Clinical experience with one hundred consecutive patients undergoing orthotopic heart transplantation with bicaval and pulmonary venous anastomoses

Cardiac Implantable Electronic Devices Following Heart Transplantation

Permanent pacemaker (PPM) implantation is required in a subset of patients (∼10%) for sinus node dysfunction or atrioventricular block both early and late after heart transplantation. The incidence of PPM implantation has decreased to <5% with the advent of bicaval anastamosis transplantation surgery. Pacing dependence upon follow-up has been variably reported. An even smaller percentage of transplantation recipients (1.5% to 3.4%) undergo implantable cardioverter-defibrillator (ICD) placement. Rigorous data are lacking for the use of ICDs in the transplantation population and is largely derived from cohort studies and case series. Sudden cardiac death occurs in approximately 10% of transplantation recipients, but multiple nonarrhythmic factors are believed to be responsible, including acute rejection, late graft failure with electromechanical dissociation, and ischemia due to cardiac allograft vasculopathy. This review provides a comprehensive analysis of the existing data regarding the role for PPMs and ICDs in this population, including leadless PPMs and subcutaneous ICDs, special considerations, and future directions.

Combined Heart and Kidney Transplantation: Clinical Experience in 100 Consecutive Patients

Background

Combined heart and kidney transplantation (HKTx) is performed in patients with severe heart failure and advanced renal insufficiency. We analyzed the long‐term survival after HKTx, the influence of age and dialysis status, the rates of cardiac rejection, and the influence of sensitization.

Methods and Results

From June 1992 to December 2016, we performed 100 HKTx procedures. We compared older (≥60 years, n=53) with younger (<60 years, n=47) recipients, and recipients on preoperative dialysis (n=49) and not on dialysis (n=51). We analyzed actuarial freedom from any cardiac rejection, acute cellular rejection, and antibody‐mediated rejection, and survival rates by sensitized status with panel‐reactive antibody levels <10%, 10% to 50%, and >50%, and compared these survival rates with those from the United Network for Organ Sharing database. There was no difference in 15‐year survival between the 2 age groups (35±12.4% and 49±17.3%, ≥60 versus <60 years; P=0.45). There was no difference in 15‐year survival between the dialysis and nondialysis groups (44±13.4% and 37±15.2%, P=0.95). Actuarial freedom from any cardiac rejection (acute cellular rejection>0 or antibody‐mediated rejection>0) was 92±2.8% and 84±3.8%, acute cellular rejection (≥2R/3A) 98±1.5% and 94±2.5%, and antibody‐mediated rejection (≥1) 96±2.1% and 93±2.6% at 30 days and 1 year after HKTx. There was no difference in the 5‐year survival among recipients by sensitization status with panel‐reactive antibody levels <10%, 10% to 50%, and >50% (82±5.9%, 83±10.8%, and 92±8.0%; P=0.55). There was no difference in 15‐year survival after HKTx between the United Network for Organ Sharing database and our center (38±3.2% and 40±10.1%, respectively; P=0.45).

Conclusions

HKTx is safe to perform in patients 60 years and older or younger than 60 years and with or without dialysis dependence, with excellent outcomes. The degree of panel‐reactive antibody sensitization did not appear to affect survival after HKTx.

Controversies in the Postoperative Management of the Critically Ill Heart Transplant Patient

Heart transplant recipients are susceptible to a number of complications in the immediate postoperative period. Despite advances in surgical techniques, mechanical circulatory support (MCS), and immunosuppression, evidence supporting optimal management strategies of the critically ill transplant patient is lacking on many fronts. This review identifies some of these controversies with the aim of stimulating further discussion and development into these gray areas.

Combined Heart and Kidney Transplantation: A 23-Year Experience

BACKGROUND

We report clinical experience with combined heart and kidney transplantation (HKTx) over a 23-year time period.

METHODS

From June 1992 to August 2015, we performed 83 combined HKTx procedures at our institution. We compared the more recent cohort of 53 HKTx recipients (group 2, March 2009 to August 2015) with the initial 30 previously reported HKTx recipients (group 1, June 1992 to February 2009). Pre-operative patient characteristics, peri-operative factors, and post-operative outcomes including survival were examined.

RESULTS

The baseline characteristics of the two groups were similar, except for a lower incidence of ethanol use and higher pre-operative left-ventricular ejection fraction, cardiac output, and cardiac index in group 2 when compared with group 1 (P = .007, .046, .037, respectively). The pump time was longer in group 2 compared with group 1 (153.30 ± 38.68 vs 129.60 ± 37.60 minutes; P = .007), whereas the graft ischemic time was not significantly different between the groups, with a trend to a longer graft ischemic time in group 2 versus group 1 (195.17 ± 45.06 vs 178.07 ± 52.77 minutes; P = .056, respectively). The lengths of intensive care unit (ICU) and hospital stay were similar between the groups (P = .083 and .39, respectively). In addition, pre-operative and post-operative creatinine levels at peak, discharge, 1 year, and 5 years and the number of people on post-operative dialysis were similar between the groups (P = .37, .75, .54, .87, .56, and P = .139, respectively). Overall survival was not significantly different between groups 2 and 1 for the first 5 years after transplant, with a trend toward higher survival in group 2 (P = .054).

CONCLUSIONS

The most recent cohort of combined heart and kidney transplant recipients had similar ICU and hospital lengths of stay and post-operative creatinine levels at peak, discharge, and 1 and 5 years and a similar number of patients on post-operative dialysis when compared with the initial cohort. Overall survival was not significantly different between the later and earlier groups, with a trend toward higher overall survival at 5 years in the more recent cohort of patients. In selected patients with co-existing heart and kidney failure, combined heart and kidney transplantation is safe to perform and has excellent outcomes.

Similar Mortality and Morbidity of Orthotopic Heart Transplantation for Patients 70 Years of Age and Older Compared With Younger Patients

BACKGROUND

The upper age limit of heart transplantation remains controversial. The goal of the present study was to investigate the mortality and morbidity of orthotopic heart transplantation (HT) for recipients ≥70 compared with those <70 years of age.

METHODS

Of 704 adults who underwent HT from December 1988 to June 2012 at our institution, 45 were ≥70 years old (older group) and 659 were <70 years old (younger group). Survival, intraoperative blood product usage, intensive care unit (ICU) and hospital stays, and frequency of reoperation for chest bleeding, dialysis, and >48 hours ventilation were examined after HT.

RESULTS

The older group had 100% 30-day and 60-day survival compared with 96.8 ± 0.7% 30-day and 95.9 ± 0.8% 60-day survival rates in the younger group. The older and younger groups had similar 1-year (93.0 ± 3.9% vs 92.1 ± 1.1%; P = .79), 5-year (84.2 ± 6.0% vs 73.4 ± 1.9%; P = .18), and 10-year (51.2 ± 10.7% vs 50.2 ± 2.5%; P = .43) survival rates. Recipients in the older group had higher preoperative creatinine levels, frequency of coronary artery disease, and more United Network for Organ Sharing status 2 and fewer status 1 designations than recipients in the younger group (P < .05 for all). Pump time and intraoperative blood usage were similar between the 2 groups (P = NS); however, donor-heart ischemia time was higher in the older group (P = .002). Older recipients had higher postoperative creatinine levels at peak (P = .003) and at discharge (P = .007). Frequency of postoperative complications, including reoperation for chest bleeding, dialysis, >48 hours ventilation, pneumonia, pneumothorax, sepsis, in-hospital and post-discharge infections, were similar between groups (P = NS for all comparisons). ICU and hospital length of stays were similar between groups (P = .35 and P = .87, respectively). In Cox analysis, recipient age ≥70 years was not identified as a predictor of lower long-term survival after HT.

CONCLUSIONS

HT recipients ≥70 years old had similar 1, 5, and 10-year survival rates compared with younger recipients. Both patient groups had similar intra- and postoperative blood utilization and frequencies of many postoperative complications. Older and younger patients had similar morbidity and mortality rates following HT. Carefully selected older patients (≥70 years) can safely undergo HT and should not be excluded from HT consideration based solely on age.

Stability of pacing indices and need for pacing in cardiac transplant patients over 1 year of follow-up

BACKGROUND

A significant minority of cardiac transplant patients require permanent pacemaker (PPM) implant, primarily for sinus node dysfunction. The stability of pacing indices has not been determined in this unique patient population, and data regarding ongoing need for pacing are limited.

METHODS

Pacing indices (sensing, threshold, and impedance) as well as the percentage of time patients required pacing were recorded, from 30 cardiac transplant patients that underwent PPM implant, over 1 year of follow-up. Repeated measure ANOVA (analysis of variance) was used to compare pacing indices and the percentage of time patients required pacing in each cardiac chamber (right atrium (RA) and right ventricle (RV)) and at different time points.

RESULTS

There was no difference in sensing among the follow-up time points (p = 0.9). Thresholds at 3 months were significantly higher compared to the day of implant (p = 0.005) and the day after implant (p = 0.03). Impedances at implant were significantly higher compared to day 1 (p < 0.001), 3 months (p < 0.003), and 12 months (p < 0.001) post-implant. The mean percentage of RA pacing was 85 ± 6% the day after implant, 74 ± 6% at 3 months, and 80 ± 6% at 1 year (p = 0.17).

CONCLUSION

In cardiac transplant patients, pacing impedances decrease and thresholds trend up in short-term follow-up, but subsequent sensing, threshold, and impedance remain stable at 1 year. This is comparable to the pattern observed among noncardiac transplant PPM recipients. The atrial pacing percentage was stable over 1 year, suggesting continued relative sinus node dysfunction.

Combined heart-kidney transplantation after total artificial heart insertion

We present the first single-center report of 2 consecutive cases of combined heart and kidney transplantation after insertion of a total artificial heart (TAH). Both patients had advanced heart failure and developed dialysis-dependent renal failure after implantation of the TAH. The 2 patients underwent successful heart and kidney transplantation, with restoration of normal heart and kidney function. On the basis of this limited experience, we consider TAH a safe and feasible option for bridging carefully selected patients with heart and kidney failure to combined heart and kidney transplantation. Recent FDA approval of the Freedom driver may allow outpatient management at substantial cost savings. The TAH, by virtue of its capability of providing pulsatile flow at 6 to 10 L/min, may be the mechanical circulatory support device most likely to recover patients with marginal renal function and advanced heart failure.

Heart transplantation for end-stage heart failure due to cardiac sarcoidosis

BACKGROUND

Cardiac sarcoidosis with end-stage heart failure has a poor prognosis without transplantation. The rates of sarcoid recurrence and rejection are not well established after heart transplantation.

METHODS

A total of 19 heart transplant recipients with sarcoid of the explanted heart were compared with a contemporaneous control group of 1,050 heart transplant recipients without cardiac sarcoidosis. Assessed outcomes included 1st-year freedom from any treated rejection, 5-year actuarial survival, 5-year freedom from cardiac allograft vasculopathy (CAV), 5-year freedom from nonfatal major adverse cardiac events (NF-MACE), and recurrence of sarcoid in the allograft or other organs. Patients with sarcoidosis were maintained on low-dose corticosteroids after transplantation.

RESULTS

There were no significant differences between the sarcoid and control groups in 1st-year freedom from any treated rejection (79% and 90%), 5-year posttransplantation survival (79% and 83%), 5-year freedom from CAV (68% and 78%), and 5-year freedom from NF-MACE (90% and 88%). Causes of death (n = 5) in the sarcoid group were coccidioidomycosis, pneumonia, rejection, hemorrhage, and CAV. No patient had recurrence of sarcoidosis in the cardiac allograft. Three of 19 patients (16%) experienced recurrence of extracardiac sarcoid, with no mortality.

CONCLUSIONS

Patients with cardiac sarcoidosis undergoing heart transplantation have acceptable long-term outcomes without evidence of recurrence of sarcoidosis in the allograft when maintained on low-dose corticosteroids. Progression of extracardiac sarcoid was uncommon, possibly related to immunosuppression. In patients with cardiac sarcoidosis, heart transplantation is a viable treatment modality.

Antithymocyte globulin induction therapy adjusted for immunologic risk after heart transplantation

INTRODUCTION

The efficacy of antithymocyte globulin (ATG) induction in the therapy of immunologically low- and high-risk patients after heart transplantation is not known.

METHODS

All patients who received ATG induction from January 2000 through January 2010 were divided into two groups based on the risk of rejection. A higher-risk group (age younger than 60 years, multiparous females, African Americans, panel-reactive antibody >10%, or positive cross-match) received ATG (1.5 mg/kg) for 7 days (ATG7), and the remaining lower-risk group received ATG for 5 days (ATG5), all followed by calcineurin inhibitor, mycophenolate, and prednisone. Endomyocardial biopsies were performed based a standard protocol for up to 3 years after heart transplantation, and for suspected rejection.

RESULTS

Of 253 heart transplant recipients, 87 received ATG5 and 166 ATG7. Absolute lymphocyte count <200 per microliter was achieved within 10 days in 88% of ATG5 and 86% of ATG7. Baseline creatinine was 1.3 ± 0.8 pre-transplantation, 1.8 ± 0.9 post-transplantation, and 1.0 ± 0.4 mg/dL at discharge (mean ± standard deviation [SD]; P < .001, compared with pre-transplantation). Of 3667 biopsies, 33 (0.90%) had ≥3A/2R cellular rejection (CR). Of 3599 biopsies, 16 (0.44%) had definite antibody-mediated rejection (AMR). At 5 years, freedom from ≥3A/2R CR (94% ± 2.8% vs 83% ± 7.7%; P = .31) and freedom from AMR (95% ± 2.4% vs 90% ± 6.4%; P = .98) were similar between ATG5 and ATG7, respectively. Survival for ATG5 and ATG7 was comparable at one year (94% ± 2.5% vs 93% ± 2.0%), and at 8 years (61% ± 6.9% and 61% ± 4.7%; P = .88). At 5 years, ATG5 and ATG7 were similar in freedom from cytomegalovirus (CMV) infection (92.3% vs 94.3%; P = not significant [NS]), freedom from pneumonia (83.8% vs 82.1%; P = NS), and in rate of malignancy (excluding skin cancer; 8.0% vs 6.0%; P = NS).

CONCLUSIONS

ATG induction therapy (prospectively dose-adjusted for immunologic risk) in low- and high-risk patients results in excellent and equivalent short- and long-term survival rates, with a low incidence of CR and AMR. The use of ATG does not increase rates of CMV infection with appropriate prophylaxis. ATG may benefit renal function by delaying calcineurin inhibitor exposure, and may have a role in the prevention of AMR.

Exercise performance comparison of bicaval and biatrial orthotopic heart transplant recipients

BACKGROUND

The standard biatrial technique for orthotopic heart transplantation uses a large atrial anastomosis to connect the donor and recipient atria. A modified technique involves bicaval and pulmonary venous anastomoses and is believed to preserve the anatomic configuration and physiological function of the atria. Bicaval heart transplantation reduces postoperative valvular regurgitation and is associated with a lower incidence of pacemaker insertion.

OBJECTIVE

The aim of this study was to compare postoperative functional capacity and exercise performance in patients with bicaval and biatrial orthotopic heart transplantation.

METHODS

Patients were selected for the study if they did not have any of the following: obstructive coronary artery disease (>50% stenosis), severe mitral or tricuspid regurgitation, signs of rejection (grade≥1B-1R) on endomyocardial biopsy during the prior year, respiratory impairment, a permanent pacemaker, orthopedic or muscular impediments, or lived more than 150 miles from the medical center. A total of 27 patients qualified. In 15 patients who received a biatrial heart transplant and 12 patients with a bicaval heart transplant, a stationary bicycle exercise test was performed. Ventilatory gas exchange and maximum oxygen consumption measurements were measured.

RESULTS

Recipient and donor characteristics, including body surface area, donor/recipient weight mismatch, immunosuppressive regimen, and self-reported weekly exercise activity, did not differ between the biatrial and bicaval groups (P=not significant [NS]). At peak exercise, similar heart rate, workload, oxygen consumption, carbon dioxide production, ventilation, functional capacity, and exercise duration were found between the 2 groups (P=NS). Patients in the biatrial group were studied later than patients in the bicaval group (6.54±0.71 vs 4.68±0.28 years; P<.001).

CONCLUSION

There were no significant differences in the exercise capacity between patients with biatrial versus bicaval techniques for orthotopic heart transplantation. Factors other than the atrial connection (such as cardiac denervation, immunosuppressive drug effect, or physical deconditioning) may be more important determinants of subnormal exercise capacity after heart transplantation. Nevertheless, the reduction in morbidity and postoperative complications and the simplicity in the bicaval technique suggest that bicaval heart transplantation offers advantages when compared with the standard biatrial technique.

Long-term outcomes and clinical predictors for pacemaker-requiring bradyarrhythmias after cardiac transplantation: analysis of the UNOS/OPTN cardiac transplant database

BACKGROUND

Pacemaker-requiring bradyarrhythmias after cardiac transplantation are common, and rarely can lead to sudden cardiac death. Prior outcomes studies have been limited to single-center data.

OBJECTIVE

This study sought to define the long-term outcomes and clinical predictors for pacemaker-requiring bradyarrhythmias in the cardiac transplant population.

METHODS

This study used multivariable analysis of the United Network for Organ Sharing/Organ Procurement and Transplantation Network (UNOS/OPTN) database of sequential U.S. cardiac transplant recipients from 1997 to 2007 stratified by postoperative bradyarrhythmias requiring a pacemaker. The primary end point was all-cause mortality.

RESULTS

Among 35,987 cardiac transplant recipients (age 46.1 ± 18.3 years, 76% male, 22% bicaval technique) with a follow-up of 6.3 ± 4.7 years, pacemaker-requiring bradyarrhythmias occurred in 3,940 patients (10.9%). Pacemaker recipients demonstrated improved survival (median 8.0 years vs. 5.2 years, P < .001), decreased 5-year mortality (13.8% vs. 17.7%, P < .001), and overall crude mortality (42.9% vs. 45.9%, P < .001). Multivariable propensity-score-adjusted analysis demonstrated improved survival among pacemaker recipients (adjusted hazard ratio 0.84, 95% confidence interval [CI] 0.80 to 0.88, P < .001) after adjustment for donor/recipient age, UNOS listing status, donor heart ischemic time, surgical technique, graft rejection, and other common comorbidities. The bicaval surgical technique was strongly protective against a postoperative pacemaker requirement (odds ratio [OR] 0.33, 95% CI 0.29 to 0.36, P < .001) in multivariable analysis. Among the other variables studied, only increasing donor age (OR 1.04, 95% CI 1.00 to 1.09, P < .001) and recipient age (OR 1.09, 95% CI 1.0 to 1.12, P < .001) were associated with a permanent pacemaker requirement.

CONCLUSION

Cardiac transplant recipients with pacemaker-requiring bradyarrhythmias have an excellent long-term prognosis. Increased mortality in the nonpacemaker group merits further investigation. Biatrial surgical technique and increasing donor/recipient age are associated with postoperative pacemaker requirement.

Case report: Inferior vena-cava right atrial anastomotic stenosis after bicaval orthotopic heart transplantation

PURPOSE

This case report describes the occurrence of acute postoperative liver and renal failure after bicaval orthotopic heart transplantation (OHT) due to stenosis of the inferior vena cava (IVC)-right atrial (RA) anastomosis. We also discuss the role of measuring femoral venous pressure and transesophageal echocardiography (TEE) in establishing the diagnosis.

CLINICAL FEATURES

A 42-yr-old female patient with idiopathic dilated cardiomyopathy underwent an OHT, using the bicaval anastomotic technique. During the first 12 hr postoperatively she developed unexplained kidney and liver failure. Her left and right ventricular functions were excellent and the right and left sided filling pressures were normal. The femoral pressure was elevated while the RA pressure was normal. An emergent TEE showed colour-flow and Doppler characteristics consistent with IVC-RA anastomotic stenosis. Emergent surgical re-exploration was undertaken; a hemostatic suture was found at the RA cannulation site that had caused the constriction of the IVC-RA anastomosis.

CONCLUSIONS

Acute liver and renal failure after OHT can have multiple causes including ischemia due to a low flow state. This case demonstrates the importance of doing a detailed intraoperative TEE after OHT, and the importance of repeating the intraoperative examination after any hemostatic sutures are placed. Femoral venous pressure monitoring can be a useful diagnostic tool in detecting IVC-RA stenosis.

Electromechanical synchronization of the heterotopic and native heart by dual atrial stimulation following heart transplantation

After heterotopic heart transplantation, a 59-year-old woman presented with remarkable symptoms of breathlessness and fatigue, despite excellent donor heart function. Asynchrony of donor and native heart provoked haemodynamic instability. Dual atrial pacemaker implantation lead to linkage and synchronization of atrial and ventricular contraction in both the donor and native heart with the faster organ executing the synchronization. Remarkable relief of symptoms has been evident during the long-term follow-up.

Orthotopic cardiac transplantation: comparison of outcome using biatrial, bicaval, and total techniques

BACKGROUND

For more than 35 years, the biatrial technique of performing orthotopic cardiac transplantation has been the gold standard, and involves anastomoses of donor and recipient atrial cuffs. More recently, however, bicaval and total techniques have been devised in an attempt to improve cardiac anatomy, physiology, and postoperative outcome. A bicaval approach preserves the donor atria and combines the standard left atrial anastomosis with a separate bicaval anastomosis. Total orthotopic heart transplantation involves complete excision of the recipient atria with separate bicaval end-to-end anastomoses, as well as pulmonary venous anastomoses. The aim of this study was to conduct a literature review of studies that compared the three surgical techniques (biatrial, bicaval, and total) for performing orthotopic cardiac transplantation. Numerous outcome variables were evaluated, and included post-transplant survival, atrial dimensions, atrioventricular valvular insufficiency, arrhythmias, pacing requirements, vasopressor requirements, and hospital stay.

METHODS

We conducted a Medline (Pubmed) search using the terms "biatrial and cardiac transplantation,""bicaval and cardiac transplantation," and "total technique and cardiac transplantation," which yielded 192 entries: 39 of these were studies that compared surgical techniques and were included in the review.

RESULTS

There was overwhelming evidence that the bicaval technique provided anatomic and functional advantages, with improvements in post-transplant survival, atrial geometry, and hemodynamics, as well as decreased valvular insufficiency, arrhythmias, pacing requirements, vasopressor requirements, and hospital stay.

CONCLUSIONS

The bicaval technique was superior to both biatrial and total techniques for numerous outcome variables. To further elucidate this issue, a prospective randomized trial comparing the three techniques, with long-term follow-up, is warranted.

Surgical advances in heart and lung transplantation

The successes of thoracic transplantation have led to the expansion of indications and a subsequent growth in demand for a short supply of organs. In response to this disparity, the criteria for organ donation have been liberalized. Despite these difficult challenges, with advances in surgical techniques and perioperative care of both the donor and recipient, outcomes have continued to improve over time. This article focuses on the more recent surgical advances in donor selection and management, procurement and implantation, and the impact of these advances on patient outcome.

Surgical treatment for chronic heart failure

Advances in the surgical treatment of chronic heart failure including ventricular re-modeling, artificial heart technology and bridge to recovery have revolutionized cardiac surgical management. This article summarizes the most popular surgical treatment of heart failure with experiences from various institutes.

Heart transplantation--surgical results

Heart transplantation has become a widely used therapeutic option for the treatment of end-stage heart failure. Since the first human orthotopic heart transplant in the late 1960s, the surgical technique has undergone several revisions. These revisions have addressed certain anatomic and geometric distortions that occurred with the original biatrial technique of Lower and Shumway. Early revisions have included the use of a bicaval technique for implanting the right atrium. Subsequently, the additional use of a direct pulmonary venous anastomosis has lead to the surgical concept of the total orthotopic heart transplant. These revisions of the original bi-atrial technique have led to a decrease in atrial size and distortion, conduction abnormalities and tricuspid and mitral valve regurgitation. This has also resulted in less atrial thromboembolic events, less need for permanent postoperative pacemaker placement, and in an overall increase in right and left heart performance in the early postoperative period. Overall, this has contributed to better clinical results with patients returning sooner to their normal exercise capacity. Ninety percent of heart transplant patients lead a relatively normal lifestyle having no limitations in their activity and 40 % return to work. We believe that the technique of total orthotopic heart transplantation has improved surgical results and clinical outcomes.

Surgical treatment of chronic heart failure. What to tell patients about heart-saving options

Patients with severe, chronic heart failure can be managed by several surgical techniques that lead to cure for some or provide a bridge to heart transplantation for others. Although transplantation is currently the only proved curative therapy for end-stage heart failure, the supply of donor hearts has not kept pace with the demand. Therefore, procedures such as reduction ventriculoplasty, transmyocardial laser revascularization, or dynamic cardiomyoplasty and the use of assist devices or artificial hearts hold promise for helping patients maintain heart function until a cure can be offered.

Impaired exercise parameters in pediatric heart transplant recipients: comparison of biatrial and bicaval techniques

The exercise performance of pediatric heart transplant recipients and the effects of bicaval anastomosis were studied in 19 children using a Bruce protocol. Although all children had decreased exercise capacity and heart rates when compared with normals, the bicaval anastomosis patients had similar endurance and peak heart rates as the standard biatrial group.

Cardiac pacemakers in the transplanted heart: short term with the biatrial anastomosis and unnecessary with the bicaval anastomosis

Sinus node dysfunction occurs commonly after orthotopic heart transplantation and may be caused by surgical trauma, ischemia to the sinus node, rejection, drug therapy and increasing donor age. In the past, using the standard biatrial technique described originally by Lower and Shumway, many series have reported permanent pacing in more than 10% of patients. Unlike sinus node dysfunction in nontransplanted patients, which typically worsens with time, sinus node dysfunction in the transplanted heart usually improves over a period of weeks to months. Delaying the implantation of a permanent pacemaker may render it unnecessary. The development of the bicaval technique for implantation of the donor heart appears to have decreased even further or even eliminated the need for early permanent pacing. Because sinus node dysfunction in the transplanted heart does not predict subsequent development of atrioventricular (AV) node dysfunction, rate-responsive atrial pacing should be used in the majority of cases. Even after appropriate pacing for sinus node dysfunction, the sinus node may recover and permanent pacing may be discontinued. AV conduction abnormalities are far less common and generally occur late after transplantation. Dual-chamber pacing is required and permanent pacing should be continued indefinitely.

Blood versus crystalloid cardioplegia for myocardial protection of donor hearts during transplantation: A prospective, randomized clinical trial

OBJECTIVE

To assess the safety and efficacy of myocardial protection of the donor heart during transplantation with the use of blood cardioplegia, a prospective randomized clinical trial was undertaken between January 1997 and March 1998.

METHODS

Forty-seven consecutive patients were assigned either to crystalloid (27 patients; group 1) or blood cardioplegia (20 patients; group 2). Comparison of recipient age (54 +/- 11 years vs 55 +/- 7 years; P =. 9), sex (89% vs 90% male patients; P =.9), diagnosis (63% vs 65% dilated cardiomyopathy; P =.8), elevated pulmonary vascular resistance (30% vs 30%; P =.9), prior cardiac operations (22% vs 30%; P =.5), need for urgent heart transplantation (7% vs 20%; P =. 2), donor age (32 +/- 11 years vs 31 +/- 13 years; P =.7), cause of death (33% vs 40% vascular; P =.5), and global myocardial ischemia (176 +/- 51 minutes vs 180 +/- 58 minutes; P =.5) showed no difference. Hemodynamically unstable donors (15% vs 45%; P =.02) were more prevalent in group 2.

RESULTS

Operative mortality rates (4% vs 5%; P =.8), high-dose inotropic support (41% vs 30%; P = 0.6), and postoperative mechanical assistance (11% vs 10%; P = 0.9) were comparable in the 2 groups. Prevalence of acute right heart failure (27% vs 0; P =.02) and of temporary complete atrioventricular block (52% vs 20%; P =.02) were greater in group 1. Spontaneous sinus rhythm recovery was more prevalent in group 2 (11% vs 40%; P =.02). Higher peak creatine kinase (1429 +/- 725 u/L vs 868 +/- 466 u/L; P =.01) and creatine kinase MB (144 +/- 90 u/L vs 102 +/- 59 u/L; P =. 06) levels suggested more severe ischemic injury in group I.

CONCLUSION

Use of blood cardioplegia was associated with a lower prevalence of right heart failure, cardiac rhythm dysfunction, and laboratory evidence of ischemia.

Declining need for pacemaker implantation after cardiac transplantation

The need for permanent pacemaker implantation was retrospectively reviewed in 436 consecutive cardiac transplant recipients at our center between 1985 and 1998. The incidence of pacemaker implantation was examined in three arbitrarily defined periods: period 1, 1985-1990, before a review of pacemaker implantation policy; period 2, 1991-1995, after a change in policy to delay pacemaker implantation resulting from the review; and period 3, 1996-1998, after audit of this policy change, and the introduction of a change in surgical technique, from the standard atrial anastomosis to the bicaval anastomosis. Pacemaker implantation was not required in any recipient after the change in surgical technique, suggesting that the bicaval technique preserves sinus node function much better than does the standard atrial anastomosis.

Superior vena cava syndrome after heart transplantation: percutaneous treatment of a complication of bicaval anastomoses

OBJECTIVES

Our objectives were (1) to investigate the incidence and cause of symptomatic superior vena caval anastomotic stenosis and central venous thrombosis in patients receiving heart or heart-lung transplantation and (2) to explore percutaneous methods of thrombolysis and endoluminal intervention to treat these complications.

METHODS

Review of 1016 cases revealed three cases of superior vena cava syndrome. Anatomy, surgical technique, and medical risk factors were examined. Percutaneous treatments, including urokinase thrombolysis, mechanical thrombolysis, balloon angioplasty, and stent placement, were attempted.

RESULTS

All three of these patients underwent transplantation by means of the bicaval anastomotic technique. In addition, the diameters of the donor and recipient cavae were grossly mismatched in all three. Stenoses in all three patients were successfully treated percutaneously with balloon angioplasty and stent placement. Treatment of the accompanying large-volume thrombosis was problematic in these patients, and two had hemorrhagic complications of urokinase thrombolysis. A mechanical thrombolysis device was used successfully in the third patient.

CONCLUSIONS

Anastomotic stricture and central venous thrombosis is an uncommon complication of the bicaval anastomotic technique of heart and heart-lung transplantation. Discrepancy between donor and recipient caval diameters appears to be the major risk factor. Endoluminal thrombolysis and stenting provides rapid and enduring relief of symptoms and precludes repeat sternotomy, cardiopulmonary bypass, and general anesthesia.

Pulmonary vascular impedance and recipient chronic pulmonary hypertension following cardiac transplantation

STUDY OBJECTIVES

Recipient chronic pulmonary hypertension (CPH), secondary to long-standing congestive heart failure, represents a significant risk factor for right ventricular (RV) dysfunction following orthotopic cardiac transplantation (TX). This study was designed to characterize the changes occurring in pulmonary hemodynamics, pre-TX and post-TX, using Fourier analysis, a canine model of bicaval TX, and monocrotaline pyrrole (MCTP)-induced recipient CPH.

DESIGN

Prospective, controlled study.

SETTING

Experimental laboratory.

PARTICIPANTS

Twenty adult male mongrel dogs (23 to 26 kg).

INTERVENTIONS

Recipients underwent pulmonary artery injection of 3 mg/kg MCTP 4 months pre-TX. On the day of TX, donor hearts were instrumented with an ultrasonic flow probe and micromanometers. Harmonic derivation of functional data was achieved with Fourier analysis.

MEASUREMENTS AND RESULTS

At the time of TX, significant increases were observed in the mean pulmonary artery pressure and pulmonary vascular resistance of recipient animals in comparison to donors, which were further significantly increased following the termination of cardiopulmonary bypass. Significant increases were also observed in the input resistance, characteristic impedance, and RV hydraulic power post-TX compared to pre-TX, and occurred in association with a significant decrease in the transpulmonary efficiency.

CONCLUSIONS

In the setting of MCTP-induced recipient CPH donor hearts were exposed to significant alterations in cardiopulmonary hemodynamics following bicaval TX. Pulmonary blood flow is maintained by a significantly higher energy expenditure by the RV, but at a lower level of efficiency. This experimental model may provide a useful means by which to evaluate therapeutic options to better manage cardiopulmonary hemodynamics in order to prevent RV failure following TX in the setting of recipient CPH.