Nabil A. Munfakh

The Cox maze IV procedure: predictors of late recurrence.

OBJECTIVES The Cox maze III procedure achieved high cure rates and became the surgical gold standard for the treatment of atrial fibrillation. Because of its invasiveness, a more simplified ablation-assisted procedure, the Cox maze IV procedure, has been performed at our institution since January 2002. The study examined multiple preoperative and perioperative variables to determine predictors of late recurrence. METHODS Data were collected prospectively on 282 patients who underwent the Cox maze IV procedure from January 2002 through December 2009. Forty-two percent of patients had paroxysmal and 58% had either persistent or long-standing persistent atrial fibrillation. All patients were available for follow-up. Follow-up included electrocardiograms in all patients. Since 2006, 24-hour Holter monitoring was obtained in 94% of patients at 3, 6, and 12 months. Data were analyzed by means of logistic regression analysis at 12 months, with 13 preoperative and perioperative variables used as covariates. RESULTS Sixty-six percent of patients had a concomitant procedure. After an ablation-assisted Cox maze procedure, the freedom from atrial fibrillation was 89%, 93%, and 89% at 3, 6, and 12 months, respectively. The freedom from both atrial fibrillation and antiarrhythmic drugs was 63%, 79%, and 78% at 3, 6, and 12 months, respectively. The risk factors for atrial fibrillation recurrence at 1 year were enlarged left atrial diameter (P = .027), failure to isolate the entire posterior left atrium (P = .022), and early atrial tachyarrhythmias (P = .010). CONCLUSIONS The Cox maze IV procedure has a high success rate at 1 year, even with improved follow-up and stricter definitions of failure. In patients with large left atria, there might be a need for more extensive size reduction or expanded lesion sets.

Recurrent Mitral Regurgitation and Risk Factors for Early and Late Mortality After Mitral Valve Repair for Functional Ischemic Mitral Regurgitation

BACKGROUND Mortality for patients with coronary artery disease and functional ischemic mitral regurgitation (IMR) remains high regardless of the treatment strategy. Data regarding risk factors, progression of MR, and cause of death in this subgroup are limited. METHODS A retrospective study was performed on 257 consecutive patients undergoing mitral valve repair exclusively for IMR from 1996 to 2005. Potential preoperative and perioperative risk factors for death and postoperative echocardiographic data were recorded. RESULTS Preoperative echocardiography demonstrated 3+ to 4+ MR in 98.4% (252 of 257). Concomitant coronary artery bypass grafting was performed in 80.9% (208 of 257). Operative mortality was 10.1% (26 of 257). Overall survival by Kaplan-Meier analysis was 68.3% at 3 years and 52.0% at 5 years. Factors associated with late mortality by multivariate analysis include advanced age (relative risk [RR], 1.037; 95% confidence interval [CI], 1.016 to 1.059; p < or = 0.001), preoperative dialysis (RR, 3.504; 95% CI, 1.590 to 7.720; p = 0.008), and diabetes (RR, 2.047; 95% CI, 1.319 to 3.177; p = 0.001). Echocardiographic data at 20 +/- 25 months were available in 57% (147 of 257). Their survival by Kaplan-Meier analysis was 76.4% at 3 years and 65.1% at 5 years with 0 to 2+ MR postoperatively (n = 106) vs 61.3% and 35.8% with 3+ to 4+ MR (n = 41; p = 0.003). Cause of death was available in 72.3% (60 of 83) of late deaths, with 42.2% (35 of 83) attributed to cardiac causes and 30.1% (25 of 83) noncardiac. CONCLUSIONS Mortality for IMR remains high despite surgical management and may be related to risk factors for progression of coronary artery disease. Despite repair, MR progresses in many patients and is associated with poor survival, although more detailed prospective data are needed to characterize this relationship.

A New Era in the Surgical Treatment of Atrial Fibrillation: The Impact of Ablation Technology and Lesion Set on Procedural Efficacy

Background/Objective:While the Cox-Maze procedure remains the gold standard for the surgical treatment of atrial fibrillation (AF), the use of ablation technology has revolutionized the field. To simplify the procedure, our group has replaced most of the incisions with bipolar radiofrequency ablation lines. The purpose of this study was to examine results using bipolar radiofrequency in 130 patients undergoing a full Cox-Maze procedure, a limited Cox-Maze procedure, or pulmonary vein isolation alone. Methods:A retrospective review was performed of patients who underwent a Cox-Maze procedure (n = 100), utilizing bipolar radiofrequency ablation, a limited Cox-Maze procedure (n = 7), or pulmonary vein isolation alone (n = 23). Follow-up was available on 129 of 130 patients (99%). Results:Pulmonary vein isolation was confirmed by intraoperative pacing in all patients. Cross-clamp time in the lone Cox-Maze procedure patients was 44 ± 21 minutes, and 104 ± 42 minutes for the Cox-Maze procedure with a concomitant procedure, which was shortened considerably from our traditional cut-and-sew Cox-Maze procedure times (P < 0.05). There were 4 postoperative deaths in the Cox-Maze procedure group and 1 in the pulmonary vein isolation group. The mean follow-up was 13 ± 10, 23 ± 15, and 9 ± 10 months for the Cox-Maze IV, the pulmonary vein isolation, and the limited Cox-Maze procedure groups, respectively. At last follow-up, freedom from AF was 90% (85 of 94), 86% (6 of 7), and 59% (10 of 17) in the in the Cox-Maze procedure group, limited Cox-Maze procedure group, and pulmonary vein isolation alone group, respectively. Conclusions:The use of bipolar radiofrequency ablation to replace Cox-Maze incisions was safe and effective at controlling AF. Pulmonary vein isolation alone was much less effective, and should be used cautiously in this population.

Isolating the entire posterior left atrium improves surgical outcomes after the Cox maze procedure.

OBJECTIVES The importance of each ablation line in the Cox maze procedure for treatment of atrial fibrillation remains poorly defined. This study evaluated differences in surgical outcomes of the procedure performed either with a single connecting lesion between the right and left pulmonary vein isolations versus 2 connecting lesions (the box lesion), which isolated the entire posterior left atrium. METHODS Data were collected prospectively on 137 patients who underwent the Cox maze procedure from April 2002 through September 2006. Before May 2004, the pulmonary veins were connected with a single bipolar radiofrequency ablation lesion (n = 56), whereas after this time, a box lesion was routinely performed (n = 81). The mean follow-up was 11.8 +/- 9.6 months. RESULTS The incidence of early atrial tachyarrhythmia was significantly higher in the single connecting lesion group compared with that in the box lesion group (71% vs 37%, P < .001). The overall freedom from atrial fibrillation recurrence was significantly higher in the box lesion group at 1 (87% vs 69%, P = .015) and 3 (96% vs 85%, P = .028) months. The use of antiarrhythmic drugs was significantly lower in the box lesion group at 3 (35% vs 58%, P = .018) and 6 (15% vs 44%, P = .002) months. CONCLUSIONS Isolating the entire posterior left atrium by creating a box lesion instead of a single connecting lesion between the pulmonary veins showed a significantly lower incidence of early atrial tachyarrhythmias, higher freedom from atrial fibrillation recurrence at 1 and 3 months, and lower use of antiarrhythmic drugs at 3 and 6 months. A complete box lesion should be included in all patients undergoing the Cox maze procedure.

Cox-Maze IV Results for Patients With Lone Atrial Fibrillation Versus Concomitant Mitral Disease

BACKGROUND This study compared Cox-Maze IV (CMIV) outcomes for the treatment of atrial fibrillation (AF) in patients with lone AF vs those with AF and mitral valve (MV) disease. METHODS Since 2002, 200 patients have undergone a CMIV procedure for lone AF (n=101) or concomitantly with MV operations (n=99). Preoperative, perioperative, and late outcomes between these groups were compared. Data were collected prospectively and reported at 3, 6, and 12 months. RESULTS Lone AF patients had AF of longer duration; patients with AF and MV disease were older, with larger left atria and worse New York Heart Association classification (p<0.05). Operative mortality (1% vs 4%, p>0.05, respectively) was similar between both groups. Perioperative atrial tachyarrhythmias were more prevalent in patients with concomitant MV operations (57% vs 41%, p=0.03); however, freedom from AF and antiarrhythmics was similar for both groups at 12 months (76% and 77%). The only predictor for atrial tachyarrhythmia recurrence or arrhythmic drug dependence was failure to isolate the posterior left atrium (p<0.01). CONCLUSIONS Patients with AF and MV disease have distinct comorbidities compared with patients with lone AF. However, the CMIV is safe and effective in both groups and should be considered for patients with AF undergoing MV operations. Patients with MV disease had more atrial tachyarrhythmias at 3 months, but freedom from AF and antiarrhythmics was similar to patients with lone AF at 1 year. The posterior left atrium should be isolated in every patient, because this was the only predictor for failure of the CMIV for either group.

Carbon Dioxide Field Flooding Minimizes Residual Intracardiac Air After Open Heart Operations

Transesophageal echocardiographic studies were used to monitor the presence of air bubbles in the heart after open heart operations. After cardiac valvular procedures all 22 patients managed with careful deairing procedures had persistence of air bubbles for at least 30 minutes and usually for 45 minutes. In 56 patients with CO2 field flooding, all foam disappeared in less than 1 minute in 48 patients and the remaining 8 had complete disappearance in 1 to 24 minutes. These observations demonstrate the ineffectiveness of the usual deairing maneuvers and the effectiveness of CO2 field flooding in displacing air.

POINT: Prosthesis–patient mismatch does not affect survival for patients greater than 70 years of age undergoing bioprosthetic aortic valve replacement

OBJECTIVE The purpose of this investigation was to examine the impact of prosthesis-patient mismatch after bioprosthetic aortic valve replacement on long-term survival in patients greater than 70 years of age compared with those less than or equal to 70 years of age. METHODS Between 1992 and 2007, 1399 patients underwent bioprosthetic aortic valve replacement, including 881 (63%) patients older than 70 years of age. Prosthesis-patient mismatch was defined as severe (prosthetic effective orifice area/body surface area < 0.65 cm(2)/m(2)), moderate (0.65-0.85 cm(2)/m(2)), or absent (>0.85 cm(2)/m(2)). For patients less than or equal to 70 years of age, mismatch was severe in 62 (12%), moderate in 251 (48%), and absent in 205 (40%). For patients greater than 70 years of age, mismatch was severe in 109 (12%), moderate in 451 (51%), and absent in 321 (37%). There was no difference in the distribution of prosthesis-patient mismatch between age groups (P = .50). RESULTS For patients less than or equal to 70 years, prosthesis-patient mismatch was associated with impaired long-term survival (P = .02). Survival at 5 and 10 years was 61% +/- 7% and 28% +/- 12% for severe mismatch, 65% +/- 3% and 40% +/- 5% for moderate mismatch, and 73% +/- 5% and 46% +/- 9% for no mismatch. For patients greater than 70 years, prosthesis-patient mismatch did not affect long-term survival (P = .25). Survival at 5 and 10 years was 62% +/- 5% and 42% +/- 6% for severe mismatch, 62% +/- 2% and 30% +/- 5% for moderate mismatch, and 53% +/- 4% and 29% +/- 5% for absent mismatch. CONCLUSIONS After bioprosthetic aortic valve replacement, prosthesis-patient mismatch had a negative impact on late survival for patients less than or equal to 70 years of age, but for patients greater than 70 years of age, prosthesis-patient mismatch did not influence late survival.

Surgical Management of Tetralogy of Fallot in the First Year of Life

BACKGROUND The surgical approach to tetralogy of Fallot (TOF) continues to evolve and now many centers favor early repair for TOF. METHODS Our experience includes 82 consecutive patients less than 1 year old with TOF (n = 74) and TOF with pulmonary atresia (n = 8) who were operated on between January 1992 and March 1998. Mean age at repair was 5.2 +/- 1.2 months and mean weight was 4.5 +/- 0.4 kg. Seven patients (anomalous left anterior descending artery [n = 1], pulmonary atresia with hypoplastic pulmonary arteries [n = 6]), underwent palliative procedures in the neonatal period followed by complete repair. Forty-nine patients (59%) were symptomatic (severe cyanosis or hypoxic spells), and 33 patients (41%) were asymptomatic. A combined transatrial-transpulmonary approach was employed in 28 patients (34%), and transannular patch or conduit for reconstruction of the right ventricular outflow tract (RVOT) was required in 54 patients (66%). The mean Nakata index was 160 +/- 25 mm2/m2. RESULTS There were no hospital deaths. Mean post-repair peak right ventricular/systemic pressure ratio was 0.48 +/- 0.1. There were no late deaths or reoperations during a mean follow-up of 23 +/- 5 months. All patients are currently asymptomatic and in New York Heart Association class 1. Postoperative evaluation by two-dimensional and Doppler echocardiography or cardiac catheterization showed minimal pulmonary artery stenosis with a mean pressure gradient of 15 +/- 6 mm Hg across the RVOT. CONCLUSIONS Our experience suggests that early repair of TOF can yield excellent results and initial palliation does not preclude early complete repair.

The beneficial hemodynamic effects of selective patent vertical vein following repair of obstructed total anomalous pulmonary venous drainage in infants

OBJECTIVES Postoperative low cardiac output may persist after repair of total anomalous pulmonary venous drainage (TAPVD) because of a relatively small and non-compliant left atrium and left ventricle. We examined the effects of selective vertical vein patency on postoperative hemodynamics. METHODS Thirty-four patients less than 3 months of age with TAPVD were operated from July 1993 to June 2000. The mean age at operation was 21+/-8 days (range, 3-62 days) and the mean weight was 3+/-0.2 kg (range, 2-4.1 kg). Supracardiac type drainage was found in 12 (35%), cardiac in three (9%), mixed in one (3%), and infracardiac in 18 (53%) patients. Twenty-two patients (65%) had obstructed venous drainage. All operations were performed with deep hypothermic circulatory arrest. Supracardiac, mixed and infracardiac types were repaired through a posterior approach, whereas, in the cardiac type, the coronary sinus was unroofed and the atrial septal defect was patched. The decision whether to keep the vertical vein open was made at the end of the operation and was based on the hemodynamic state of the patient. RESULTS There were no operative deaths. The suture on the vertical vein was released in 22 patients who had obstructed pulmonary venous drainage (infracardiac type, n=18; supracardiac type, n=3; and mixed type, n=1), resulting in a significant drop in the left atrial pressure from 19+/-2 to 12+/-2 mmHg (P<0.05), and in the mean pulmonary artery pressure from 42+/-6 to 35+/-3 mmHg (P<0.05), associated with an immediate increase in the mean arterial blood pressure from a mean of 46+/-3 to 60+/-4 mmHg (P<0.05). During a mean follow-up of 38+/-6 months (range, 8-71 months), there were no late deaths. Follow-up, two-dimensional echocardiography with Doppler studies demonstrated good left ventricular function and trivial or no left to right shunt through the vertical vein in those patients in whom the snare was released. CONCLUSIONS Maintaining the vertical vein patent in a selective group of patients with infracardiac total anomalous venous drainage contributes to a favorable outcome following surgery.

Congenital bilateral pulmonary venous stenosis in an adult:: Diagnosis by Echo-Doppler

A 22‐year‐old man with life‐long exertional fatigue and dyspnea was diagnosed as having bilateral congenital pulmonary venous stenosis by echocardiography with color Doppler examination. Fibrous membranes overlying the entrances of the veins to left atrium were the cause of obstruction and were easily resected. Cathet. Cardiovasc. Intervent. 49:328–330, 2000.