Cardiac transplantation under new legislation for organ transplantation in Japan: report of two cases

Effect of Therapeutic Modification on Outcomes in Heart Transplantation Over the Past Two Decades - A Single-Center Experience in Japan

BACKGROUND

During these 2 decades (1999-2019), many therapeutic strategies have been developed in the field of heart transplant (HTx) to improve post-HTx outcomes. In the present study, 116 consecutive HTx adults between 1999 and 2019 were retrospectively reviewed to evaluate the influences of a therapeutic modification on post HTx outcomes.Methods and Results:Patient survival, functional status and hemodynamics after HTx and modification of therapeutic strategies were reviewed. The overall cumulative survival rate at 10 and 20 years post-HTx was 96.4 and 76.7%, respectively. There were no significant differences in survival rate or exercise tolerance after HTx between extracorporeal and implantable continuous flow-LVAD. Post-HTx patient survival in patients, irrespective of the donor risk factors such as donor age, low LVEF, history of cardiac arrest, was equivalent across cohorts, while longer TIT and higher inotrope dosage prior to procurement surgery were significant risk factors for survival. In 21 patients given everolimus (EVL) due to renal dysfunction, serum creatinine significantly decreased 1 year after initiation. In 22 patients given EVL due to transplant coronary vasculopathy (TCAV), maximum intimal thickness significantly decreased 3 years after initiation.

CONCLUSIONS

The analysis of a 20-year single-center experience with HTx in Japan shows encouraging improved results when several therapeutic modifications were made; for example, proactive use of donor hearts declined by other centers and the use of EVL in patients with renal dysfunction and TCAV.

Heart transplantation in Japan: a critical appraisal for the results and future prospects

As of September 30, 2011, a total of 113 patients with end-stage heart failure underwent heart transplantation in Japan, and the early and late (10 years) survival rates appear better than those reported in 2011 by the Registry of the International Society of Heart and Lung Transplantation (ISHLT). Among the risk factors determining survival, use of both left ventricular assist devices (LVADs) during the pretransplant care and marginal donor hearts increased the risk while factors favoring survival included younger adult recipients and fewer patients with ischemic cardiomyopathy; factors noted in Japanese patients in comparison with those registered in the ISHLT report. Although only a few patients have reached 10 years follow-up, so far none has died or required retransplantation due to cardiac allograft vasculopathy (CAV). CAV may develop later in Japanese heart transplant patients than in those of mixed inter-ethnic transplants. Recently, survival rates with newer LVADs have dramatically improved and therefore, selection criteria for the permanent or destination use of an LVAD or for heart transplantation require further evaluation, depending upon the various factors in candidates with profound heart failure.

Hemodynamic and echocardiographic evaluation of orthotopic heart transplantation with the modified bicaval anastomosis technique

BACKGROUND

The purpose of this study was to evaluate the hemodynamic and echocardiographic function of hearts transplanted with the modified bicaval anastomosis technique (mBCAT).

METHODS AND RESULTS

Twenty consecutive patients (14 males, 6 females, age range 14-61 [41.3 +/-11.5 years]) were evaluated 3.4 +/-2.2 years after heart transplantation using the mBCAT. All patients were in status I on the waiting list, and 18 (90%) had had a left ventricular assist device. The donor age was 39 +/-12 years. Triple immunosuppressive regimen and cardiac biopsy were routinely performed. There was no hospital mortality. One death occurred 4.2 years after the operation because of bone marrow dysplasia and infection. The 8-year survival was 89% (95% confidence interval: 0.43-0.98). All the hemodynamic variables returned to the normal range. Low right atrial pressure (3.2 +/-1.5 mmHg) and low pulmonary wedge pressure (6.7 +/-2.1 mmHg) were associated with an excellent cardiac index (3.9 +/-0.7 L . min(-1) . m(-2)). Echocardiography revealed an excellent late peak velocity (52 +/-19 cm/s) and an E/A ratio (1.4 +/-0.6) of tricuspid flow. The grade (0-4) of tricuspid regurgitation averaged 1.5 +/-0.8.

CONCLUSIONS

Hemodynamic and echocardiographic results for mBCAT were excellent. The 8-year survival was 89% with all surviving patients in New York Heart Association class I. The mBCAT is easy to perform and further facilitates cardiac transplantation.

Heart Preservation Using Continuous Ex Vivo Perfusion Improves Viability and Functional Recovery

BACKGROUND

Cold static storage (CS) is a proven preservation method for heart transplantion, yet early postoperative graft dysfunction remains prevalent, so continuous perfusion (CP) during ex vivo transport may improve viability and function of heart grafts.

METHODS AND RESULTS

Canine hearts underwent CP (n=9) or CS (n=9) for 6 h while intramyocardial pH was continuously monitored. Biopsies were assayed for ATP, caspase-3, malondialdehyde (MDA), and endothelin-1 (ET-1) levels at baseline, after preservation (t1), and after 1 h of blood reperfusion on a Langendorff model (t2). Functional recovery was determined at t2 by +dP/dt, -dP/dt, developed pressure, peak pressure and end-diastolic pressure. CP resulted in higher tissue pH and ATP stores and reduced caspase-3, MDA and ET-1 levels compared with CS at both t1 and t2. Post reperfusion recovery was significantly greater in CP vs CS for all myocardial functional parameters except end-diastolic pressure. Weight gain was significantly increased in CP vs CS at t1, but not at t2.

CONCLUSIONS

Low-grade tissue acidosis and energy depletion occur during CS and are associated with oxidative injury and apoptosis during reperfusion. CP attenuates these biochemical and pathologic manifestations of tissue injury, together with improved myocardial recovery, despite mild, transient edema.

Special Report From the Heart Transplant Candidate Registry Committee in Japan

BACKGROUND

Heart transplantation had been withheld for long time in Japan. In October 1997 organ transplant legislation was implemented and the heart transplantation program began. In February 1999 the first heart transplantation was performed. Since then a total of 17 successful transplantations have been done.

METHODS

This report describes the profiles of heart transplant applicants presented to the Heart Transplant Candidate Registry Committee of the Japanese Circulation Society from 1997 to 2003.

RESULTS

Two hundred eighty-four applications were submitted to the Committee for the evaluation. All applicants were <60 years of age (mean 32 years). Ninety-two percent of these applicants had chronic severe heart failure with New York Heart Association (NYHA) Class III or IV status. Etiology of heart failure was dilated cardiomyopathy in 80% of applicants, although only 6% had ischemic heart disease, which is in notable contrast to Western countries. Most applicants died while waiting for transplantation and thus only 17 patients underwent heart transplantation, with an average waiting time of 514 days. Recipient prognosis was satisfactory with a survival rate of 100%.

CONCLUSION

In Japan, heart transplantation is not yet considered a viable treatment option for severe heart failure.

Epidemiologic and clinical characteristics of cardiomyopathies in Japan: results from nationwide surveys

Nationwide clinico-epidemiological surveys of cardiomyopathies in Japan were carried out. Disorders surveyed included idiopathic dilated cardiomyopathy (DCM), hypertrophic cardiomyopathy (HCM), restrictive cardiomyopathy (RCM), arrhythmogenic right ventricular dysplasia (ARVD), mitochondrial disease, Fabry's disease of the heart and prolonged Q-T interval syndrome. The total number of patients was estimated at 17,700 for DCM, 21,900 for HCM, 300 for RCM, 520 for ARVD, 640 for mitochondrial disease, 150 for Fabry's disease of the heart, and 1,000 for prolonged Q-T interval syndrome. The prevalence of both DCM and HCM was higher in men than women: the male-to-female ratios were 2.6 and 2.3 for DCM and HCM, respectively. Detailed data on patients with DCM or HCM were collected by a follow-up survey. In 1 year more patients with DCM (5.6%) died than with HCM (2.8%): congestive heart failure (CHF) and arrhythmias were the leading causes of death for DCM and HCM, respectively. Angiotensin converting enzyme inhibitors (64.6%) and beta-adrenergic blockers (40.9%) are commonly used to treat the CHF complicating DCM and may be associated with the clinical improvement in a significant number of DCM patients. Thus, the nationwide surveys of Japanese patients have yielded important current epidemiological and clinical information on the characteristics of cardiomyopathies in Japan.

Modification of bicaval anastomosis technique for orthotopic heart transplantation

A modified bicaval anastomosis technique was utilized for 4 consecutive patients undergoing heart transplantation. Instead of transecting the superior and inferior vena cavae, a strip of the posterior right atrial wall was left undivided as a bridge connecting the superior and inferior vena cavae. This minor modification perfectly prevented shrinkage and retraction of the caval tissue, thus providing easier anastomotic orientation and better estimation of the appropriate tissue length that fits well, particularly when a small donor heart was available.