Registry Report on Heart Transplantation in Japan (June 2016)

Impact of prolonged cardiopulmonary resuscitation on outcomes in heart transplantation with higher risk donor heart

OBJECTIVES

To evaluate the influence of prolonged cardiopulmonary resuscitation (CPR) on outcomes in heart transplantation with higher risk donor hearts (HRDHs).

METHODS

Patients transplanted in our hospital between May 2006 and December 2019 were divided into 2 groups, HRDH recipients and non HRDH recipients. HRDH was defined as meeting at least one of the following criteria: (1) donor left ventricular ejection fraction ≤ 50%, (2) donor-recipient predicted heart mass ratio < 0.8 or > 1.2, (3) donor age ≥ 55 years, (4) ischemic time > 4 h and (5) catecholamine index > 20. Recipients of HRDHs were divided into 3 groups according to the time of CPR (Group1: non-CPR, Group 2: less than 30 min-CPR, and Group 3: longer than 30 min CPR).

RESULTS

A total of 125 recipients were enrolled in this study, composing of HRDH recipients (n = 97, 78%) and non HRDH recipients (n = 28, 22%). Overall survival and the rate of freedom from cardiac events at 10 years after heart transplantation were comparable between two groups. Of 97 HRDH recipients, 54 (56%) without CPR, 22 (23%) with CPR < 30 min, and 21 (22%) with CPR ≥ 30 min were identified. One-year survival rates were not significantly different among three groups. The 1-year rate of freedom from cardiac events was not also statistically different, excluding the patients with coronary artery disease found in early postoperative period, which was thought to be donor-transmitted disease. Multivariate logistics regression for cardiac events identified that the CPR duration was not a risk factor even in HRDH-recipients.

CONCLUSION

The CPR duration did not affect the outcomes after heart transplantation in HRDH recipients.

Age and Pre-operative HbA1c levels affect renal function compensation in living kidney donors

OBJECTIVES

About 90% of Japanese kidney transplantations are conducted from living donors, and their safety and the maintenance of their renal function are critical. This study aims to identify factors that affect the compensation of renal function in living kidney donors after donor nephrectomy.

METHOD

In a retrospective cohort study, we reviewed data from 120 patients who underwent nephrectomy as living kidney transplant donors in our department from 2012 to 2021. Univariable and multivariable linear regression analyses were performed for donor factors affecting renal function after donor nephrectomy.

RESULT

The multivariable linear regression model revealed that the donor's age (p = 0.025), preoperative estimated Glomerular Filtration Rate (eGFR) (p < 0.001), and hemoglobin A1c (HbA1c) (p = 0.043) were independent risk factors for eGFR at six months after nephrectomy. The eGFR deterioration was more strongly associated with age in females than in males, whereas higher HbA1c values were more strongly associated with eGFR deterioration in males. Higher donor age and higher HbA1c each enhance the deterioration of eGFR six months after living donor nephrectomy. The data suggest that old age in especially female donors and preoperative higher HbA1c in male donors have a harmful impact on their renal function compensation.

Right Heart Reserve Function Assessed With Fluid Loading Predicts Late Right Heart Failure After Left Ventricular Assist Device Implantation

BACKGROUND

A left ventricular assist device (LVAD) is an effective therapeutic option for advanced heart failure. Late right heart failure (LRHF) is a complication after LVAD implantation that is associated with increasing morbidity and mortality; however, the assessment of right heart function, including right heart reserve function after LVAD implantation, has not been established. We focused on a fluid-loading test with right heart catheterization to evaluate right heart preload reserve function and investigate its impact on LRHF.

METHODS

Patients aged > 18 years who received a continuous-flow LVAD between November 2007 and December 2022 at our institution, and underwent right heart catheterization with saline loading (10 mL/kg for 15 minutes) 1 month after LVAD implantation, were included.

RESULTS

Overall, 31 cases of LRHF or death (right heart failure [RHF] group) occurred in 149 patients. In the RHF vs the non-RHF groups, the pulmonary artery pulsatility index (PAPi) at rest (1.8 ± 0.89 vs 2.5 ± 1.4, P = 0.02) and the right ventricular stroke work index (RVSWi) change ratio with saline loading (0.96 ± 0.32 vs 1.1 ± 0.20, P = 0.03) were significantly different. The PAPi at rest and the RVSWi change ratio with saline loading were identified as postoperative risks for LRHF and death. The cohort was divided into 3 groups based on whether the PAPi at rest and the RVSWi change ratio were low. The event-free curve differed significantly among the 3 groups (P < 0.001).

CONCLUSIONS

Hemodynamic assessment with saline loading can evaluate the right ventricular preload reserve function of patients with an LVAD. A low RVSWi change with saline loading was a risk factor for LRHF following LVAD implantation.

An Examination of Packing Methods for Grafts to Prevent Freezing Injury during Transportation for Liver Transplantation

BACKGROUND

University of Wisconsin solution (UW) may freeze at temperatures below -0.7 °C, damaging the graft. The present study assessed the effectiveness of the liver graft package protocol, which recommends filling a package with sufficient liquid to prevent grafts from sustaining freezing injury.

METHODS

We filled ice cubes at two temperatures (-80 and -20 °C) around packages and performed a comparative study with four groups based on the temperature and filling of the second layer with lactated Ringer's solution (LR) (A: -80 °C, LR-; B: -80 °C, LR+; C: -20 °C, LR-; D: -20 °C, LR+). The bovine liver was used as a graft and preserved for 6 h in the first isolation bag filled with UW.

RESULTS

While temperatures dropped below -0.7 °C at some points for 6 h in groups A, B, C, they never dropped to -0.7 °C in group D. The macroscopic findings in groups A, B, C showed freezing of the UW and grafts, but no such results in group D. A pathological study including electron microscopy showed freezing injury in groups A, B, and C but no significant changes in group D.

CONCLUSIONS

The graft package protocol prevents freezing of the UW and liver grafts.

Open-chest epicardial ablation of ventricular tachycardia during a left ventricular assist device implantation: a case report

Background

Ventricular arrhythmias (VAs) are common after a left ventricular assist device (LVAD) implantation. Further, the majority of post-LVAD ventricular tachycardias (VTs) are secondary to a preexisting cardiomyopathy substrate. Intraoperative ablation of patients with recurrent preoperative VTs may reduce post-LVAD VTs.

Case summary

A 59-year-old female with advanced heart failure due to non-ischaemic cardiomyopathy (LV ejection fraction = 24%) and recurrent VTs was referred for an LVAD implantation as a bridge to a heart transplant (INTERMACS Profile-5A). The previous endocardial ablation failed due to an epicardial arrhythmogenic substrate. Therefore, open-chest epicardial mapping during the LVAD implantation was indicated and three target areas of the arrhythmogenic substrate were found, which were ablated by radiofrequency applications. To minimize the cardiopulmonary bypass time, cardiopulmonary bypass was initiated after ablation, and then, an LVAD was implanted. An additional 68 min was required for mapping and ablation. All procedures were performed without any complications, and the post-operative course was uneventful. Thereafter, no VT episodes were observed without any anti-arrhythmic drugs during a 15-month follow-up with LVAD support.

Discussion

Intraoperative epicardial mapping and ablation during an LVAD implantation can play an important role in the management of LVAD recipients with recurrent VAs.

Outcomes of Pancreas Transplantation for Lower-Ranked Candidates

BACKGROUND

To perform more pancreas transplantation (PTx), our center sometimes performs pancreas transplantation for candidates ranked sixth place or lower. In this study, we analyzed the outcomes of PTx performed in our center to compare the outcomes of higher- and lower-ranked candidates.

METHODS

Seventy-two cases in which PTx was performed at our center were divided into 2 groups according to the candidate's rank. Cases in which PTx was performed for candidates up to fifth place were classified into the higher rank candidate group (HRC group; n = 48), whereas PTx for candidates who were ranked sixth place or lower were classified into the lower rank candidate group (LRC group; n = 24). The outcomes of PTx were retrospectively compared.

RESULTS

Although the LRC group included a greater number of older donors (age ≥60 years), a greater number of donors with deteriorated renal function, and a greater number of HLA mismatches, the 1- and 5-year patient survival rates in the HRC group were 91.6% and 91.6%, respectively, compared with 95.8% and 87.0%, respectively, in the LRC group (P = .755). In terms of both pancreas and kidney graft survival, there were no significant differences between the 2 groups. Additionally, there were no significant differences between the 2 groups regarding the glucagon stimulation test and 75 g OGTT results, insulin independence rate, HbA1c, or serum creatinine level after transplantation.

CONCLUSIONS

In Japan, where there is a severe donor shortage, the performance of transplantation for lower-ranked candidates would increase the number of opportunities for patients to receive PTx.

Controversies and challenges of coil embolization for intracranial aneurysm in a continuous-flow LVAD implanted patient: A case report

Background

Continuous-flow left ventricular assist device (CF-LVAD) technology has rapidly developed to support the failing heart refractory to standard medical treatments. Although the expected prognosis has improved dramatically, ischemic and hemorrhagic strokes are possible complications and the leading causes of death in the CF-LVAD population.

Case Description

We encountered a case of an unruptured large internal carotid aneurysm in a patient with a CF-LVAD. Following a detailed discussion of his expected prognosis, the risk of aneurysm rupture, and the inherited risk of aneurysm treatment, coil embolization was performed without adverse events. The patient remained recurrence-free for 2-year postoperatively.

Conclusion

This report illustrates the feasibility of coil embolization in a CF-LVAD recipient and emphasizes the necessity of vigilant consideration of whether to intervene in an intracranial aneurysm after CF-LVAD implantation. We confronted several challenges during the treatment: optimal endovascular technique, management of antithrombotic drugs, safe arterial access, desirable perioperative imaging modalities, and prevention of ischemic complications. This study aimed to share this experience.

Stratification of Destination Therapy Candidates by J-HeartMate Risk Score Among Elderly Non-Responders to Cardiac Resynchronization Therapy

Background: For elderly patients with refractory heart failure (HF), destination therapy (DT) with a continuous-flow left ventricular assist device (LVAD) is a possible treatment. The aim of DT is for long-term, satisfying quality of life on LVAD support. Previously, elderly non-responders to cardiac resynchronization therapy (CRT) were primarily destined for palliative care, but DT has been available in Japan since April 30, 2021. This study investigated the prognosis of elderly CRT non-responders and assessed the feasibility of DT in these patients based on the J-HeartMate Risk Score (J-HMRS).

Methods and Results: Of the 559 patients who underwent CRT at Tokyo Women’s Medical University between 2000 and 2018, 198 were aged 65–75 years. Among these, 76 were identified as non-responders based on echocardiographic data, and were included in this study. We calculated patients’ J-HMRS and investigated associations between the J-HMRS and cardiac events after CRT. Patients were divided into 3 groups according to the J-HMRS: low (n=23), medium (n=29), and high (n=24) risk. Patients in the low-risk group experienced as many HF rehospitalizations and ventricular arrhythmia events as those in the other groups. However, survival analysis revealed that, after CRT, survival was higher for patients in the low- compared with high-risk group (P=0.04).

Conclusions: The J-HMRS classified 30% of elderly CRT non-responders as low risk and as suitable candidates for DT in Japan.

Successful bridge to transplantation with long-term support using Berlin heart EXCOR in a child with failing Fontan

A 2-year-old girl underwent the Fontan operation for aortic valve stenosis, mitral valve stenosis, a hypo-plastic left ventricle, and a non-compacted right ventricle. The patient's cardiac function reduced gradually thereafter, mainly due to systemic ventricular dysfunction. A Berlin Heart EXCOR (BHE) ventricular assist device with a 10-mL pump was implanted at 4 years of age. After 465 days, BHE support without major complications, the patient underwent heart transplantation. A safe and long-term BHE support was achieved with proper case selection and repeated examinations.

Bioartificial pulsatile cuffs fabricated from human induced pluripotent stem cell-derived cardiomyocytes using a pre-vascularization technique

There is great interest in the development of techniques to bioengineer pulsatile myocardial tissue as a next-generation regenerative therapy for severe heart failure. However, creation of thick myocardial grafts for regenerative medicine requires the incorporation of blood vessels. In this study, we describe a new method of constructing a vascular network in vivo that allows the construction of thick human myocardial tissue from multi-layered cell sheets. A gelatin sheet pre-loaded with growth factors was transplanted onto the superficial femoral artery and vein of the rat. These structures were encapsulated together within an ethylene vinyl alcohol membrane and incubated in vivo for 3 weeks (with distal superficial femoral artery ligation after 2 weeks to promote blood flow to the vascular bed). Subsequently, six cardiomyocyte sheets were transplanted onto the vascular bed in two stages (three sheets, two times). Incubation of this construct for a further week generated vascularized human myocardial tissue with an independent circulation supplied by an artery and vein suitable for anastomosis to host vessels. Notably, laminating six cell sheets on the vascular bed in two stages rather than one allowed the creation of thicker myocardial tissue while suppressing tissue remodeling and fibrosis. Finally, the pulsatile myocardial tissue was shown to generate auxiliary pressure when wrapped around the common iliac artery of a rat. Further development of this technique might facilitate the generation of circulatory assist devices for patients with heart failure.

Sarcopenia and risk of infection in adult heart transplant recipients in Japan

AIMS

Heart transplantation (HT) is an effective therapeutic option for end-stage heart failure. Infection is a major cause of morbidity and mortality after HT. Sarcopenia, defined as the loss of muscle mass and strength, is a common comorbidity in HT candidates with end-stage heart failure. However, the effects of sarcopenia on the occurrence of post-HT infections are not well understood. Therefore, we explored the association between the skeletal muscle mass and post-transplant infections in adult HT recipients.

METHODS AND RESULTS

We retrospectively examined the records of 135 patients who underwent HT between August 2007 and November 2019 at our institution. Pre-transplant computed tomography was used to calculate the skeletal muscle index (SMI) at the level of the third lumbar vertebra. Muscle wasting was defined as the SMI of the lowest sex-based tertiles. The primary endpoint was infections within 6 months of HT. The study included 109 patients (80 men, mean age: 41.6 ± 12.0 years): 37 patients in the muscle wasting group and 72 patients in the non-muscle wasting group. The mean SMI values in the muscle wasting and non-muscle wasting groups were 29.9 ± 4.8 cm² /m² and 40.7 ± 6.7 cm² /m² , respectively. Prior to HT, 108 (99.1%) patients were on left ventricular assist device support, and during that support, the rate of late right heart failure was significantly higher in the muscle wasting group than non-muscle wasting group (P = 0.012). Sixteen infections occurred within 6 months of HT. The most common infection sites included the respiratory tract (n = 5) and the upper gastrointestinal tract (n = 5), followed by the urinary tract (n = 4). Overall, 10 patients experienced infections in the muscle wasting group (27.0%) and 6 in the non-muscle wasting group (8.3%) (P = 0.009). Two patients in the muscle wasting group required intensive care unit admission, compared to none in the non-muscle wasting group. Low skeletal muscle mass was associated with infections in the univariate and multivariate logistic regression models (hazard ratio: 3.68, 95% confidence interval: 1.19-11.3; P = 0.023). However, the duration of all-cause mortality within 3 years did not differ between the groups (P = 0.56).

CONCLUSIONS

Low skeletal muscle mass is a predictor of post-HT infections within 6 months of HT.

Phase I investigator-initiated study of the safety of MTC001 in patients with chronic ischemic heart failure

BACKGROUND

: Heart failure (HF) is a global pandemic most commonly caused by coronary artery disease. Despite coronary revascularization, the infarcted myocardium can develop into an irreversible scar toward chronic ischemic HF. This is due to the limited regenerative capacity of the adult human heart. Recently, the vascular cell adhesion molecule 1 positive cardiac fibroblast (VCF) has been shown to directly improve cardiac contractility in addition to promoting myocardial growth in preclinical studies. This clinical trial aims to explore the safety and, in part, the efficacy of autologous VCF therapy for chronic ischemic HF.

METHODS

: This first-in-human trial is an open-label, single-arm, phase 1 study conducted at a single center. This study will include 6 patients with chronic ischemic HF in stage C and NYHA class II or III despite receiving the standard of care, including coronary revascularization. Participants will undergo cardiac biopsy to manufacture autologous VCFs expressing CD90 and CD106. Under electro-anatomical mapping guidance, participants will receive a transendocardial injection of VCF in a modified 3 + 3 design. The first 3 patients will receive a standard dose (2 × 107 cells) of VCF with a 4-week interval for safety assessment before subsequent enrollment. In the absence of safety issues, the final 3 patients will receive the standard dose of VCF without a 4-week interval. In the presence of safety issues, the final 3 patients will receive a reduced dose (1.5 × 107 cells) of VCF with the 4-week interval.

DISCUSSION

This is the first clinical study of cardiac regeneration using VCFs for the treatment of chronic ischemic HF. The study results will contribute to the development of a minimally invasive cell therapy for patients with HF failed by the standard of care.

TRIAL REGISTRATION

This study was registered with the Japan Registry of Clinical Trials (jRCT2033210078).

Long-Term renal function after implantation of continuous-flow left ventricular assist devices: A single center study

Background

Implantable continuous-flow left ventricular assist device (LVAD) improve renal function in advanced heart failure. However, the long-term effects of LVAD on renal function have not been investigated thoroughly. We aimed to assess long-term renal function in patients with LVAD support and to identify predictors for late deterioration in renal function (LDRF).

Methods

One hundred patients underwent LVAD implantation as a bridge to transplant at the University of Tokyo Hospital between May 2011 and December 2018. We assessed renal function at intervals (preoperative, 1, 6, 12, 18, 24 and 30 months after LVAD implantation). We divided patients into two groups: “with LDRF,” whose renal function at 30 months had decreased by >25% compared with preoperatively (n = 14), and “without LDRF” (n = 55).

Results

Renal function improved at 1 month, returned to preoperative levels at 6 months, and remained there up to 30 months after LVAD implantation. However, renal function impairment became evident in patients with LDRF 18 months after LVAD implantation. A ratio of right atrial pressure/pulmonary artery wedge pressure > 0.57 and left ventricular dimension diastole ≤ 67 mm were preoperative independent risk factors for LDRF. In addition, the incidence of perioperative acute kidney injury, ventricular arrhythmia, aortic insufficiency, and late right ventricular failure was significantly higher in patients with LDRF.

Conclusion

LDRF after LVAD implantation corresponded to several risk factors, including a small left ventricle and LVAD-related complications, such as right ventricular failure.

[A novel way of modification of AT1 angiotensin receptors to alleviate neonatal and infantile heart failure]

Heart failure is an important cause of death of children. Especially, overt one within the preweaning period is fulminant and severe. However, there are no drugs with evidence for it. We recently found that angiotensin II (AngII) activates L-type Ca²⁺ channels through AT₁ receptors (AT₁R) and β-arrestin 2 in murine cardiac myocytes only in the preweaning period, indicating that AT₁R/β-arrestin 2 pathway mediates positive inotropic effects before weaning. Indeed, β-arrestin-bias AT₁R agonist (BBA), TRV027 caused significant long-lasting positive inotropic effects in preweaning mice without increasing serum aldosterone concentrations or inducing tachycardia, arrhythmias, increased cardiac oxygen consumption, and reactive oxygen species generation. TRV027 increased the peak amplitude of twitch Ca²⁺ transients not only in preweaning mouse cardiac myocytes but in human iPS cell-derived cardiac myocytes exhibiting the fetal to neonatal phenotype. Moreover, TRV027 also increased contraction of the compromised heart of the model knock-in mice mimicking human congenital dilated cardiomyopathy. Although ~80% of these mice died before weaning, TRV027 significantly increased their survival rate. TRV027 did not cause any obvious adverse effects on their preweaning wildtype littermates. Thus, we reason in this review that BBA can be important therapeutics for preweaning heart failure.

Emergent catheter ablation for atrial fibrillation in a patient with acute decompensated heart failure on a mechanical haemodynamic support: a case report

Background

Atrial fibrillation (AF) is associated with the exacerbation of heart failure (HF). Although AF ablation has become an established treatment for patients with HF, it is usually an elective procedure. Here, we present a case of acute decompensated heart failure (ADHF) exacerbated by refractory AF, which was successfully treated with emergent AF ablation.

Case summary

A 53-year-old, obese man with a history of myocardial infarction presented to our hospital. Heart function deteriorated with an ejection fraction of 9.8%, and he was repeatedly hospitalized due to worsening HF. This time, the patient was emergently admitted due to ADHF associated with persistent AF. Atrial fibrillation was refractory to electrical cardioversion. Despite optimized medical support, the patient developed haemodynamic collapse and multiple organ failure. Intra-aortic balloon pump (IABP) and mechanical ventilation were initiated in addition to intravenous catecholamines. Emergent AF ablation was performed. Following pulmonary vein isolation, sinus rhythm was restored and the patient's haemodynamic status dramatically improved. The IABP and mechanical ventilation were withdrawn within a few days, and the catecholamine dose was reduced. After cardiac rehabilitation, the patient was discharged.

Discussion

Our case suggests that an emergent AF ablation is feasible and effective even in a patient with severe ADHF. An emergent AF ablation could be a therapeutic option to treat a critically unwell patient who has deteriorated due to a vicious cycle of AF and HF.

National survey on deceased donor organ transplantation during the COVID-19 pandemic in Japan

PURPOSE

We investigated the status of deceased organ donation and transplantation through a questionnaire distributed to transplant centers in Japan during the COVID-19 pandemic.

METHODS

The questionnaire was distributed electronically to 206 transplant centers for heart (n = 11), lung (n = 10), liver (n = 25), kidney (n = 130), pancreas (n = 18), and small intestine (n = 12) transplantation. Organ donations and organ transplantation data were extracted from the Japan Organ Transplant Network website.

RESULTS

We received questionnaire responses from 177 centers (response rate, 86%). In 2020, the number of brain-dead donors (BDDs) decreased to 68 (69% of the year-on-year average) and the number of donors after cardiac death (DCDs) decreased to 9 (32% of the year-on-year average). Eighty-five (48%) transplant centers (heart, n = 0; lung, n = 0; liver, n = 4; kidney, n = 78; pancreas, n = 22; and small intestine, n = 0) suspended transplant surgeries in response to the COVID-19 pandemic. Consequently, the number of organ transplantations from deceased donors was significantly lower in 2020 than in 2019.

CONCLUSION

Although the COVID-19 pandemic has had less impact in Japan than in other countries, it has affected transplantation activity significantly, suspending transplantation surgeries in 48% of the transplantation centers, including 78% of the kidney transplantation centers, and reducing the number of organ donations to 61% of the year-on-year average.

Carbon Monoxide Diffusing Capacity Predicts Cardiac Readmission in Patients Undergoing Left Ventricular Assist Device Implantation in Japan

Carbon monoxide diffusion capacity (DLCO) is impaired in heart failure patients; however, its clinical impact has not been well investigated in the left ventricular assist device (LVAD) population. We explored the predictive value of preoperative DLCO in the survival and cardiac readmission rates after LVAD implantation. Seventy-six patients who received continuous-flow LVAD as bridge-to-transplant therapy from November 2007 to September 2018 and underwent pulmonary function test before LVAD implantation were included. The primary study endpoints were death and readmission for heart failure or arrhythmia (cardiac readmission). Patients were stratified into two groups according to the percent of predicted DLCO (%DLCO). Pulmonary vascular resistance (PVR) was equivocal between the groups preoperatively, whereas the low DLCO group (%DLCO < 80%) showed significantly high PVR postoperatively. The mortality rate was not different between the groups. The 2 year cardiac readmission rate was 33.5% in the low DLCO group and 8.7% in the high DLCO group (%DLCO ≥ 80%) (P = 0.028). The %DLCO was associated with cardiac readmission in univariate and multivariate analyses (hazard ratio: 4.32; 95% CI: 1.50-15.9; P = 0.005). Low %DLCO was associated with high PVR postoperatively and was a risk factor for cardiac readmission after LVAD implantation.

Depressive symptoms interfere with the improvement in exercise capacity by cardiac rehabilitation after left ventricular assist device implantation

BACKGROUND

Although depressive symptoms are associated with an increased risk of readmission after left ventricular assist device (LVAD) implantation, it is unclear whether they affect the efficacy of exercise-based cardiac rehabilitation (EBCR). This study aimed to investigate the effect of depressive symptoms on EBCR efficacy.

METHODS

We analyzed 48 patients who participated in EBCR after LVAD implantation (mean age 45 ± 12 years; 60% male). Patients were classified into two groups using the Zung Self-Rating Depression Scale (SDS): depressive group (SDS ≥40, n = 27) and non-depressive group (SDS <40, n = 21). We examined changes in peak oxygen uptake (VO₂ ), knee extensor muscular strength (KEMS), and quality of life (QOL) during EBCR using analysis of covariance.

RESULTS

Although baseline characteristics were similar between the two groups, the non-depressive group was less likely to receive diuretics (22% vs. 52%, p = 0.030). Peak VO₂ , KEMS, and QOL significantly increased over time in both groups (all p < 0.05). The depressive group had a significantly lower change in peak VO₂ than the non-depressive group (2.7 vs. 1.6 ml/kg/min; mean difference: -1.1 ml/kg/min, 95% confidence interval [CI]: -0.045 to -2.17; p = 0.041, d = 0.59). There was no between-group difference regarding the change in KEMS or QOL. Adjusting for the baseline value, a significant difference between groups was observed only in peak VO₂ (p = 0.045).

CONCLUSIONS

Although EBCR significantly improved exercise capacity after LVAD implantation, depressive symptoms interfered with this improvement. Further studies are needed to determine whether psychological interventions for depression, in addition to EBCR, would improve the response to EBCR after LVAD implantation.

Comparison of Impella 5.0 and extracorporeal left ventricular assist device in patients with cardiogenic shock

INTRODUCTION

Choice of mechanical circulatory support to stabilize hemodynamics until cardiac recovery or next treatment is a strategic cornerstone for improving outcomes in patients with severe cardiogenic shock. We aimed to clarify the difference in treatment course and outcomes with the use of Impella 5.0 and an extracorporeal left ventricular assist device (eLVAD) in patients with cardiogenic shock refractory to medical therapy or other mechanical circulatory support.

METHODS

We performed a retrospective medical record review of consecutive patients who were implanted with Impella 5.0 or eLVAD as a bridge to decision at our medical center.

RESULTS

A total of 26 patients (median age 40 years, 16 males) were analyzed. Of seven patients managed with Impella 5.0, the Impella 5.0 was removed successfully in two patients and five patients underwent surgery for durable LVAD implantation. Of 19 patients managed with eLVAD, the eLVAD was successfully removed in 3 patients, 9 patients required durable LVAD, and 7 patients died during eLVAD management. The period between Impella 5.0 or eLVAD implantation to durable LVAD surgery was significantly shorter with Impella 5.0 (58 vs 235 days, p = 0.001). Cardiopulmonary bypass time was significantly shorter and a significantly smaller amount of red blood cell transfusion was required with Impella 5.0 (149 vs 192 min, p = 0.042; 7.0 vs 15.0 units, p = 0.019). There were four massive stroke events with eLVAD, but no massive stroke event with Impella 5.0.

CONCLUSION

Impella 5.0 facilitates smoother management as a bridge to decision and reduces surgical invasiveness during durable LVAD implantation.

Heart Failure Association of the ESC, Heart Failure Society of America and Japanese Heart Failure Society Position statement on endomyocardial biopsy

Endomyocardial biopsy (EMB) is an invasive procedure, globally most often used for the monitoring of heart transplant (HTx) rejection. In addition, EMB can have an important complementary role to the clinical assessment in establishing the diagnosis of diverse cardiac disorders, including myocarditis, cardiomyopathies, drug-related cardiotoxicity, amyloidosis, other infiltrative and storage disorders, and cardiac tumours. Improvements in EMB equipment and the development of new techniques for the analysis of EMB samples have significantly improved diagnostic precision of EMB. The present document is the result of the Trilateral Cooperation Project between the Heart Failure Association of the European Society of Cardiology, the Heart Failure Society of America, and the Japanese Heart Failure Society. It represents an expert consensus aiming to provide a comprehensive, up-to-date perspective on EMB, with a focus on the following main issues: (i) an overview of the practical approach to EMB, (ii) an update on indications for EMB, (iii) a revised plan for HTx rejection surveillance, (iv) the impact of multimodality imaging on EMB, and (v) the current clinical practice in the worldwide use of EMB.

Heart Failure Association, Heart Failure Society of America, and Japanese Heart Failure Society Position Statement on Endomyocardial Biopsy

Endomyocardial biopsy (EMB) is an invasive procedure, globally most often used for the monitoring of heart transplant rejection. In addition, EMB can have an important complementary role to the clinical assessment in establishing the diagnosis of diverse cardiac disorders, including myocarditis, cardiomyopathies, drug-related cardiotoxicity, amyloidosis, other infiltrative and storage disorders, and cardiac tumors. Improvements in EMB equipment and the development of new techniques for the analysis of EMB samples has significantly improved the diagnostic precision of EMB. The present document is the result of the Trilateral Cooperation Project between the Heart Failure Association of the European Society of Cardiology, Heart Failure Society of America, and the Japanese Heart Failure Society. It represents an expert consensus aiming to provide a comprehensive, up-to-date perspective on EMB, with a focus on the following main issues: (1) an overview of the practical approach to EMB, (2) an update on indications for EMB, (3) a revised plan for heart transplant rejection surveillance, (4) the impact of multimodality imaging on EMB, and (5) the current clinical practice in the worldwide use of EMB.

Contemporary outcomes of continuous-flow biventricular assist devices

Background

Significant right ventricular failure (RVF) complicating left ventricular assist device (LVAD) placement has been reported at 10-30%. Although primarily indicated for left ventricular failure, ventricular assist devices (VADs) have become utilized in a biventricular setup to combat right ventricular failure (RVF) following LVAD implantation. With the advent of continuous-flow LVADs (CF-LVADs) superseding their pulsatile predecessors, the shift towards CF-biventricular assist devices (CF-BiVADs) come with the prospect of improved outcomes over previous pulsatile BiVADs. We aim to review the literature and determine the outcomes of CF-BiVAD recipients.

Methods

A systematic review was performed to determine the outcomes of CF-BiVADs. Pre-operative demographics and device configuration data was collected. Primary outcomes evaluated were short-term survival, long-term survival, duration of support, and survival to transplant. Secondary outcomes evaluated included intensive care unit (ICU) and hospital length of stay (ICU-LOS and HLOS, respectively), pump thrombosis, pump exchange. Median and interquartile range was reported where appropriate. A major limitation was the likely overlap of cohorts across publications, which may have contributed to some selection bias.

Results

Of 1,282 screened, 12 publications were evaluated. Sample size ranged from 4 to 93 CF-BiVAD recipients, and follow-up ranged from 6 to 24 months. Mean age ranged from 34 to 52 years old. Forty-five percent of CF-BiVADs had right atrial (RA-) inflow cannulation, with the remaining being right ventricular (RV). Thirty-day survival was a median of 90% (IQR 82-97.8%) and 12-month survival was a median of 58.5% (IQR 47.5-62%). Where reported, rate of pump thrombosis (predominantly the right VAD) was a median of 31% (IQR 14-36%), although pump exchange was only 9% (IQR 1.5-12.5%).

Conclusions

RVF post-LVAD implantation is a high morbidity and mortality complication. There is no on-label continuous-flow RVAD currently available. Thus, the modifications of LVADs for right ventricular support to combat pump thrombosis has resulted in various techniques. BiVAD recipients are predominantly transplant candidates, and complications of pump thrombosis and driveline infection whilst on wait-list are of great consequence. This study demonstrates the need for an on-label CF-BiVAD.

Impact of the revision of the law on pancreatic transplants in Japan-An analysis of the Japanese Pancreas Transplants Registry

BACKGROUND

In Japan, it has been about 10 years since the revision of the law on donating brain-dead organs. The present study compared the outcomes of pancreatic transplant before and after the revision of the law.

METHODS

The 437 patients who had received pancreas transplantation were divided into two groups according to the time when pancreas transplantation was performed between era 1 (before the revision) and 2 (after the revision), and compared in the patient and pancreas graft survival.

RESULTS

While the annual number of brain-dead donors was <10 in era 1, and this number significantly increased in era 2 to >50. This resulted in an increased number of pancreas transplantations: >30 cases per year. The comparison data after a propensity score-matched analysis revealed that the death-censored pancreatic graft survival at 1, 3, and 5 years after pancreas transplantation in era 2 was 94.9%, 92.0%, and 92.0%, which, while lacking significance, tended to be better than the values of 90.5%, 83.1%, and 78.2%, respectively, in era 1.

CONCLUSIONS

The revision of the law on donating brain-dead organs increased the number of pancreas transplantations. Technical improvements in surgery due to increased experience with performing pancreas transplants may help improve pancreatic graft survival.

Clinical Characteristics and Contemporary Management of Patients With Cardiomyopathies in Japan - Report From a National Registry of Clinical Personal Records

Background: The clinical features of patients with cardiomyopathy, including dilated cardiomyopathy (DCM), hypertrophic cardiomyopathy (HCM), or restrictive cardiomyopathy (RCM), have not been recently elucidated in Japan.

Methods and Results: We collected individual patient data regarding demographics, echocardiogram, and treatment in DCM from 2003 to 2014 and in HCM and RCM from 2009 to 2014 from the national registry of clinical personal records organized by the Japanese Ministry of Health, Labour and Welfare. In all, 44,136 patients were included in this registry: 40,537 with DCM, 3,553 with HCM, and 46 with RCM. The median age at diagnosis was older for DCM and HCM than RCM (54 and 55 vs. 42 years, respectively). Male patients accounted for 74.6%, 58.7%, and 60.9% of the DCM, HCM, and RCM groups, respectively. NYHA functional Class III–IV was found in 26.9%, 11.3%, and 58.1% of patients in the DCM, HCM, and RCM groups, respectively. In the DCM group, the rates of β-blocker and angiotensin-converting enzyme inhibitor/angiotensin receptor blocker prescription were 69% and 76%, respectively. In regional subgroup analysis, the median age at diagnosis of DCM and HCM was younger in the Kanto region. A family history of HCM was less frequent in the Hokkaido/Tohoku region.

Conclusions: The national registry of clinical personal records of cardiomyopathy could provide important information regarding the demographics, clinical characteristics, and management of cardiomyopathy throughout Japan.

Long-term outcomes of autologous skeletal myoblast cell-sheet transplantation for end-stage ischemic cardiomyopathy

We evaluated the cardiac function recovery following skeletal myoblast cell-sheet transplantation and the long-term outcomes after applying this treatment in 23 patients with ischemic cardiomyopathy. We defined patients as “responders” when their left ventricular ejection fraction remained unchanged or improved at 6 months after treatment. At 6 months, 16 (69.6%) patients were defined as responders, and the average increase in left ventricular ejection fraction was 4.9%. The responders achieved greater improvement degrees in left ventricular and hemodynamic function parameters, and they presented improved exercise capacity. During the follow-up period (56 ± 28 months), there were four deaths and the overall 5-year survival rate was 95%. Although the responders showed higher freedom from mortality and/or heart failure admission (5-year, 81% versus 0%; p = 0.0002), both groups presented an excellent 5-year survival rate (5-year, 93% versus 100%; p = 0.297) that was higher than that predicted using the Seattle Heart Failure Model. The stepwise logistic regression analysis showed that the preoperative estimated glomerular filtration rate and the left ventricular end-systolic volume index were independently associated with the recovery progress. Approximately 70% of patients with “no-option” ischemic cardiomyopathy responded well to the cell-sheet transplantation. Preoperative renal and left ventricular function might predict the patients’ response to this treatment.

Cardiac rehabilitation program improves exercise capacity in heart transplantation recipients regardless of marginal donor factors

Cardiac rehabilitation (CR) is recommended to improve exercise capacity after heart transplantation (HTx); however, the effects of marginal donor factors are unclear. Forty-one recipients participated in a 3-month CR program early after HTx (mean age 39 ± 14 years; 88% male). Patients were divided into marginal (≥ 2 marginal donor factors; n = 24) and control groups (< 2 marginal donor factors; n = 17). We examined donor and recipient factors related to change in peak oxygen uptake (peak VO₂) during the CR program using multiple linear regression analysis. Baseline characteristics were similar between groups, although the mean age was higher in the marginal group (43 ± 13 vs. 34 ± 14 years, p = 0.043). Peak VO₂ and knee extensor muscular strength (KEMS) improved significantly in both groups (p < 0.05), but there were no observed inter-group differences. Multiple analysis revealed change in KEMS (β = 0.52, 95% CI = 0.023-1.01) as an independent predictor of change in peak VO₂ after adjustment for recipients' age, sex, and CR attendance frequency (adjusted R² = 0.25, p = 0.0084), whereas marginal donor factors were not a predictor (p = 0.76). The CR program improved exercise capacity in HTx recipients regardless of marginal donor factors, suggesting that recipients of marginal donor hearts should be referred to CR programs.

Association between infectious event and de novo malignancy after heart transplantation

The aim of the study was to investigate the incidence of and risk factors for de novo malignancy after heart transplantation (HTx) in a single center. We assessed 102 consecutive patients who received HTx and were followed-up in our center regularly for > 1 year from June 2006 to May 2018. We investigated the incidence of and risk factors for de novo malignancy. The cumulative incidence of each malignancy type during the follow-up period was one (0.98%) for skin cancer, four (3.92%) for nonskin solid organ cancer, and six (5.88%) for posttransplant lymphoproliferative disorder (PTLD). The percentage of patients with more than one infectious event ≤ 1 year after HTx was higher in the malignancy group than in the non-malignancy group. Furthermore, Kaplan-Meier analysis revealed that the incidence rate of infectious events was higher in patients with malignancies than in those without (log-rank P < 0.001). After dividing malignancies into a PTLD group and a solid organ malignancy group, we found that negative Epstein-Barr virus serostatus, cytomegalovirus-positive antigenemia, and the occurrence of any viral or gastrointestinal infectious event at ≤ 1 year were more frequent in patients with PTLD than in patients without it. The survival rate was significantly lower for patients with solid organ malignancy than for patients without malignancy. In conclusion, there was a correlation between infectious events and de novo malignancy, particularly in patients with PTLD. We should confirm this finding by conducting a larger cohort study.

Sex differences in continuous-flow ventricular assist device therapy for advanced heart failure

OBJECTIVE

The effect of patient sex in continuous-flow ventricular assist device (c-VAD) therapy has not been well described. We investigated sex-specific differences in clinical outcomes related to c-VAD therapy for Japanese patients.

METHODS

We retrospectively analyzed 153 patients, including 41 (27%) female patients who underwent c-VAD implantation over the last 13 years in our institution for a mean follow-up of 766 ± 446 days. Clinical outcomes were compared between male and female patients RESULTS: There was no significant difference in mortality, cerebral vascular accidents, the severity of heart failure, or driveline infection in patients who underwent c-VAD implantation, regardless of sex. While male patients tended to have more bleeding at the time of surgery, female patients had significantly higher rates of non-surgical bleeding during subsequent c-VAD therapy, mainly from gynecological origins.

CONCLUSIONS

Female patients treated with c-VAD had a significantly higher incidence of non-surgical bleeding events. Careful attention to gynecological complications and sex-specific care is required in female patients with c-VAD.

Heart transplant candidate with medical complexity in the era of prolonged left ventricular assist device support - A case report

Heart transplantation improves quality of life and survival in patients with advanced heart failure. However, the shortage of available heart donors and technological advances for left ventricular assist devices (LVAD) have led to longer waiting times for transplantation, and long-term use of LVAD may increase the medical complexity of subsequent transplantation. We present the case of a 35-year-old man who underwent heart transplantation after being supported by an LVAD for 1490 days (∼4 years). He was sensitized with kidney dysfunction and recurrent infections, including candidemia, at the time of transplantation. He underwent a successful heart transplantation with pretransplant plasma exchange, intravenous immunoglobulin administration, early initiation of everolimus, and prompt management of infections. <Learning objective: With a growing number of heart transplant candidates who are supported by left ventricular assist devices for long duration, managing such candidates is becoming increasingly complex and difficult to standardize. The present case had three problems that were linked to each other: (1) anti-HLA antibodies, (2) fungal infection, and (3) pre-transplantation renal dysfunction. Management of heart transplant candidates, including desensitization and immunosuppressive therapies, should be tailored to the individual and the clinical presentation to improve the survival and quality of life.>.

Gap junction protein beta 4 plays an important role in cardiac function in humans, rodents, and zebrafish

Aims

GJB4 encodes a transmembrane connexin protein (Cx30.3) that is a component of gap junctions. This study investigated whether GJB4 plays an important role in human heart disease and function.

Methods and results

We examined a patient and her older brother who both presented with complicated severe hypertrophic cardiomyopathy (HCM) and whose parents are healthy married cousins. The gene exome analysis showed 340 single nucleotide polymorphisms (SNPs) that caused amino acid changes for which the patient was homozygous and both parents were heterozygous. After excluding all known common (>10%) SNP gene mutations, the gene for GJB4 was the only identified gene that is possibly associated with cardiac muscle. The resultant E204A substitution exists in the 4th transmembrane domain. GJB4-E204A impaired the binding with gap junction protein A1 (GJA1) compared with GJB4-WT. The expression of GJB4 was induced in rat disease models of left and right ventricle hypertrophy and mouse disease models of adriamycin-induced cardiomyopathy and myocardial infarction, while it was not detected at all in control. An immunohistochemical study was performed for autopsied human hearts and the explanted heart of the patient. GJB4 was expressed and colocalized with GJA1 in intercalated discs in human diseased hearts, which was extensively enhanced in the explanted heart of the patient. The abnormal expression and localization of GJB4 were observed in beating spheres of patient’s induced pluripotent stem cell (iPSC)-derived cardiomyocytes (CMs). We generated knockout zebrafish of GJB4 by CRISPR/Cas9 and the endodiastolic volume and the ventricular ejection fraction were significantly lower in GJB4-deficient than in wild-type zebrafish at five days post-fertilization.

Conclusions

These results indicate both that GJB4 is defined as a new connexin in diseased hearts, of which mutation can cause a familial form of HCM, and that GJB4 may be a new target for the treatment of cardiac hypertrophy and dysfunction.

Trends and Limitations in the Assessment of the Contractile Properties of Human Induced Pluripotent Stem Cell-Derived Cardiomyocytes From Patients With Dilated Cardiomyopathy

The application of human induced pluripotent stem cell-derived cardiomyocytes (hiPSCMs) from patients is expected in disease modeling and drug screening in vitro. Dilated cardiomyopathy (DCM) is an intractable disease characterized by the impairment of systolic function and leads to severe heart failure. A number of researchers have focused on disease modeling of DCM and reproduced its pathologic phenotypes in hiPSCMs, but a robust method to evaluate the contractile properties of cardiomyocytes in vitro has not been standardized. In addition, it is unknown whether the throughput of measurements and analyses could be increased sufficiently for compound screening. Here, we reviewed the articles in which the contractile abnormalities of DCM hiPSCMs were recapitulated and assessed the trends and problems in sample preparation and evaluation. We found that single-cell level analysis was ineffective in some cases, and a tissue engineering approach has become dominant recently because of its increased efficiency in reproducing impaired contractility. We also examined two commercially available automated measurement devices with moderate throughput for motion analysis using two-dimensional hiPSCM sheets composed of originally established DCM hiPSCMs. As a result, both of the tested devices, an impedance analyzer and a video image-based cell motion analyzer, were not effective in detecting the expected reduction of contractility in the DCM clone. These findings collectively suggest that a tissue engineering approach could expand the potential of disease modeling with hiPSCMs, and so far, appropriate methods for in vitro force measurement with sufficient throughput, but without sacrificing physiological fidelity, are awaited.

Thoracoscopic repair of diaphragmatic hernia following ventricular assist device implantation

Background

Diaphragmatic hernia is a rare complication of ventricular assist device (VAD), mainly developing after explantation of the device. We herein report a case of diaphragmatic hernia that developed following the implantation of VAD.

Case presentation

A 4-month-old girl with a diagnosis of dilated cardiomyopathy underwent VAD implantation for a bridge to heart transplantation. Three months later, intermittent vomiting developed, and left-sided diaphragmatic hernia was confirmed on plain X-ray and computed tomography. Without any findings of ischemia, we performed elective thoracoscopic repair of the diaphragmatic hernia. In the right decubitus position, thoracoscopy revealed the small intestine to be herniated into the left thorax. After reduction of the herniated intestine, the defect of the diaphragm (3 × 2 cm in size) was directly closed with interrupted non-absorbable sutures. Her postoperative course was uneventful.

Conclusion

Thoracoscopic repair of diaphragmatic hernia associated with VAD implantation may be a safe approach.

Impact of tacrolimus versus cyclosporin A on renal function during the first year after heart transplant

AIMS

Nephrotoxicity of calcineurin inhibitors (CNIs) is associated with adverse events in patients undergoing heart transplant (HTx), although studies directly comparing tacrolimus (TAC) versus cyclosporin A (CsA), especially in combination with everolimus and low-dose CNIs approach, are limited. Thus, we sought to investigate the associations of TAC and CsA with clinical outcomes in HTx recipients, with specific focus on renal function.

METHODS AND RESULTS

From August 2007 to February 2017, 72 consecutive patients (39 treated with TAC vs. 33 with CsA) receiving de novo HTx in a single transplant centre were retrospectively evaluated. We used the instrumental variable method to account for unmeasured confounding. The study outcomes were percentage change in estimated glomerular filtration rates (eGFR) (safety endpoint) and biopsy-proven acute rejection (efficacy endpoint) within the first year after HTx. The enrolled patients (median age 40 years) were predominantly men (68%). There were no significant differences in baseline characteristics, including eGFR (64.8 [45.7-96.4] mL/min/1.73 m² in TAC vs. 65.6 [57.9-83.0] mL/min/1.73 m² for CsA; P = 0.48), other than sex (male, 49% for TAC vs. 91% for CsA; P < 0.001) between the two groups. Within the first year after HTx, 23 (59%) in the TAC group switched mycophenolate mofetil to everolimus, whereas 16 (48%) in the CsA group (P = 0.52). At 12 months, the rates of mortality and end-stage renal disease requiring renal replacement therapies were both 0%. In the instrumental variable analysis, no differences in renal function as well as graft rejection for 1 year after HTx existed between the TAC and CsA groups. These results were similar when taking into account of everolimus use.

CONCLUSIONS

Irrespective of everolimus use with low-dose CNIs, our analysis using the instrumental variable method showed no differences in renal function as well as graft rejection during the first year after HTx between HTx recipients who received TAC or CsA.

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.

Future development of artificial organs related with cutting edge emerging technology and their regulatory assessment: PMDA's perspective

Future development of innovative artificial organs is closely related with cutting edge emerging technology. These technologies include brain machine or computer interface, organs made by three dimensional bioprinting, organs designed from induced-pluripotent stem cell for personalized tissue or organ, and xenotransplantation. To bridge the gap between scientific innovation and regulatory product review, Pharmaceuticals and Medical Devices Agency of Japan (PMDA) started the science board to discuss about the new scientific topics regarding medical products including medical device and regenerative products with external experts since 2012. Topics which PMDA raised for science board included cellular and tissue-based products from iPS cells, artificial intelligence and genome editing technology. In addition, PMDA started the horizon scanning to identify a new cutting edge technology which could potentially lead to innovative health technology or product, which has a strong impact on clinical medicine. Although the effectiveness and safety of the medical products must be reasonably assured before clinical use, PMDA introduced Sakigake review assignment (a review partner of device development) and conditional approval system to balance between pre-market and post-market evaluation.

Coil Embolization for a Cerebral Aneurysm in a Heart Transplantation Patient: A Case Report

The number of heart transplantations performed in Japan has been continuously increasing. Here, we report the case of a patient with an unruptured cerebral artery aneurysm after undergoing heart transplantation and was treated using coil embolization. The patient was a 50-year-old woman who was positive for heparin-induced thrombocytopenia (HIT) antibodies and underwent heart transplantation for dilated cardiomyopathy. An unruptured middle cerebral artery aneurysm was treated with coil embolization using argatroban as a heparin substitute. The patient was discharged without any complications. Despite these patients with heart transplantation are characterized by high HIT antibodies rate and the need for immunosuppressive agents, they currently have an excellent prognosis, especially in Japan. Therefore, the knowledge of patient characteristics after heart transplantation is essential for ensuring that these patients receive the most appropriate treatment.

Hypoxic-conditioned cardiosphere-derived cell sheet transplantation for chronic myocardial infarction

OBJECTIVES

Cell therapy provides a suitable environment for regeneration through paracrine effects such as secretion of growth factors. Cardiosphere-derived cells (CDCs) have a high capacity for growth factor secretion and are an attractive target for clinical applications. In particular, a cell sheet technique was reported to have clinical advantages by covering a specific region. Here, we examined the effect of the hypoxic-conditioned (HC) autologous CDC sheet therapy on a rabbit chronic myocardial infarction model.

METHODS

CDC sheet function was assessed by the enzyme-linked immunosorbent assay and quantified by polymerase chain reaction in vitro (days 1-3 of conditioning). The rabbit chronic myocardial infarction model was established by left coronary ligation. Autologous CDCs were isolated from the left atrial specimen; CDC sheets with or without 2-day HC were transplanted onto the infarcted hearts at 4 weeks. The cardiac function was assessed by an echocardiography at 0, 4 and 8 weeks. A histological analysis of the host hearts was performed by tomato lectin staining at 8 weeks.

RESULTS

The optimal HC duration was 48 h. HC significantly increased the mRNA expression levels of VEGF and ANG2 on day 2 compared to the normoxic-conditioned (NC) group. The HC group showed significant improvement in the left ventricular ejection fraction (64.4% vs 58.8% and 53.4% in the NC and control) and a greater lectin-positive area in the ischaemic region (HC:NC:control = 13:8:2).

CONCLUSIONS

HC enhances the paracrine effect of a CDC sheet on angiogenesis to improve cardiac function in the chronic myocardial infarction model, which is essential for cardiomyocyte proliferation during cardiac regeneration.

Generation of a large-scale vascular bed for the in vitro creation of three-dimensional cardiac tissue

Introduction

The definitive treatment for severe heart failure is transplantation. However, only a small number of heart transplants are performed each year due to donor shortages. Therefore, novel treatment approaches based on artificial organs or regenerative therapy are being developed as alternatives. We have developed a technology known as cell sheet-based tissue engineering that enables the fabrication of functional three-dimensional (3D) tissue. Here, we report a new technique for engineering human cardiac tissue with perfusable blood vessels. Our method involved the layering of cardiac cell sheets derived from human induced pluripotent stem cells (hiPSCs) on a vascular bed derived from porcine small intestinal tissue.

Methods

For the vascular bed, a segment of porcine small intestine was harvested together with a branch of the superior mesenteric artery and a branch of the superior mesenteric vein. The small intestinal tissue was incised longitudinally, and the mucosa was resected. Human cardiomyocytes derived from hiPSCs were co-cultured with endothelial cells and fibroblasts on a temperature-responsive dish and harvested as a cardiac cell sheet. A triple-layer of cardiac cell sheets was placed onto the vascular bed, and the resulting construct was subjected to perfusion culture in a bioreactor system.

Results

The cardiac tissue on the vascular bed pulsated spontaneously and synchronously after one day of perfusion culture. Electrophysiological recordings revealed regular action potentials and a beating rate of 105 ± 13/min (n = 8). Furthermore, immunostaining experiments detected partial connection of the blood vessels between the vascular bed and cardiac cell sheets.

Conclusions

We succeeded in engineering spontaneously beating 3D cardiac tissue in vitro using human cardiac cell sheets and a vascular bed derived from porcine small intestine. Further development of this method might allow the fabrication of functional cardiac tissue that could be used in the treatment of severe heart failure.

Endovascular treatment for large vessel occlusion stroke in patients with ventricular assist devices

Background

Embolic stroke with large vessel occlusion (LVO) is a major adverse event during ventricular assist device (VAD) support. In this study we aimed to clarify the efficacy of, and problems associated with, endovascular treatment (EVT) of LVO in patients with VAD support.

Methods

We retrospectively reviewed EVT for LVO in patients with VAD support between 2006 and 2017 at our institute and evaluated baseline characteristics, treatment variables, outcomes, and complications.

Results

The study cohort comprised 12 consecutive patients (age 35.4±20.4 years), with 15 LVO events involving 20 arterial occlusions, who had undergone EVT. The median Alberta Stroke Program Early CT score was 10 and good collaterals were observed in 10 of 17 occluded middle cerebral artery areas. No study patients had received intravenous thrombolysis therapy. EVT was performed on 18 of the 20 occluded arteries and mechanical thrombectomy on 13 vessels. The successful reperfusion (modified Thrombolysis in Cerebral Infarction grade ≥2 b) rate was 67% in all EVTs and 85% with mechanical thrombectomy. Histological analysis showed fibrin-rich thrombi in four of five samples. Seven of 12 patients (58%) maintained their neurological function (modified Rankin Scale score ≤2 or equal to pre-stroke score) at 90 days. Periprocedural complications comprised two symptomatic intracranial hemorrhages and the 90-day mortality rate was 13%. Seven of 10 cardiac transplant candidates (70%) returned to the waiting list and three of them received transplants.

Conclusions

Endovascular therapy for acute LVO stroke is feasible even in patients with VAD support.

Abdominal skeletal muscle mass as a predictor of mortality in Japanese patients undergoing left ventricular assist device implantation

Aims

We assessed preoperative muscle wasting in patients undergoing left ventricular assist device (LVAD) implantations using abdominal skeletal muscle images on computed tomography (CT) and explored the associations between the preoperative muscle wasting and clinical outcomes after LVAD implantation.

Methods and results

We retrospectively examined the records of 111 patients who underwent continuous‐flow LVAD implantations as bridge‐to‐transplant therapy from January 2010 to December 2016 at our institution. After 33 patients were excluded, the study cohort consisted of 78 individuals. CT images used to calculate the skeletal muscle index (SMI) at the third lumbar vertebra level were obtained before the LVAD implantation procedures. Patients were classified as having muscle wasting if their SMI fell into the lowest gender‐based tertile. The median SMI for the study patients was 37.6 cm²/m². The SMI cut‐off values for the lowest tertiles were 36.7 cm²/m² for men and 28.2 cm²/m² for women, resulting in 26 patients (33.3%) with muscle wasting in this study. During the mean follow‐up of 738 ± 379 days, there were 10 deaths (12.8% mortality). Seven of the 26 patients with muscle wasting (26.9%) died, and 3 of the 52 patients without muscle wasting (5.8%) died. The times to all‐cause mortality were significantly different between patients with and without muscle wasting (P = 0.0094). Muscle wasting was found to be associated with mortality in univariate and multivariate Cox analyses (hazard ratio: 4.32; 95% CI: 1.19–20.2).

Conclusions

Preoperative muscle wasting was associated with a higher mortality in patients with LVAD. Assessment of the abdominal skeletal muscle area on CT prior to LVAD implantation can help predict mortality.