Clinical Utility of Donor-Derived Cell-Free DNA in Heart Transplant Recipients With Multi-Organ Transplants.

BACKGROUND: Donor-derived cell-free DNA (dd-cfDNA) has emerged as a reliable, noninvasive method for the surveillance of allograft rejection in heart transplantation (HT) patients, but its utility in multi-organ transplants (MOT) is unknown. We describe our experience using dd-cfDNA in simultaneous MOT recipients. METHODS: A single-center retrospective review of all HT recipients between 2018 and 2022 that had at least one measurement of dd-cfDNA collected. Patients who had simultaneous MOT were identified and included in this study. Levels of dd-cfDNA were paired with endomyocardial biopsies (EMB) performed within 1 month of blood testing if available. Acute cellular rejection (ACR) was defined as ISHLT (International Society for Heart and Lung Transplantation) grade ≥ 2R. and antibody-mediated rejection (AMR) was defined as pAMR grade > 0. The within-patient variability score of the dd-cfDNA was calculated by the variance/average. RESULTS: The study included 25 multiorgan transplant recipients: 13 heart-kidney (H-K), 8 heart-liver (H-Li), and 4 heart-lung (H-Lu). The median age was 55 years, 44% were female; the median time from HT until the first dd-cfDNA measurement was 4.5 months (IQR 2, 10.5). The median dd-cfDNA level was 0.18% (IQR 0.15%, 0.27%) for H-K, 1.15% (IQR 0.77%, 2.33%) for H-Li, and 0.69% (IQR 0.62%, 1.07%) for H-Lu patients (p < 0.001). Prevalence of positive dd-cfDNA tests (threshold of 0.20%) were 42.2%, 97.3%, and 92.3% in the H-K, H-Li, and H-Lu groups, respectively. The within-patient variability score was highest in the H-Li group (median of 0.45 [IQR 0.29, 0.94]) and lowest in the H-K group (median of 0.09 [IQR 0.06, 0.12]); p = 0.002. No evidence of cardiac ACR or AMR was found. Three patients experienced renal allograft ACR and/or AMR, two patients experienced rejection of the liver allograft, and one patient experienced an episode of AMR-mediated lung rejection. One person in the H-K group experienced an episode of cardiac allograft dysfunction that was not associated with biopsy-confirmed rejection. CONCLUSION: Dd-cfDNA is chronically elevated in most MOT recipients. There is a high degree of within-patient variability in levels (particularly for H-Li and H-Lu recipients), which may limit the utility of this assay in monitoring MOT recipients.

Clinical Utility of the Molecular Microscope Diagnostic System in a Real-World Transplant Cohort: Moving Towards a New Paradigm.

Objectives: To evaluate the clinical implications of adjunctive molecular gene expression analysis (MMDx ) of biopsy specimens in heart transplant (HT ) recipients with suspected rejection. Introduction: Histopathological evaluation remains the standard method for rejection diagnosis in HT. However, the wide interobserver variability combined with a relatively common incidence of "biopsy-negative" rejection has raised concerns about the likelihood of false-negative results. MMDx, which uses gene expression to detect early signs of rejection, is a promising test to further refine the assessment of HT rejection. Methods: Single-center prospective study of 418 consecutive for-cause endomyocardial biopsies performed between November 2022 and May 2024. Each biopsy was graded based on histology and assessed for rejection patterns using MMDx. MMDx results were deemed positive if borderline or definitive rejection was present. The impact of MMDx results on clinical management was evaluated. Primary outcomes were 1-year survival and graft dysfunction following MMDx-guided clinical management. Secondary outcomes included changes in donor-specific antibodies, MMDx gene transcripts, and donor-derived cell-free DNA (dd-cfDNA) levels. Results: We analyzed 418 molecular samples from 237 unique patients. Histology identified rejection in 32 cases (7.7%), while MMDx identified rejection in 95 cases (22.7%). Notably, in 79 of the 95 cases where MMDx identified rejection, histology results were negative, with the majority of these cases being antibody-mediated rejection (62.1%). Samples with rejection on MMDx were more likely to show a combined elevation of dd-cfDNA and peripheral blood gene expression profiling than those with borderline or negative MMDx results (36.7% vs 28.0% vs 10.3%; p<0.001). MMDx results led to the implementation of specific antirejection protocols or changes in immunosuppression in 20.4% of cases, and in 73.4% of cases where histology was negative and MMDx showed rejection. 1-year survival was better in the positive MMDx group where clinical management was guided by MMDx results (87.0% vs 78.6%; log rank p=0.0017). Conclusions: In our cohort, MMDx results more frequently indicated rejection than histology, often leading to the initiation of antirejection treatment. Intervention guided by positive MMDx results was associated with improved outcomes.

Impact of Age of Heart Transplant Program on Patient Survival and Post-Transplant Outcomes.

BACKGROUND: The relationship between age of a heart transplant (HT) program and outcomes has not been explored. METHODS: We performed a retrospective cohort analysis of the United Network for Organ Sharing database of all adult HTs between 2009 and 2019. For each patient, we created a variable that corresponded to program age: new (<5), developing (≥5 but <10) and established (≥10) years. RESULTS: Of 20 997 HTs, 822 were at new, 908 at developing, and 19 267 at established programs. Patients at new programs were significantly more likely to have history of cigarette smoking, ischemic cardiomyopathy, and prior sternotomy. These programs were less likely to accept organs from older donors and those with a history of hypertension or cigarette use. As compared to patients at new programs, transplant patients at established programs had less frequent rates of treated rejection during the index hospitalization (HR 0.43 [95% CI, 0.36-0.53] p < 0.001) and at 1 year (HR 0.58 [95% CI, 0.49-0.70], p < 0.001), less frequently required pacemaker implantations (HR 0.50 [95% CI, 0.36-0.69], p < 0.001), and less frequently required dialysis (HR 0.66 [95% CI, 0.53-0.82], p < 0.001). However, there were no significant differences in short- or long-term survival between the groups (log-rank p = 0.24). CONCLUSION: Patient and donor selection differed between new, developing, and established HT programs but had equivalent survival. New programs had increased likelihood of treated rejection, pacemaker implantation, and need for dialysis. Standardized post-transplant practices may help to minimize this variation and ensure optimal outcomes for all patients.

Coronary vasospasm during infusion of CD-19 directed chimeric antigen receptor T-cell therapy: a case report.

Background: Cardiovascular events have been reported to occur in one in five patients receiving chimeric antigen receptor T-cell (CAR-T) therapy. Commonly reported effects including cardiomyopathy, heart failure, myocardial infarction (MI), and arrhythmia. Here, we present a novel case of a patient who developed acute ST segment elevations during CAR-T cell infusion. Case summary: A 76-year-old man with diffuse large B cell lymphoma was admitted for an investigational CD-19 directed, autologous CAR-T cell therapy. Less than 5 min into the CAR-T cell infusion, he developed severe chest pain, dyspnea, flushing, hypotension, and tachycardia. Electrocardiogram (EKG) showed inferior ST elevations and reciprocal lateral ST depressions. Emergent coronary angiography revealed mild non-obstructive coronary disease. ST segment changes and patient symptoms resolved after catheterization. Discussion: Given the complete resolution of symptoms and EKG abnormalities in the context of non-obstructive coronary artery disease, this clinical presentation was thought to be most consistent with ST elevation MI due to coronary vasospasm. The mechanism of this vasospasm is as yet not understood and may be related to an anaphylactic reaction or a cardiotoxicity related to the cell therapy agent. As the use of CAR-T therapy continues to expand, there is a need to further characterize the full spectrum of its cardiotoxic effects.

Letermovir for cytomegalovirus prophylaxis in high-risk heart transplant recipients.

Letermovir is a novel agent for the prevention of cytomegalovirus (CMV) infection and disease that, unlike traditional CMV DNA polymerase inhibitors, does not carry the risk of myelosuppression. The purpose of this study was to evaluate the safety, efficacy, and clinical application of letermovir for CMV prophylaxis in heart transplant (HT) recipients. Between November 1, 2019, and October 1, 2021, at a single, tertiary care hospital, 17 HT recipients were initiated on letermovir due to leukopenia while on valganciclovir. Fifteen (88%) had high-risk mismatch (CMV D+/R-). Median time on letermovir was 5 months (interquartile range, 2-8 months.) At the end of the study period, nine of 17 patients (52.9%) were still on letermovir and four of the 17 (23.5%) had successfully completed the prophylaxis window on letermovir and been switched to the pre-emptive strategy. One patient developed clinically significant CMV viremia in the setting of being unable to obtain medication due to insurance barriers but was later successfully restarted on letermovir. One patient was unable to tolerate letermovir due to symptoms of headache and myalgias. Two patients developed low-level non-clinically significant CMV viremia and were switched back to valacyclovir. All patients had tacrolimus dosages reduced at time of letermovir initiation to minimize the risk of supratherapeutic tacrolimus concentration. One patient required hospitalization due to symptomatic tacrolimus toxicity. For HT recipients who cannot tolerate valganciclovir, letermovir presents an alternative for CMV prophylaxis. Close monitoring for breakthrough CMV and calcineurin inhibitor levels is necessary. Larger studies are required to further delineate its use and help provide further evidence of its safety and efficacy.

Structural and functional cardiac changes in endomyocardial fibrosis treated with endomyocardial resection: Disease progression captured by multimodality imaging.

Eosinophilic myocarditis, a rare and under-recognized disease process, occurs due to cytotoxic inflammation of the endomyocardium that over time may lead to a restrictive cardiomyopathy. We report clinical, multimodality imaging, and pathologic findings in a 45-year-old woman over a 17-month period as she progressed from suspected acute eosinophilic myocarditis to phenotypic endomyocardial fibrosis resulting in recurrent ascites. Interval echocardiograms demonstrate definitive pathologic structural changes that reflect the hemodynamic consequences of the underlying cardiomyopathy. Despite a negative myocardial biopsy, characteristic findings on cardiovascular magnetic resonance imaging clarified the diagnosis which led to successful treatment with endomyocardial resection and valve replacements.

An early experience on the effect of solid organ transplant status on hospitalized COVID-19 patients.

We compared the outcome of COVID-19 in immunosuppressed solid organ transplant (SOT) patients to a transplant naïve population. In total, 10 356 adult hospital admissions for COVID-19 from March 1, 2020 to April 27, 2020 were analyzed. Data were collected on demographics, baseline clinical conditions, medications, immunosuppression, and COVID-19 course. Primary outcome was combined death or mechanical ventilation. We assessed the association between primary outcome and prognostic variables using bivariate and multivariate regression models. We also compared the primary endpoint in SOT patients to an age, gender, and comorbidity-matched control group. Bivariate analysis found transplant status, age, gender, race/ethnicity, body mass index, diabetes, hypertension, cardiovascular disease, COPD, and GFR <60 mL/min/1.73 m2 to be significant predictors of combined death or mechanical ventilation. After multivariate logistic regression analysis, SOT status had a trend toward significance (odds ratio [OR] 1.29; 95% CI 0.99-1.69, p = .06). Compared to an age, gender, and comorbidity-matched control group, SOT patients had a higher combined risk of death or mechanical ventilation (OR 1.34; 95% CI 1.03-1.74, p = .027).

COVID-19 in recent heart transplant recipients: Clinicopathologic features and early outcomes.

BACKGROUND: The impact of COVID-19 on heart transplant (HTx) recipients remains unclear, particularly in the early post-transplant period. METHODS: We share novel insights from our experience in five HTx patients with COVID-19 (three within 2 months post-transplant) from our institution at the epicenter of the pandemic. RESULTS: All five exhibited moderate (requiring hospitalization, n = 3) or severe (requiring ICU and/or mechanical ventilation, n = 2) illness. Both cases with severe illness were transplanted approximately 6 weeks before presentation and acquired COVID-19 through community spread. All five patients were on immunosuppressive therapy with mycophenolate mofetil (MMF) and tacrolimus, and three that were transplanted within the prior 2 months were additionally on prednisone. The two cases with severe illness had profound lymphopenia with markedly elevated C-reactive protein, procalcitonin, and ferritin. All had bilateral ground-glass opacities on chest imaging. MMF was discontinued in all five, and both severe cases received convalescent plasma. All three recent transplants underwent routine endomyocardial biopsies, revealing mild (n = 1) or no acute cellular rejection (n = 2), and no visible viral particles on electron microscopy. Within 30 days of admission, the two cases with severe illness remain hospitalized but have clinically improved, while the other three have been discharged. CONCLUSIONS: COVID-19 appears to negatively impact outcomes early after heart transplantation.

Outcomes Following Noncardiac Surgery in Patients with Ventricular Assist Devices: A Single-Center Experience.

the prevalence of ventricular assist devices (VADs) is increasing as advanced cardiac therapies progress. These patients commonly require non-cardiac surgical procedures (NCS), although data are scant regarding the safety, timing, and operations that may safely be performed. We aim to describe our experience with VAD patients undergoing NCS. We retrospectively reviewed records on patients who underwent NCS after VAD implantation between 2013 and 2015 at a single Joint Commission-accredited VAD institution. Data collection included demographics, ischemic cardiomyopathy or nonischemic cardiomyopathy, operative details, and perioperative anticoagulation management and outcomes. Seventy-two NCS were performed by general surgeons, thoracic surgeons, plastic surgeons, urologists, vascular surgeons, ENTs, and other services. Procedures were similarly varied, including video-assisted thoracoscopy with decortications or lung biopsy, tracheostomies, percutaneous endoscopic gastrostomies , exploratory laparotomies, and wound debridements and/or closures. The ten deaths in the study group were judged not to be directly related to NCS. Eleven cases had postoperative bleeding and two cases had postoperative thrombosis, including one pump thrombosis. Based on our results, VAD is not an absolute contraindication to NCS, and a variety of NCS procedures can safely be performed. Further study should focus on quantifying and mitigating the risk that VADs bring to NCS.

Meta-analysis of randomized trials of effect of milrinone on mortality in cardiac surgery: an update.

OBJECTIVE: The long-term use of milrinone is associated with increased mortality in chronic heart failure. A recent meta-analysis suggested that it might increase mortality in patients undergoing cardiac surgery. The authors conducted an updated meta-analysis of randomized trials in patients undergoing cardiac surgery to determine if milrinone impacted survival. DESIGN: A meta-analysis. SETTING: Hospitals. PARTICIPANTS: One thousand thirty-seven patients from 20 randomized trials. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Biomed, Central, PubMed, EMBASE, the Cochrane central register of clinical trials, and conference proceedings were searched for randomized trials that compared milrinone versus placebo or any other control in adult and pediatric patients undergoing cardiac surgery. Authors of trials that did not include mortality data were contacted. Only trials for which mortality data were available were included. Overall analysis showed no difference in mortality between patients receiving milrinone versus control (12/554 [2.2%] in the milrinone group v 10/483 [2.1%] in the control arm; relative risk [RR] = 1.15; 95% confidence interval [CI], 0.55-2.43; p = 0.7) or in analysis restricted to adults (11/364 [3%] in the milrinone group v 9/371 [2.4%] in the control arm; RR = 1.17; 95% CI, 0.54-2.53; p = 0.7). Sensitivity analyses in trials with a low risk of bias showed a trend toward an increase in mortality with milrinone (8/153 [5.2%] in the milrinone arm v 2/152 [1.3%] in the control arm; RR = 2.71; 95% CI, 0.82-9; p for effect = 0.10). CONCLUSIONS: Despite theoretic concerns for increased mortality with intravenous milrinone in patients undergoing cardiac surgery, the authors were unable to confirm an adverse effect on survival. However, sensitivity analysis of high-quality trials showed a trend toward increased mortality with milrinone.