Management of the ACC/AHA Stage D patient: cardiac transplantation

Cytomegalovirus Donor Seropositivity Negatively Affects Survival After Heart Transplantation

OBJECTIVES

Prior studies have shown that cytomegalovirus(CMV) infection is a risk factor for the development of cardiac allograft vasculopathy(CAV) and is associated with reduced long-term survival after heart transplantation. The aim of this ISHLT Transplant Registry study was to compare post-transplant survival in different CMV donor:recipient serologic combinations.

METHODS

We performed a retrospective cohort study, using the ISHLT Thoracic Transplant Registry, on 15,885 adult primary heart transplant recipients with known CMV serologic status between 7/2004 and 6/2014. Post-transplant survival and risk of developing CAV were compared across 4 groups: CMV-seronegative recipients(R-) receiving CMV-positive grafts(D+), intermediate-risk patients(D+R+ and D-R+), and low-risk patients(D-R-).

RESULTS

Baseline characteristics (donor/recipient age, BMI, recipient serum creatinine, blood group, donor cause of death, recipient diagnosis and ischemic time) were mostly balanced between the groups. Kaplan Meier survival analyses over a follow up of 10 years revealed significantly worse survival for both D+ groups as compared to the CMV low risk group (D+R+:56.61% (95%CI 53.94,59.41) vs. D-R-:63.09% (59.74,66.64) p<.01 and D+R-:57.69% (56.03,59.39) vs. D-R-; p<.001), whereas recipient seropositivity alone was not associated with reduced survival (D-R+ vs. D-R- p=.178). The risk of developing CAV after HTx was not significantly increased in D+ as compared to D- groups.

CONCLUSION

In a large contemporary cohort, CMV status at the time of heart transplantation was not associated with CAV development. However, there was a significant association between donor CMV seropositivity and reduced short- and long-term survival after heart transplantation. Approaches to mitigate the impact of CMV on post-transplant survival are needed.Supplemental Visual Abstract; http://links.lww.com/TP/C292.

Heart transplantation outcomes in cardiac sarcoidosis

BACKGROUND

Cardiac sarcoidosis (CS) is a progressive inflammatory cardiomyopathy that can lead to heart failure, arrhythmia, and death. There is limited data on Orthotopic Heart Transplantation (OHT) outcomes in patients with CS. Here we examine outcomes in patients with CS who have undergone OHT at centers throughout the United States from 1987 to 2019.

METHODS

This was an analysis of 63,947 adult patients undergoing OHT captured in the United Network for Organ Sharing (UNOS) registry. Patients were characterized as cardiac sarcoidosis (CS) or Non-CS. Baseline characteristics were compared using chi-square and Kruskal-Wallis Tests. Outcomes of interest included primary graft failure, patient survival, treated graft rejection, hospitalization for infection, and post-transplant malignancy.

RESULTS

During the study period 227 patients with CS underwent OHT. Patients with CS were younger, had higher proportion of non-white patients, and received transplants at more urgent statuses. After multivariable modeling there was no difference in survival (HR 0.86, CI 0.59-1.3, p = 0.446) or graft failure (HR 0.849, CI 0.58-1.23, p = 0.394) between patients with CS and Non-CS. Patients with CS had lower odds of rejection (OR 0.558, CI 0.315- 0.985, p = 0.0444). Patients with CS had similar odds of hospitalization for infection and post-transplant malignancy, as Non-CS patients.

CONCLUSIONS

Patients with CS and Non-CS had similar post OHT survival, odds of graft failure, hospitalizations for infection, and post-transplant malignancy. Results of this study confirm the role of heart transplantation as a viable option for patients with CS.

Impact of risk-stratified mycophenolate dosing in heart transplantation

Mycophenolate mofetil (MMF), the prodrug of mycophenolic acid, is a highly effective immunosuppressive agent in heart transplant therapy. While the FDA approved dose is 1500 mg twice daily, dosing is often reduced due to dose-dependent adverse effects. However, empiric MMF dose reductions may lead to sub-therapeutic dosing and impair clinical outcomes. Our single center protocolized a risk-stratified approach based on age and weight to dose 500 mg twice daily or 1000 mg twice daily to patients after heart transplantation. This retrospective single-center study analyzed 140 consecutive heart transplant patients who were initiated on our risk-stratified MMF protocol post-transplant. The analysis revealed that the composite rate of biopsy-proven rejection, graft loss, or mortality at 1-year post-transplantation was similar between the two groups. Incidence of neutropenia, thrombocytopenia, infection, cardiac allograft vasculopathy, or acute kidney injury by 1-year also showed similar results between the two groups. Risk-stratification of MMF dosing appears to be a safe and effective strategy after heart transplantation.

p63 Silencing induces reprogramming of cardiac fibroblasts into cardiomyocyte-like cells

OBJECTIVE

Reprogramming of fibroblasts into induced cardiomyocytes represents a potential new therapy for heart failure. We hypothesized that inactivation of p63, a p53 gene family member, may help overcome human cell resistance to reprogramming.

METHODS

p63 Knockout (^-/-) and knockdown murine embryonic fibroblasts (MEFs), p63^-/- adult murine cardiac fibroblasts, and human cardiac fibroblasts were assessed for cardiomyocyte-specific feature changes, with or without treatment by the cardiac transcription factors Hand2-Myocardin (HM).

RESULTS

Flow cytometry revealed that a significantly greater number of p63^-/- MEFs expressed the cardiac-specific marker cardiac troponin T (cTnT) in culture compared with wild-type (WT) cells (38% ± 11% vs 0.9% ± 0.9%, P < .05). HM treatment of p63^-/- MEFs increased cTnT expression to 74% ± 3% of cells but did not induce cTnT expression in wild-type murine embryonic fibroblasts. shRNA-mediated p63 knockdown likewise yielded a 20-fold increase in cTnT microRNA expression compared with untreated MEFs. Adult murine cardiac fibroblasts demonstrated a 200-fold increase in cTnT gene expression after inducible p63 knockout and expressed sarcomeric α-actinin as well as cTnT. These p63^-/- adult cardiac fibroblasts exhibited calcium transients and electrically stimulated contractions when co-cultured with neonatal rat cardiomyocytes and treated with HM. Increased expression of cTnT and other marker genes was also observed in p63 knockdown human cardiac fibroblasts procured from patients undergoing procedures for heart failure.

CONCLUSIONS

Downregulation of p63 facilitates direct cardiac cellular reprogramming and may help overcome the resistance of human cells to reprogramming.

Direct Cardiac Cellular Reprogramming for Cardiac Regeneration

OPINION STATEMENT

Direct cardiac cellular reprogramming of endogenous cardiac fibroblasts directly into induced cardiomyocytes is a highly feasible, promising therapeutic option for patients with advanced heart failure. The most successful cardiac reprogramming strategy will likely be a multimodal approach involving an optimal combination of cardio-differentiating factors, suppression of fibroblast gene expression, and induction of angiogenic factors.

Mechanoactive materials in cardiac science

Mechanically active biomaterials such as shape memory materials, liquid crystal elastomers, dielectric elastomer actuators, and conductive polymers could be used in mechanical devices to augment heart function or condition cardiac cells and artificial tissues for regenerative medicine solutions.

Cardiac Transplantation: Considerations for the Intensive Care Unit Nurse

Heart transplantation is a recommended and curative treatment option for patients with advanced heart failure symptoms despite receiving optimal medical and device therapy. The availability of donor organs limits the number of patients able to receive a heart transplant. The overall outcome of patients able to receive a heart transplant is determined by the successful delivery of essential nursing care. Understanding the specific interventions and therapies unique to this patient population is critical to their care. This article reviews considerations for the intensive care unit clinician in the management of heart transplant patients in this setting.

Thermal vasodilation using a portable infrared thermal blanket in decompensated heart failure

Adjunctive and non-pharmacological therapies, such as heat, for the treatment of heart failure patients have been proposed. Positive results have been obtained in clinically stable patients, but no studies of the use of thermal therapy in patients with decompensated heart failure (DHF) have been reported. An open randomized clinical trial was designed in patients with DHF and controls. We studied 38 patients with a mean age of 56.9 years. A total of 86.8% were men, and 71% had nonischemic myocardiopathy. All participants were using dobutamine, and the median brain natriuretic peptide (BNP) level was 1396 pg/mL. An infrared thermal blanket heated the patients, who were divided into 2 groups: group T (thermal therapy) and group C (control). Group T underwent vasodilation using the thermal blanket at 50°C for 40 minutes in addition to drug treatment. The cardiac index increased by 24.1% (P = 0.009), and systemic vascular resistance decreased by 16.0% in group T (P < 0.024) after thermal therapy. Heat as a vasodilator increased the cardiac index and lowered systemic vascular resistance in DHF patients. These data suggest thermal therapy as a therapeutic approach for the adjuvant treatment of DHF patients.

Electrically contractile polymers augment right ventricular output in the heart

Research into the development of artificial heart muscle has been limited to assembly of stem cell-derived cardiomyocytes seeded around a matrix, while nonbiological approaches to tissue engineering have rarely been explored. The aim of the study was to apply electrically contractile polymer-based actuators as cardiomyoplasty for positive inotropic support of the right ventricle. Complex trilayer polypyrrole (PPy) bending polymers for high-speed applications were generated. Bending motion occurred directly as a result of electrochemically driven charging and discharging of the PPy layers. In a rat model (n = 5), strips of polymers (3 × 20 mm) were attached and wrapped around the right ventricle (RV). RV pressure was continuously monitored invasively by direct RV cannulation. Electrical activation occurred simultaneously with either diastole (in order to evaluate the polymer's stand-alone contraction capacity; group 1) or systole (group 2). In group 1, the pressure generation capacity of the polymers was measured by determining the area under the pressure curve (area under curve, AUC). In group 2, the RV pressure AUC was measured in complexes directly preceding those with polymer contraction and compared to RV pressure complexes with simultaneous polymer contraction. In group 1, the AUC generated by polymer contraction was 2768 ± 875 U. In group 2, concomitant polymer contraction significantly increased AUC compared with complexes without polymer support (5987 ± 1334 U vs. 4318 ± 691 U, P ≤ 0.01). Electrically contractile polymers are able to significantly augment right ventricular contraction. This approach may open new perspectives for myocardial tissue engineering, possibly in combination with fetal or embryonic stem cell-derived cardiomyocytes.