Access to Heart Transplantation: A Proper Analysis of the Competing Risks of Death and Transplantation Is Required to Optimize Graft Allocation

Lyotropic Liquid Crystals: A Biocompatible and Safe Material for Local Cardiac Application

The regeneration of cardiac tissue is a multidisciplinary research field aiming to improve the health condition of the post-heart attack patient. Indeed, myocardial tissue has a poor ability to self-regenerate after severe damage. The scientific efforts focused on the research of a biomaterial able to adapt to heart tissue, thus guaranteeing the in situ release of active substances or growth promoters. Many types of hydrogels were proposed for this purpose, showing several limitations. The aim of this study was to suggest a new usage for glyceryl monooleate-based lyotropic liquid crystals (LLCs) as a biocompatible and inert material for a myocardial application. The main advantages of LLCs are mainly related to their easy in situ injection as lamellar phase and their instant in situ transition in the cubic phase. In vivo studies proved the biocompatibility and the inertia of LLCs after their application on the myocardial tissue of mice. In detail, the cardiac activity was monitored through 28 days, and no significant alterations were recorded in the heart anatomy and functionality. Moreover, gross anatomy showed the ability of LLCs to be bio-degraded in a suitable time frame. Overall, these results permitted us to suppose a potential use of LLCs as materials for cardiac drug delivery.

Long-term administration of intravenous inotropes in advanced heart failure

BACKGROUND

Patients in heart transplantation (HTx) waiting list for advanced heart failure (HF) are susceptible to acute deterioration refractory to standard HF medical therapies. Limited data are available on long-term in-hospital continuous intravenous (IV) inotropic therapy as bridge to definite therapies.

METHODS AND RESULTS

We reviewed medical records of all heart transplant recipients treated in the pre-HTx phase with in-hospital continuous IV inotropes at our institution between 2012 and 2018. We analysed data before the beginning of continuous IV therapy and at the moment of HTx. We report data of 24 patients (mean age of 43.5 ± 15.7 years) treated with IV inotropes as bridge to HTx (median follow-up of 28 months after HTx). The main length of IV inotropic therapy was 84 ± 66 days (min 22; max 264 days). At the beginning, the most frequently used inotrope was dopamine (median dosage of 3 mcg/kg/min, interquartile range 2.5-3.75), alone (n = 11, 46%) or in combination with other inotropes (n = 13, 54%). In 18 patients, the class of inotropes was changed during the hospitalization. We registered a progressive improvement of perfusion markers and neuro-hormonal activation.

CONCLUSION

In-hospital continuous parenteral inotropic therapy may serve as a temporary pharmacological bridge to HTx in patients with advanced HF that are actively listed to HTx with good reply in terms of prognosis and perfusion markers.

Left Ventricular Assist Device: Indication, Timing, and Management

Left ventricular assist devices (LVADs) are indicated in inotrope-dependent heart failure (HF) patients with pure or predominant LV dysfunction. Survival benefit is less clear in ambulatory, advanced HF. Timing is crucial: early, unnecessary exposure to the risks of surgery, and device-related complications (infections, stroke, and bleeding) should be weighed against the probability of dying or developing irreversible right ventricular and/or end-organ dysfunction while deferring implant. The interplay between LVAD and heart transplantation depends largely on donor availability and allocation rules. Postoperatively, quality of life depends on patients' expectations and is influenced by complications. Patients' preferences, prognosis, and alternative options-including palliation-should be openly discussed and reviewed before and after the operation.

Cardiac Stem Cell-Loaded Delivery Systems: A New Challenge for Myocardial Tissue Regeneration

Cardiovascular disease (CVD) remains the leading cause of death in Western countries. Post-myocardial infarction heart failure can be considered a degenerative disease where myocyte loss outweighs any regenerative potential. In this scenario, regenerative biology and tissue engineering can provide effective solutions to repair the infarcted failing heart. The main strategies involve the use of stem and progenitor cells to regenerate/repair lost and dysfunctional tissue, administrated as a suspension or encapsulated in specific delivery systems. Several studies demonstrated that effectiveness of direct injection of cardiac stem cells (CSCs) is limited in humans by the hostile cardiac microenvironment and poor cell engraftment; therefore, the use of injectable hydrogel or pre-formed patches have been strongly advocated to obtain a better integration between delivered stem cells and host myocardial tissue. Several approaches were used to refine these types of constructs, trying to obtain an optimized functional scaffold. Despite the promising features of these stem cells’ delivery systems, few have reached the clinical practice. In this review, we summarize the advantages, and the novelty but also the current limitations of engineered patches and injectable hydrogels for tissue regenerative purposes, offering a perspective of how we believe tissue engineering should evolve to obtain the optimal delivery system applicable to the everyday clinical scenario.

The Public Health Burden of Cardiomyopathies: Insights from a Nationwide Inpatient Study

Cardiomyopathies are responsible for heart failure and sudden cardiac death, but epidemiological data are scarce and the public health burden may be underestimated. We studied aggregating data from all public or private hospitals in France. Patients were categorized from relevant ICD-10 codes into dilated, hypertrophic, restrictive, or other cardiomyopathies (DCM, HCM, RCM, or OCM, respectively). Between 2008 and 2015, a total of 326,461 distinct patients had cardiomyopathy-related hospitalizations. The hospital-based prevalence of cardiomyopathy was 809 per million inhabitants (PMI) per year, including 428 PMI for DCM, 101 PMI for HCM, 26 PMI for RCM, and 253 PMI for OCM. Patients with cardiomyopathies accounted for 51% of all heart transplants, 33% of defibrillator implantations, 38% of mechanical circulatory supports, and 11.3% of hospitalizations for heart failure. In patients less than 40 years of age, these figures were 71%, 51%, 63%, and 23%, respectively. Over 2008–2015 and considering all cardiomyopathies, there was a significant increase for heart transplant (average annual percentage change, AAPC: +3.86%, p = 0.0015) and for defibrillator implantation (AAPC: +6.98%, p < 0.0001), and a significant decrease of in-hospital mortality (AAPC: −4.7%, p = 0.0002). This nationwide study shows that cardiomyopathies constitute an important cause of hospitalization, with increasing invasive therapeutic procedures and decreasing mortality.

Cost and Factors Associated With the Hospitalization of Patients Undergoing Heart Transplantation

OBJECTIVES

The aim of the study was to describe the cost and factors associated with the hospitalization of patients undergoing heart transplantation.

METHODS

A cross-sectional, descriptive study with a quantitative approach developed at an important heart transplant center in southern Brazil. Twenty patients who had undergone transplantation during the period 2007 to 2016 were included in the study. Central tendency measures and values presented as mean ± SD or median and quartiles were calculated. Multiple linear regression was performed to verify the variables that interfered with the cost.

RESULTS

The cost of hospitalization of patients undergoing heart transplantation was $522,997.26 in Brazilian reals ($220,002.58 in US dollars). The Brazilian public health system was responsible for paying the hospital bill of all patients. Female sex, patients up to 40 years of age, and length of stay in the hospital units were variables that were related to the highest values for the hospital service. Clinical complications of the patients during the hospitalization period were also factors that were related to the greater length of stay in the hospitalization units, reflecting higher expenses for the health institution.

CONCLUSIONS

There is a need for health managers to implement strategies that will minimize complications, such as health care-related infections, that can be prevented during hospitalization and to stimulate the allocation of resources in order to improve care and reduce hospital expenses.

Does the Canadian allocation system for highly sensitized patients work?

PURPOSE OF REVIEW

The number of sensitized heart transplant candidates is rising. Highly sensitized patients are disadvantaged because they encounter longer waiting times to heart transplant. Strategies to reduce their waiting times include waitlist prioritization and desensitization therapies. The purpose of this review is to describe the listing category for highly sensitized patients in the Canadian allocation system, examine the advantages and limitations of this strategy and provide an approach to the management of the highly sensitized patient awaiting heart transplant.

RECENT FINDINGS

Analysis of data from the United Network of Organ Sharing shows that the incidence of death or removal from the waitlist in patients listed for heart transplant increases as the calculated panel reactive antibody (cPRA) increases and is independent of medical urgency. In the Canadian allocation system, patients with cPRA more than 80% have a similar incidence of death on the waitlist as less sensitized patients, suggesting they survive to be transplanted. Furthermore, prioritizing and transplanting highly sensitized patients has been associated with acceptable post-transplant outcomes.

SUMMARY

The Canadian allocation system prioritizes highly sensitized patients to increase equity and access to transplantation while maintaining good post-transplant outcomes. Not all highly sensitized patients can wait for an organ, even if prioritized. A pragmatic individualized approach would consider the medical stability of the patient, the likelihood of transplant with a negative crossmatch and then determine whether waitlist prioritization or desensitization is the more appropriate strategy.

Hospitalisation and life support in the year before and during heart transplantation: a French national study

Objective

The objective of this study was to define the characteristics of hospital care use during the year prior to heart transplantation.

Methods

A retrospective cohort of heart transplant recipients registered on the national hospital discharge database between 2010 and 2015 was analysed.

Results

In this cohort of 2379 heart transplant recipients (mean age: 48 years, 74% men), 91% had been admitted at least once, for at least 1 day, to a short-stay hospital during the year before transplantation (mean: 4.3 days), and 84% had at least one cardiovascular diagnosis (heart failure and cardiogenic shock: 60%). At least one intensive care stay was reported for 61% of patients, a rehabilitation stay was reported for 30%, mechanical circulatory support was reported for 12%, and ventilatory support was reported for 15%. The median interval between admission and transplantation was 5 days (interquartile QI-Q3, 0-16). The hospital mortality was higher for patients not hospitalised before transplantation (18% vs 15%). Their transplantation hospitalisation diagnosis, compared with patients hospitalised before transplantation, was more frequently cardiomyopathy (31% vs 27%) or heart failure (28% vs 18%), and less frequently myocardial infarction (1% vs 12%).

Conclusion

This study demonstrates a high hospitalisation rate before heart transplantation and identifies three groups of patients: 1-patients with a high hospitalisation rate and terminal heart failure requiring circulatory support who experienced at least one intensive care unit stay; 2-patients with a history of hospitalisation, mainly for heart disease, without circulatory support requirement; and 3-patients with no pretransplantation overnight stay. These findings provide useful information to evaluate the medical benefits and needs for transplantation, and identify areas for improvement in heart transplantation listing criteria.

Outcomes of Induction Therapy with Rabbit Anti-Thymocyte Globulin in Heart Transplant Recipients: A Single Center Retrospective Cohort Study

Background

Induction immunosuppression is used in transplantation to prevent early acute rejection. The survival benefit of rabbit anti-thymocyte globulin (rATG) induction has not been established yet. We sought to determine the role of rATG in preventing rejection and improving overall survival.

Material/Methods

A retrospective cohort study was conducted from 2005 to 2009 and data of consecutive 268 heart transplant recipients were reviewed.

Results

The data of 144 patients who received induction with rATG were compared to 124 patients who did not. Although overall survival was not different between the 2 groups (P=0.12), there was a significant difference in restricted mean survival time (RMST) at 5 years (RMST=4.8 months; 95% CI: 1.0–8.6, P=0.01) and 10 years (RMST=10.4 months; 95% CI: 1.6–19.3, P=0.02) in favor of the non-induced patients. No difference was observed between induced and non-induced patients who developed de novo donor specific antibodies. There was a significant difference in median days to first rejection in favor of the induced group (P<0.001).

Conclusions

Induction with rATG adds no survival benefit in heart transplant recipients. Patients who did not receive induction therapy had higher life expectancy at 5 years and 10 years. Although there was significant delay in the first rejection episode in favor of the rATG induced group, no difference was observed in donor specific antibodies. This study indicates a need for separate analysis of peri-transplantation co-morbidities and mainly the incidence of acute kidney injury, which could affect long-term survival.

Between-center disparities in access to heart transplantation in France: contribution of candidate and center factors - A comprehensive cohort study

Transplantation represents the last option for patients with advanced heart failure. We assessed between-center disparities in access to heart transplantation in France 1 year after registration and evaluated the contribution of factors to these disparities. Adults (n = 2347) registered on the French national waiting list between January 1, 2010, and December 31, 2014, in the 23 transplant centers were included. Associations between candidate and transplant center characteristics and access to transplantation were assessed by proportional hazards frailty models. Candidate blood groups O and A, sensitization, and body mass index ≥30 kg/m² were independently associated with lower access to transplantation, while female gender, severity of heart failure, and high serum bilirubin levels were independently associated with greater access to transplantation. Center factors significantly associated with access to transplantation were heart donation rate in the donation service area, proportion of high-urgency candidates among listed patients, and donor heart offer decline rate. Between-center variability in access to transplantation increased by 5% after adjustment for candidate factors and decreased by 57% after adjustment for center factors. After adjustment for candidate and center factors, five centers were still outside of normal variability. These findings will be taken into account in the future French heart allocation system.