Status on Heart Transplantation in China

Impact of Donor-Recipient BMI Ratio on Survival Outcomes of Heart Transplant Recipients: A Retrospective Analysis Study

OBJECTIVE

This study aimed to investigate the impact of the donor-recipient BMI ratio on the survival outcomes of heart transplant recipients.

METHODS

A retrospective analysis was conducted on 641 heart transplant patients who underwent surgery between September 2008 and June 2021. The BMI ratio (donor BMI divided by recipient BMI) was calculated for each patient. Kaplan-Meier survival analysis and Cox proportional hazards regression were performed to evaluate survival rates and determine the hazard ratio (HR) for mortality.

RESULTS

Significant differences were found in donor age and donor-recipient height ratio between the BMI ratio groups. The BMI ratio ≥ 1 group had a higher mean donor age (37.27 ± 10.54 years) compared to the BMI ratio < 1 group (34.72 ± 11.82 years, p = 0.008), and a slightly higher mean donor-recipient height ratio (1.02 ± 0.06 vs. 1.00 ± 0.05, p = 0.002). The Kaplan-Meier survival analysis indicated that the survival rate in the BMI ratio ≥ 1 group was significantly lower than in the BMI ratio < 1 group. Cox multivariate analysis, adjusted for confounding factors, revealed a HR of 1.50 (95% CI: 1.08-2.09) for mortality in patients with a BMI ratio ≥ 1. No significant differences were observed in ICU stay, postoperative hospitalization days, or total mechanical ventilation time between the groups.

CONCLUSION

A higher donor-recipient BMI ratio was associated with an increased risk of mortality in heart transplant recipients.

Effect of preoperative pulmonary artery pressure on the prognosis of end-stage heart failure patients after heart transplantation

OBJECTIVE

To evaluate the effect of preoperative pulmonary artery pressure on perioperative outcome of end-stage heart failure patients undergoing heart transplantation.

METHODS

Retrospective analysis was undertaken on the clinical data of patients receiving heart transplantation in the Department of Cardiovascular Surgery of our hospital from March 2017 to March 2022. A ROC curve analysis was developed between mean pulmonary artery pressure (mPAP) and postoperative mortality using mPAP as diagnostic criteria. Patients were divided into groups based on this threshold to determine the best mPAP threshold value for predicting postoperative nosocomial mortality, and the differences in preoperative and intraoperative data, postoperative complications, and clinical prognosis of patients in the two groups were compared. Patients were followed up to draw the survival curve of patients in the two groups.

RESULTS

The study enlisted the participation of 105 patients. ROC curve research revealed that preoperative pulmonary artery pressure was substantially linked with death following heart transplantation, with mPAP = 30.5mmHg being the best threshold. The group with mPAP ≥ 30.5mmHg had a greater incidence of postoperative ECMO support (28.2% vs. 10.6%, P = 0.021) and a higher incidence of in-hospital mortality (15.4% vs. 1.5%, P = 0.019) than the group with mPAP < 30.5mmHg. The postoperative survival rates of 105 patients were 91.3%, 88.7%, 81.6%, and 77.5% at 1, 2, 3, and 4 years, respectively, however, there was no significant difference between the two groups of patients in the postoperative intermediate-far survival rate (P = 0.431).

CONCLUSIONS

Preoperative pulmonary artery pressure in patients with end-stage heart failure is intimately correlated with perioperative prognosis of heart transplant recipients. The optimal cut-off mPAP value in predicting perioperative prognosis of heart transplant recipients is 30.5mmHg. In the high mPAP group, perioperative ECMO support rate and perioperative mortality rate are high, which do not affect the medium and long-term prognosis of the recipients undergoing heart transplantation.

Efficacy and Safety of mesenchymal stem cell therapy in patients with acute myocardial infarction: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND AND OBJECTIVES

The adjuvant treatment of stem cell therapy for acute myocardial infarction (AMI) has been studied in multiple clinical trials, but many questions remain to be addressed, such as efficacy, safety, identification of the optimal cell type, tractable route of delivery, transplant dosage, and transplant timing. The current meta-analysis aimed to explore the issues of mesenchymal stem cells (MSCs) transplantation in patients with AMI based on published randomized controlled trials (RCTs) and guide the design of subsequent clinical trials of MSCs therapy for AMI.

METHODS

The Cochrane Library, PubMed, EMBASE databases were searched for relevant clinical trials from January 1, 2000, to January 23, 2021. Results from RCTs involving MSCs transplantation for the treatment of AMI were identified. According to the Cochrane systematic review method, the literature quality, including studies, was evaluated and valid data was extracted. RevMan 5.3 and Stata 15.1 software were used for Meta-analysis.

RESULTS

After a literature search and detailed evaluation, 9 randomized controlled trials enrolling 460 patients were included in the quantitative analysis. Pooled analyses indicated that MSCs therapy was associated with a significantly greater improvement in overall left ventricular ejection fraction (LVEF), and the effect was maintained for up to 24 months. No significant difference in favor of MSCs treatment in left ventricular (LV) volume and in the risk of rehospitalization as a result of heart failure (HF) was noted, compared with the controls. For transplantation dose, the LVEF of patients accepting a MSCs dose of 107-108 cells was significantly increased by 2.62% (95% CI 1.54 to 3.70; P < 0.00001; I2 =0%), but this increase was insignificant in the subgroup that accepted an MSCs dose of < 107 cells (1.65% in LVEF, 95% CI, 0.03 to 3.27; P =0.05; I2 =75%) or >108 cells (4.65% in LVEF, 95% CI, -4.55 to 13.48; P =0.32; I2 =95%), compared with the controls. For transplantation timing, a significant improvement of LVEF of 3.18% was achieved in the group of patients accepting a MSCs infusion within 2 to 14 days Percutaneous coronary intervention (PCI) (95% CI, 2.89 to 3.47; P <0.00001; I2 = 0). There was no association between MSCs therapy and major adverse events.

CONCLUSION

Results from our systematic review suggest that MSCs therapy for patients with AMI appears to be safe and might induce a significant increase in LVEF with a limited impact on LV volume and rehospitalization caused by HF. The effect was maintained for up to 24 months. MSCs dose of 107-108 cells was more likely to achieve better clinical endpoints than <107 or >108 cells. The optimal time window for cell transplantation might be within 2-14 days after PCI. This meta-analysis was registered with PROSPERO, number CRD 42021241104.

The Human Explanted Heart Program: A translational bridge for cardiovascular medicine

The progression of cardiovascular research is often impeded by the lack of reliable disease models that fully recapitulate the pathogenesis in humans. These limitations apply to both in vitro models such as cell-based cultures and in vivo animal models which invariably are limited to simulate the complexity of cardiovascular disease in humans. Implementing human heart tissue in cardiovascular research complements our research strategy using preclinical models. We established the Human Explanted Heart Program (HELP) which integrates clinical, tissue and molecular phenotyping thereby providing a comprehensive evaluation into human heart disease. Our collection and storage of biospecimens allow them to retain key pathogenic findings while providing novel insights into human heart failure. The use of human non-failing control explanted hearts provides a valuable comparison group for the diseased explanted hearts. Using HELP we have been able to create a tissue repository which have been used for genetic, molecular, cellular, and histological studies. This review describes the process of collection and use of explanted human heart specimens encompassing a spectrum of pediatric and adult heart diseases, while highlighting the role of these invaluable specimens in translational research. Furthermore, we highlight the efficient procurement and bio-preservation approaches ensuring analytical quality of heart specimens acquired in the context of heart donation and transplantation.

D-dimer level and long-term outcome in patients with end-stage heart failure secondary to idiopathic dilated cardiomyopathy

Background

Previous studies had demonstrated hemostatic abnormalities in patients with heart failure (HF) and several studies have shown that abnormal coagulation indices, represented by elevated D-dimer, had prognostic significance in patients with compatible or acute decompensated HF. However, the impact of D-dimer on the outcome in patients with end-stage HF remains unclear.

Methods

A total of 244 consecutive patients with end-stage HF due to idiopathic dilated cardiomyopathy (DCM) were prospectively enrolled from February 2011 to September 2014. D-dimer levels were measured and its prognostic value was assessed. Primary endpoint was all-cause mortality during the follow-up period. Secondary endpoints were stroke, bleeding, occurrence of sustained ventricular tachycardia or ventricular fibrillation, and major adverse cardiovascular events (MACE).

Results

D-dimer was significantly elevated in the non-survivors (median: 0.8 vs. 1.1 mg/L, P < 0.001). Traditional markers including B-type natriuretic peptide, troponin I, left ventricular ejection fraction, and left ventricular end-diastolic dimension provided limited prognostic value; but the addition of D-dimer refined the risk stratification. The optimal cut-off value of D-dimer to predict all-cause mortality was 0.84 mg/L by receiver operator characteristic analysis. Elevated D-dimer level was independently associated with increased risk of long-term all-cause mortality (HR = 2.315, 95% CI: 1.570–3.414, P < 0.001) and MACE (HR = 1.256, 95% CI: 1.058–1.490, P = 0.009), and the predictive value was independent of age, sex, atrial fibrillation and anticoagulation status.

Conclusions

Elevated D-dimer level was independently associated with poor long-term outcome in patients with end-stage HF secondary to idiopathic DCM, and the predictive value was superior to that of traditional prognostic markers.

Population pharmacokinetic analysis of tacrolimus in Chinese cardiac transplant recipients

Objective

Usage of tacrolimus is complicated by its narrow therapeutic index and wide between- and within-subject pharmacokinetic variability. We aimed to obtain more information regarding the influence of various covariates on the disposition of tacrolimus in the early phase after cardiac transplantation using a population pharmacokinetic method, and provide information for the individualisation of drug dosing in the clinical setting.

Methods

Routine therapeutic drug monitoring concentrations (897 observations) were retrospectively collected from 146 hospitalised patients. One compartment model with first-order absorption (absorption rate constant K_a was fixed as 4.48/hour) was employed to establish the population pharmacokinetic model using a non-linear mixed-effects modelling approach. Various demographic parameters, postoperative day and concomitant medications influencing drug clearance and distribution volume were investigated in this study. Bootstrap and prediction-corrected visual predictive check were employed to validate the final model. With the goal of tacrolimus trough concentrations within the therapeutic window, simulation was performed.

Results

Pharmacokinetic parameter population typical estimates for clearance (CL/F) and apparent distribution volume (V/F) were 14.23 L/hour and 760.80 L, respectively. Postoperative day and co-administration of Wuzhi capsules were identified as important factors affecting CL/F. Total body weight was significantly associated with the V/F. Results of model evaluation indicated a good stable and precise performance of the final model. Based on the simulation results, a simple-touse dosage regimen table to guide clinicians with drug dosing was created.

Conclusion

The final population model could provide information for the individualised dosing of tacrolimus for cardiac transplant recipients.

Heart Transplantation in Asia

Heart transplantation (HTx) is the effective way to improve quality of life as well as survival in terminal heart failure (HF) patients. Since the first heart transplant in 1968 in Japan and in earnest in 1987 at Taiwan, HTx has been continuously increasing in Asia. Although the current percentage of heart transplants from Asia comprises only 5.7% of cases in the International Society of Heart and Lung Transplantation (ISHLT) registry, the values were under-reported and soon will be greatly increased. HTx in Asia shows comparable with or even better results compared with ISHLT registry data. Several endemic infections, including type B hepatitis, tuberculosis, and cytomegalovirus, are unique aspects of HTx in Asia, and need special attention in transplant care. Although cardiac allograft vasculopathy (CAV) is considered as a leading cause of death after HTx globally, multiple observations suggest less prevalence and benign nature of CAV among Asian populations. Although there are many obstacles such as religion, social taboo or legal process, Asian countries will keep overcoming obstacles and broaden the field of HTx.