Dubrava University Hospital Zagreb, Croatia DEPARTMENT OF CARDIAC SURGERY RF Ablation of Atrial Fibrillation in Valvular Heart Surgery Patients Željko Sutlić

Dubrava University Hospital Zagreb, Croatiawww.kbd.hr/kardkir Department of Cardiac SurgeryIntroduction 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 % in pts with significant mitral valve disease

Dubrava University Hospital Zagreb, Croatiawww.kbd.hr/kardkir Department of Cardiac Surgery AF - TYPES paroxsismal AF persistant AF permanent AF

Dubrava University Hospital Zagreb, Croatiawww.kbd.hr/kardkir Department of Cardiac Surgery Criteria for Success Sinus Rhythm Absence of intermittent AF Absence of atrial flutter Atrial transport function Restricted antiarrhythmic medication

Dubrava University Hospital Zagreb, Croatiawww.kbd.hr/kardkir Department of Cardiac SurgeryCriteria 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

Dubrava University Hospital Zagreb, Croatiawww.kbd.hr/kardkir Department of Cardiac Surgery 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

Dubrava University Hospital Zagreb, Croatiawww.kbd.hr/kardkir Department of Cardiac Surgery 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

Dubrava University Hospital Zagreb, Croatiawww.kbd.hr/kardkir Department of Cardiac Surgery 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!

Dubrava University Hospital Zagreb, Croatiawww.kbd.hr/kardkir Department of Cardiac Surgery Cox-Maze III Procedure Cox-Maze III first performed in 1988 Maze-like surgical incisions Based on theory of multiple macro-reentrant circuits

Dubrava University Hospital Zagreb, Croatiawww.kbd.hr/kardkir Department of Cardiac Surgery 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

Dubrava University Hospital Zagreb, Croatiawww.kbd.hr/kardkir Department of Cardiac Surgery The Cox-Maze Procedure: Surgical Objectives Cure of atrial fibrillation Restoration of A-V synchrony Preservation of atrial function Discontinuation of anticoagulation and anti- arrhythmic drugs

Dubrava University Hospital Zagreb, Croatiawww.kbd.hr/kardkir Department of Cardiac Surgery Cox-Maze III Procedure Patient Populations Lone atrial fibrillation Atrial fibrillation in association with organic heart disease: valvular heart disease ischemic heart disease

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

Dubrava University Hospital Zagreb, Croatiawww.kbd.hr/kardkir Department of Cardiac Surgery 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!

Dubrava University Hospital Zagreb, Croatiawww.kbd.hr/kardkir Department of Cardiac Surgery 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

Dubrava University Hospital Zagreb, Croatiawww.kbd.hr/kardkir Department of Cardiac Surgery 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

Dubrava University Hospital Zagreb, Croatiawww.kbd.hr/kardkir Department of Cardiac Surgery 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

Dubrava University Hospital Zagreb, Croatiawww.kbd.hr/kardkir Department of Cardiac Surgery 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

Dubrava University Hospital Zagreb, Croatiawww.kbd.hr/kardkir Department of Cardiac Surgery Radiofrequency energy similar to electrocautery very fast AC current no depolarisation of the heart monopolar or bipolar irrigated or not irrigated (early)

Dubrava University Hospital Zagreb, Croatiawww.kbd.hr/kardkir Department of Cardiac Surgery Dry vs- Irrigated Electrode Tissue Heat Distribution

Dubrava University Hospital Zagreb, Croatiawww.kbd.hr/kardkir Department of Cardiac Surgery

Dubrava University Hospital Zagreb, Croatiawww.kbd.hr/kardkir Department of Cardiac Surgery 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

Dubrava University Hospital Zagreb, Croatiawww.kbd.hr/kardkir Department of Cardiac Surgery Surgical procedure (began on april 2003) MVR and TVP 6 patients MVR and CABG1 patient average aortic clamp time94 ± 42 min average pump time124 ± 25 min

Dubrava University Hospital Zagreb, Croatiawww.kbd.hr/kardkir Department of Cardiac Surgery Table 1. Clinical characteristics (n=7) 3/4

Dubrava University Hospital Zagreb, Croatiawww.kbd.hr/kardkir Department of Cardiac Surgery Table 2. Echocardiographic variables

Dubrava University Hospital Zagreb, Croatiawww.kbd.hr/kardkir Department of Cardiac Surgery Table 3. Single case (male, 58 years old, MVR + TVP)

Dubrava University Hospital Zagreb, Croatiawww.kbd.hr/kardkir Department of Cardiac Surgery 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

Dubrava University Hospital Zagreb, Croatiawww.kbd.hr/kardkir Department of Cardiac Surgery 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

Dubrava University Hospital Zagreb, Croatiawww.kbd.hr/kardkir Department of Cardiac Surgery 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

Dubrava University Hospital Zagreb, Croatiawww.kbd.hr/kardkir Department of Cardiac Surgery Everything should be made as simple as possible. But not simpler. Albert Einstein