Outcomes of treatment for deep left ventricular assist device infection

OBJECTIVE

Among left ventricular assist device patients, the most commonly infected component is the drive line, which can be managed with antibiotics and local debridement. Infection of intrathoracic device components is less common but more difficult to manage. Herein we describe the incidence of deep device infection (DDI) at our center as well as management and outcomes.

METHODS

We retrospectively reviewed 658 patients who underwent implantable left ventricular assist device insertion with HeartMate 2 (Abbott) or HeartMate 3 (Abbott) devices between January 2004 and June 2021. DDI was defined according to radiographic and clinical criteria. Cumulative incidence was calculated using a Fine-Gray subdistribution model; survival analysis was performed using the method of Kaplan and Meier.

RESULTS

There were 32 (4.8%) DDIs during this study period. Drive line infection and re-exploration for bleeding were associated with development of DDI. Cumulative incidence of DDI increased over time, affecting 11% (7%-18%) at 5 years. The dominant microbes involved in DDI were Pseudomonas aeruginosa (19%) and methicillin-resistant Staphylococcus aureus (13%). Nineteen patients (59%) with device infection underwent device exchange, 6 (19%) underwent initial transplant, and 7 (22%) were treated solely with debridement and antibiotics. Of those who underwent device exchange, 12 (63%) developed reinfection of their new device and 6 underwent subsequent heart transplant. Patients who underwent transplantation for management of device infection had improved 5-year survival (80% vs 11%; P = .01) but 3 patients (25%) developed deep sternal wound infection after transplant.

CONCLUSIONS

DDI is a rare but challenging complication in this destination era. Heart transplantation is the preferred management strategy for eligible patients but infectious complication is common.

Modifiable risk factor reduction for pediatric ventricular assist devices and the influence of persistent modifiable risk factors at transplant

OBJECTIVES

Ventricular assist devices (VADs) are associated with a mortality benefit in children. Database-driven analyses have associated VADs with reduction of modifiable risk factors (MRFs), but validation with institutional data is required. The authors studied MRF reduction on VAD and the influence of persistent MRFs on survival after heart transplant.

METHODS

All patients at the authors' institution requiring a VAD at transplant (2011-2022) were retrospectively identified. MRFs included renal dysfunction (estimated glomerular filtration rate <60 mL/min/1.73 m2), hepatic dysfunction (total bilirubin ≥1.2 mg/dL), total parenteral nutrition dependence, sedatives, paralytics, inotropes, and mechanical ventilation.

RESULTS

Thirty-nine patients were identified. At time of VAD implantation, 18 patients had ≥3 MRFs, 21 had 1 to 2 MRFs, and 0 had 0 MRFs. At time of transplant, 6 patients had ≥3 MRFs, 17 had 1 to 2 MRFs, and 16 had 0 MRFs. Hospital mortality occurred in 50% (3 out of 6) patients with ≥3 MRFs at transplant vs 0% of patients with 1 to 2 and 0 MRFs (P = .01 for ≥3 vs 1-2 and 0 MRFs). MRFs independently associated with hospital mortality included paralytics (1.76 [range, 1.32-2.30]), ventilator (1.59 [range, 1.28-1.97]), total parenteral nutrition dependence (1.49 [range, 1.07-2.07]), and renal dysfunction (1.31 [range, 1.02-1.67]). Two late mortalities occurred (3.6 and 5.7 y), both in patients with 1 to 2 MRFs at transplant. Overall posttransplant survival was significantly worse for ≥3 versus 0 MRFs (P = .006) but comparable between other cohorts (P > .1).

CONCLUSIONS

VADs are associated with MRF reduction in children, yet those with persistent MRFs at transplant experience a high burden of mortality. Transplanting VAD patients with ≥3 MRFs may not be prudent. Time should be given on VAD support to achieve aggressive pre-transplant optimization of MRFs.

Donation after circulatory death improves probability of heart transplantation in waitlisted candidates and results in post-transplant outcomes similar to those achieved with brain-dead donors

OBJECTIVE

To quantitate the impact of heart donation after circulatory death (DCD) donor utilization on both waitlist and post-transplant outcomes in the United States.

METHODS

The United Network for Organ Sharing database was queried to identify all adult waitlisted and transplanted candidates between October 18, 2018, and December 31, 2022. Waitlisted candidates were stratified according to whether they had been approved for donation after brain death (DBD) offers only or also approved for DCD offers. The cumulative incidence of transplantation was compared between the 2 cohorts. In a post-transplant analysis, 1-year post-transplant survival was compared between unmatched and propensity-score-matched cohorts of DBD and DCD recipients.

RESULTS

A total of 14,803 candidates were waitlisted, including 12,287 approved for DBD donors only and 2516 approved for DCD donors. Overall, DCD approval was associated with an increased sub-hazard ratio (HR) for transplantation and a lower sub-HR for delisting owing to death/deterioration after risk adjustment. In a subgroup analysis, candidates with blood type B and status 4 designation received the greatest benefit from DCD approval. A total of 12,238 recipients underwent transplantation, 11,636 with DBD hearts and 602 with DCD hearts. Median waitlist times were significantly shorter for status 3 and status 4 recipients receiving DCD hearts. One-year post-transplant survival was comparable between unmatched and propensity score-matched cohorts of DBD and DCD recipients.

CONCLUSIONS

The use of DCD hearts confers a higher probability of transplantation and a lower incidence of death/deterioration while on the waitlist, particularly among certain subpopulations such as status 4 candidates. Importantly, the use of DCD donors results in similar post-transplant survival as DBD donors.

Incidence of Acute Rejection Compared With Endomyocardial Biopsy Complications for Heart Transplant Patients in the Contemporary Era

BACKGROUND

The reference standard of detecting acute rejection (AR) in adult heart transplant (HTx) patients is an endomyocardial biopsy (EMB). The majority of EMBs are performed in asymptomatic patients. However, the incidence of treated AR compared with EMB complications has not been compared in the contemporary era (2010-current).

METHODS

The authors retrospectively analyzed 2769 EMBs obtained in 326 consecutive HTx patients between August 2019 and August 2022. Variables included surveillance versus for-cause indication, recipient and donor characteristics, EMB procedural data and pathological grades, treatment for AR, and clinical outcomes.

RESULTS

The overall EMB complications rate was 1.6%. EMBs performed within 1 mo after HTx compared with after 1 mo from HTx showed significantly increased complications (OR, 12.74, P  < 0.001). The treated AR rate was 14.2% in the for-cause EMBs and 1.2% in the surveillance EMBs. We found the incidence of AR versus EMB complications was significantly lower in the surveillance compared with the for-cause EMB group (OR, 0.05, P  < 0.001). We also found the incidence of EMB complications was higher than treated AR in surveillance EMBs.

CONCLUSIONS

The yield of surveillance EMBs has declined in the contemporary era, with a higher incidence of EMB complications compared with detected AR. The risk of EMB complications was highest within 1 mo after HTx. Surveillance EMB protocols in the contemporary era may need to be reevaluated.

Acute Kidney Injury After Heart Transplantation: Risk Factors and Clinical Outcomes

OBJECTIVE

Acute kidney injury (AKI) requiring renal-replacement therapy (RRT) after heart transplantation (OHT) is common and impairs outcomes. This study aimed to identify independent donor and recipient risk factors associated with RRT after OHT.

DESIGN

A retrospective data analysis.

SETTING

Data were collected from clinical routines in a maximum-care university hospital.

PARTICIPANTS

Patients who underwent OHT.

INTERVENTIONS

The authors retrospectively analyzed data from 264 patients who underwent OHT between 2012 and 2021; 189 patients were eligible and included in the final analysis.

MEASUREMENTS AND MAIN RESULTS

The mean age was 48.0 ± 12.3 years, and 71.4% of patients were male. Ninety (47.6%) patients were on long-term mechanical circulatory support (lt-MCS). Posttransplant AKI with RRT occurred in 123 (65.1%) patients. In a multivariate analysis, preoperative body mass index >25 kg/m² (odds ratio [OR] 4.74, p < 0.001), elevated preoperative creatinine levels (OR for each mg/dL increase 3.44, p = 0.004), administration of red blood cell units during transplantation procedure (OR 2.31, p = 0.041) and ischemia time (OR for each hour increase 1.77, p = 0.004) were associated with a higher incidence of RRT. The use of renin-angiotensin-aldosterone system blockers before transplantation was associated with a reduced risk of RRT (OR 0.36, p = 0.013). The risk of mortality was 6.9-fold higher in patients who required RRT (hazard ratio 6.9, 95% CI: 2.1-22.6 p = 0.001). Previous lt-MCS, as well as donor parameters, were not associated with RRT after OHT.

CONCLUSIONS

The implementation of guideline-directed medical therapy, weight reduction, minimizing ischemia time (ie, organ perfusion systems, workflow optimization), and comprehensive patient blood management potentially influences renal function and outcomes after OHT.

Role of Radiology in Assessment of Postoperative Complications of Heart Transplantation

Heart transplantation is a pivotal treatment of end-stage heart failure, and recent advancements have extended median posttransplant life expectancy. However, despite the progress in surgical techniques and medical treatment, heart transplant patients still face complications such as rejection, infections, and drug toxicity. CT is a reliable tool for detecting most of these complications, whereas MR imaging is particularly adept at identifying pericardial pathologies and signs of rejection. Awareness of these nuances by radiologists, cardiologists, and surgeons is desired to optimize care, reduce morbidities, and enhance survival.

MEK1/2-PKM2 Pathway Modulates the Immunometabolic Reprogramming of Proinflammatory Allograft-infiltrating Macrophages During Heart Transplant Rejection

BACKGROUND

Emerging evidence has highlighted the role of macrophages in heart transplant rejection (HTR). However, the molecular signals modulating the immunometabolic phenotype of allograft-infiltrating macrophages (AIMs) during HTR remain unknown.

METHODS

We analyzed single-cell RNA sequencing data from cardiac graft-infiltrating immunocytes to characterize the activation patterns and metabolic features of AIMs. We used flow cytometry to determine iNOS and PKM2 expression and MEK/ERK signaling activation levels in AIMs. We then generated macrophage-specific Mek1/2 knockout mice to determine the role of the MEK1/2-PKM2 pathway in the proinflammatory phenotype and glycolytic capacity of AIMs during HTR.

RESULTS

Single-cell RNA sequencing analysis showed that AIMs had a significantly elevated proinflammatory and glycolytic phenotype. Flow cytometry analysis verified that iNOS and PKM2 expressions were significantly upregulated in AIMs. Moreover, MEK/ERK signaling was activated in AIMs and positively correlated with proinflammatory and glycolytic signatures. Macrophage-specific Mek1/2 deletion significantly protected chronic cardiac allograft rejection and inhibited the proinflammatory phenotype and glycolytic capacity of AIMs. Mek1/2 ablation also reduced the proinflammatory phenotype and glycolytic capacity of lipopolysaccharides + interferon-γ-stimulated macrophages. Mek1/2 ablation impaired nuclear translocation and PKM2 expression in macrophages. PKM2 overexpression partially restored the proinflammatory phenotype and glycolytic capacity of Mek1/2 -deficient macrophages. Moreover, trametinib, an Food and Drug Administration-approved MEK1/2 inhibitor, ameliorated chronic cardiac allograft rejection.

CONCLUSIONS

These findings suggest that the MEK1/2-PKM2 pathway is essential for immunometabolic reprogramming of proinflammatory AIMs, implying that it may be a promising therapeutic target in clinical heart transplantation.

Successful treatment of gastric cancer 10 years after heart transplantation: A case report

BACKGROUND

While survival rates among cardiac allograft recipients have improved, there has been a rise in post-transplant malignancies, with gastric cancer being less commonly reported. This study presented a successful treatment of gastric cancer in an individual 10 years after undergoing a heart transplant.

CASE PRESENTATION

A 66-year-old Chinese man presented to the gastrointestinal clinic with a complaint of diagnosis of gastric cancer for 4 months and treated with neoadjuvant therapy for 1 month. He has undergone orthotopic heart transplantation 10 years earlier due to a myocardial infarction. Physical examination and laboratory tests did not reveal any significant abnormalities. Abdominal contrast-enhanced computed tomography (CT) imaging indicated a gastric mass near the greater curvature, with gastroscopy suggesting a carcinoma at the esophagogastric junction, Siewert III. An echocardiogram indicated left atrial enlargement with mild mitral and tricuspid regurgitation. The diagnosis suggested that his gastric cancer at the esophagogastric junction was a consequence of long-term immunosuppressive therapy. A multidisciplinary team (MDT) consultation recommended a proximal radical gastrectomy. Postoperatively, the patient received 4 cycles of adjuvant chemotherapy with XELOX combined with Herceptin, initiated a month after surgery. During the 1-year follow-up, the patient showed commendable recovery, with no signs of tumor recurrence or metastasis.

CONCLUSION

This case underscores the potential risk of malignancy from immunosuppressive agents in transplant recipients. The successful management of this complex scenario underscores the indispensable role of an MDT approach in treating such unique and challenging cases.

Impact of Everolimus Initiation and Corticosteroid Weaning During Acute Phase After Heart Transplantation on Clinical Outcome: Data from the Korean Organ Transplant Registry (KOTRY)

The effect of changes in immunosuppressive therapy during the acute phase post-heart transplantation (HTx) on clinical outcomes remains unclear. This study aimed to investigate the effects of changes in immunosuppressive therapy by corticosteroid (CS) weaning and everolimus (EVR) initiation during the first year post-HTx on clinical outcomes. We analyzed 622 recipients registered in the Korean Organ Transplant Registry (KOTRY) between January 2014 and December 2021. The median age at HTx was 56 years (interquartile range [IQR], 45-62), and the median follow-up time was 3.9 years (IQR 2.0-5.1). The early EVR initiation within the first year post-HTx and maintenance during the follow-up is associated with reduced the risk of primary composite outcome (all-cause mortality or re-transplantation) (HR, 0.24; 95% CI 0.09-0.68; p < 0.001) and cardiac allograft vasculopathy (CAV) (HR, 0.39; 95% CI 0.19-0.79; p = 0.009) compared with EVR-free or EVR intermittent treatment regimen, regardless of CS weaning. However, the early EVR initiation tends to increase the risk of acute allograft rejection compared with EVR-free or EVR intermittent treatment.

Right Ventricular Function on Cardiovascular Magnetic Resonance Imaging and Long-Term Outcomes in Stable Heart Transplant Recipients

BACKGROUND

In heart transplant recipients, right ventricular (RV) dysfunction may occur for a variety of reasons. Whether RV dysfunction in the stable phase after heart transplantation is associated with long-term adverse outcomes is unknown. We aimed to determine the long-term prognostic significance of RV dysfunction identified on cardiovascular magnetic resonance imaging (CMR) at least 1 year after heart transplantation.

METHODS

In consecutive heart transplant recipients who underwent CMR for surveillance, we assessed 2 CMR measures of RV function: RV ejection fraction and RV global longitudinal strain (RVGLS). We investigated associations between RV dysfunction and a composite end point of death or major adverse cardiac events, including retransplantation, nonfatal myocardial infarction, coronary revascularization, and heart failure hospitalization.

RESULTS

A total of 257 heart transplant recipients (median age, 59 years; 75% men) who had CMR at a median of 4.3 years after heart transplantation were included. Over a median follow-up of 4.4 years after the CMR, 108 recipients experienced death or major adverse cardiac events. In a multivariable Cox regression analysis adjusted for age, time since transplantation, indication for transplantation, cardiac allograft vasculopathy, history of rejection, and CMR covariates, RV ejection fraction was not associated with the composite end point, but RVGLS was independently associated with the composite end point with a hazard ratio of 1.08 per 1% worsening in RVGLS ([95% CI, 1.00-1.17]; P=0.046). RVGLS provided incremental prognostic value over other variables in multivariable analyses. The association was replicated in subgroups of recipients with normal RV ejection fraction and recipients with late gadolinium enhancement imaging. A similar association was seen with a composite end point of cardiovascular death or major adverse cardiac events.

CONCLUSIONS

CMR feature tracking-derived RVGLS assessed at least 1 year after heart transplantation was independently associated with the long-term risk of death or major adverse cardiac events. Future studies should investigate its role in guiding clinical decision-making in heart transplant recipients.

Racial Differences in Donor-Derived Cell-Free DNA and Mitochondrial DNA After Heart Transplantation, on Behalf of the GRAfT Investigators

BACKGROUND

Black heart transplant patients are at higher risk of acute rejection (AR) and death than White patients. We hypothesized that this risk may be associated with higher levels of donor-derived cell-free DNA (dd-cfDNA) and cell-free mitochondrial DNA.

METHODS

The Genomic Research Alliance for Transplantation is a multicenter, prospective, longitudinal cohort study. Sequencing was used to quantitate dd-cfDNA and polymerase chain reaction to quantitate cell-free mitochondrial DNA in plasma. AR was defined as ≥2R cellular rejection or ≥1 antibody-mediated rejection. The primary composite outcome was AR, graft dysfunction (left ventricular ejection fraction <50% and decrease by ≥10%), or death.

RESULTS

We included 148 patients (65 Black patients and 83 White patients), median age was 56 years and 30% female sex. The incidence of AR was higher in Black patients compared with White patients (43% versus 19%; P=0.002). Antibody-mediated rejection occurred predominantly in Black patients with a prevalence of 20% versus 2% (P<0.001). After transplant, Black patients had higher levels of dd-cfDNA, 0.09% (interquartile range, 0.001-0.30) compared with White patients, 0.05% (interquartile range, 0.001-0.23; P=0.003). Beyond 6 months, Black patients showed a persistent rise in dd-cfDNA with higher levels compared with White patients. Cell-free mitochondrial DNA was higher in Black patients (185 788 copies/mL; interquartile range, 101 252-422 133) compared with White patients (133 841 copies/mL; interquartile range, 75 346-337 990; P<0.001). The primary composite outcome occurred in 43% and 55% of Black patients at 1 and 2 years, compared with 23% and 27% in White patients, P<0.001. In a multivariable model, Black patient race (hazard ratio, 2.61 [95% CI, 1.35-5.04]; P=0.004) and %dd-cfDNA (hazard ratio, 1.15 [95% CI, 1.03-1.28]; P=0.010) were associated with the primary composite outcome.

CONCLUSIONS

Elevated dd-cfDNA and cell-free mitochondrial DNA after heart transplant may mechanistically be implicated in the higher incidence of AR and worse clinical outcomes in Black transplant recipients.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifier: NCT02423070.

Myocardial edema, inflammation, and injury in human heart donated after circulatory death are sensitive to warm ischemia and subsequent cold storage

BACKGROUND

Single-dose del Nido solution was recently used in human donation after circulatory death (DCD) heart procurement. We compared the effect of del Nido cardioplegia on myocardial edema, inflammatory response, and injury in human DCD hearts and human donation after brain death (DBD) hearts with different warm ischemic times (WIT) and subsequent cold saline storage times (CST).

METHODS

A total of 24 human hearts, including 6 in the DBD group and 18 in the DCD group-were procured for the research study. The DCD group was divided into 3 subgroups based on WIT: 20, 40, and ≥60 minutes. All hearts received 1 L of del Nido cardioplegia before being placed in cold saline for 6 hours. Left ventricular biopsies were performed at 0, 2, 4, and 6 hours. Temporal changes in myocardial edema, inflammatory cytokines (TNF-α, IL-6, and IL-1β), and histopathology injury scores were compared between the DBD and DCD groups.

RESULTS

DCD hearts showed more profound changes in myocardial edema, inflammation, and injury than DBD hearts at baseline and subsequent CST. The DCD heart with WIT of 20 and 40 minutes with CST of 4 and 2 hours, respectively, appeared to have limited myocardial edema, inflammation, and injury. DCD hearts with WIT ≥60 minutes showed severe myocardial edema, inflammation, and injury at baseline and subsequent CST.

CONCLUSIONS

Single-dose cold del Nido cardioplegia and subsequent cold normal saline storage can preserve both DCD and DBD hearts. DCD hearts have been shown to be able to tolerate a WIT of 20 minutes and subsequent CST of 4 hours without experiencing significant myocardial edema, inflammation, and injury.

Changing Strategy Between Bridge to Transplant and Destination LVAD Therapy After the First 3 Months: Analysis of the STS-INTERMACS Database

BACKGROUND

Left ventricular assist devices (LVADs) have been implanted as bridge to transplantation (BTT), bridge to candidacy (BTC) or destination therapy (DT) on the basis of relative and absolute contraindications to transplantation. Multiple factors may lead to changes in the strategy of support after LVAD implantation.

METHODS

Based on INTERMACS (Interagency Registry for Mechanically Assisted Circulatory Support) 2012-2020 data, 11,262 patients survived to 3 months on continuous-flow LVADs with intent of BTT or DT. Preimplant characteristics and early events post-LVAD were analyzed in relation to changes in BTT or DT strategy during the next 12 months.

RESULTS

Among 3216 BTT patients at 3 months, later transplant delisting or death without transplant occurred in 536 (16.7%) and was more common with age, profiles 1-2, renal dysfunction, and independently for prior cardiac surgery (HR 1.25, 95% CI 1.04-1.51; P = 0.02). Post-LVAD events of infections, gastrointestinal bleeding, stroke, and right heart failure as defined by inotropic therapy, predicted delisting and death, as did in-hospital location at 3 months (HR 1.67, 95% CI 1.20-2.33; P = 0.0024). Of 8046 patients surviving to 3 months with the intent of destination therapy, 750 (9.3%) subsequently underwent listing or transplantation, often with initial histories of acute HF (HR 1.70, 95% CI 1.27-2.27; P = 0.0012) or malnutrition-cachexia (1.73, 95% CI 1.14-2.63; P = 0.0099). Multiple gastrointestinal bleeding events (≥ 4) with LVAD increased transition from BTT to DT (HR 4.22, 95% CI 1.46-12.275; P = 0.0078) but also from DT to BTT (HR 5.17, 95% CI 1.92-13.9; P = 0.0011).

CONCLUSIONS

Implant strategies change over time in relation to preimplant characteristics and adverse events post implant. Preimplant recognition of factors predicting later change in implant strategy will refine initial triage, whereas further reduction of post-LVAD complications will expand options, including eventual consideration of heart transplantation.

A heart transplant center experience with basiliximab induction strategies: A double edged sword?

BACKGROUND

The use of induction immunosuppression for heart transplantation (HT) is debated given the uncertain benefit and potential risks of infection and malignancy.

METHODS

This is a retrospective single-center analysis of 475 consecutive HT recipients from 2003 to 2020 grouped by use of induction with basiliximab group (BG) and the no basiliximab group (NBG). Subgroup analysis by era compared pre-2016 standard-basiliximab (BX) induction and 2016-2020 with selective-BX use as part of a calcineurin-inhibitor-sparing regimen.

RESULTS

When adjusted for confounders (sex, age, PRA, eGFR), the BG was less likely to have acute cellular rejection (ACR) (OR.42, p < .001), but had more antibody mediated rejection (AMR) (OR 11.7, p < .001) and more cardiac allograft vasculopathy (CAV) (OR 3.8, p = .04). There was no difference between BG and NBG in the incidence of malignancies or infections. When stratified by era (pre-2016 vs. 2016-2020), ACR remained less common in the BG than the NBG (36% vs. 50%, p = .045) groups, while AMR remained more common (9.7 vs. 0% p = .005). There was no significant difference in conditional survival comparing pre-and post-2016 NBG (HR 2.20 (95% CI.75-6.43); however, both pre-2016 BG and post-2016 BG have significantly higher mortality (HR 2.37 [95% CI 1.02-5.50) and HR 2.69 (95% CI 1.08-6.71), p = .045 and.03, respectively].

CONCLUSION

Basiliximab reduces the incidence of ACR but increases the risk of AMR, CAV, and may be associated with increased mortality. Mechanistic studies are needed to describe a potential T-cell-escape mechanism with enhanced humoral immunity.

Stabilization of Rapidly Progressive Cardiac Allograft Vasculopathy Using mTOR Inhibition After Heart Transplantation

BACKGROUND

Inhibition of the mammalian target of rapamycin (mTor) pathway after heart transplantation has been associated with reduced progression of coronary allograft vasculopathy (CAV). The application of low-dose mTOR inhibition in the setting of modern immunosuppression, including tacrolimus, remains an area of limited exploration.

METHODS

This retrospective study included patients who received heart transplantation between January 2009 and January 2019 and had baseline, 1-year and 2-3-year coronary angiography with intravascular ultrasound (IVUS). Intimal thickness in 5 segments along the left anterior descending artery was compared across imaging time points in patients who were transitioned to low-dose mTOR inhibitor (sirolimus) vs standard treatment with mycophenolate on a background of tacrolimus. Long-term adverse cardiovascular outcomes (revascularization, severe CAV, retransplant, and cardiovascular death) were also assessed.

RESULTS

Among 216 patients (mean age 51.5 ± 11.9 years, 77.8% men, 80.1% white), 81 individuals (37.5%) were switched to mTOR inhibition. mTOR inhibition was associated with a reduction in intimal thickness by 0.05 mm (95% CI 0.02-0.07; P < 0.001). This reduction was driven by patients who met the criteria for rapidly progressive CAV 1-year post-transplant (0.12 mm; P = 0.016 for interaction). After a median follow-up of 8.6 (IQR 6.6-11) years, 40 patients had major adverse cardiovascular outcomes. The use of mTOR inhibitors was not significantly associated with cardiovascular outcomes (P = 0.669).

CONCLUSION

Transitioning patients after heart transplantation to an immunosuppression regimen composed of low-dose mTOR inhibition and tacrolimus was associated with a lack of progression of CAV, particularly in those with rapidly progressive CAV at 1 year, but not with long-term cardiovascular outcomes.

Evolution of the impact of the COVID-19 pandemic on heart transplant recipients: Decreasing risk, improving perspective

BACKGROUND AND METHODS

Heart transplant recipients (HTr) have a higher probability of suffer from severe coronavirus disease-2019 (COVID-19) in comparison to general population, but their risk has changed over the course of the pandemic in relation to various factors. We conducted a prospective study including all HTr at risk of COVID-19 in a tertiary center between February 2020 and October 2022. The aim was to analyze how the prognosis (incidence of pneumonia and mortality) of COVID-19 in HTr has evolved over time, contextualizing variants, vaccination, and other treatments.

RESULTS

Of 308 HTr included, 124 got the infection (39.2%). COVID and non-COVID HTr had similar baseline characteristics. COVID-19 patients with pneumonia had a poorer prognosis than those with less severe presentations, with a higher rate of hospitalization (93.3 vs. 14.1%, p < .001) and death (41.0 vs. 1.2%, p < .001). Multivariate analysis identified age ≥60 years (odds ratio [OR] 3.65, 95% confidence interval [CI] 1.16-11.49, p = .027), and chronic kidney disease ≥3a (OR 4.95, 95% CI 1.39-17.54, p = .014) as predictors of pneumonia. Two-dose vaccination (OR 0.20, CI 95% 0.05-0.72, p = .02) and early remdesivir administration (OR 0.17, CI 0.03-0.90, p = .037) were protective factors. Over the course of the pandemic considering three periods in the follow-up (prevaccination February-December 2020, postvaccination January-December 2021, and post early remdesivir indication January-October 2022), we observed a reduction in pneumonia incidence from 62% to 19% (p < .001); and mortality (from 23% to 4%, p < .001).

CONCLUSIONS

The prognosis of COVID-19 in HTr has improved over time, likely due to vaccination and early administration of remdesivir.

Long-term implantable ventricular assist device support in children

BACKGROUND

In pediatrics, implantable continuous-flow ventricular assist devices (IC-VAD) are often used as a "temporary" support, bridging children to cardiac transplantation during the same hospital admission.

METHODS

We conducted a retrospective review of our consecutive patients undergoing IC-VAD support at a tertiary pediatric heart center between 2008 and 2022.

RESULTS

We identified 100 IC-VAD implant encounters: HeartWare HVAD (67; 67%), HeartMate II (17; 17%), and HeartMate 3 (16; 16%). The median (range) age, weight, and body surface area at implantation were 14.1 (3.0-56.5) years, 54.8 (13.3-140) kg, and 1.6 (0.6-2.6) m2, respectively. Cardiomyopathy (58; 58%) was the most common etiology, followed by congenital heart disease (37; 37%, including 13 single ventricle). At 6 months of IC-VAD support, 94 (94%) encounters achieved positive outcomes: ongoing support (59; 59%), transplant (33; 33%), and cardiac recovery (2; 2%). Eighty-two encounters (82%) resulted in home discharge with ongoing VAD support, including 38 (46%, out of 82) requiring readmission and 7 (9%, out of 82) resulting in death. There was a clinically significant decrease in morbidity rates before versus after home discharge: bleeding (1.55 vs 0.06), infection (0.84 vs 0.37), and stroke (0.84 vs 0.15 event per patient-year). Overall, 86 encounters (86%) reached positive end points at the latest follow-up (64 transplant, 15 ongoing support, and 7 recovery). Infection (29%; 4 of 14) was the most common cause of negative outcomes, followed by cerebrovascular accident (21%; 3), and unresolved frailty (21%; 3). The estimated overall survival at 1, 2, and 5 years was 90%, 86%, and 77%, respectively.

CONCLUSIONS

This study suggests the feasibility of outpatient management of pediatric IC-VAD support. The ability to offer true long-term support maximizes the potential of IC-VAD support, not limited to a temporary bridging tool for heart transplantation.

Cardiac allograft vasculopathy in heart transplant recipients from hepatitis C viremic donors

BACKGROUND

Recent studies suggest the transplantation of Hepatitis C (HCV) hearts from viremic donors is associated with comparable 1 year survival to nonviremic donors. Though HCV viremia is a known risk factor for accelerated atherosclerosis, data on cardiac allograft vasculopathy (CAV) outcomes are limited. We compared the incidence of CAV in heart transplant recipients from HCV viremic donors (nucleic acid amplification test positive; NAT+) compared to non-HCV infected donors (NAT-).

METHODS

We retrospectively reviewed annual coronary angiograms with intravascular ultrasound from April 2017 to August 2020 at two large cardiac transplant centers. CAV was graded according to ISHLT guidelines. Maximal intimal thickness (MIT) ≥ 0.5 mm was considered significant for subclinical disease.

RESULTS

Among 270 heart transplant recipients (mean age 54; 77% male), 62 patients were transplanted from NAT+ donors. CAV ≥ grade 1 was present in 8.8% of the NAT+ versus 16.8% of the NAT- group at 1 year, 20% versus 28.8% at 2 years, and 33.3% versus 41.5% at 3 years. After adjusting for donor age, donor smoking history, recipient BMI, recipient, hypertension, and recipient diabetes, NAT+ status did not confer increased risk of CAV (HR.80; 95% CI.45-1.40, p = 0.43) or subclinical IVUS disease (HR.87; 95% CI.58-1.30, p = 0.49). Additionally, there was no difference in the presence of rapidly progressive lesions on IVUS.

CONCLUSION

Our data show that NAT+ donors conferred no increased risk for early CAV or subclinical IVUS disease following transplantation in a cohort of heart transplant patients who were treated for HCV, suggesting the short-term safety of this strategy to maximize the pool of available donor hearts.

Exploring personalized treatment for cardiac graft rejection based on a four-archetype analysis model and bioinformatics analysis

Heart transplantation is the gold standard for treating patients with advanced heart failure. Although improvements in immunosuppressive therapies have significantly reduced the frequency of cardiac graft rejection, the incidences of T cell-mediated rejection (TCMR) and antibody-mediated rejection remain almost unchanged. A four-archetype analysis (4AA) model, developed by Philip F. Halloran, illustrated this problem well. It provided a new dimension to improve the accuracy of diagnoses and an independent system for recalibrating the histology guidelines. However, this model was based on the invasive method of endocardial biopsy, which undoubtedly increased the postoperative risk of heart transplant patients. Currently, little is known regarding the associated genes and specific functions of the different phenotypes. We performed bioinformatics analysis (using machine-learning methods and the WGCNA algorithm) to screen for hub-specific genes related to different phenotypes, based Gene Expression Omnibus accession number GSE124897. More immune cell infiltration was observed with the ABMR, TCMR, and injury phenotypes than with the stable phenotype. Hub-specific genes for each of the four archetypes were verified successfully using an external test set (accession number GSE2596). Logistic-regression models based on TCMR-specific hub genes and common hub genes were constructed with accurate diagnostic utility (area under the curve > 0.95). RELA, NFKB1, and SOX14 were identified as transcription factors important for TCMR/injury phenotypes and common genes, respectively. Additionally, 11 Food and Drug Administration-approved drugs were chosen from the DrugBank Database for each four-archetype model. Tyrosine kinase inhibitors may be a promising new option for transplant rejection treatment. KRAS signaling in cardiac transplant rejection is worth further investigation. Our results showed that heart transplant rejection subtypes can be accurately diagnosed by detecting expression of the corresponding specific genes, thereby enabling precise treatment or medication.

The Effects of Exercise on Cardiogenic Shock with an Intra-Aortic Balloon Pump: A Case Report

This case report describes the exercise program on a hospitalized 54-year-old male patient with cardiogenic shock waiting for a heart transplant assisted by an intra-aortic balloon pump, a temporary mechanical circulatory support device. The temporary mechanical circulatory support device, an intra-aortic balloon pump, was placed in the left subclavian artery, enabling the exercise protocol. Measurements and values from Swan-Ganz catheter, blood sample, brain natriuretic peptide (NT-proBNP), and high-sensitivity C-reactive protein (hs-CRP), as well as the six-minute walk test (6MWT) and venous oxygen saturation (SvO2) were obtained before and after an exercise protocol. The exercise training protocol involved the use of an unloaded bed cycle ergometer once a day, for a maximum of 30 minutes, to the tolerance limit. No adverse events or events related to the dislocation of the intra-aortic balloon pump were observed during the exercise protocol. The exercise program resulted in higher SvO2 levels, with an increased 6MWT with lower Borg dyspnea scores (312 meters vs. 488 meters and five points vs. three points, respectively). After completing the ten-day exercise protocol, the patient underwent a non-complicated heart transplant surgery and a full recovery in the ICU. This study showed that exercise is a feasible option for patients with cardiogenic shock who are using an intra-aortic balloon pump and that it is well-tolerated with no reported adverse events.

Ten-year outcomes post percutaneous coronary intervention in cardiac transplant recipients

BACKGROUND

Cardiac allograft vasculopathy (CAV) is one of the major late causes of mortality in cardiac transplant recipients beyond the first year. Given the lack of longer term data for PCI in cardiac transplant recipients, we report ten year follow up of such cardiac transplant recipients who underwent PCI at Mayo Clinic.

METHODS

A retrospective observational study was conducted that included cardiac transplant recipients who underwent PCI at the Mayo Clinic. Continuous variables were presented as mean (SD) or median (IQR) and discrete variables were presented as frequency (percentage).

RESULTS

Thirty-eight consecutive cardiac transplant recipients underwent PCI from January 1, 1995, to June 30, 2023, at the Mayo Clinic. The median age of the cohort was 61.00 years (IQR:51.00-70.00) comprised predominantly of men (65.80%), and 47.40% of the cohort presented with an acute coronary syndrome. The antirejection therapy prior to the PCI included steroids (47.30%), cyclosporine (26.30%), tacrolimus (15.80%), mycophenolate (42.10%), azathioprine (13.10%), & sirolimus (31.57%). Intravascular ultrasound during PCI was utilized in 10.50% of the cases. The median time duration between heart transplant and PCI was 9.00 years (IQR:6.00-13.00 years). Two individuals needed repeat heart transplant for severe CAV. In hospital mortality was 5.20% and the long-term median survival was 7.20 years with a 10-year mortality rate of 65.70%.

CONCLUSIONS

This is the first publication reporting ten-year outcomes for PCI in cardiac transplant patients. The salient features for our cohort were a 65.70% mortality rate at 10 years and a median survival of 7.20 years.

Sex-Linked Differences in Cardiac Atrophy After Mechanical Unloading Induced by Heterotopic Heart Transplantation

No information is available about sex-related differences in unloading-induced cardiac atrophy. We aimed to compare the course of unloading-induced cardiac atrophy in intact (without gonadectomy) male and female rats, and in animals after gonadectomy, to obtain insight into the influence of sex hormones on this process. Heterotopic heart transplantation (HT((x)) was used as a model for heart unloading. Cardiac atrophy was assessed as the weight ratio of heterotopically transplanted heart weight (HW) to the native HW on days 7 and 14 after HTx in intact male and female rats. In separate experimental groups, gonadectomy was performed in male and female recipient animals 28 days before HT(x) and the course of cardiac atrophy was again evaluated on days 7 and 14 after HT(x). In intact male rats, HT(x) resulted in significantly greater decreases in whole HW when compared to intact female rats. The dynamics of the left ventricle (LV) and right ventricle (RV) atrophy after HT(x) was quite similar to that of whole hearts. Gonadectomy did not have any significant effect on the decreases in whole HW, LV, and RV weights, with similar results in male and female rats. Our results show that the development of unloading-induced cardiac atrophy is substantially reduced in female rats when compared to male rats. Since gonadectomy did not alter the course of cardiac atrophy after HTx, similarly in both male and female rats, we conclude that sex-linked differences in the development of unloading-induced cardiac atrophy are not caused by the activity of sex hormones.

Metabolic Syndrome and Heart Transplantation: An Underestimated Risk Factor?

Metabolic Syndrome (MetS), a multifactorial condition that increases the risk of cardio-vascular events, is frequent in Heart-transplant (HTx) candidates and worsens with immunosuppressive therapy. The aim of the study was to analyze the impact of MetS on long-term outcome of HTx patients. Since 2007, 349 HTx patients were enrolled. MetS was diagnosed if patients met revised NCEP-ATP III criteria before HTx, at 1, 5 and 10 years of follow-up. MetS was present in 35% of patients pre-HTx and 47% at 1 year follow-up. Five-year survival in patients with both pre-HTx (65% vs. 78%, p < 0.01) and 1 year follow-up MetS (78% vs 89%, p < 0.01) was worst. At the univariate analysis, risk factors for mortality were pre-HTx MetS (HR 1.86, p < 0.01), hypertension (HR 2.46, p < 0.01), hypertriglyceridemia (HR 1.50, p=0.03), chronic renal failure (HR 2.95, p < 0.01), MetS and diabetes at 1 year follow-up (HR 2.00, p < 0.01; HR 2.02, p < 0.01, respectively). MetS at 1 year follow-up determined a higher risk to develop Coronary allograft vasculopathy at 5 and 10 year follow-up (25% vs 14% and 44% vs 25%, p < 0.01). MetS is an important risk factor for both mortality and morbidity post-HTx, suggesting the need for a strict monitoring of metabolic disorders with a careful nutritional follow-up in HTx patients.

Unraveling the Uncommon: A Case Report of Giant Cell Myocarditis and Examination of Existing Literature

BACKGROUND Idiopathic giant cell myocarditis (IGCM) is an uncommon and frequently fatal type of myocarditis. It primarily affects young individuals and has the potential to result in heart failure and life-threatening arrhythmias. IGCM seems to be dependent on activation of CD4-positive T lymphocytes and can show improvement with treatment aimed at reducing T-cell function. We present a case of a 65-year-old patient who presented with features of acute heart failure refractory to guideline-directed medical therapy (GDMT), due to IGCM. A review of the natural history and treatment of IGCM is also presented. CASE REPORT A 65-year-old woman with multiple comorbidities was admitted to our hospital for ventricular tachycardia in the setting of progressive non-ischemic heart failure, unresponsive to GDMT. This led to further investigation, including an endomyocardial biopsy, which revealed inflammatory infiltration, with multinucleated giant cells and lymphocytes in the absence of granuloma formation, prompting a diagnosis of IGCM. An implantable cardioverter-defibrillator (ICD) was placed for secondary prevention of sudden cardiac death and the patient was initiated on combined immunosuppressive therapy. Owing to numerous comorbidities, she was determined to be unsuitable for a heart transplant. Unfortunately, she eventually died from complications secondary to the disease. CONCLUSIONS IGCM remains a challenging clinical diagnosis with a poor long-term outcome without heart transplantation. This case highlights the importance of considering atypical causes of heart failure in patients who do not respond to conventional therapies. Early recognition and appropriate management, involving medical and interventional approaches, are crucial in improving outcomes for patients with IGCM.

Outcomes following successful decannulation from extracorporeal life support for cardiogenic shock

OBJECTIVE

Although extracorporeal life support (ECLS) has increasingly been used for the treatment of patients with cardiogenic shock (CS), the outcomes of those successfully weaned from support remain poorly defined.

METHODS

Of 510 venoarterial ECLS CS patients at our institution between January 2015 and December 2020, 249 were decannulated and survived for 30 days or until discharge (ie, successfully weaned). Factors associated with survival to discharge were assessed and 1-year survival was described.

RESULTS

Of 510 eligible CS ECLS patients, 249 (48.8%) were successfully decannulated, 227 (44.5%) died during/following ECLS, and 34 (6.7%) were bridged to heart transplantation or a ventricular assist device. Patients with a primary graft dysfunction etiology of CS had a greater chance of successful decannulation (odds ratio [OR], 3.088; 95% CI, 1.1-8.671; P = .0323), whereas patients with ECLS during cardiopulmonary resuscitation had a reduced chance of successful decannulation (OR, 0.354; 95% CI, 0.17-0.735; P = .0054). Of successfully decannulated patients, 218 (87.6%) survived to hospital discharge and 31 (12.4%) died in the hospital. Acute myocardial infarction etiology (OR, 4.751; 95% CI, 1.623-13.902; P = .0044), preexisting chronic kidney disease (OR, 3.422; 95% CI, 1.374-8.52; P = .0082), and initiation of continuous renal replacement therapies (OR, 3.188; 95% CI, 1.291-7.871; P = .012) were significantly associated with in-hospital mortality despite successful decannulation. One-year survival in successfully decannulated patients surviving to hospital discharge was 95.0% and comparable to 1-year survival in patients who received a heart transplant or ventricular assist device.

CONCLUSIONS

Successful decannulation can be achieved in a significant proportion of patients treated with ECLS for CS but does not guarantee survival to hospital discharge. However, 1-year survival of hospital survivors remains high and is comparable to patients bridged to transplant or a ventricular assist device.

Use and Outcomes of Hepatitis B Virus-positive Grafts for Kidney or Heart Transplantation in the United States From 1999 to 2021

BACKGROUND

The gap between demand and supply for solid organ transplants requires strategies to expand the donor pool. Successful use of hepatitis B virus (HBV)-positive grafts has been reported in liver transplantation.

METHODS

In this United Network for Organ Sharing database (January 1999 to June 2021) retrospective cohort study, outcomes of kidney transplant (KT) or heart transplant (HT) recipients with HBV donor grafts (hepatitis B surface antigen and/or for HBV nucleic acid test-positive) were examined. Propensity score matching was performed for HBV-positive to negative graft recipients (1:5 for renal transplantation and 1:10 for HT).

RESULTS

Of 448 HBV-positive donors with 896 kidneys, 352 kidneys (39.3%) and 56 hearts (12.5%) were transplanted. Of these, 312 kidneys (88.6%) and 45 hearts (80.3%) were transplanted in hepatitis B surface antigen-negative recipients. Ten-year graft survival was 47.1% and 49% (log-rank P = 0.353), and patient survival was 58% and 59% ( P = 0.999) for KT recipients. Similar figures among HT recipients were 41.9% and 38.9% for graft survival ( P = 0.471), and 54.3% and 61.2% for patient survival ( P = 0.277). Subgroup analyses in recipients with HBV nucleic acid test-positive grafts irrespective of antibodies to HBV core antigen-positive status, and recipients negative for anti-HBs (548 renal transplantation and 209 HT) were similar.

CONCLUSIONS

Although we are limited by lack of available data on posttransplant anti-HBV treatment, the study observations suggest that using HBV-positive grafts is a reasonable strategy to expand the donor pool among candidates waiting for KT or HT.

HLA sensitization is associated with an increased risk of primary graft dysfunction after heart transplantation

Primary graft dysfunction (PGD) is a leading cause of early morbidity and mortality following heart transplantation (HT). We sought to determine the association between pretransplant human leukocyte antigen (HLA) sensitization, as measured using the calculated panel reactive antibody (cPRA) value, and the risk of PGD.

METHODS

Consecutive adult HT recipients (n = 596) from 1/2015 to 12/2019 at 2 US centers were included. Severity of PGD was based on the 2014 International Society for Heart and Lung Transplantation consensus statement. For each recipient, unacceptable HLA antigens were obtained and locus-specific cPRA (cPRA-LS) and pre-HT donor-specific antibodies (DSA) were assessed.

RESULTS

Univariable logistic modeling showed that peak cPRA-LS for all loci and HLA-A was associated with increased severity of PGD as an ordinal variable (all loci: OR 1.78, 95% CI: 1.01-1.14, p = 0.025, HLA-A: OR 1.14, 95% CI: 1.03-1.26, p = 0.011). Multivariable analysis showed peak cPRA-LS for HLA-A, recipient beta-blocker use, total ischemic time, donor age, prior cardiac surgery, and United Network for Organ Sharing status 1 or 2 were associated with increased severity of PGD. The presence of DSA to HLA-B was associated with trend toward increased risk of mild-to-moderate PGD (OR 2.56, 95% CI: 0.99-6.63, p = 0.053), but DSA to other HLA loci was not associated with PGD.

CONCLUSIONS

Sensitization for all HLA loci, and specifically HLA-A, is associated with an increased severity of PGD. These factors should be included in pre-HT risk stratification to minimize the risk of PGD.

Protein Phosphatase 2A Activation Promotes Heart Transplant Acceptance in Mice

BACKGROUND

Although heart transplantation is the definitive treatment for heart failure in eligible patients, both acute and chronic transplant rejection frequently occur. Protein phosphatase 2A (PP2A) activity is critical in maintaining tissue and organ homeostasis. In this study, we evaluated the effect of a novel class of small molecule activators of PP2A (SMAPs) on allograft rejection in a mouse heterotopic heart transplantation model.

METHODS

Recipient mice were administered with DT-061 (a pharmaceutically optimized SMAP) or vehicle by oral gavage beginning 1 d after transplantation. Histological and immunofluorescence analyses were performed to examine allograft rejection. Regulatory T cells (Treg) from recipient spleens were subjected to flow cytometry and RNA sequencing analysis. Finally, the effect of DT-061 on smooth muscle cells (SMCs) migration and proliferation was assessed.

RESULTS

DT-061 treatment prolonged cardiac allograft survival. SMAPs effectively suppressed the inflammatory immune response while increasing Treg population in the allografts, findings corroborated by functional analysis of RNA sequencing data derived from Treg of treated splenic tissues. Importantly, SMAPs extended immunosuppressive agent cytotoxic T lymphocyte-associated antigen-4-Ig-induced cardiac transplantation tolerance and allograft survival. SMAPs also strongly mitigated cardiac allograft vasculopathy as evidenced by a marked reduction of neointimal hyperplasia and SMC proliferation. Finally, our in vitro studies implicate suppression of MEK/ERK pathways as a unifying mechanism for the effect of PP2A modulation in Treg and SMCs.

CONCLUSIONS

PP2A activation prevents cardiac rejection and prolongs allograft survival in a murine model. Our findings highlight the potential of PP2A activation in improving alloengraftment in heart transplantation.

Determination of Risk Factors for Acute Kidney Injury In Orthotopic Cardiac Transplantation

BACKGROUND

In this study, we try to determine risk factors for acute kidney injury in orthotopic cardiac transplantation patients.

METHODS

Between February 2003 and December 2022, all cardiac transplantation patients were retrospectively reviewed. Finally, 102 patients enrolled in this study. Demographic data, comorbidities, preoperative cardiac catheterization parameters, preoperative and postoperative blood test results, intraoperative parameters, acute kidney injury developed or not, stage of acute kidney injury, and whether renal replacement therapy was required or not was recorded.

RESULTS

Of the 102 patients, 68 were male. Fifty-four of these patients developed acute kidney injury, and 31 required renal replacement therapy postoperatively. The mean age of developed acute kidney injury group (AKI+) was older than non-developed acute kidney injury group (non-AKI) (P = .01). The average body surface area of the AKI+ was 1.81 ± 0.32, whereas in non-AKI it was 1.57 ± 0.35 (P = .01). More patients were ex-smokers (P = .007) and had a history of hypertension (P= .011) in the AKI+ group. Preoperative serum creatinine was 1.12 ± 0.26 mg/dL in the AKI+ group and 0.82 ± 0.13 mg/dL in the non-AKI group (P = .02). The intraoperative urine output was 491.20 ± 276.48 mL for AKI+ and 676.45 ± 478.84 mL for the non-AKI group (P = .03).

CONCLUSIONS

Acute kidney injury development after cardiac transplantation is common. In our study, high body surface area, older age, ex-smoker, hypertension, low intraoperative urine output, and high preoperative serum creatinine levels were risk factors for acute kidney injury development in cardiac transplantation patients. Mortality and morbidity after cardiac transplantation might be reduced if acute kidney injury development can be lowered.

Right ventricular dysfunction in left ventricular assist device candidates: is it time to change our prospective?

The use of left ventricular assist devices (LVAD) has significantly increased in the last years, trying to offer a therapeutic alternative to heart transplantation, in light also to the significant heart donor shortage compared to the growing advanced heart failure population. Despite technological improvements in the devices, LVAD-related mortality is still fairly high, with right heart failure being one of the predominant predictors. Therefore, many efforts have been made toward a thorough right ventricular (RV) evaluation prior to LVAD implant, considering clinical, laboratory, echocardiographic, and invasive hemodynamic parameters. However, there is high heterogeneity regarding both which predictor is the strongest as well as the relative cut-off values, and a consensus has not been reached yet, increasing the risk of facing patients in which the distinction between good or poor RV function cannot be surely reached. In parallel, due to technological development and availability of mechanical circulatory support of the RV, LVADs are being considered even in patients with suboptimal RV function. The aim of our review is to analyze the current evidence regarding the role of RV function prior to LVAD and its evaluation, pointing out the extreme variability in parameters that are currently assessed and future prospective regarding new diagnostic tools. Finally, we attempt to gather the available information on the therapeutic strategies to use in the peri-operative phase, in order to reduce the incidence of RV failure, especially in patients in which the preoperative evaluation highlighted some conflicting results with regard to ventricular function.

Correlation between peripheral endothelial function, oxygen consumption and ventilatory efficiency in heart transplantation recipients

BACKGROUND

Endothelial dysfunction and peak oxygen uptake (VO2peak) are also predictors of increased risk of cardiovascular events in heart transplantation (HTx) recipients. The preservation of endothelial function may contribute to exercise tolerance.

OBJECTIVE

To investigate the correlation between peripheral endothelial function and exercise tolerance through VO2peak and ventilation to carbon dioxide production slope (VE / VCO2 slope) in HTx recipients.

METHODS

A pilot cross-sectional study was conducted with adult individuals aged 18-65 years, HTx ≥ six months after surgery, who had a stable medical condition and no changes over the last three months of immunosuppressive treatment. The patients underwent an assessment of endothelial function through PAT (EndoPAT-2000®) and performed a cardiopulmonary exercise test (CPET).

RESULTS

A total of 41% of the studied population presented endothelial dysfunction. The individuals were divided into two groups: the endothelial dysfunction (GED; n=9) group and the normal endothelial function (GNEF; n=13) group according to the logarithm of the reactive hyperemia index (LnRHI). There was a positive and moderate correlation between the LnRHI and VO2 peak (r=0.659, p=0.013) and a negative and moderate correlation between the LnRHI and VE/VCO2 slope (r= -0.686, p= 0.009) in the GNEF. However, no significant correlations were found in the GED.

CONCLUSION

The results showed that the preservation of peripheral endothelial function is significantly correlated with an increase in exercise tolerance in individuals after HTx. These findings bring important considerations for cardiovascular risk prevention and emphasize that therapeutic strategies with physical training programs must be implemented early.

Understanding Tricuspid Regurgitation Post Cardiac Transplantation; Why "Anatomical" and "Functional" Just Won't Cut It

Tricuspid regurgitation (TR) is common after cardiac transplantation and results in poorer outcomes. Transplant recipients are at high prohibitive risk for redo surgical procedures because of risks associated with a subsequent sternotomy, immunosuppression, and renal failure. Percutaneous therapies have recently become available and may be an option for transplant recipients. However, transplant recipients have complex geometry, and there is a myriad of causes of TR posttransplant. There is a need for careful patient selection for all percutaneous valve interventions, and this is particularly true in transplant recipients who suffer from right ventricular failure and rejection and may undergo repeated endomyocardial biopsies. Cognizant of the rapid developments in this space, this review article focuses on the causes of TR, treatments, and future therapies in heart transplantation recipients to the transplant cardiologist navigate this complex area.

Type A Aortic Dissection in Heart Transplantation Recipients in the United States

BACKGROUND

Type A aortic dissection in heart transplantation recipients is rare and lethal, with limited research beyond case reports. This study aimed to analyze patient characteristics and clinical outcomes of this condition through a US national database.

METHODS

The National Inpatient Sample database (2002-2018) was used to identify all type A aortic dissection in heart transplantation recipients aged >18 years. Incidence was quantified annually. Primary outcomes were in-hospital mortality; secondary outcomes were hospital length of stay and complications.

RESULTS

We identified 78 cases of type A aortic dissection in heart transplantation recipients. Compared with type A aortic dissection patients without a history of solid organ transplantation (N = 70,715), our patients were younger (55.3 vs 60.7 years), less likely female (18.5% vs 33.5%), and more frequently Black or Hispanic (55% vs 23%). They had a greater prevalence of Marfan syndrome (13% vs 3%), congestive heart failure (46% vs 19%), and chronic kidney disease (19% vs 10%), as well as increased in-hospital mortality (30% vs 18%) and a longer hospital length of stay (29.5 vs 13.7 days). They experienced elevated rates of cardiac (57% vs 31%), respiratory (70. % vs 41%), renal (76% vs 30%), and bleeding complications (37% vs 14%).

CONCLUSIONS

Type A aortic dissection in heart transplantation recipients appears to exhibit distinct characteristics and poorer outcomes compared with those in the general population. Heart transplantation recipients with predisposing risk factors warrant heightened attention to help prevent this devastating condition.

Early left ventricular systolic function is a more sensitive predictor of adverse events after heart transplant

BACKGROUND

First-phase ejection fraction (EF1) is a novel measure of early changes in left ventricular systolic function. This study was to investigate the prognostic value of EF1 in heart transplant recipients.

METHODS

Heart transplant recipients were prospectively recruited at the Union Hospital, Wuhan, China between January 2015 and December 2019. All patients underwent clinical examination, biochemistry measures [brain natriuretic peptide (BNP) and creatinine] and transthoracic echocardiography. The primary endpoint was a combined event of all-cause mortality and graft rejection.

RESULTS

In 277 patients (aged 48.6 ± 12.5 years) followed for a median of 38.7 [26.8-45.0] months, there were 35 (12.6%) patients had adverse events including 20 deaths and 15 rejections. EF1 was negatively associated with BNP (β = -0.220, p < 0.001) and was significantly lower in patients with events compared to those without. EF1 had the largest area under the curve in ROC analysis compared to other measures. An optimal cut-off value of 25.8% for EF1 had a sensitivity of 96.3% and a specificity of 97.1% for prediction of events. EF1 was the most powerful predictor of events with hazard ratio per 1% change in EF1: 0.628 (95%CI: 0.555-0.710, p < 0.001) after adjustment for left ventricular ejection fraction and global longitudinal strain.

CONCLUSIONS

Early left ventricular systolic function as measured by EF1 is a powerful predictor of adverse outcomes after heart transplant. EF1 may be useful in risk stratification and management of heart transplant recipients.

Textbook outcome: A novel metric in heart transplantation outcomes

OBJECTIVE

Assessing heart transplant program quality using short-term survival is insufficient. We define and validate the composite metric textbook outcome and examine its association with overall survival.

METHODS

We identified all primary, isolated adult heart transplants in the United Network for Organ Sharing/Organ Procurement and Transplantation Network Standard Transplant Analysis and Research files from May 1, 2005, to December 31, 2017. Textbook outcome was defined as length of stay 30 days or less; ejection fraction greater than 50% during 1-year follow-up; functional status 80% to 100% at 1 year; freedom from acute rejection, dialysis, and stroke during the index hospitalization; and freedom from graft failure, dialysis, rejection, retransplantation, and mortality during the first year post-transplant. Univariate and multivariate analyses were performed. Factors independently associated with textbook outcome were used to create a predictive nomogram. Conditional survival at 1 year was measured.

RESULTS

A total of 24,620 patients were identified with 11,169 (45.4%, 95% confidence interval, 44.7-46.0) experiencing textbook outcome. Patients with textbook outcome were more likely free from preoperative mechanical support (odds ratio, 3.504, 95% confidence interval, 2.766 to 4.439, P < .001), free from preoperative dialysis (odds ratio, 2.295, 95% confidence interval, 1.868-2.819, P < .001), to be not hospitalized (odds ratio, 1.264, 95% confidence interval, 1.183-1.349, P < .001), to be nondiabetic (odds ratio, 1.187, 95% confidence interval, 1.113-1.266, P < .001), and to be nonsmokers (odds ratio, 1.160, 95% confidence interval,1.097-1.228, P < .001). Patients with textbook outcome have improved long-term survival relative to patients without textbook outcome who survive at least 1 year (hazard ratio for death, 0.547, 95% confidence interval, 0.504-0.593, P < .001).

CONCLUSIONS

Textbook outcome is an alternative means of examining heart transplant outcomes and is associated with long-term survival. The use of textbook outcome as an adjunctive metric provides a holistic view of patient and center outcomes.

A Preliminary Study of One Year Safety and Tolerability of Attention-Deficit/Hyperactivity Disorder Medications in Youth with Fontan Palliation or Heart Transplant

There are no published studies that examine the safety and tolerability of medication to treat attention-deficit/hyperactivity disorder (ADHD) in children with histories of Fontan palliation (Fontan) or heart transplant (HT), despite the high prevalence of ADHD in these populations. To address this gap, we examined the cardiac course, somatic growth, and incidence of side effects for one year after medication initiation amongst children with Fontan or HT and comorbid ADHD. The final sample comprised 24 children with Fontan (12 medication-treated, 12 control) and 20 children with HT (10 medication-treated, 10 control). Demographic, somatic growth (height and weight percentile-for age), and cardiac data (blood pressure, heart rate, results of 24 h Holter monitoring, electrocardiograms) were extracted from electronic medical records. Medication-treated and control subjects were matched by cardiac diagnosis (Fontan or HT), age, and sex. Nonparametric statistical tests were utilized to compare between- and within-group differences prior to, and one year post, medication initiation. There were no differences in somatic growth or cardiac data when comparing medication-treated participants to matched controls, regardless of cardiac diagnosis. Within the medication group, a statistically significant increase in blood pressure was observed, though the group average remained within clinically acceptable limits. While results are preliminary in nature due to our very limited sample size, our findings suggest that ADHD medications can be tolerated with minimal cardiac or somatic growth effects amongst complex cardiac patients. Our preliminary results favor treating ADHD with medication, which has considerable implications for long-term academic/employment outcomes and quality of life for this population. Close collaboration between pediatricians, psychologists, and cardiologists is essential to individualizing and optimizing interventions and outcomes for children with Fontan or HT.

Acetylsalicylic acid use and development of cardiac allograft vasculopathy: A national prospective study using highly automated 3-D optical coherence tomography analysis

BACKGROUND

There is conflicting evidence on the role of acetylsalicylic acid (ASA) use in the development of cardiac allograft vasculopathy (CAV).

METHODS

A nationwide prospective two-center study investigated changes in the coronary artery vasculature by highly automated 3-D optical coherence tomography (OCT) analysis at 1 month and 12 months after heart transplant (HTx). The influence of ASA use on coronary artery microvascular changes was analyzed in the overall study cohort and after propensity score matching for selected clinical CAV risk factors.

RESULTS

In total, 175 patients (mean age 52 ± 12 years, 79% male) were recruited. During the 1-year follow-up, both intimal and media thickness progressed, with ASA having no effect on its progression. However, detailed OCT analysis revealed that ASA use was associated with a lower increase in lipid plaque (LP) burden (p = .013), while it did not affect the other observed pathologies. Propensity score matching of 120 patients (60 patient pairs) showed similar results, with ASA use associated with lower progression of LPs (p = .002), while having no impact on layered fibrotic plaque (p = .224), calcification (p = .231), macrophage infiltration (p = .197), or the absolute coronary artery risk score (p = .277). According to Kaplan-Meier analysis, ASA use was not associated with a significant difference in survival (p = .699) CONCLUSION: This study showed a benefit of early ASA use after HTx on LP progression. However, ASA use did not have any impact on the progression of other OCT-observed pathologies or long-term survival.

A Case of Abnormal Right Ventricular Color-Flow Doppler Jet

Transthoracic echocardiography is used routinely during the follow-up after heart transplant surgery to screen possible complications and adverse events such as rejection. It often results in incidental findings that bring diagnostic challenges for sonographers. This E-challenge shows a Doppler flow abnormality associated with a rare cardiovascular diagnosis. Its physiopathology and its association with echocardiography findings are reviewed.

Cytomegalovirus infection is associated with impaired myocardial flow reserve after heart transplantation

BACKGROUND

Cardiac allograft vasculopathy (CAV) limits long-term survival after heart transplantation (HT). This study evaluates the relationship between clinically significant cytomegalovirus infection (CS-CMVi) and CAV using cardiac positron emission tomography (PET).

METHODS

We retrospectively evaluated HT patients from 2005 to 2019 who underwent cardiac PET for CAV evaluation. Multivariable linear and logistic regression models were used to evaluate the association between CS-CMVi and myocardial flow reserve (MFR). Kaplan-Meier and Cox regression analyses were used to assess the relationship between CS-CMV, MFR, and clinical outcomes.

RESULTS

Thirty-two (31.1%) of 103 HT patients developed CS-CMVi at a median 9 months after HT. Patients with CS-CMVi had a significantly lower MFR at year 1 and 3, driven by reduction in stress myocardial blood flow. Patients with CS-CMVi had a faster rate of decline in MFR compared to those without infection (-0.10 vs -0.06 per year, p < 0.001). CS-CMVi was an independent predictor of abnormal MFR (<2.0) (odds ratio: 3.8, 95% confidence intervals (CI): 1.4-10.7, p = 0.001) and a lower MFR (β = -0.39, 95% CI: -0.63 to -0.16, p = 0.001) at year 3. In adjusted survival analyses, both abnormal MFR (log-rank p < 0.001; hazard ratio [HR]: 5.7, 95% CI: 4.2-7.2) and CS-CMVi (log-rank p = 0.028; HR: 3.3, 95% CI: 1.8-4.8) were significant predictors of the primary outcome of all-cause mortality, retransplantation, heart failure hospitalization, and acute coronary syndrome.

CONCLUSIONS

CS-CMVi is an independent predictor of reduced MFR following HT. These findings suggest that CMV infection is an important risk factor in the development and progression of CAV.

Early post-transplant hyperglycemia and post-transplant diabetes mellitus following heart transplantation

INTRODUCTION

Heart transplantation is an important treatment for end-stage heart failure. Early post-transplant hyperglycemia (EPTH) and post-transplant diabetes mellitus (PTDM) are common following heart transplantation and are associated with increased morbidity and mortality.

AREAS COVERED

This review summarizes the clinical characteristics, diagnosis, and treatment of EPTH and PTDM in cardiac transplant patients, incorporating findings from non-cardiac solid organ transplant studies where relevant due to limited heart-specific research.

EXPERT OPINION

EPTH following heart transplantation is common yet understudied and is associated with the later development of PTDM. PTDM is associated with adverse outcomes including infection, renal dysfunction, microvascular disease, and an increased risk of re-transplantation and mortality. Risk factors for EPTH include the post-operative immunosuppression regimen, recipient and donor age, body mass index, infections, and chronic inflammation. Early insulin treatment is recommended for EPTH, whereas PTDM management is varied and includes lifestyle modification, anti-glycemic agents, and insulin. Given the emerging evidence on the transplant benefits associated with effective glucose control, and the cardioprotective potential of newer anti-glycemic agents, further focus on the management of EPTH and PTDM within heart transplant recipients is imperative.

Improved waitlist and comparable post-transplant outcomes in simultaneous heart-kidney transplantation under the 2018 heart allocation system

OBJECTIVE

This study aimed to investigate the clinical trends and the impact of the 2018 heart allocation policy change on both waitlist and post-transplant outcomes in simultaneous heart-kidney transplantation in the United States.

METHODS

The United Network for Organ Sharing registry was queried to compare adult patients before and after the allocation policy change. This study included 2 separate analyses evaluating the waitlist and post-transplant outcomes. Multivariable analyses were performed to determine the 2018 allocation system's risk-adjusted hazards for 1-year waitlist and post-transplant mortality.

RESULTS

The initial analysis investigating the waitlist outcomes included 1779 patients listed for simultaneous heart-kidney transplantation. Of these, 1075 patients (60.4%) were listed after the 2018 allocation policy change. After the policy change, the waitlist outcomes significantly improved with a shorter waitlist time, lower likelihood of de-listing, and higher likelihood of transplantation. In the subsequent analysis investigating the post-transplant outcomes, 1130 simultaneous heart-kidney transplant recipients were included, where 738 patients (65.3%) underwent simultaneous heart-kidney transplantation after the policy change. The 90-day, 6-month, and 1-year post-transplant survival and complication rates were comparable before and after the policy change. Multivariable analyses demonstrated that the 2018 allocation system positively impacted risk-adjusted 1-year waitlist mortality (sub-hazard ratio, 0.66, 95% CI, 0.51-0.85, P < .001), but it did not significantly impact risk-adjusted 1-year post-transplant mortality (hazard ratio, 1.03; 95% CI, 0.72-1.47, P = .876).

CONCLUSIONS

This study demonstrates increased rates of simultaneous heart-kidney transplantation with a shorter waitlist time after the 2018 allocation policy change. Furthermore, there were improved waitlist outcomes and comparable early post-transplant survival after simultaneous heart-kidney transplantation under the 2018 allocation system.

Use of induction therapy post-heart transplantation: Clinical practice recommendations based on systematic review and network meta-analysis of evidence

BACKGROUND

The use of induction therapy (IT) agents in the early post-heart transplant period remains controversial. The following recommendations aim to provide guidance on the use of IT agents, including Basiliximab and Thymoglobulin, as part of routine care in heart transplantation (HTx).

METHODS

We recruited an international, multidisciplinary panel of 15 stakeholders, including patient partners, transplant cardiologists and surgeons, nurse practitioners, pharmacists, and methodologists. We commissioned a systematic review on benefits and harms of IT on patient-important outcomes, and another on patients' values and preferences to inform our recommendations. We used the GRADE framework to summarize our findings, rate certainty in the evidence, and develop recommendations. The panel considered the balance between benefits and harms, certainty in the evidence, and patient's values and preferences, to make recommendations for or against the routine post-operative use of Thymoglobulin or Basiliximab.

RESULTS

The panel made recommendations on three major clinical problems in HTx: (1) We suggest against the routine post-operative use of Basiliximab compared to no IT, (2) we suggest against the routine use of Thymoglobulin compared to no IT, and (3) for those patients for whom IT is deemed desirable, we suggest for the use of Thymoglobulin as compared to Basiliximab.

CONCLUSION

This report highlights gaps in current knowledge and provides directions for clinical research in the future to better understand the clinical utility of IT agents in the early post heart transplant period, leading to improved management and care.

Flap management following orthotopic heart transplantation: A single institution's review of 66 sternal wound complications

BACKGROUND

Sternotomy wound complications are more frequent after orthotopic heart transplantation (OHT) compared to other cardiac surgeries, primarily due to additional risk factors, including immunosuppression. Flap closure often becomes necessary for definitive treatment, although there is a scarcity of data on the outcomes of sternal wound reconstruction in this specific population.

METHODS

A retrospective analysis was conducted on 604 sternal wound reconstructions performed by a single surgeon between 1996 and 2023. Inclusion criteria comprised patients who underwent OHT as their primary cardiac procedure. Surgical interventions involved sternal hardware removal, debridement, and muscle flap closure.

RESULTS

The study included 66 patients, with culture-positive wound infection being the most common indication for reconstruction (51.5%). The median duration between transplantation and sternal wound reconstruction was 25 days. Bilateral pectoralis major myocutaneous advancement flaps (n = 63), rectus abdominis flaps (n = 2), or pectoralis major turnover flaps (n = 1) were used. Intraoperative wound cultures revealed positivity in 48 patients (72.7%), with Staphylococcus epidermidis being the most frequently cultured organism (25.0%). The overall complication rate was 31.8%, and two patient deaths were related to sternal wounds, resulting from multiorgan failure following septic shock. The majority of the patients reported excellent long-term functional and esthetic outcomes.

CONCLUSIONS

Sternal wounds following OHT pose a significant morbidity risk. Our strategy focuses on immediate and aggressive antibiotic therapy, thorough debridement, and definitive closure with bilateral pectoralis myocutaneous advancement flaps. This approach has demonstrated complication and mortality rates comparable to the general cardiac surgery population, as well as excellent functional and esthetic results.

Routine screening for HLA Antibodies in Heart Transplant patients-Does it affect clinical decision making?

BACKGROUND

We aimed to assess outcomes in patients with and without donor specific antibodies (DSA) and to evaluate the relationship between DSA presence and graft function, cardiac allograft vasculopathy (CAV), and mortality.

METHODS

The study population comprises 193 consecutive long-term heart transplanted (HTx) patients who underwent DSA surveillance between 2016 and 2022. The patients were prospectively screened for CAV through serial coronary angiograms, graft function impairment through serial echocardiograms, and cardiac biomarkers. The patients were followed from the first DSA measurement until death, 5 years follow-up or right censuring on the 30th of June 2023.

RESULTS

DSAs were detected in 50 patients using a cut-off at MFI ≥1000 and 45 patients using a cut-off at ≥2000 MFI. The median time since HTx was 9.0 years [3.0-14.4]. DSA positive patients had poorer graft function and higher values of NT-proBNP and troponin T, and more prevalent CAV than DSA negative patients. In total, 25 patients underwent endomyocardial biopsies due to DSA presence while another eight patients underwent endomyocardial biopsies for other reasons. Histological antibody mediated rejection (AMR) signs were seen in three biopsies. During a median follow-up of five years [4.7-5], a total of 41 patients died. Mortality rates did not differ between DSA positive and DSA negative patients (HR 1.2, 95% CI .6-2.4). DSA positive patients were more likely to experience CAV progression than DSA negative patients (HR 2.7, 95% CI 1.5-4.8) CONCLUSIONS: Routine screening reveals DSA in approximately 25% of long-term HTx patients but is rarely related to histopathological AMR signs. DSA presence was associated with poorer graft function and more prevalent and progressive CAV. However, DSA positive patients had similar survival rates to DSA negative patients.