Three hundred robotic-assisted mitral valve repairs: the Cedars-Sinai experience.

OBJECTIVE: The study objective was to review our first 300 consecutive robotic-assisted mitral repairs performed from June 2005 to October 2012 and to compare the surgical outcomes of our previously reported initial 120 cases with the subsequent 180 procedures. METHODS: Our initial 120 robotic-assisted mitral repairs were previously reported, and we now compare our early experience with the recent 180 consecutive procedures for a total of 300 robotic-assisted mitral repairs. There was no patient selection. Every patient in need of isolated mitral valve repair underwent this procedure. All patients received an annuloplasty band and 1 or more of the following: leaflet resection, secondary chordal transposition, or polytetrafluoroethylene neochordal replacement and edge-to-edge repair. RESULTS: All 300 patients had preoperative echocardiographic findings of severe mitral regurgitation. There were no differences (P = not significant) between the initial and the recent cohorts for preoperative characteristics, including age (58.4 ± 10.5 years vs 59.9 years), female gender (35.8% vs 36.1%), ejection fraction (61.9% vs 60.6%), congestive heart failure (35.0% vs 36.7%), creatinine (0.94 mg/dL vs 0.98 mg/dL), and New York Heart Association class. The incidence of anterior and posterior leaflet prolapse was similar in both groups, whereas Barlow syndrome was higher in group 2 (5.8% vs 27.8%). There was 1 (0.33%) hospital mortality and no deaths in the last 180 cases. Overall, 8 patients (2.7%) required subsequent mitral valve replacement via a median sternotomy, 6 (5.0%) in the first group and 2 (1.1%) in the second group (P = .06). One patient in each group had mitral valve re-repair through a right mini-thoracotomy, and 1 patient in the first group required a mitral valve replacement via a mini-thoracotomy during the original procedure. Two of the 180 patients had documented cerebrovascular accident, but both fully recovered clinically. There was no cerebrovascular accident in the last 120 patients. Crossclamp times decreased from 116 minutes to 91 minutes in the second group despite starting a training program with a junior associate performing part of the procedure at the console in the last 100 cases. Post-pump echocardiograms showed no/trace mitral regurgitation in 86.1% of the last 180 patients and mild mitral regurgitation in 11.1%. Follow-up echocardiography for the last 180 patients from 1 month to more than 1 year showed no/trace mitral regurgitation in 64.6% of patients and mild mitral regurgitation in 23.1% of patients. Seven patients (10.8%) had moderate mitral regurgitation, and 1 patient (1.5%) had severe mitral regurgitation. CONCLUSIONS: The majority of complications and reoperations occurred early in our experience, especially using the first-generation da Vinci robot (Intuitive Surgical Inc, Sunnyvale, Calif). The newer da Vinci Si HD system with the addition of an adjustable left atrial roof retractor together with increased experience has made robotic-assisted mitral repair of all types of degenerative mitral valve pathology reproducible. The training of young surgeons in a stepwise fashion in high-volume centers will help to avoid the complications encountered during the introduction of this technology.

Coronary artery bypass graft surgery using the radial artery as a secondary conduit improves patient survival.

BACKGROUND: The clinical benefits of the left internal thoracic artery-to-left anterior descending coronary artery graft are well established in coronary artery bypass graft surgery (CABG). However, limited data are available regarding the long-term outcome of the radial artery (RA) as a secondary conduit over the established standard of the saphenous venous graft. METHODS AND RESULTS: We compared the 12-year survival outcome in a set of propensity-matched CABG patients who received either the RA or the saphenous vein as a secondary conduit. A multivariable logistic regression that included 18 baseline characteristics was used to define the propensity of receiving an RA graft. The propensity model resulted in 260 matched pairs who underwent first-time isolated CABG from 1996 to 2001 with similar preoperative characteristics (C statistic=0.86). The cumulative 12-year survival estimated by use of the Kaplan-Meier method was higher for the RA graft patients (hazard ratio 0.76; P=0.03). This survival advantage was especially significant in diabetics (P=0.005), in women (P=0.02), and in the elderly (P=0.04.) The protective effect appeared beginning at year 5 post surgical intervention. CONCLUSION: The RA as a secondary conduit provided superior long-term survival after CABG, especially in diabetic patients, women, and the elderly. This effect was most pronounced >5 years after surgery.

Quadricuspid aortic valve defined by echocardiography and cardiac computed tomography.

A 54 year old female presented with lower extremity edema, fatigue, and shortness of breath with physical findings indicative of advanced aortic insufficiency. Echocardiography showed severe aortic regurgitation and a probable quadricuspid aortic valve. In anticipation of aortic valve replacement, cardiac computed tomography (Cardiac CT) was performed using 100 kV, 420 mA which resulted in 6 mSv of radiation exposure. Advanced computing algorithmic software was performed with a non-linear interpolation to estimate potential physiological movement. Surgical photographs and in-vitro anatomic pathology exam reveal the accuracy and precision that preoperative Cardiac CT provided in this rare case of a quadricuspid aortic valve. While there have been isolated reports of quadricuspid diagnosis with Cardiac CT, we report the correlation between echocardiography, Cardiac CT, and similar appearance at surgery with confirmed pathology and interesting post-processed rendered images. Cardiac CT may be an alternative to invasive coronary angiography for non-coronary cardiothoracic surgery with the advantage of providing detailed morphological dynamic imaging and the ability to define the coronary arteries non-invasively. The reduced noise and striking depiction of the valve motion with advanced algorithms will require validation studies to determine its role.

Impact of virtual cross match on waiting times for heart transplantation.

BACKGROUND: Heart transplantation for sensitized patients has been a significant challenge. In this study, outcome of heart transplantation in sensitized patients with virtual cross match was compared with prospective cross match. METHODS: Prior to July 2007, prospective cross match was used and afterward, virtual cross match with Luminex (One Lambda, Inc, Canoga Park, CA) based antibody analysis was used for potential heart transplant recipients. Prospectively collected data for the 3 years before and after July 2007, in sensitized (panel reactive antibody greater than 10%) and nonsensitized heart transplant recipients were reviewed. RESULTS: One hundred sixty-eight patients met inclusion criteria for analysis (78 patients for prospective cross match and 90 patients for virtual cross match). Multiple parameters were compared for the prospective cross match and virtual cross match eras. Three-year survivals in nonsensitized patients were 84.6% and 77.2% and in sensitized patients were 76.9% and 77.4% (p = 0.49) for prospective cross match and virtual cross match eras, respectively. Freedom from 3A (2R) cellular rejection in nonsensitized patients was 96.9% and 95.3%, and in sensitized patients was 90.9% and 100% (p = 0.83). Freedom from antibody-mediated rejection in nonsensitized patients was 95.3% and 96.8%, and in sensitized patients was 90.9% and 90.5% (p = 0.65). Mean waiting time was 129 ± 246 days (mean ± SD) for the period before virtual cross match and 59 ± 78 days with virtual cross match (p = 0.018). Donor geographic area was similar for prospective and virtual cross match. CONCLUSIONS: In sensitized heart transplant candidates, virtual cross match may shorten waiting time to heart transplantation without increasing subsequent occurrence of cellular rejection, antibody mediated rejection, and mortality after heart transplantation.

Is robotic mitral valve repair a reproducible approach?

OBJECTIVE: We sought to review the surgical outcomes of our initial 120 robotic mitral valve repairs from June 2005 through April 2009. METHODS: The initial 74 repairs were performed with the first-generation da Vinci robot (Intuitive Surgical, Inc, Sunny Vale, Calif), and the last 46 were performed with the da Vinci Si HD model. All patients received an annuloplasty band and 1 or more of the following: leaflet resection; annuloplasty; basal chord transposition, polytetrafluoroethylene neochordal replacement, or both; and edge-to-edge repair. RESULTS: The overall mean age was 58.4 +/- 10.5 years, and 64% were male. There was 1 (0.8%) hospital mortality. Five patients required mitral valve replacement for a failed repair. Another patient had mitral valve rerepair on postoperative day 2. Except for 2 early reoperations for postoperative bleeding, all of the complications and failed repairs requiring operative revision occurred with the original robot. Postdischarge transthoracic echocardiographic follow-up was available on 107 (93%) of 115 patients, with a median follow-up of 321 days. None to mild mitral regurgitation was seen in 102 (89%) patients, moderate mitral regurgitation was seen in 9 (8.4%) patients, and severe mitral regurgitation was seen in 3 (2.8%), with 1 patient undergoing mitral valve replacement and 2 patients being medically managed. CONCLUSIONS: The majority of complications and all the repeat operations for failed mitral valve repair occurred with the older-model da Vinci robot. The newer da Vinci Si HD system, with the addition of an adjustable left atrial roof retractor, improves mitral valve exposure, enhancing the surgeon's ability to repair and test the valve. We have progressed to successful repair of all types of degenerative mitral valve pathology and have found the approach reproducible.

Coronary revascularization alone or with mitral valve repair: outcomes in patients with moderate ischemic mitral regurgitation.

We sought to evaluate retrospectively the outcomes of patients at our hospital who had moderate ischemic mitral regurgitation and who underwent coronary artery bypass grafting (CABG) alone or with concomitant mitral valve repair (CABG+MVr).A total of 83 patients had a reduced left ventricular ejection fraction and moderate mitral regurgitation: 28 patients underwent CABG+MVr, and 55 underwent CABG alone. Changes in mitral regurgitation, functional class, and left ventricular ejection fraction were compared in both groups.The mean follow-up was 5.1 +/- 3.6 years (range, 0.1-15.1 yr). Reduction of 2 mitral-regurgitation grades was found in 85% of CABG+MVr patients versus 14% of CABG-only patients (P < 0.0001) at 1 year, and in 56% versus 14% at 5 years, respectively (P = 0.1), as well as improvements in left ventricular ejection fraction and functional class. One- and 5-year survival rates were similar in the CABG+MVr and CABG-only groups: 96% +/- 3% versus 96% +/- 4%, and 87% +/- 5% versus 81% +/- 8%, respectively (P = NS). Propensity analysis showed similar results. Recurrent (3+ or 4+) mitral regurgitation was found in 22% and 47% at late follow-up, respectively.In patients with moderate ischemic mitral regurgitation, either surgical approach led to an improvement in functional class. Early and intermediate-term mortality rates were low with either CABG or CABG+MVr. However, an increased rate of late recurrent mitral regurgitation in the CABG+MVr group was observed.

Induction therapy with thymoglobulin after heart transplantation: impact of therapy duration on lymphocyte depletion and recovery, rejection, and cytomegalovirus infection rates.

BACKGROUND: This retrospective single-center study compared lymphocyte depletion in 144 heart transplant recipients using 2 different induction protocols with Thymoglobulin (Genzyme Transplant, Cambridge, MA). METHODS: Thymoglobulin (1.5 mg/kg) was given to 105 patients for 7 days (Thymo7) and 39 patients for 5 days (Thymo5). RESULTS: Patient clinical characteristics were similar except that the Thymo7 group had a higher prevalence of women (33% vs 15%, p = 0.04), gender mismatch (35% vs 19%, p = 0.07), donor African American race (19% vs 2%, p = 0.008), older donor age (35 +/- 13 vs 31 +/- 12, p = 0.08), and higher pre-transplant creatinine (1.43 +/- 0.67 vs 1.25 +/- 0.48 mg/dl, p = 0.095). Seventy-five percent of the Thymo7 group reached target (absolute lymphocyte count or=1B) within the first year (7% vs 22%, p = 0.02). No humoral rejection occurred. At 1 year, freedom from rejection was 93% in the Thymo7 group vs 80% in the Thymo5 group (p = 0.007), and cytomegalovirus disease (9% and 5%, p = 0.5) and bacterial infection (26% vs 32%, p = 0.5) were similar. One-year actuarial survival was 92% +/- 3% in the Thymo7 and 100% in the Thymo5 group (p = 0.07), and at 3 years, 85 +/- 4% and 90 +/- 6%, respectively (p = 0.4). CONCLUSIONS: Both Thymoglobulin regimens were well tolerated. The 7-day treatment led to more efficient and prolonged lymphocyte depletion and significantly less rejection at 1 year, without an increase in cytomegalovirus infection rate.

Intravenous immunoglobulin treatment for acute fulminant inflammatory cardiomyopathy: series of six patients and review of literature.

BACKGROUND: Although an autoimmune mechanism has been postulated for myocarditis and acute-onset inflammatory dilated cardiomyopathy (DCM), immunomodulatory treatment strategies are still under investigation. METHODS AND RESULTS: The clinical data of six patients with acute inflammatory DCM referred for evaluation for possible heart transplantation were reviewed. All patients were admitted with acute congestive heart failure and severely impaired left ventricular (LV) function and were treated with high-dose (2 g/kg) intravenous immunoglobulin (IVIG). The diagnosis of acute inflammatory DCM was based on recent onset of congestive heart failure (New York Heart Association functional class III or IV) with severely depressed LV ejection fraction ([LVEF] 30% or lower) occurring shortly after viral-like illness. All patients had inflammation on endomyocardial biopsy or elevated cardiac enzymes, as well as a normal coronary angiogram. All patients were in New York Heart Association class I or II at the time of hospital discharge. The mean LVEF improved from 21.7+/-7.5% at baseline to 50.3+/-8.6% at discharge (P=0.005). Four patients had complete recovery (LVEF 50% or higher) and two patients had partial LV recovery. Patients were followed for a median 13.2 months (range two to 24 months) and had a mean LVEF of 53+/-6% (P not significant versus LVEF at discharge). CONCLUSIONS: Therapy with intravenous high-dose IVIG may be a potentially useful treatment in selected patients if given early in the course of acute fulminant inflammatory DCM. A randomized, prospective trial is warranted to prove the real benefit of IVIG in this patient population.

Use of cardiac allografts with mild and moderate left ventricular hypertrophy can be safely used in heart transplantation to expand the donor pool.

OBJECTIVES: The purpose of this study was to evaluate outcomes of heart transplantation (HTx) and changes in left ventricular wall thickness (LVWT) post-HTx using donors with left ventricular hypertrophy (LVH). BACKGROUND: Limited data are available on use of donor hearts with LVH in HTx. METHODS: We reviewed 427 patients who underwent HTx: 62 received hearts with LVH (interventricular septum [IVS] or posterior wall [PW] thickness >or=1.2 cm) by echocardiography, and 365 received hearts without LVH. The median follow-up was 3.8 years (range 0 to 16.2 years). RESULTS: Recipient age was 56 +/- 11 years and donor age was 30 +/- 12 years. Baseline recipient characteristics were similar in both groups. Donors with LVH were older (35 +/- 12 years vs. 29 +/- 12 years, p = 0.001) and had higher rates of intracranial hemorrhage (38% vs. 15%, p = 0.001). The LVWT was increased in the LVH group compared with LVWT in the non-LVH group (IVS: 1.28 +/- 0.18 cm vs. 0.85 +/- 0.19 cm, PW: 1.27 +/- 0.19 cm vs. 0.85 +/- 0.20 cm, p = 0.0001 for both groups). Mild LVH (1.2 to 1.3 cm) was found in 42%, moderate (>1.3 to 1.7 cm) in 53%, and severe (>1.7 cm) in 5% of donors with LVH. Left ventricular wall thickness regression occurred in both IVS and PW (1.28 +/- 0.18 cm vs. 1.10 +/- 0.13 cm vs. 1.13 +/- 0.14 cm, and 1.27 +/- 0.19 cm vs. 1.11 +/- 0.11 cm vs. 1.13 +/- 0.14 cm, at baseline, 1 year, and 5 years, respectively; p < 0.001 for change from baseline to 1 and 5 years for both locations). Patients with or without donor LVH had similar 1-year (3.5% vs. 9.5%, p = 0.2) and 5-year survival rates (84 +/- 5.9% vs. 70 +/- 2.7%, p = 0.07). CONCLUSIONS: Short- and long-term survival rates and rates of LVH at follow-up were similar in both groups, suggesting that donor hearts with mild and moderate LVH can be safely used in HTx.

Pre-existing pulmonary hypertension in patients with end-stage heart failure: impact on clinical outcome and hemodynamic follow-up after orthotopic heart transplantation.

BACKGROUND: The purpose of this investigation was to determine the influence of pre-existing pulmonary hypertension (PHT) on outcome and to assess the pulmonary hemodynamic changes after heart transplantation (HT). METHODS: A total of 410 patients were studied before and after (1 month and 1 year) HT: Group 1 (n = 266) had no PHT (PVR < 3 Wood units [WU], TPG < 10 mm Hg); Group 2 (n = 112) had mild-moderate PHT (PVR 3 to 6 WU, TPG 10 to 20 mm Hg); and Group 3 (n = 32) had severe PHT (PVR > 6 WU, TPG > 20 mm Hg). RESULTS: Mean (+/- SD) follow-up was 5.2 +/- 4.1 years, mean recipient age was 57 +/- 11, and mean donor age was 30 +/- 12 years. Baseline characteristics were similar in all groups, except donor/recipient weight ratio, which was higher in patients with PHT (p = 0.002). There was a significant (p < 0.0001) decrease in mean TPG to 11.0 within the first month and to 9.5 mm Hg after the first year. Decreases in PVR to 2.2 and 2.0 WU at 1 month and 1 year, respectively (p < 0.0001 for both) were also found. Reversibility (after vasodilation) of PHT was obtained in 85% of patients in Group 2 and in 84% in Group 3. Patients' PHT did not show a significant difference in 30-day mortality (p = 0.9) and long-term survival (p = 0.8). Patients with residual post-transplant PHT (PVR > or = 3 WU) had reduced long-term survival (p = 0.03). Multivariate analysis showed no evidence that elevated PVR was associated with death. CONCLUSIONS: Pre-existing elevated PVR that responds to vasodilator challenge does not have a negative influence on short- and long-term survival after HT. We found that residual post-transplant PHT is associated with decreased long-term survival.

Risk factors associated with reoperation and mortality in 252 patients after aortic valve replacement for congenitally bicuspid aortic valve disease.

BACKGROUND: We aimed to determine the risk factors associated with mortality in patients with congenitally bicuspid aortic valve disease and dilation (<5 cm) of the ascending aorta after aortic valve replacement. METHODS: We reviewed 252 patients with bicuspid aortic valve undergoing aortic valve replacement at our institution from 1971 through 2000. Patients undergoing concomitant replacement of the ascending aorta were excluded. RESULTS: The average patient age was 61 +/- 15 years; 66.3% were male, and 40.5% of patients had coronary artery disease. The ascending aorta was normal (<4.0 cm) in 60.3%, mildly dilated (4.0 to 4.4 cm) in 24.2%, and moderately dilated (4.5 to 4.9 cm) in 15.5% of patients. Patients with moderate aortic dilatation had significantly lower prevalence of coronary artery disease compared with patients with normal ascending aortas (20.5% and 45.4%; p = 0.006). Mean follow-up was 8.9 +/- 6.3 years. Long-term survival was significantly different across the three groups (p = 0.004). The 5-, 10-, and 15-year estimates were 78%, 59%, and 37%, respectively, in the normal aorta group; 88%, 77%, and 46%, respectively, in the mild aortic dilation group; and 92%, 83%, and 70%, respectively, in the moderate aortic dilation group. No significant difference in cardiac death was found among the groups (p = 0.08). The significant predictors of survival using the Cox regression model were coronary artery disease, age, decade of surgery, and ejection fraction. Aortic dilation was not significant after adjusting for these other variables. At follow-up, 18 patients required reoperation, 17 for aortic valve prosthesis failure and 1 for ascending aorta aneurysm. CONCLUSIONS: The present study highlights the important adverse effect of concomitant coronary artery disease, advanced age, earlier decade of surgery, and reduced left ventricular ejection fraction on survival after aortic valve replacement for bicuspid aortic valve in patients with no or mild and moderate (<5 cm) dilation of the ascending aorta.

In the current era, complete revascularization improves survival after coronary artery bypass surgery.

BACKGROUND: Complete revascularization has been the standard for coronary bypass grafting. However, surgical intervention has evolved with increasing use of arterial conduits and off-pump techniques. METHODS: Patients undergoing non-redo bypass surgery from January 1998 through December 2000 were followed up with questionnaires and telephone contact. Incomplete revascularization was defined as absence of bypass grafts placed to a coronary territory supplied by a vessel with 50% or greater stenosis. RESULTS: One thousand thirty-four patients were followed for a mean of 3.3 +/- 1.6 years. Complete revascularization was found in 937 (90.6%) patients, and incomplete revascularization was found in 97 (9.4%) patients. Eight hundred twenty-seven (80.4%) patients underwent on-pump operations, and 207 (19.6%) underwent off-pump operations. Incomplete revascularization was more prevalent in off-pump versus on-pump operations (21.7% vs 6.3%, P < .001). Multivariable Cox regression analysis indicated that in-hospital cerebrovascular accidents (hazard ratio, 5.49; P < .001), chronic obstructive pulmonary disease (hazard ratio, 1.97; P = .019), and incomplete revascularization (hazard ratio, 1.85; P = .040) predicted an increased hazard (risk) of cardiac death. Left internal thoracic artery (hazard ratio, 0.38; P = .047), right internal thoracic artery (hazard ratio, 0.25; P = .019), and radial artery (hazard ratio, 0.36; P < .001) grafting reduced the risk of cardiac death. The 5-year unadjusted survival rate was 52.6% versus 82.4% in patients undergoing incomplete and complete revascularization ( P < .001), with cardiac survival rates of 74.5% versus 93.1%, respectively ( P < .001). However, this difference in cardiac survival was smaller in octogenarians with incomplete versus complete revascularizations (77.4% vs 87.6%, P = .101) and was essentially absent in off-pump versus on-pump operations if complete revascularization was achieved in both cases (93.6% vs 93.1%, P > .200). CONCLUSIONS: Complete revascularization and arterial grafting improve 5-year survival. Off-pump techniques do not affect survival. Complete revascularization should be performed whenever possible.

Ischemic mitral regurgitation: revascularization alone versus revascularization and mitral valve repair.

BACKGROUND: In this study we compared the surgical management of ischemic mitral regurgitation (IMR) by revascularization alone and by revascularization combined with mitral valve repair. METHODS: We studied 355 patients who underwent revascularization alone (n = 168) or revascularization combined with mitral valve repair (n = 187) for IMR from March 1994 to September 2003. Preoperative and operative characteristics, postoperative mitral regurgitation severity, operative mortality, and late survival were examined for each surgical group. RESULTS: No differences were noted between the two groups in age, sex, history of diabetes or hypertension, and number of bypass grafts. The combined surgical group had a lower preoperative left ventricular ejection fraction (0.38 +/- 0.14 versus 0.44 +/- 0.15), greater severity of IMR, higher frequency of prior myocardial infarction, and longer cross-clamp and pump times (p < 0.01). The combined surgical group had a greater reduction in IMR grade (2.7 +/- 0.1 grades versus 0.2 +/- 0.1 grade), a lower postoperative IMR grade (0.9 +/- 0.1 versus 2.3 +/- 0.1), and a higher success with reduction of IMR by two or more grades (89% versus 11%) (p < 0.001). In patients with 3+ or 4+ IMR, both groups had similar operative mortality (11.0% in the combined group compared with 4.7% for revascularization alone, p = 0.11) and actuarial survival at 5 years (44% +/- 5% versus 41% +/- 7%, p = 0.53). Independently predictive of higher early mortality (< or = 30 days) by Cox analysis were longer pump time (p < 0.001) and older age (p < 0.02). Predictive of late mortality (> 30 days) were older age (p < 0.001), fewer bypass grafts (p < 0.01), and lower ejection fraction (p < 0.01). After adjustment for these variables, there was a trend (p = 0.08) toward a higher late survival with the combined surgical procedure. CONCLUSIONS: In patients with IMR, combined mitral valve repair and revascularization resulted in less postoperative mitral regurgitation and similar 5-year survival when compared with revascularization alone. Attempts to reduce pump time by using off-pump techniques may reduce early mortality in these high-risk patients.

Thoracic vein ablation terminates chronic atrial fibrillation in dogs.

The thoracic vein hypothesis of chronic atrial fibrillation (AF) posits that rapid, repetitive activations from muscle sleeves within thoracic veins underlie the mechanism of sustained AF. If this is so, thoracic vein ablation should terminate sustained AF and prevent its reinduction. Six female mongrel dogs underwent chronic pulmonary vein (PV) pacing at 20 Hz to induce sustained (>48 h) AF. Bipolar electrodes were used to record from the atria and thoracic veins, including the vein of Marshall, four PVs, and the superior vena cava. Radio frequency (RF) application was applied around the PVs and superior vena cava and along the vein of Marshall until electrical activity was eliminated. Computerized mapping (1,792 electrodes, 1 mm resolution) was also performed. Sustained AF was induced in 30.6 +/- 6.5 days, and ablation was done 17.3 +/- 8.5 days afterward. Before ablation, the PVs had shorter activation cycle lengths than the atria, and rapid, repetitive activations were observed in the PVs. All dogs converted to sinus rhythm during (n = 4 dogs) or within 90 min of completion of RF ablation. Rapid atrial pacing afterward induced only nonsustained (<60 s) AF in all dogs. Average AF cycle lengths after reinduction were significantly (P = 0.01) longer (183 +/- 31.5 ms) than baseline (106 +/- 16.2 ms). There were no activation cycle length gradients after RF application. We conclude that thoracic vein ablation converts canine sustained AF into sinus rhythm and prevents the reinduction of sustained AF. These findings suggest that thoracic veins are important in the maintenance of AF in dogs.

Biventricular support in patients with profound cardiogenic shock: a single center experience.

Options for managing heart failure patients with cardiogenic shock refractory to inotropic and intra-aortic balloon pump (IABP) therapy are limited. Ventricular assist devices (VADs) can bridge these patients to heart transplantation. However, controversy exists over whether extracorporeal membrane oxygenation (ECMO) before VAD placement is beneficial. We report our use of biventricular assist devices (BiVADs) as a direct bridge to transplant. Since July 1999, 19 Thoratec BiVADs were implanted for heart failure unresponsive to medical therapy. Patient ages ranged from 20 to 67 years. Causes of heart failure included idiopathic 32%, ischemic 26%, postcardiotomy 21%, and other 21%. All patients were in cardiogenic shock, and three were receiving cardiopulmonary resuscitation (CPR) before implant. Preimplant conditions included IABP 89%, mechanical ventilation 68%, three or more inotropes 84%, hyperbilirubinemia 59%, acute renal failure 63%, and hemodialysis 16%. Fifty-nine percent of patients bridged successfully to transplantation, with 90% posttransplant survival. Duration of BiVAD support ranged from 0 to 91 days, with two patients currently on support awaiting transplantation. Complications included bleeding requiring reoperation 26%, stroke 11%, infection (any positive culture) 68%, and cannula site infection 5%. The Thoratec BiVAD can successfully be used as a direct bridge to transplantation in heart failure patients with cardiogenic shock.

Off-pump coronary surgery: effect on early mortality and stroke.

BACKGROUND: Avoiding cardiopulmonary bypass in coronary artery bypass grafting is thought to reduce early mortality and morbidity. METHODS: We used our prospective database to compare all patients having off-pump coronary surgery (n = 389) with those having on-pump coronary surgery (n = 2412) between March 15, 1995, and November 1, 2000. Patients were grouped by age (years) in decades (>90, 80-89, 70-79, 60-69, <60 years). The Northern New England risk model was applied. Thirty-two independent variables were entered into a stepwise logistic regression analysis with the end points being surgical mortality and postoperative stroke. RESULTS: Patients undergoing off-pump operations were older (70.9 +/- 12 vs 68.1 +/- 11 years; P <.001), and their Northern New England predicted risk was higher (11.9% +/- 13% vs 9.2% +/- 10%; P <.001). However, patients having on-pump bypass had significantly more bypass grafts constructed (3.3 +/- 0.8 vs 1.9 +/- 0.8; P <.001) and triple-vessel coronary artery disease (58% vs 28%; P <.001). There were no significant differences in postoperative mortality, stroke rate, complications, and length of stay between the groups. Logistic regression analysis did not show that cardiopulmonary bypass was a risk factor for either surgical mortality (odds ratio, 1.08; P =.83) or stroke (odds ratio, 1.59; P =.27). CONCLUSION: Off-pump coronary bypass did not reduce early mortality and morbidity. Early and late results should be compared in a prospective randomized study.

Simultaneous biatrial computerized mapping during permanent atrial fibrillation in patients with organic heart disease.

INTRODUCTION: Activation patterns during permanent atrial fibrillation (AF) in patients with organic heart diseases are unclear. METHODS AND RESULTS: We studied six patients with permanent AF and organic heart diseases undergoing surgery. The duration of AF averaged 4.9+/-7.6 years. Computerized epicardial mappings of the right atrial (RA) free wall and the left atrial (LA) posterior wall were simultaneously performed with 224 bipolar electrodes at 3-mm spatial resolution. In the RA, large wavefronts and conduction blocks were frequently observed. The lines of block correlated with the crista terminalis and large pectinate muscles. In contrast, the LA had rapid repetitive activities originated from corners of the electrode plaque, near the four pulmonary veins (PVs). On average, 2.8+/-1.2 sites of rapid repetitive activities were identified per patient. They activated continuously, intermittently, or alternately during AF. The mean activation cycle length in the RA (196+/-22 msec) was significantly longer than that in the LA (179+/-26 msec; P = 0.004). The maximum dominant frequency in the LA was higher than that in the RA (6.41+/-1.18 Hz vs 5.66+/-0.55 Hz; P = 0.049). The maximum dominant frequency was consistently located in areas with rapid repetitive activations near the PVs. CONCLUSION: During human permanent AF associated with organic heart diseases, the activation cycle length was shorter in the LA posterior wall than in the RA free wall. Rapid repetitive activities are consistently observed in the LA posterior wall, at or near the PVs.