80 years
Informed consent
Department of Cardiac Surgery
Dubrava University Hospital
Zagreb, Croatia www.kbd.hr/kardkir
Atrial fibrillation in Patients
Undergoing Mitral Valve Surgery:
Why AF Surgery?
Incidence of AF varies between 30 – 50%
Curative AF surgery can eliminate the need for
anticoagulation by restoring sinus rhythm, particulary
important in patients having valve repair
Rate of anticoagulation-related bleeding after
mechanical valve surgery is between 0,3 to 4,9 events/
patient year
Bleeding rates with mitral bioprosthesesare less but
stillsignificant (0,6 – 2,1 episodes/patient year) in part
due to the need for anticoagulation for AF
Department of Cardiac Surgery
Dubrava University Hospital
Zagreb, Croatia www.kbd.hr/kardkir
Atrial Fibrillation: Surgical Therapy
Cox developed the Maze Procedure – first
performed in 1987 at Barnes Jewish Hospital
High rate of surgical cure for atrial fibrillation
(>90%) without antiarrhythmic therapy
Indications:
Drug refractory AF
Arrhythmia intolerance
Recurrent thromboembolism
Department of Cardiac Surgery
Dubrava University Hospital
Zagreb, Croatia www.kbd.hr/kardkir
Atrial fibrillation and Mitral Valve
Disease
Should all patients with atrial fibrillation who
are referred for mitral valve surgery undergo a
concomitant Cox-Maze procedure?
Let's look at our long term surgical results in
these patients!
Department of Cardiac Surgery
Dubrava University Hospital
Zagreb, Croatia www.kbd.hr/kardkir
Cox-Maze III Procedure
Cox-Maze III first performed in 1988
Maze-like surgical incisions
Based on theory of multiple macro-reentrant
circuits
Department of Cardiac Surgery
Dubrava University Hospital
Zagreb, Croatia www.kbd.hr/kardkir
The Cox Maze Procedure:
Evolution of the Surgical Approach
The Cox Maze I was abandoned because of a high
incidence of chronotropic incompetence and
pacemaker implantation
The Cox Maze II was replaced because of its' technical
difficulty
The Cox Maze III has remained the gold standard
since 1988 and has extraordinary long term efficacy
Department of Cardiac Surgery
Dubrava University Hospital
Zagreb, Croatia www.kbd.hr/kardkir
The Cox-Maze Procedure:
Surgical Objectives
Cure of atrial fibrillation
Restoration of A-V synchrony
Preservation of atrial function
Discontinuation of anticoagulation and antiarrhythmic drugs
Department of Cardiac Surgery
Dubrava University Hospital
Zagreb, Croatia www.kbd.hr/kardkir
Cox-Maze III Procedure
Patient Populations
Lone atrial fibrillation
Atrial fibrillation in association with organic
heart disease:
valvular heart disease
ischemic heart disease
Department of Cardiac Surgery
Dubrava University Hospital
Zagreb, Croatia www.kbd.hr/kardkir
Freedom form AF
All Patients
Cox JL. Surg Treat of AF, San Francisco, June 2003
Freedom from AF
LM versus CM
Cox JL. Surg Treat of AF, San Francisco, June 2003
Efficacy of Surgical Maze Procedure for
Atrial Fibrillation
Cox-Maze III Procedure with Mitral Surgery:
Washington University Experience
65 consecutive patients between January 1988
– May 2003; mean follow-up = 3.6 years
Avarage duration AF: 5.2 years (0,5–28 years)
Paroxysmal AF: 41%
Operative mortality : 1/65 ( 1.5% )
Freedom from AF at 10 years: 97%
No late strokes!
Department of Cardiac Surgery
Dubrava University Hospital
Zagreb, Croatia www.kbd.hr/kardkir
Advantages of the COX-MAZE III
Procedure
High cure rate (>90%)
Proven long-term efficacy
Applicable to both persistent and paroxysmal
AF
Eliminates the late risk of stroke in a high risk
population
Requires no additional devices except for a
cryoprobe
Department of Cardiac Surgery
Dubrava University Hospital
Zagreb, Croatia www.kbd.hr/kardkir
Shortcomings of the COX-MAZE III
Procedure
Requires cardiopulmonary bypass and an
arrested heart
Adds to cross-clamp time
Few surgeons perform the operation due to its'
complexity
Significant morbidity
pacemaker requirement and left atrial dysfunction
Department of Cardiac Surgery
Dubrava University Hospital
Zagreb, Croatia www.kbd.hr/kardkir
Cox-Maze III Procedure for AF
Postoperative Management
Diuretics
Lasix
Spironolactone
Coumadin
3 months
Discontinue if in NSR
Anti-arrhythmic drugs
2 months
Discontinue if in NSR
Postoperative sinus node dysfunction
10 – 15 % of patients
Wait 7-10 days before implanting pacemaker
Department of Cardiac Surgery
Dubrava University Hospital
Zagreb, Croatia www.kbd.hr/kardkir
The Cox Maze Procedure:
Goals of a Less Invasive Approach
Preserve the high success rates of the Cox-Maze III
procedure while decreasing its' morbidity
Simplify and/or decrease the number of atrial incisions
to shorten the procedure and increase its' adoption rate
among surgeons
Replace surgical incisions with linear lines of ablation
using various energy sources:
Cryosurgery
Radiofrequency
Microwave
Laser
Ultrasound
Department of Cardiac Surgery
Dubrava University Hospital
Zagreb, Croatia www.kbd.hr/kardkir
Radiofrequency energy
similar to electrocautery
very fast AC current
no depolarisation of the heart
monopolar or bipolar
irrigated or not irrigated (early)
Department of Cardiac Surgery
Dubrava University Hospital
Zagreb, Croatia www.kbd.hr/kardkir
Dry vs- Irrigated Electrode Tissue
Heat Distribution
Department of Cardiac Surgery
Dubrava University Hospital
Zagreb, Croatia www.kbd.hr/kardkir
Department of Cardiac Surgery
Dubrava University Hospital
Zagreb, Croatia www.kbd.hr/kardkir
Complications of RF Ablation for
Atrial Fibrillation
CVA
TIA
Tamponade
Aortic tear
Pulmonary vein stenosis
Damage to MV apparatus
Phrenic nerve injury
Coronary artery injury
Department of Cardiac Surgery
Dubrava University Hospital
Zagreb, Croatia www.kbd.hr/kardkir
Surgical procedure (began on april
2003)
MVR and TVP
MVR and CABG
6 patients
1 patient
average aortic clamp time
average pump time
94 ± 42 min
124 ± 25 min
Department of Cardiac Surgery
Dubrava University Hospital
Zagreb, Croatia www.kbd.hr/kardkir
Table 1. Clinical characteristics (n=7)
Age (years)
58 (45-72)
Male/female
3/4
Power p wave
25 W
AF duration
< 3 years
5
3-6 years
1
> 6 years
1
Antiarrhythmic drug tested
amjoderon
4
atenolol
1
verapamil
1
metildigoxin
1
DM (n)
1
Arterial
hypertension (n)
1
Reoperation (n)
1
Death (n)
1
Department of Cardiac Surgery
Dubrava University Hospital
Zagreb, Croatia www.kbd.hr/kardkir
Table 2. Echocardiographic variables
preoperative postoperative
values
values
anteroposterior LA
diameter (mm)
mediolateral LA
diameter (mm)
superinferior LA
diameter (mm)
anteroposterior RA
diameter (mm)
mediolateral RA
diameter (mm)
superinferior RA
diameter (mm)
49 (45-59)
47 (42-51)
50 (50-52)
49 (48-55)
61 (60-69)
62(60-67)
40 (39-45)
38 (31-43)
45 (42-56)
39 (31-45)
56 (52-60)
47 (45-52)
LVED (mm)
57 (50-64)
53 (48-64)
LVES (mm)
43 (38-47)
42 (37-48)
EF (%)
47 (45-51)
48 (41-56)
Department of Cardiac Surgery
Dubrava University Hospital
Zagreb, Croatia www.kbd.hr/kardkir
Table 3. Single case (male, 58 years old, MVR + TVP)
preoperative postoperative
anteroposterior LA
diameter (mm)
mediolateral LA
diameter (mm)
superinferior LA
diameter (mm)
anteroposterior RA
diameter (mm)
mediolateral RA
diameter (mm)
superinferior RA
diameter (mm)
3 month
postoperative
45
47
45
52
48
46
61
67
48
39
31
31
45
45
34
56
52
48
LVED (mm)
64
52
55
LVES (mm)
47
39
35
EF (%)
51
49
65
Department of Cardiac Surgery
Dubrava University Hospital
Zagreb, Croatia www.kbd.hr/kardkir
Surgery for Atrial Fibrillation:
Established Facts and Surgical
Approach
We have very effective, though invasive, operation with
high success rates
Patients who are candidates for Cox Maze procedure
should not be deprived of a curative, known procedure
for a theoretical lesion set performed with unproven
technology
New procedures and technology should be subject to
rigorous prospective clinical trials
New lesion sets should be based on known
mechanisms of atrial fibrillation
Department of Cardiac Surgery
Dubrava University Hospital
Zagreb, Croatia www.kbd.hr/kardkir
Will There Be a Role for Surgery in
the Future?
Yes, for the symptomatic patient:
Who requires other concomitant cardiac surgical procedures
Coronary artery disease
Valvular heart disease
Congenital disease
With prior thromboembolic complications
For persistent and "permanent" atrial fibrillation
Possibly
With paroxysmal atrial fibrillation if performed via minimally
invasive techniques
Department of Cardiac Surgery
Dubrava University Hospital
Zagreb, Croatia www.kbd.hr/kardkir
Catheter Ablation Techniques for Atrial
Fibrillation: Conclusions
Effective (60-80%) for drug refractory paroxysmal AF
with pulmonary vein triggers
Targets PV-LA junction, with linear line to MVA,
possible linear lesion across Bachman's bundle
Prolonged procedures, requires transseptal access to
the LA
Lesions constrained by biophysical properties of tissue
Complications approach 5%
TIA/CVA
Pulmonary vein stenosis
Cardiac tamponade
Aortic tear, coronary injury
One of multiple tools available
Department of Cardiac Surgery
Dubrava University Hospital
Zagreb, Croatia www.kbd.hr/kardkir
Everything should be made as
simple as possible. But not
simpler.
Albert Einstein
Department of Cardiac Surgery
Dubrava University Hospital
Zagreb, Croatia www.kbd.hr/kardkir