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.

The cox-maze procedure for lone atrial fibrillation: a single-center experience over 2 decades.

BACKGROUND: The Cox-Maze procedure (CMP) has achieved high success rates in the therapy of atrial fibrillation (AF) while becoming progressively less invasive. This report evaluates our experience with the CMP in the treatment of lone AF over 2 decades and compares the original cut-and-sew CMP-III to the ablation-assisted CMP-IV, which uses bipolar radiofrequency and cryoenergy to create the original lesion pattern. METHODS AND RESULTS: Data were collected prospectively on 212 consecutive patients (mean age, 53.5±10.4 years; 78% male) who underwent a stand-alone CMP from 1992 through 2010. The median duration of preoperative AF was 6 (interquartile range, 2.9-11.5) years, with 48% paroxysmal and 52% persistent or long-standing persistent AF. Univariate analysis with preoperative and perioperative variables used as covariates for the CMP-III (n=112) and the CMP-IV (n=100) was performed. Overall, 30-day mortality was 1.4%, with no intraoperative deaths. Freedom from AF was 93%, and freedom from AF off antiarrhythmics was 82%, at a mean follow-up time of 3.6±3.1 years. Freedom from symptomatic AF at 10 years was 85%. Only 1 late stroke occurred, with 80% of patients not receiving anticoagulation therapy. The less invasive CMP-IV had significantly shorter cross-clamp times (41±13 versus 92±26 minutes; P<0.001) while achieving high success rates, with 90% freedom from AF and 84% freedom from AF off antiarrhythmics at 2 years. CONCLUSIONS: The CMP, although simplified and shortened by alternative energy sources, has excellent results, even with improved follow-up and stricter definition of failure.

Impact of pulmonary hypertension on outcomes after aortic valve replacement for aortic valve stenosis.

OBJECTIVE: The presence of pulmonary hypertension historically has been considered a significant risk factor affecting early and late outcomes after valve replacement. Given the number of recent advances in the management of pulmonary hypertension after cardiac surgery, a better understanding of its impact on outcomes may assist in the clinical management of these patients. The purpose of this study was to determine whether pulmonary hypertension remains a risk factor in the modern era for adverse outcomes after aortic valve replacement for aortic valve stenosis. METHODS: From January 1996 to June 2009, a total of 1080 patients underwent aortic valve replacement for primary aortic valve stenosis, of whom 574 (53%) had normal systolic pulmonary artery pressures (sPAP) and 506 (47%) had pulmonary hypertension. Pulmonary hypertension was defined as mild (sPAP 35-44 mm Hg), moderate (45-59 mm Hg), or severe (≥ 60 mm Hg). In the group of patients with pulmonary hypertension, 204 had postoperative echocardiograms. RESULTS: Operative mortality was significantly higher in patients with pulmonary hypertension (47/506, 9%, vs 31/574, 5%, P = .02). The incidence of postoperative stroke was similar (P = .14), but patients with pulmonary hypertension had an increased median hospital length of stay (8 vs 7 days, P = .001) and an increased incidence of prolonged ventilation (26% vs 17%, P < .001). Preoperative pulmonary hypertension was an independent risk factor for decreased long-term survival (relative risk 1.7, P = .02). Those with persistent pulmonary hypertension postoperatively had decreased survival. Five-year survival (Kaplan-Meier) was 78% ± 6% with normal sPAP and 77% ± 7% with mild pulmonary hypertension postoperatively, compared with 64% ± 8% with moderate and 45% ± 12% with severe pulmonary hypertension (P < .001). CONCLUSIONS: In patients undergoing aortic valve replacement, preoperative pulmonary hypertension increased operative mortality and decreased long-term survival. Patients with persistent moderate or severe pulmonary hypertension after aortic valve replacement had decreased long-term survival. These data suggest that pulmonary hypertension had a significant impact on outcomes in patients undergoing aortic valve replacement and should be considered in preoperative risk assessment.

The Cox-maze IV procedure for lone atrial fibrillation: a single center experience in 100 consecutive patients.

PURPOSE: The Cox-maze III procedure (CMP) has achieved high success rates for the surgical treatment of atrial fibrillation (AF). In 2002, our group introduced a simplified CMP, in which most incisions were replaced with linear lines of ablation using bipolar radiofrequency and cryoenergy. This operation, termed the CMP-IV, has significantly shortened operative times and allowed for a minimally invasive approach. This report evaluates our results in 100 consecutive patients undergoing a stand-alone CMP-IV. METHODS: Data were collected prospectively on 100 patients (mean age, 56 ± 10 years) who underwent a CMP-IV from January 2002 through May 2010. All patients were available for follow-up with a mean follow-up of 17 ± 10 months. Electrocardiograms or 24-h Holter monitorings were obtained at 6, 12, and 24 months. Data were analyzed using a longitudinal database containing over 380 variables. RESULTS: Thirty-one percent of patients had paroxysmal AF, with the remainder having persistent (6%) or longstanding persistent AF (63%). The mean preoperative duration of AF was 7.4 ± 6.7 years. The mean left atrial diameter was 4.7 ± 1.1 cm. In this group, 40 patients had failed with a mean of 2.6 ± 1.3 catheter ablations. Mean aortic cross-clamp time was 41 ± 13 min. There was one postoperative mortality. Postoperative freedom from AF was 93%, 90%, and 90% at 6, 12, and 24 months, respectively. Freedom from AF off antiarrhythmic medication was 82%, 82%, and 84% at 6, 12, and 24 months, respectively. CONCLUSION: The less invasive CMP-IV has a high single procedure success rate, even with improved follow-up and stricter definitions of failure.

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.

A minimally invasive cox-maze procedure: operative technique and results.

OBJECTIVE: The Cox-Maze procedure (CMP) for the surgical treatment of atrial fibrillation (AF) traditionally has required a median sternotomy and cardiopulmonary bypass. This study describes a method using ablation technologies to create the full Cox-Maze lesion set through a 5- to 6-cm right minithoracotomy. METHODS: Twenty-two consecutive patients underwent a CMP through a right mini-thoracotomy and cardiopulmonary bypass. All patients were followed prospectively with electrocardiogram and 24-hour Holter monitoring at 3, 6, and 12 months. The CMP lesion set was created using bipolar radiofrequency energy and cryotherapy. RESULTS: There was no operative mortality or major complications.Two patients required a permanent pacemaker. Five patients (23%) had early atrial tachyarrhythmias. At last follow-up(mean, 18 ± 12 months), all the patients (n=22) were free from atrial dysrhythmias. At 3 months (n=19), 84% of patients were off antiarrhythmic drugs. At 6 months (n=18), 94% of patients were free from AF and off antiarrhythmic medications. At 12 months (n=16), 81% of patients were free from AF and off antiarrhythmic drugs and three patients remained on warfarin for a mechanical mitral valve. CONCLUSIONS: A full CMP can be performed through a right mini-thoracotomy with outstanding short-term results. This less invasive procedure can be offered to patients without compromising efficacy.

The surgical treatment of atrial fibrillation.

For two decades, the cut-and-sew Cox-maze III procedure was the gold standard for the surgical treatment of atrial fibrillation (AF) and has proven to be effective at eliminating AF. The incidence of late stroke was also very low. However, this procedure was not widely adopted owing to its complexity and technical difficulty. Over the last 5-10 years, the introduction of new ablation technology has led to the development of the Cox-maze IV procedure as well as more limited lesion sets, with the ultimate goal of performing a minimally invasive lesion set on the beating heart without the need for cardiopulmonary bypass. This review summarizes the current state of the art and future directions in the stand-alone surgical treatment of AF. The hope is that as more is learned about the mechanisms of AF and with better preoperative diagnostic technologies capable of precisely locating the areas responsible for AF, it will become possible to tailor specific lesion sets and ablation modalities to individual patients, making the surgical treatment of AF available to a larger population of patients.

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.

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.

NORMAL QUALITY OF LIFE AFTER THE COX MAZE PROCEDURE FOR ATRIAL FIBRILLATION.

BACKGROUND/OBJECTIVE: Atrial fibrillation(AF) has been shown in numerous studies to significantly decrease patient quality of life. The Cox-Maze procedure has excellent long-term efficacy in curing AF. However, it is unknown whether this procedure improves long-term quality of life in these patients. The purpose of this study was to examine late quality of life in patients that underwent a lone Cox-Maze procedure. METHODS: Between 1987 and 2003, 163 patients underwent a Cox-Maze procedure for lone AF at our institution. Of these, 68 patients agreed and completed the Medical Outcomes Study Short Form 36 Health Survey. Scores from the age-matched general US population were normalized to a mean of 50 and standard deviation of 10 to facilitate comparison. Collected data were compared to the norm-based score for each domain using a one-sample t-test. Four patients were removed from analysis because of AF recurrence. RESULTS: There were 52 males(81%). Mean age was 52.6±9.5 years. Preoperatively, 37 patients(58%) had paroxysmal and 25 patients(39%) had persistent or permanent AF. The mean duration of AF before surgery was 9.8±8.2 years. There was no statistical difference in norm-based scores between the Cox-Maze procedure group and the age-matched general US population in any of the eight health domains at a mean follow-up of 8.7±3.7 years. CONCLUSION: Our results suggest that the Cox-Maze procedure cures atrial fibrillation in the majority of patients, and that those patients that are cured obtain a normal quality of life as compared to the general population at late follow-up.

The effect of ablation technology on surgical outcomes after the Cox-maze procedure: a propensity analysis.

OBJECTIVES: Since its introduction in 1987, the Cox-maze procedure has been the gold standard for the surgical treatment of atrial fibrillation. At our institution, this procedure has evolved from the cut-and-sew technique (Cox-maze III procedure) to one using bipolar radiofrequency energy and cryoablation as ablative sources to replace most incisions (Cox-maze IV procedure). This study compared surgical outcomes of patients undergoing the Cox-maze III procedure versus those of patients undergoing the Cox-maze IV procedure by using propensity analysis. METHODS: From April 1992 through July 2005, 242 patients underwent the Cox-maze procedure for atrial fibrillation. Of these, 154 patients had the Cox-maze III procedure, and 88 had the Cox-maze IV procedure. Logistic regression analysis was used to identify covariates among 7 baseline patient variables. Using the significant regression coefficients, each patient's propensity score was calculated, allowing selectively matched subgroups of 58 patients each. Operative outcomes were analyzed for differences. Late follow-up was available for 112 (97%) patients. Freedom from atrial fibrillation recurrence and survival was calculated at 1 year by using Kaplan-Meier analysis. RESULTS: The Cox-maze III procedure had significantly longer crossclamp times. There was no significant difference in intensive care unit and hospital stay, 30-day mortality, permanent pacemaker placement, early atrial tachyarrhythmias, late stroke, and survival. Freedom from atrial fibrillation recurrence was greater than 90% in both groups at 1 year. CONCLUSIONS: The use of bipolar radiofrequency ablation has simplified the Cox-maze procedure, making it applicable to virtually all patients with atrial fibrillation undergoing concomitant cardiac surgery. The Cox-maze IV procedure produces similar surgical outcomes to the Cox-maze III procedure at 1 year of follow-up.

Wide variations in energy delivery using an impedance-controlled algorithm in bipolar radiofrequency ablation: evidence against fixed time ablation.

OBJECTIVE: : Bipolar radiofrequency ablation recently has been used to replace many of the incisions of the Cox-Maze procedure in the surgical treatment of atrial fibrillation. The unique aspect of this technology is that it uses an algorithm based on changes in tissue conductance to determine the energy required to achieve a transmural lesion instead of relying on predetermined time and/or temperature criteria to determine ablation duration, as with most other ablation technologies. The purpose of this study was to determine variations in the different parameters of ablation needed to create transmural lesions in human atria. METHODS: : Initial impedance, total energy, temperature, and ablation time were measured in 38 patients undergoing surgery, using an impedance-controlled bipolar radiofrequency device (AtriCure Isolator, Cincinnati, OH). Lesions were categorized into the following groups: right atrial free wall, left atrial free wall, atrium up to mitral valve annulus, atrium up to tricuspid valve annulus, and right or left pulmonary veins. RESULTS: : There was a wide range of initial impedance (32.3 to 760.7 Ohms), and this correlated with total energy delivered (r = -0.31, P = 0.002). Ablation times varied widely (2.0 to 29.9 seconds) and were longer on left atrial structures than right (P < 0.005) and shortest near the tricuspid annulus (P < 0.001). Mean tissue temperature 1 mm from the electrode was only 45.7 ± 7.8°C (range, 23.7°C to 69.3°C). CONCLUSIONS: : Bipolar ablation of different atrial structures required widely different amounts of energy and ablation times, probably as the result of the inhomogeneity of atrial geometry and tissue impedance. These data cast doubt on the efficacy of any fixed-time or temperature ablations in the clinical setting.

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.

Morbidity and mortality of cardiac surgery following renal transplantation.

BACKGROUND: With improved survival following renal transplantation, the number of patients undergoing cardiac surgery has increased. The purpose of this study was to review the morbidity, mortality, and allograft function in renal transplant patients undergoing major cardiac surgery. METHODS: Retrospective database review of consecutive renal transplant patients undergoing cardiac surgery from 1987 to 2002. Patients requiring dialysis (D) before cardiac surgery versus those with stable renal transplants (ND) were compared. RESULTS: Cardiac surgery was performed in 46 patients during the study period. Twenty patients (42%) required dialysis (D) before surgery while 26 (58%) had stable allograft function (ND). Among patients who had stable allograft function prior to surgery, there was no allograft loss. In the ND group, preoperative and discharge creatinine levels were 2.17 +/- 1.0 and 2.4 +/- 1.5 mg/dL, respectively. All operative deaths occurred in the dialysis dependent group. The 30-day and 3-year survival, respectively was 80% and 20% in the D group compared to 100% and 69% amongst the ND group (p

Strategies for temporary mechanical support: contemporary experience with pulsatile and non-pulsatile support systems.

Despite advances in mechanical circulatory support, cardiogenic shock continues to have a high mortality. We reviewed our experience with pulsatile versus non-pulsatile temporary mechanical support at our institution to determine optimal strategy for survival. From January 2001 to December 2003, mechanical support for cardiogenic shock was instituted in 38 patients. Non-pulsatile devices (NP group) were used in 22 patients and pulsatile devices (P group) in 16 patients. Indications for the NP group were post-cardiotomy shock (PCS) in 17, myocardial infarction in 2, and isolated post-cardiotomy right ventricular failure in 3 patients. In the P group, 9 had the device placed for PCS, 3 for viral myocarditis, 1 after myocardial infarction, and 3 for right ventricular (RV) failure. Overall, bleeding, limb ischemia, and multi-system organ failure were higher in NP group with 5 weaned and 3 surviving to discharge (14%). In the P group, survivors included 7 weaned and 3 transplanted patients (63%). With the exception of isolated RV failure, we obtained a dismal survival result with ECMO/centrifugal circuits for treatment of cardiogenic shock. For refractory pump failure, improved survival was achieved by using intermediate-term pulsatile devices with early transition to a chronic device and/or heart transplantation.

Radial artery grafts in women: utilization and results.

BACKGROUND: Despite a known survival benefit with the use of the left internal mammary artery, it is used less frequently in women when compared with men. This study evaluated the hypotheses that the radial artery graft is used less frequently in women compared with men, that the radial artery is smaller in women compared with men, and that the use of the radial artery influences operative mortality and long-term survival in women. METHODS: The use of a radial artery graft was evaluated in 2,633 patients who underwent isolated coronary artery bypass. Radial artery size and flow were compared in 207 patients who had intraoperative radial artery diameter and flow measurements. Propensity scoring was utilized to compare short- and long-term outcomes in a matched cohort of 588 women. RESULTS: Of 862 women (33%) who had isolated coronary artery bypass grafting, only 301 (35%) received a radial artery graft versus 44% of men (786 of 1,771, p < 0.001). Radial artery size and flow were significantly less in women. Operative mortality was not different between women with a radial artery graft and women without; however, 5-year survival was significantly better in women with a radial artery graft than in those without. CONCLUSIONS: Women received fewer radial artery grafts than men. Radial artery size and flow were significantly less in women than in men. Use of a radial artery graft did not influence operative mortality among women. However, 5-year survival among women who received a radial artery graft was significantly better than among women who did not.

Surgical treatment of atrial fibrillation: predictors of late recurrence.

OBJECTIVE: The Cox maze procedure was introduced in 1987 for the treatment of atrial fibrillation. This study evaluated the predictors of late atrial fibrillation recurrence in 276 consecutive patients who underwent this procedure at our institution. METHODS: From 1987 through June 2003, 276 patients (79 female and 197 male patients; mean age, 55 +/- 11 years) underwent the Cox maze procedure. Thirty-three patients had Cox maze procedure I, 16 patients had Cox maze procedure II, and 197 patients had Cox maze procedure III. The last 30 patients underwent a modified procedure (Cox maze procedure IV) with bipolar radiofrequency ablation. There were 113 (41%) patients who had a concomitant operation, most commonly either a mitral valve procedure (19%) or coronary artery bypass grafting (20%). Data were analyzed by means of univariate analysis, with preoperative and perioperative variables used as covariates. Patient follow-up was conducted by means of questionnaire, physician examination, and electrocardiographic documentation. All patients had a minimum of 6 months of follow-up. RESULTS: Patient follow-up was achieved in 92.8% of cases, with a mean follow-up time of 5.8 +/- 3.6 years. Risk factors for late atrial fibrillation recurrence were duration of preoperative atrial fibrillation (P = .01) and Cox maze procedure version (P = .001). There was no difference in actuarial 10-year survival between the Cox maze procedure versions. CONCLUSION: The Cox maze procedure remains the gold standard for the treatment of atrial fibrillation and has excellent long-term efficacy. The most significant predictor of late recurrence was duration of preoperative atrial fibrillation, suggesting that earlier surgical intervention would further increase efficacy.

Mechanical support for isolated right ventricular failure in patients after cardiotomy.

BACKGROUND: Patients with acute right ventricular (RV) failure after cardiotomy have a poor prognosis. We evaluated the surgical and long-term outcomes of patients with isolated RV failure that required right ventricular assist device (RVAD) support. METHODS: Between 1991 and 2002, a total of 30 patients received RVAD support for isolated RV dysfunction. We evaluated survival, duration of mechanical support, post-RVAD hemodynamics, and RV function. RESULTS: Right ventricular failure developed in patients after coronary artery bypass surgery alone or combined with valve surgery (12 patients), valvular surgery (5), ascending aortic replacement (6), heart transplantation (3), and pulmonary endarterectomy (4). Mean age was 58 +/- 15 years, and 17 (57%) were women. Surgery was emergent in 5 (73%) patients. Centrifugal pumps were used in 21, extra corporeal membrane oxygenation in 8, and as Abiomed pump in 1 patient. Overall, 17 (57%) patients died while receiving assist device support, 3 of sepsis, 2 of stroke, and 12 of inability to wean from the device. We successfully weaned RVAD support in 13 (43%) patients, with a median duration of support of 5 days (range, 2-8 days). Ten survived to hospital discharge. After RVAD removal, mean pulmonary artery pressure was 25.1 +/- 6.5 mmHg, cardiac output was 4.8 +/- 2.0 liters, and central venous pressure was 16.5 +/- 3.7 mmHg. Echocardiogram after RVAD removal showed normal RV function in 2 patients and in 11 patients demonstrated improvement. CONCLUSION: After cardiotomy, patients with RV failure who require mechanical support continue to have increased mortality. For patients successfully weaned from the RVAD, residual RV dysfunction is compatible with survival. More liberal use of RV mechanical support may be indicated for patients with acute RV failure.

A prospective multicenter trial of bipolar radiofrequency ablation for atrial fibrillation: early results.

BACKGROUND: The Cox-Maze III remains the gold standard for the surgical treatment of atrial fibrillation. However, the "cut-and-sew" technique is time consuming and technically challenging. The pulmonary veins are the source of ectopy in the majority of patients with atrial fibrillation. The safety and efficacy of bipolar radiofrequency to electrically isolate the pulmonary veins was evaluated in a prospective multi-center trial. METHODS: Beginning in January 2002, 30 patients at three medical centers underwent pulmonary vein isolation using bipolar radiofrequency and were followed for 6 months. Twenty-four of the patients also underwent a modified Cox-Maze III. Electrical isolation of the pulmonary veins was confirmed with intraoperative pacing. Pulmonary vein patency was assessed by magnetic resonance imaging or three-dimensional computed tomography in 15 patients at 1 month. RESULTS: Mean age was 60.9 +/- 11.7 years. Nineteen patients had paroxysmal atrial fibrillation. All pulmonary veins were isolated in every patient. The left pulmonary veins underwent 3.0 +/- 1.4 applications for a total of 26.4 +/- 10.5 seconds. The right pulmonary veins underwent 2.8 +/- 1.1 applications for a total of 26.3 +/- 12.6 seconds. There was no operative mortality. At 1 month, imaging revealed no evidence of pulmonary vein stenosis. At 6 months, 96% of patients were in normal sinus rhythm. CONCLUSIONS: The use of bipolar radiofrequency for electrical isolation of pulmonary veins and to replace other Cox-Maze III incisions is safe and effective at controlling atrial fibrillation. This emerging technology may shorten and simplify the surgical management of atrial fibrillation.

Flow dynamics of the internal thoracic and radial artery T-graft.

BACKGROUND: Complex use of arterial conduits has resurrected concerns about the adequacy of conduit flow. The T-graft is the extreme example of this trend. Our purpose was to identify the limitation of single source inflow and to compare flow capacity with completion coronary flow. METHODS: Between February 1999 and November 2001, 372 patients underwent total arterial revascularization with the T-graft alone. Intraoperative flows were recorded for each limb of the T-graft before and after distal anastomoses in 204 patients. Independent predictors of T-graft flow were identified by multivariate analysis. RESULTS: Free flow for the radial arterial (RA) limb was 161 +/- 81 mL/min, the internal thoracic artery (ITA) limb 137 +/- 57 mL/min (combined 298 +/- 101 mL/min) versus simultaneous limb flow of 226 +/- 84 mL/min giving a flow restriction of 24% +/- 14%. Completion coronary flow was 88 +/- 49 mL/min for the RA, 60 +/- 45 mL/min for the ITA, and 140 +/- 70 mL/min for both limbs simultaneously to give a flow reserve (vs simultaneous free flow) of 160% or 1.6. Independent predictors of completion RA limb flow are RA proximal diameter (p = 0.005), number of anastomoses (p = 0.018), and target stenosis (p = 0.005). CONCLUSIONS: A flow reserve of 1.6 compares favorably with an ITA flow reserve of 1.8 at 1-month postoperatively and 1.8 for both the ITA T-graft and the ITA/RA T-graft at 1-week postoperatively as reported by others. Proximal RA diameter and competitive coronary flow influence completion T-graft flow. These data quantitate the limitation of single source inflow of the T-graft configuration and support its continued use.