The Maze Procedure in Mitral Vale Disease Ki-Bong Kim, MD Dept. of Thoracic & Cardiovascular Surgery Seoul National University Hospital

Atrial Fibrillation Atrial Fibrillation Prevalence : % of general population 8-17 % of population > 60 yrs % in pts w/ MV disease % in pts undergoing surgery for Tx of MV disease Incidence of asso. thromboembolism : 33 % 75 % of episodes can involve the brain 60 % of those events can result in death or severe morbidity

Three Untoward Effects of AF Unpleasantness of an irregular heart beat Impaired hemodynamics because of the loss of AV synchrony Vulnerability to the thromboembolic complications

  The extended op time needed for complicated multiple atrial incisions may preclude application of the CM-III as a concomitant op w/ standard OHS.   We modified the CM-III to decrease op time, while retaining the important principles of the maze incisions. The Cox-Maze III Procedure

Conventional CM-IIIModified CM-III Modification of the Cox-Maze III Procedure Ki-Bong Kim, et al Ann Thorac Surg 2001;71:816-22

An 8½ -Year Clinical Experience with Surgery for Atrial Fibrillation Cox JL, et al Ann Surg 1996;224:267-75

Methods  Sept 1987 – March 1996  164 pts between 3 mo & 8½ yrs after op CM-I ; 32 pts CM-II ; 14 pts CM-III ; 118 pts  59 pts (33%) underwent concomitant op in addition to the Maze procedure Ann Surg 1996;224:267

Surgical Indications  Arrhythmia intolerance ; DOE, easy fatigability, lethargy, malaise, general sense of impending doom during AF  Drug intolerance ; unsuccessful tx of max amount of tolerable drug therapy  Previous TE ; significant temporary or permanent neurological deficit  Documented cerebral TE in the absence of other demonstrable etiologies  absolute Ix for surgery because anticoagulation does not protect from a second stroke Ann Surg 1996;224:267

Indications for Surgical Tx for AF Indication n / Total % Arrhythmia Intolerance 118 / Drug Intolerance 16 / Previous TE 44 /

Results  93 % ; arrhythmia free w/o any antiarrhythmic medication  7 % ; converted to SR w/ medical tx  Of the 107 pts who were documented to have normal SA node pre-op, only 1 pt required a permanent PM Ann Surg 1996;224:267

Restoration of Atrial Transport Function Following the MAZE procedure Procedure RA Function (+) LA Function (+) Maze-I 32/32 (100%) 23/32 (72%) Maze-II 11/11 (100%) 7/11 (64%) Maze -III 80/82 (98%) 77/82 (94%) Total 123/125 (98%) 107/125 (86%)

Contraindications  Significant LV dysfunction, not attributable to the arrhythmia itself  Concomitant cardiac / non-cardiac disease that constitutes an excessive surgical risk  Pts w/ severe HOCM because of the excessive risk asso. w/ the combined procedures Ann Surg 1996;224:267

Restoration of Atrial Function After the Maze Procedure for Patients with Atrial Fibrillation ; Assessment by Doppler Echocardiography Feinberg MS, et al Circulation 1994;5 (pt II):II

METHODS  46 pts  8 ± 7 mo after the Maze  Additional procedures in 13 pts Circulation 1994;5 (pt II):II-285

RESULTS Restoration of RA contraction ; 83% (38/46) LA contraction ; 61% (28/46) % atrial filling fraction of RA that of LA % atrial filling fraction of RA in pts w/ active atrial contraction was comparable to that of control (32±7 vs 33±8 %, p=NS), whereas that of LA was smaller (20±5 vs 36±7 %, p<0.05). Circulation 1994;5 (pt II):II-285

The Outcome and Indications of the Cox Maze III Procedure for Chronic Atrial Fibrillation With Mitral Valve Disease Isobe F, et al J Thorac Cardiovasc Surg 1998;116:220-7

METHODS  30/34 pts w/ AF + MV disease  4 pts were excluded  3 w/ incomplete cut & suture d/t severe calcification & adhesions  1 died of post LV rupture  21 Rheumatic 8 Degenerative 1 PVF JTCVS 1998;116:220

RESULTS  F/U > 6 mo after the op (2.1±0.9 yrs)  SR was restored in 27 pts (90%)  RA contractility (+) in 100 % (27/27)  LA contractility (+) in 67 % (18/27)  AF persisted in 3 pts (10%) JTCVS 1998;116:220

RESULTS (SR group vs AF group RESULTS (SR group vs AF group )  f-wave voltage in lead V1  0.23±0.10 vs 0.06±0.05 mV p=0.01  CTR  60±5 vs 78±10 % p=  LA systolic dimension (Doppler)  57±8 vs 95±24 mm p=  AF duration  5.1±4.6 vs 11.8±5.5 yrs p= » » Predisposing factors for the post-op persistence of AF JTCVS 1998;116:220

RESULTS  No pts resumed SR when CTR ≥ 70 % & LA systolic dimension ≥ 80 mm before the op JTCVS 1998;116:220

RESULTS  A/E ratio of trans-mitral flow was low in pts w/ the Maze procedure as compared w/ the normal valve  Regarding the restoration of LA function, f-wave voltage, CTR, & LA systolic dimension showed no significant difference between the pts w/ positive & negative a-waves, & only the duration of AF showed statistically significant difference ( p=0.011 ). JTCVS 1998;116:220

Rationale of the Cox Maze Procedure for Atrial Fibrillation During Redo Mitral Valve Operations Kobayashi J, Kosakai Y, Isobe F, et al J Thorac Cardiovasc Surg 1996;112:

METHODS  42 pts w/ redo MV + Maze procedure  37 Kosakai’s modified Maze 2 CM-II 3 CM-III  F-U after op : 25.5 ± 10.8 mo.  Control group : 54 pts w/ redo MV w/o Maze procedure JTCVS 1996;112:1216

RESULTS  SR was regained in 28/42 pts (67 %)  Doppler study LA contraction in 16/28 pts (57%) RA contraction in 21/28 pts (75 %) JTCVS 1996;112:1216

Comparison between pts w/ & w/o restored sinus rhythm Variables SR (+) SR(-) p-value No Age (yr) 57.8± ±9.3 NS Rheumatic 23(82%) 13(94%) NS Duration of AF (yr) 9.0± ± f-wave on V1 (mV) 0.18± ± CT ratio (%) 63±8 67± LAD (mm) 57±9 57±6 NS

JTCVS 1996;112:1216 Results of op in the maze & control groups Maze group Control groupp-value Maze group Control group p-value No ACC time (min) 133±28 121± CPB time (min) 211±43 197± C-tube drainage(ml) 890± ±480 NS Blood transfusion (ml) 2120± ±1760 NS # Transfusion 7(17%) 11(20%) NS Hospital Mortality 0(0%) 4(7.4%) NS Bleeding reop 6(14%) 4(7.4%) NS Mediastinitis 0(0%) 2(3.7%) NS

CONCLUSION  The Maze procedure should be considered in selected pts who have a high possibility of regaining SR during redo MV op.  The Maze procedure should be performed concomitantly w/ MVR while preserving the MV apparatus for moderately depressed LV function, inasmuch as atrial contraction is very important. JTCVS 1996;112:1216

The Cox Maze III Procedure for Atrial Fibrillation Associated With Rheumatic Mitral Valve Disease Ki-Bong Kim, et al Ann Thorac Surg 1999;68:

METHODS  75 CM-III pts for AF asso w/ rheumatic MV disease  14 cases ; Reop because of PVF ANTS 1999;68:799

INDICATIONS  Indications to perform concomitant CM-III Chronic AF >1 yr LA thrombi (+) Medical history of previous TE events in the absence of other demonstrable etiologies ANTS 1999;68:799

RESULTS  In-hospital Mortality ; 2.7% (2/75)  73 survivors were followed for 30±13 mo (12-56) ANTS 1999;68:799

Cardiac Rhythms in the Latest F-U NSR 66 / 73 (90 %) NSR 66 / 73 (90 %)  w/o drug therapy 60 (82 %)  w/ addition of one drug 6 (8 %) AF 3 / 73 (4 %) AF 3 / 73 (4 %) JR 2 / 73 (3 %) JR 2 / 73 (3 %) PM implantation 2 / 73 (3 %) PM implantation 2 / 73 (3 %) ANTS 1999;68:799

Follow-Up TTE  66 pts w/ NSR  RA contractility (+) : 66 / 66 (100 %) LA contractility (+) : 41 / 66 (62 %)* LA contractility (+) : 41 / 66 (62 %)*  Restoration of RA contractility : 69±93 days Restoration of LA contractility :126±136 days* Restoration of LA contractility :126±136 days* * * p < 0.05 ANTS 1999;68:799

Factors Predisposing to Persisting AF Factors NSR (n=66) AF (n=3) p-value (univariate) Age (>60 yrs) 13.6 % 33.3 % ns AF Duration (>60 Mo) 40.9 % % ns LAD (>55 mm) 63.1 % 66.7 % ns LVEDD (>55 mm) 36.9 % 33.3 % ns EF (<45 %) 23.1 % 33.3 % ns

Factors Affecting Recovery of LA Contractility Factors LA(+) LA(-) p-value Factors LA(+) LA(-) p-value Univariate Multivariate Univariate Multivariate Age (<60 yrs) 87.5% 92.3% NS Duration of AF (<60 mo) 75.0% 42.3% LAD (<55 mm) 41.0 % 38.5 % NS EF (>45 %) 74.4% 80.8% NS mPAP (<20 mmHg) 19.0% 14.3% NS C.I. (>2.0 L/min/m2) 72.4% 37.5% NS RA contractility (<60 d) 75.0% 37.5% < 0.01

Non-redo vs. Redo OHS Non-redo Redo p-value Non-redo Redo p-value AF duration (Mo) 52±57 132±91 <0.01 ACC time (min) 154±45 137±32 ns CPB time (min) 250±69 258±95 ns C-tube drain (ml) 985± ±261 ns Bleeding reop 3 1 ns Conversion rate (%) ns

Conclusions  CM-III for AF asso w/ RMVD demonstrated a high sinus conversion rate & recovery of atrial contractility  LA contractility is restored significantly later & a lower rate than RA contractility in RMVD  CM-III can be performed in redo op w/ comparable sinus conversion rate & acceptable op risk ANTS 1999;68:799

Restoration of Atrial Mechanical Function After Maze Operation in Patients With Structural Heart Disease Kim Y-J, Sohn D-W, et al Am Heart J 1998;136:1070-4

METHODS  32 pts w/ the Maze procedure  SR was restored in 81 % (26/32) By surgery alone in 69 % (22/32)  By the addition of one drug in 13% (4/32)  Of the remaining 6 pts,  Four (13%, 4/32) pts ; paroxysmal AF despite antiarrhythmic therapy  One ; sustained AF  One ; permanent PM insertion d/t SSS Am Heart J 1998;136:1070

RESULTS  RA function (+) ; 30 / 30 pts w/ SR or paroxysmal AF  LA function (+) ; 19 / 30 pts (63 %) Am Heart J 1998;136:1070

RESULTS  Peak A velocity & A/E ratio of mitral inflow in pts w/ restored LA function, were significantly lower than in the 16 post-op control pts (p<0.01). Am Heart J 1998;136:1070

RESULTS  In pts w/ LA mechanical function, duration of AF was significantly shorter than in pts w/o LA mechanical function (1.9±2.9 vs 7.1±3.0 yrs, p<0.01), but there were no significant differences in LA size & volume. Am Heart J 1998;136:1070

Surgical Outcome of Maze Procedure for Atrial Fibrillation in Mitral Valve Disease: Rheumatic versus Degenerative JW Lee,et al. STS meeting, 2002

Group R (n=86) : Rheumatic Group D (n=43) : Degenerative Study interval : Immediate postop 3 Mo 6 Mo

Sinus Conversion Rate (%) P >0.05 P < 0.05

Impact of the Maze Procedure on the Stroke Rate in Patients with Atrial Fibrillation Cox JL, et al J Thorac Cardiovasc Surg 1999;118:833-40

Methods  Sept March 1999  306 pts w/ the maze procedure  paroxysmal (intermittent) AF ; 61 % chronic (continuous) AF ; 39 % chronic (continuous) AF ; 39 % JTCVS 1999;188:833

Peri-op Stroke Rates for the Major Categories of Cardiac Surgical Procedures 5.90 % 5.00 % 4.53 % 4.24 % 3.30 % 3.26 % 2.96 % 2.44 % 0.65 % 1.73 % 1.73 % 1.60 % 1.60 % 1.41 % 1.41 % 1.51 % 1.51 % 1.45 % 1.45 % 0.98 % 0.98 % 1.23 % 1.23 % 0.75 % 0.75 % 0 % 0 % 4.17 % 3.40 % 3.12 % 2.73 % 1.85 % 2.28 % 1.73 % 1.69 % 0.65 % CABG + MVR CABG + AVR CABG + MV repair AVR + MVR MV repair MVRAVRCABG Maze ± other % total stroke % transient % transient stroke stroke % permanent stroke Procedures

Whether should the pts w/o LA contractile function after the maze undergo anticoagulation?  Normal RA function & normal RA-RV synchrony  Normal right-sided CO that is delivered to left side of heart through pulmonary circulation  No difference whether LA is contracting (in the presence of normal LV) because LV will immediately adapt to normal right-sided output that has just been delivered to it  Normal LA inflow volume, regular LV filling, & no LAA to serve as a nidus for thrombus formation  There is no reason to suspect that systemic TE would be any higher in these pts than those w/ demonstrable LA contraction JTCVS 1999;188:833

 When properly performed, the results w/ this combined approach have been excellent, w/ no increase in periop morbidity or op mortality & w/ documented long-term advantages over simply leaving pts in AF. James L. Cox - James L. Cox J Thorac Cardiovasc Surg 2001;122:212 EPILOGUE