Aims: In recent years, survival in patients with breast cancer has increased. Despite the improvement in outcomes of those patients, the risk of treatment-related cardiotoxicity remains high, and its presence has been associated with a higher risk of treatment termination and thus lower therapeutic efficacy. Prior trials demonstrated that a preventive initiation of heart failure drugs, including the renin–angiotensin–aldosterone inhibitors, might reduce the risk of treatment-related cardiotoxicity. However, to date, no study investigated the efficacy of sacubitril/valsartan, a novel antineurohormonal drug shown to be superior to the previous therapies, in the prevention of cardiotoxicity in patients with early-stage breast cancer, which is the aim of the trial. Methods and results: MAINSTREAM is a randomized, placebo-controlled, double-blind, multicentre, clinical trial. After the run-in period, a total of 480 patients with early breast cancer undergoing treatment with anthracyclines and/or anti-human epidermal growth factor receptor 2 drugs will be randomized to the highest tolerated dose of sacubitril/valsartan, being preferably 97/103 mg twice daily or placebo in 1:1 ratio. The patients will be monitored, including routine transthoracic echocardiography (TTE) and laboratory biomarker monitoring, for 24 months. The primary endpoint of the trial will be the occurrence of a decrease in left ventricular ejection fraction by ≥5% in TTE within 24 months. The key secondary endpoints will be the composite endpoint of death from any cause or hospitalization for heart failure, as well as other imaging, laboratory, and clinical outcomes, including the occurrence of the cancer therapy-related cardiac dysfunction resulting in the necessity to initiate treatment. The first patients are expected to be recruited in the coming months, and the estimated completion of the study and publication of the results are expected in December 2027, pending recruitment. Conclusions: The MAINSTREAM trial will determine the efficacy and safety of treatment with sacubitril/valsartan as a prevention of cardiotoxicity in patients with early breast cancer (ClinicalTrials.gov number: NCT05465031).

Four tests assess antibody-mediated rejection (ABMR) in heart transplants: standard of care local endomyocardial biopsy (EMB) histology, EMB molecular analysis (Molecular Microscope® Diagnostic System - MMDx), donor-derived cell-free DNA (dd-cfDNA), and donor-specific antibody (DSA). These tests have become critical for the development and use of novel therapies for ABMR. The Trifecta-Heart study (NCT04707872) aimed to define the relationships among these tests. The study compared standard of care local histology diagnosis to the results of three central tests assessing ABMR: central DSA (One Lambda Inc.), dd-cfDNA (Natera, Inc.), and MMDx rejection assessments in 214 EMBs. Results were primarily expressed as positive-negative to facilitate analysis and to simulate the way all tests are used for clinical decision-making. MMDx diagnosed more ABMR, TCMR, and No rejection (NR) than histology, a pattern confirmed in a validation set from the larger INTERHEART study (NCT02670408). When correlations and partial correlation modeling were used to defined the hierarchy of relationships among all tests, MMDx ABMR correlated more strongly with dd-cfDNA and DSA than did histologic ABMR. In MMDx-histology discrepancies, biopsies with no histologic rejection but with MMDx ABMR had elevated DSA and dd-cfDNA, and biopsies with MMDx NR but histology ABMR had low DSA and dd-cfDNA. DSA-negative ABMR by MMDx or histology had elevated dd-cfDNA, similar to DSA-positive ABMR. Most cases with molecular injury and high dd-cfDNA also had concurrent molecular rejection. These inter-test relationships will be useful in guiding ABMR management, including monitoring of treatment responses and relapses, especially when discrepancies occur.

Patients with pulmonary arterial hypertension (PAH) become candidates for lung or lung and heart transplantation when the maximum specific therapy is no longer effective. The most difficult challenge is choosing one of the above options in the event of symptoms of right ventricular failure. Here, we present two female patients with PAH: (1) a 21-year-old patient with Eisenmenger syndrome, caused by a congenital defect—patent ductus arteriosus (PDA); and (2) a 39-year-old patient with idiopathic PAH and coexistent PDA. Their common denominator is PDA and the hybrid surgery performed: double lung transplantation with simultaneous PDA closure. The operation was performed after pharmacological bridging (conditioning) to transplantation that lasted for 33 and 70 days, respectively. In both cases, PDA closure effectiveness was 100%. Both patients survived the operation (100%); however, patient no. 1 died on the 2nd postoperative day due to multi-organ failure; while patient no. 2 was discharged home in full health. The authors did not find a similar description of the operation in the available literature and PubMed database. Hence, we propose this new treatment method for its effectiveness and applicability proven in our practice.

Several reviews have shown that COVID-19 in children is a relatively mild disease. However, a rare complication affecting children and adolescents after COVID-19 has been identified. Pediatric inflammatory multisystem syndrome temporally associated with COVID-19 (PIMS-TS), which in some cases manifests itself as a hyperinflammatory syndrome with a multiorgan failure, may lead to death. We report a case of a 17-year-old patient who was admitted to the hospital with cardiogenic shock of unknown etiology. The disease was life-threatening, thus necessitating mechanical ventilation, circulatory support, and extracorporeal therapy due to renal and liver dysfunction. The patient tested negative for SARS-CoV-2 Reverse Transcription Polymerase Chain Reaction. Other infectious causes of illness were excluded. However, the patient had a positive IgG antibody test result and high levels of interleukin-6, which helped to diagnose PIMS-TS. Intravenous immunoglobulin and steroid therapies were initiated, unfortunately, with poor outcome. The patient's critical condition, particularly end-stage heart failure, led to mechanical circulatory support implantation and finally orthotopic heart transplantation. After the surgery, the patient's condition improved gradually. PIMS-TS manifests itself with different clinical images and as a state of varying severity, ultimately causing multiorgan dysfunction with shock resembling toxic shock syndrome. Ultimately, myocardial complications of PIMS-TS necessitated heart transplantation in the described patient.