Bicaval Heart Transplantation Research Articles

Long-Term Outcomes of Permanent Pacemaker Implantation in Bicaval Heart Transplant Recipients

BackgroundPermanent pacemakers (PPMs) may be necessary in up to 10% of patients after heart transplantation (HT). ObjectivesThe purpose of this study was to evaluate long-term outcomes and clinical courses of heart transplant recipients who received PPM. MethodsAll patients who required PPM after bicaval HT at Columbia University between January 2005 and December 2021 were included. Cases were compared to matched heart transplant recipients by age, sex, and year of transplantation. Patient and device characteristics including complications and device interrogations were reviewed. Outcomes of re-transplantation or graft failure/death were compared between groups. ResultsOf 1,082 heart transplant recipients, 41 (3.8%) received PPMs. The median time from transplantation to PPM was 118 days (IQR: 18-920 days). The most common indications were sinus node dysfunction (60%, n = 25) and atrioventricular (AV) nodal disease (41.5%, n = 17). Post-implantation complications included pocket hematoma (n = 3), lead under-sensing (n = 2), and pocket infection requiring explant (n = 1). Rates of death and re-transplantation at 10 years post-HT were similar between groups. In multivariable analysis, after adjustment for mechanical circulatory support, pretransplantation amiodarone use, donor ischemic time and age, only older donor age was associated with increased risk of PPM implantation (P = 0.03). There was a significant decrease in PPM placement after 2018 (1.2% vs 4.4%, P = 0.02), largely driven by a decline in early PPM placement. There were no differences in mortality or need for re-transplantation between groups. ConclusionsPPMs are implanted after HT for sinus and atrioventricular node dysfunctions with low incidence of device-related complications. Our study shows a decrease in PPM implantation after 2018, likely attributable to expectant management in the early postoperative period.

Massive left atrial thrombus evades multimodality imaging as a myxoma in a bicaval heart transplant recipient

Intracardiac masses are an extremely rare and poorly described complication following a bicaval heart transplantation. We describe the case of an asymptomatic 62-year-old male with a large left atrial mass found incidentally on transthoracic echocardiography6 years post-transplant. A battery of additional imaging tests was ordered including transesophageal echocardiography, 18 F-fluorodeoxyglucose positron emission tomography/computed tomography, and T1 and T2 magnetic resonance imaging. Although imaging biomarkers were generally nonspecific, the mass was most consistent with a cardiac myxoma. However, intraoperative findings confirmed by pathology revealed a massive organizing thrombus. The patient had an uneventful recovery after surgical removal of the mass. Our case highlights a very rare phenomenon in heart transplant recipients which remains a unique diagnostic challenge even with current advances in imaging.

Assessment of biatrial function in clinically well pediatric bicaval heart transplantation patients by three-dimensional echocardiography.

Atrial size and function are closely correlated with atrial contributions to cardiovascular performance. Therefore, in this study, we aimed to assess atrial size and function in pediatric heart transplantation (HTx) patients using three-dimensional echocardiography (3DE). We enrolled 33 clinically well pediatric HTx patients and 33 healthy controls with a similar distribution of sex and age to the HTx patients. All patients underwent two-dimensional echocardiography (2DE) and 3DE. 2DE- and 3DE-derived biatrial maximal volume(Vmax), minimal volume (Vmin), ejection volume (EV), ejection fraction (EF), volume before atrial contraciton (VpreA), passive EV, passive EF, active EV and active EF were obtained in all patients. The 3D left atrail(LA) Vmax, Vmin and VpreA increased significantly in HTx patients after being indexed by BSA, while 3D LAEV and passive EV decreased significantly (P < 0.05). Moreover, the 3D LAEF, LA passive EF, and LA active EF all decreased significantly in HTx patients (P < 0.05). The 3D right atrial (RA) Vmax, Vmin, and VpreA increased significantly in HTx patients (P < 0.05), while the 3D RAEF and RA passive EF decreased significantly in HTx patients (P < 0.05). 3DE-derived LAVmax, LAVpreA, LA passive EV, LAEF, and LA passive EF were all lower than the corresponding 2D parameters. 3DE-derived RAVpreA, RA passive EV and RAEF were all lower than the corresponding 2D parameters. Atrial sizes and function assessed by 3DE- and 2DE-derived parameters, yield significantly discordant results in pediatric HTx patients. 3DE confirms significantly enlarged atrial sizes and decreased atrial functions in pediatric HTx patients.

Early Parasympathetic Reinnervation Is Not Related to Reconnection of Major Branches of the Vagus Nerve after Heart Transplantation

Background and ObjectivesBicaval heart transplantation (HTx) may promote parasympathetic reinnervation. However, the prevalence and timing of reinnervation have not been fully investigated. Heart rate variability (HRV) and direct vagal stimulation were used to evaluate the presence of parasympathetic reinnervation after bicaval HTx.Subjects and MethodsA total of 21 patients (time after HTx 0.52-4.41 years, mean 1.8±1.2 years) who received a bicaval HTx was enrolled. Reinnervation was evaluated using HRV values from 24-hour Holter recordings. A cross-sectional analysis of the HRV at 0.5-1, 1-2, and >2 years after HTx was performed. We also applied high-frequency electrical stimulation (16.7 Hz, 1 msec pulse width, ≤10 V) to the cardiac branches of the vagus nerve at the level of the superior vena cava in eight patients at 6 and 12 months after HTx.ResultsThe degree of parasympathetic reinnervation corresponded to the time after HTx. The HRV analysis revealed that the root mean square of the successive differences between consecutive RR-intervals (RMSSD) and high-frequency power were significantly higher during the late period (>2 years) compared with the early period (0.5-1 year) after HTx. None of the eight patients who underwent direct vagal stimulation responded during the stimulation at 6 and 12 months, whereas incremental trends in HRV parameters were observed, which indicated that parasympathetic reinnervation began within 1 year after HTx.ConclusionParasympathetic reinnervation seemed to begin in the early period (<1 year) after bicaval HTx. Reconnection of major branches of the vagus nerve may not be related to early reinnervation.

Prognostic Significance of Heart Rate and its Long-term Trend in Cardiac Transplant Patients

Introduction and objectivesThe aim of the present study was to examine the prognostic significance of heart rate and its trend in heart transplantation. MethodsThis observational study enrolled 170 patients who received a bicaval heart transplant between 1995 and 2005; all were in sinus rhythm. The resting heart rate was determined via electrocardiography at the end of the first posttransplant year and annually until the tenth year. Cox analysis was used to evaluate the incidence of adverse events with a mean (standard deviation) follow-up of 8.9 (3.1) years. The primary study end point was the composite outcome of death or graft dysfunction. ResultsThe resting heart rate at the end of the first posttransplant year was an independent predictor of the primary composite end point (hazard ratio=1.054; 95% confidence interval, 1.028-1.080; P<.001) and was significantly associated with total mortality (hazard ratio=1.058; 95% confidence interval, 1.030-1.087; P<.001) and mortality from cardiac causes (hazard ratio=1.069; 95% confidence interval, 1.026-1.113; P=.001), but not with graft dysfunction (hazard ratio=1.028; 95% confidence interval, 0.989-1.069; P=.161). For patients with a heart rate ≥ 105 or<90 bpm vs those with 90-104 bpm, the hazard ratios of the primary end point were 2.233 (95% confidence interval, 1.250-3.989; P=.007) and 0.380 (95% confidence interval, 0.161-0.895; P=.027), respectively. Heart rate tended to decrease in the first 10 years after transplantation (P=.001). Patients with a net increase in heart rate during follow-up showed a higher incidence of adverse events. ConclusionsAn elevated heart rate is an adverse prognostic marker after heart transplantation.

Significado pronóstico y evolución a largo plazo de la frecuencia cardiaca en los pacientes con trasplante cardiaco

Introduction and objectivesThe aim of the present study was to examine the prognostic significance of heart rate and its trend in heart transplantation. MethodsThis observational study enrolled 170 patients who received a bicaval heart transplant between 1995 and 2005; all were in sinus rhythm. The resting heart rate was determined via electrocardiography at the end of the first posttransplant year and annually until the tenth year. Cox analysis was used to evaluate the incidence of adverse events with a mean (standard deviation) follow-up of 8.9 (3.1) years. The primary study end point was the composite outcome of death or graft dysfunction. ResultsThe resting heart rate at the end of the first posttransplant year was an independent predictor of the primary composite end point (hazard ratio=1.054; 95% confidence interval, 1.028-1.080; P<.001) and was significantly associated with total mortality (hazard ratio=1.058; 95% confidence interval, 1.030-1.087; P<.001) and mortality from cardiac causes (hazard ratio=1.069; 95% confidence interval, 1.026-1.113; P=.001), but not with graft dysfunction (hazard ratio=1.028; 95% confidence interval, 0.989-1.069; P=.161). For patients with a heart rate ≥ 105 or<90 bpm vs those with 90-104 bpm, the hazard ratios of the primary end point were 2.233 (95% confidence interval, 1.250-3.989; P=.007) and 0.380 (95% confidence interval, 0.161-0.895; P=.027), respectively. Heart rate tended to decrease in the first 10 years after transplantation (P=.001). Patients with a net increase in heart rate during follow-up showed a higher incidence of adverse events. ConclusionsAn elevated heart rate is an adverse prognostic marker after heart transplantation.Full English text available from:www.revespcardiol.org/en

Orthotopic Heart Transplant for Treatment-Resistant Cardiomyopathy in Kawasaki Syndrome: Report of a Successful Case

Kawasaki disease is a systemic vascular inflammatory disorder of yet unknown cause that is associated with critical cardiovascular complications. Several long-term medical therapies, coronary revascularization, and heart transplant have been introduced to treat coronary artery lesions. This report describes a 20-year-old man with Kawasaki disease manifesting as intermittent chest pain and nausea who had advanced decompensated cardiomyopathy (ejection fraction, 15%) diagnosed. Coronary artery bypass surgery and implantation of a cardioverter defibrillator had been performed, although no significant clinical improvement was observed. Finally, a successful orthotopic bicaval heart transplant was performed. Follow-up examination after 1 year revealed normal cardiac function with no evidence of organ rejection. This experience demonstrated that heart transplant might be a successful method of treating permanent ischemic cardiomyopathy in patients with Kawasaki syndrome.

Intraoperative Echocardiographic Diagnosis of Inferior Vena Cava Stenosis After Cardiopulmonary Bypass

THE INFERIOR VENA CAVA (IVC) is responsible for about two thirds of the total venous return to the right atrium (RA). Obstruction of the IVC can be due to chronic disease or an acute insult. The etiology of chronic IVC obstruction includes congenital abnormalities, indirect compression of the IVC (retroperitoneal tumors, hepatic tumors, giant left atrium), or intravascular tumor extension (metastatic renal tumors). Chronic obstruction of the IVC is associated with findings of hepatic congestion, ascites, lower extremity edema, and venous thrombosis. The slow progression of disease results in collateral venous return to the superior vena cava (SVC) via the azygos, intrathoracic, and vertebral veins. In contrast, acute stenosis of the IVC can result in hepatic and renal dysfunction, severe hemodynamic instability, and cardiovascular collapse if left untreated. Acute IVC obstruction is rare and has been reported as a complication of operative procedures, including bicaval heart transplantation, orthotopic liver transplantation, mitral valve replacement, and extrinsic compression from implantation of a Nuss bar for repair of pectum excavatum. The authors describe a case of acute IVC stenosis at the RA junction that was diagnosed by intraoperative transesophageal echocardiography after cardiopulmonary bypass (CPB). The intraoperative echocardiographic findings included a localized area of narrowing at the IVC-RA cannulation site, turbulent flow into the RA, underfilled cardiac chambers with hyperdynamic biventricular activity, and dilated hepatic veins. The echocardiographic findings were correlated with invasive hemodynamic measurements, and a therapeutic intervention with return to CPB was performed. The authors recommend the routine examination of the IVC at the IVC-RA junction with color-flow Doppler and spectral Doppler interrogation of flow after cardiac surgery cases, especially in the case of a bicaval venous cannulation technique.

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.

O transplante cardíaco biatrial deve ainda ser realizado? Metanálise

The outcomes of total and bicaval heart transplantation techniques are better than those of the biatrial technique; however, the latter is still considered the gold-standard. The objective of this study was to determine whether the total and bicaval heart transplantation techniques are, in fact, better than the biatrial technique. A systematic review with meta-analysis was carried out. Studies were retrieved from Pubmed, Lilacs, Web of Science, Scirus, Scopus, Google Scholar, and Scielo databases, identified by sensitive strategy. Randomized, prospective, and retrospective controlled studies were selected for inclusion. Intra and postoperative parameters were assessed. A total of 11,602 studies were identified and 36 were included in our review. The number of atrial arrhythmias, tricuspid valve regurgitation, deaths, and embolic events, as well as bleeding volume; temporary and permanent pacemaker requirement; and length of stay in the intensive care unit are significantly lower for the total and bicaval techniques than for the biatrial technique. Also, hemodynamic variables such as pulmonary capillary pressure, mean pulmonary artery pressure, and right atrial pressure are lower in total and bicaval transplantation. In prognostic terms, total and bicaval orthotopic heart transplantations are better, than the biatrial transplantation. Therefore, indication of the biatrial technique for transplantation should be the exception, not the rule.

Is bicaval orthotopic heart transplantation superior to the biatrial technique?

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was whether the bicaval heart transplantation technique is superior to biatrial orthotopic heart transplantation (OHT). Altogether, 175 papers were found using the reported search, of which 20 presented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. We conclude that many papers have documented the superiority of the bicaval technique over the biatrial technique for short-term outcomes. A meta-analysis of 41 papers on this topic found significant benefits for early atrial pressure, tricuspid valve regurgitation, return to sinus rhythm and even perioperative mortality. But for longer-term outcome, the largest series of 11,931 patients found no difference in survival between the two groups and the meta-analysis found no mortality differences at 1 or 3 years. The bicaval technique is also more demanding technically and has a slightly longer bypass and ischaemic time. The United Network for Organ Sharing (UNOS) database showed that in 2005 in the USA the bicaval technique has now become more popular than the biatrial technique (1083 procedures vs. 806).

Cardiac autotransplantation for the treatment of permanent atrial fibrillation combined with mitral valve disease.

The results of current surgical options for the treatment of permanent atrial fibrillation associated with mitral valve surgery are widely different, particularly for extremely dilated left atria. The aim of this study is to assess the efficacy of cardiac autotransplantation in restoring a normal sinus rhythm via a consistent reduction in the left atrium volume associated with a complete isolation of the pulmonary veins. From April 2000 to April 2002, 28 patients (men/women, 5/23) underwent cardiac autotransplantation for the treatment of mitral disease and concomitant permanent atrial fibrillation (>1 year). A modified surgical technique derived from bicaval heart transplantation procedures maintained the connection of the right atrium with the inferior vena cava in all but 3 cases. In 2 patients, the mitral valve was repaired, and it was replaced in 26 patients. Associated procedures were 6 aortic valve replacements, 2 tricuspid valve annuloplasties, and 2 coronary revascularizations. No hospital deaths were recorded, but 1 patient died of pneumonia 3 months postoperatively. At a mean follow-up period of 17.2 +/- 6.7 months (range, 6-30 months), 24 patients (88.9%) were in sinus rhythm, and 3 (11.1%) were in atrial fibrillation. The Santa Cruz Score was 0 for 3 patients, 2 for 1 patient, and 4 for the remaining 23 patients (85.2%). The mean left atrial diameter decreased from 65.4 +/- 17.1 mm (range, 50-130 mm) before the operation to 48.4 +/- 5.6 mm (range, 37-78 mm) postoperatively (P <.001), and the mean left atrial volume decreased from 119 +/- 70.5 mL (range, 60-426 mL) to 69.1 +/- 35.1 mL (range, 31-226 mL) (P <.0001). Cardiac autotransplantation is a safe and effective surgical option for the treatment of permanent atrial fibrillation in patients with long-lasting mitral valve disease and severe enlargement of the left atrium.

Orthotopic heart transplantation: standard versus bicaval technique

We compared orthotopic heart transplantation (HT) by bicaval technique with the standard technique. Between January 1995 and December 1997, 117 patients underwent 118 HTs; 71 patients (15 women and 56 men) had 72 HTs by standard technique and 46 patients (9 women, 37 men) underwent HT using bicaval procedures. Preoperative parameters were similar in both groups; 5 patients who underwent the standard technique and no patients who underwent bicaval procedures required permanent pacemakers (p = NS). Isoproterenol infusion was significantly longer in the standard technique. Major perioperative arrhythmias (ventricular tachycardia and fibrillation, asystole) appeared in 8.2% and 7.0% of standard and bicaval HTs, respectively; atrial fibrillation appeared in 13.1% and 4.6%, respectively (p = NS). At 1 month, mitral and tricuspid regurgitation rates were higher in the standard group (p = NS); at 1 year only tricuspid regurgitation was still higher (p = NS). Right atrial pressure, Wood units, cardiac output, and cardiac index were examined (p = NS). At multivariate analysis, interaction between preoperative Wood units and transplant type was elicited for Wood units at 1 month and for right atrial pressure at 1, 3, and 6 months. In the high resistance subgroup, the patients who underwent bicaval procedures had higher resistances at 1 month. In the low resistance subgroup, right atrial pressure was higher in patients who underwent standard techniques at 1, 3, and 6 months follow-up. Thus, bicaval HT was found to be safe, without surgically related complications, it provoked significantly less blood loss, and required less isoproterenol use. No significant advantages were observed in conduction disturbances and major arrhythmias or regarding the need for temporary or permanent pacemakers.