Preclinical research in cancer therapy-related cardiovascular toxicity (CTR-CVT) is a major domain of cardio-oncology and has provided biological explanation for the cardiovascular adverse effects of many cancer therapies. However, the choice of the experimental models to investigate the mechanisms of CTR-CVT is often based on personal experience and opinion, rather than on established principles and available evidence. Moreover, presentation of methods and results is frequently approximate. This Scientific Statement outlines potential quality standards regarding methodology and reporting in preclinical cardio-oncology research, with the goal of promoting accurate, reliable, and reproducible studies. Quality standards are distinguished in first-tier, when considered essential for robustness unless there is a strong justification for their omission, and second-tier standards, when desirable, but not necessary. First-tier standards ensure credible, self-sustaining research, while second-tier ones enhance quality of investigations and accelerate understanding of CTR-CVT. Adherence to the proposed quality standards is expected to benefit researchers embarking on new investigations, facilitate funding allocation, and inform the development of novel oncological therapies, eventually moving cardio-oncology science forward.

AIMS:The Framingham risk score (FRS), a tool primarily used for atherosclerotic cardiovascular disease (ASCVD) risk stratification, incorporates factors like age, obesity, and smoking. However, its role in predicting cancer and heart failure (HF) risk remains unclear, while emerging data suggest these two conditions coincide frequently. METHODS AND RESULTS:We conducted a post hoc analysis using data from the PREVEND study and validated our findings in the UK Biobank. We examined the association between FRS tertiles at baseline and incident cancer or HF. Fine-Gray regression models were used to calculate subdistribution hazard ratios (sHRs), adjusting for estimated glomerular filtration rate and urinary albumin excretion with all-cause mortality as a competing risk. In PREVEND, we included 8123 participants (mean age 49 ± 13 years, 50% female). Over follow-up periods of 17.46 years [interquartile range (IQR) 17.15-17.80] (cancer) and 23.39 years (IQR 13.78-23.81) (HF), 1176 participants developed new-onset cancer and 758 developed new-onset HF. In a multivariable analysis, participants in the highest FRS tertile compared with the lowest had a higher hazard for both cancer (sHR 2.32, P < 0.001) and HF (sHR 10.08, P < 0.001). Participants in the highest FRS tertile also had the worst survival (log-rank P < 0.001). We validated these findings in the UK Biobank (n = 389942) wherein individuals in the highest FRS tertile also had a higher hazard for both cancer (sHR 2.05, P < 0.001) and HF (sHR 5.99, P < 0.001) compared with the lowest tertile. CONCLUSION:The FRS associates with new-onset cancer or HF, implicating a broader clinical application of the FRS beyond ASCVD risk stratification in cardio-oncology.

Immune checkpoint inhibitor (ICI)-mediated myocarditis is a notorious complication of cancer treatment; however, the role of immune checkpoints in the heart during inflammation remains unknown. We investigated myocardial expression of programmed cell death protein 1 (PD-1) and its ligand (PD-L1) in non-ICI myocarditis. We performed a cross-species single-cell/-nucleus RNA sequencing comparative analysis, including 3 different models of myocarditis in mice and human hearts, with in vitro validation in human cells. This provided compelling evidence that PD-1/PD-L1 signaling in both murine and human non-ICI myocarditis is inherent to the myocardial inflammatory response. Specifically, cardiac endothelial cells and fibroblasts exhibited robust and sustained PD-L1 up-regulation in myocarditis, while also coinciding temporally with peak PD-1 expression on T cells, which presents an important defense mechanism. Therefore, immune checkpoints have global importance in myocarditis and may serve as a therapeutic target.

Clonal hematopoiesis (CH) is the expansion of clones from a single hematopoietic stem cell (HSC) in the bone marrow. Clonal hematopoiesis of indeterminate potential (CHIP) refers to CH defined by the presence of pre-leukemic driver mutations in at least 2% of alleles in sequenced peripheral blood. This phenomenon is, by definition, associated not only with the future development of acute myeloid leukemia but also with non-malignant conditions, including cardiovascular disease. However, the underlying molecular mechanisms for CH in non-malignant diseases, such as cardiovascular disease, are not fully explained. Certain subtypes of CHIP may give rise to proinflammatory immune cells, which, in turn, may promote atherosclerosis progression. Key subtypes of CHIP include mutations in genes encoding epigenetic regulators DNMT3A (DNA methyltransferase 3A), TET2 (ten-eleven translocation methylcytosine dioxygenase 2), and ASXL1 (associated sex combs-like 1), as well as mutations in the gene encoding hematopoietic cytokine signaling: JAK2 (Janus kinase 2). The aim of this review is to summarize the current knowledge of CHIP and its association with inflammation and cardiovascular risk factors.

Background:Although uncommon (incidence <1%), cardiac immune-related adverse events (irAEs) associated with immune checkpoint inhibitor (ICI) therapy can be fatal. Their underlying mechanisms remain incompletely understood, although autoimmune predisposition and cross-antigen responses have been implicated. Case summary:We report the case of a young, immunologically predisposed patient with renal cell carcinoma who developed recurrent episodes of myocardial injury following an initial mild ICI-related myocarditis. Subsequent viral infections acted as triggers for repeated myocardial damage despite discontinuation of ICI therapy. Discussion:Novel immune biomarkers were identified, and distinctive findings on endomyocardial biopsy, together with tumour protein expression patterns, provided insight into the patient's heightened myocardial immune vulnerability to viral infections. This case highlights the complex interplay between ICI therapy, host immune predisposition, and viral triggers in the pathogenesis of cardiac irAEs.

AIMS:To examine the associations of cardiorenal-inflammatory biomarkers with cardiac vs. cancer mortality in cancer survivors. METHODS AND RESULTS:We conducted a prospective analysis of 1384 U.S. cancer survivors (mean age: 67.5 years; 52.1% women; aged ≥ 20 years) from the NHANES cohort (1999-2004), with follow-up through 2019. Using Cox proportional hazards models, we examined the associations of the following cardiorenal-inflammatory biomarkers with cardiac vs. cancer mortality: N-terminal pro-B-type natriuretic peptide (NT-proBNP), high-sensitivity troponin-T (hs-TnT), high-sensitivity troponin I (hs-TnI; measured using three assays), urinary albumin-to-creatinine ratio (UACR), fractional excretion of albumin (FEalb) and C-reactive protein (CRP). Analyses were biomarker-specific i.e. participants with missing values for a given biomarker were excluded from that analysis. During a median [P25-P75] follow-up of 11.8 [5.1-16.8] years, 199 cardiac deaths (14.4%) and 259 cancer deaths (18.7%) occurred. In multivariable models, all biomarkers except CRP were significantly associated with cardiac mortality, and all biomarkers except cardiac troponins were significantly associated with cancer mortality (P ≤ 0.001 for all). When formally compared, cardiac troponins and NT-proBNP displayed stronger associations with cardiac mortality than cancer mortality (Pdifference ≤ 0.006). By contrast, CRP displayed stronger associations with cancer mortality than cardiac mortality (Pdifference < 0.001). UACR and FEalb were similarly associated with both cardiac and cancer mortality (Pdifference > 0.7). CONCLUSION:In cancer survivors, increased cardiac stress was more strongly associated with cardiac mortality whereas systemic inflammation was more strongly associated with cancer mortality. Renal dysfunction was similarly associated with both cardiac and cancer mortality.

We summarise the current knowledge of T-cell immunoglobulin and mucin domain-containing protein 3 (TIM-3) across innate and adaptive immune cells and compile emerging evidence in cardiovascular disease (CVD). Immune checkpoints have come to light as potent regulators of immune responses in tumour biology, autoimmune disease and, more recently, in CVD. TIM-3 is a complex immune checkpoint expressed on both immune and non-immune cells. It has four known ligands, two of which are only available for binding upon cell damage or death, and binding can be either stimulatory or inhibitory. It functions as a context-dependent modulator of immune reactions in atherosclerosis, myocardial infarction and myocarditis. TIM-3 may exert functions in the cardiovascular system, but more mechanistic research is required to investigate whether interference with TIM-3 signalling can be used to improve cardiovascular health.

BACKGROUND AND AIMS:MEK1/2 inhibitors are increasingly used in neurofibromatosis type 1 (NF1) and can cause cancer therapy-related cardiac dysfunction (CTRCD). Cardiotoxicity rates of up to 12% have been reported in combination therapy, and up to 7% in monotherapy trials. Cardiac monitoring is recommended, but data on trametinib in NF1 remain limited. Therefore, we evaluated the incidence, timing, and clinical characteristics of CTRCD in adults with NF1 receiving trametinib monotherapy. METHODS:The phase II single-arm TRAIN trial included NF1 patients receiving trametinib 2 mg daily. Serial cardiovascular assessments and N-terminal pro-B-type Natriuretic Peptide (NT-proBNP) measurements were collected over 2 years. CTRCD was defined as mild, moderate or severe per 2022 European Society for Cardiology cardio-oncology guidelines. RESULTS:Of 30 patients, 7 (23%) developed CTRCD: 1 severe, 4 moderate and 2 mild. Median onset time was 5 months (range 1-12 months). All cases were asymptomatic and reversible. One severe case required permanent discontinuation, after which LVEF recovered. NT-proBNP remained normal in 6 cases; only the severe case showed a marked rise. No baseline clinical or cardiovascular parameters could predict CTRCD. CONCLUSIONS:In this NF1 cohort, cardiotoxicity occurred in 23% of patients but only one case required trametinib discontinuation. Events occurred within the first year, were usually moderate, and reversible. NT-proBNP remained normal in most cases but may help identify patients needing echocardiography. We recommend continuing echocardiography during the first year, with consideration for less frequent monitoring thereafter based on clinical findings. However, further data are needed for long-term surveillance.

Aims Immune checkpoint inhibitors (ICIs) have revolutionized cancer treatment. However, their use often leads to cardiovascular adverse effects, including cardiac dysfunction. Here, we hypothesized that a prior cardiac ischaemic injury could exacerbate cardiac dysfunction due to anti-programmed death protein 1 (PD-1) treatment. Furthermore, we investigated whether abatacept, a T-cell costimulation blocker, could ameliorate the ICI-induced cardiotoxicity in a pre-clinical model.Methods and results In a pre-clinical study, mice were treated with isoprenaline or control to induce reversible cardiac ischaemia. After 16 weeks of follow-up, recovery of cardiac function was confirmed via echocardiography, and mice from both groups were randomly treated with isotype control, anti-PD-1, or anti-PD-1 combined with abatacept, for 2 further weeks. Mice with prior ischaemic injury and anti-PD-1 treatment showed cardiac dysfunction with increased infiltration of T cells and macrophages and elevated expression of pro-inflammatory cytokines. Conversely, cardiac dysfunction and inflammation were less pronounced after anti-PD-1 treatment in mice without prior ischaemic injury. Mice with concomitant abatacept treatment exhibited normal cardiac function and alleviated pro-inflammatory response. In a parallel single-centre retrospective clinical cohort study, 1671 cancer patients receiving PD-1 inhibitors were analysed. Cases were defined as patients who developed incident heart failure (HF) after ICI initiation with a primary aim to test whether pre-existing ischaemic heart disease was associated with an increased risk for HF development post-ICI therapy. Sensitivity analyses included propensity score matching and comparison with non-ICI-treated cancer patients. Among ICI-treated patients, 109 (6.5%) developed HF over a median follow-up of 332 days. Multivariable logistic regression of the matched population showed increased odds of incident HF in patients with prior ischaemic cardiac events (odds ratio 2.11, 95% confidence interval 1.05-4.2, P = 0.033).Conclusion In mice, induction of cardiac inflammation and dysfunction by anti-PD-1 therapy was potentiated by prior transient ischaemic cardiac injury, which was ameliorated by abatacept cotreatment. Cancer patients with pre-existing ischaemic heart disease may be at greater risk for developing ICI-induced new-onset HF. Based on our findings, cardiac surveillance should be considered in patients starting ICI therapy with a prior history of ischaemic heart disease.

Heart failure and cancer share risk factors and biological pathways, yet their interplay remains underexplored. This Comment calls for coordinated research, precision medicine approaches and policy changes to advance the emerging field of cardio-oncology.

AIMS:Oxidative stress is known to be involved in the pathophysiology of heart failure (HF). To assess oxidative stress, direct quantification of reactive oxygen species would be ideal but this is not feasible due to their short half-lives. Antioxidant enzymes such as peroxiredoxins, produced as a direct response to oxidative stress, mirror the process and can be more easily quantified. The aim of this study was to examine whether circulating peroxiredoxin-4 (Prx4), a marker of systemic oxidative stress, associates with incident HF and its subtypes. METHODS AND RESULTS:We included a total of 8199 individuals from the Prevention of REnal and Vascular End-stage Disease (PREVEND) community-based cohort (mean age: 49.8 years; 50.1% women). During a median follow-up of 12.6 years, 349 (4.3%) HF events occurred of which 118 (33.8%) had HF with preserved ejection fraction. In a Cox proportional hazards model adjusting for age, sex, smoking, diabetes, hypertension, obesity, total and high-density lipoprotein cholesterol, cholesterol-lowering medication and renal disease, Prx4 was significantly associated with incident HF (hazard ratio [HR] per 1 standard deviation increase in log-Prx4: 1.22; 95% confidence interval [CI] 1.09-1.36; p < 0.001). Among HF subtypes, Prx4 remained associated with incident HF with preserved (HR 1.27; 95% CI 1.05-1.53) as well as reduced ejection fraction (HR 1.19; 95% CI 1.04-1.37), with no significant difference between the subtypes (p = 0.64). CONCLUSION:Circulating Prx4 associates with the risk of developing HF, both with preserved and reduced ejection fraction. Future studies should examine whether Prx4 can serve as a real-time marker of oxidative stress status.

It has been shown that heart failure (HF) promotes tumour growth circulating factors. Exosomes, extracellular vesicles (30–150 nm) with lipid bilayer membranes, mediate intercellular communication. We hypothesize that exosomes from failing hearts deliver oncogenic signals to tumours through the bloodstream. To track cardiac exosomes reaching tumours, we used transgenic (TG-αMHC-STOP-CD63NanoLuc) mice engineered to express CD63-NanoLuc allowing to track cardiomyocyte-derived exosomes for our studies. E0771 cancer cells were inoculated into the mammary fat pad of the experimental mice. Then, mice underwent myocardial infarction (MI) or sham surgery, with cardiac function assessed weekly by echocardiography. Three weeks post-MI, tissues, including tumours, were harvested for luciferase signal measurement. Exosomes in plasma and cardiac tissues were quantified by nanoparticle tracking analysis, and tetraspanin markers (CD9, CD63, CD81) were analysed using SP-IRIS (Leperchaun). MI mice exhibited a 2.3-fold reduction in ejection fraction (p < 0.0001), a 1.6-fold increase in tumour weight (p = 0.141), and a 2.4-fold increase in tumour volume (p = 0.0001) compared to sham mice. Tumour luciferase activity was detected in both groups and was significantly correlated with heart luciferase activity. SP-IRIS analysis in cardiac tissues revealed that exosomes with CD63/CD81/CD9 markers constituted 13.63% of the total population of exosomes in MI mice versus 7.5% in sham mice. These data demonstrate that cardiomyocyte-derived exosomes reach distant breast cancer tumours, and this potentially represents a novel route of crosstalk between the heart and tumours. The increased proportion of CD63/CD81/CD9-positive exosomes in failing cardiac tissue highlights the presence of HF-induced alterations in exosomes. Future work will analyse the cargo of these exosomes to elucidate their oncogenic potential.

Several new cancer drugs have been developed in the last years. The cardiovascular (CV) safety of most oncological therapies is not assessed in phase 3 randomized controlled trials (RCTs), but it can be promptly studied as treatments become available in clinical practice. Conversely, pre-clinical cardio-oncology research may not easily adapt to the evolving landscape of oncological pharmacotherapy. We systematically searched Pubmed for basic science (i.e., cellular and animal) articles on cancer treatment-related CV toxicity (CTR-CVT) published from 2021 to 2024. In parallel, ClinicalTrials.gov was queried for phase 3 RCTs conducted in patients with solid or hematological tumors during the same period. Cancer therapies were grouped in established classes, and the proportion of studies focusing on different treatment modalities was compared between the two datasets by chi-square test. Of 494 pre-clinical articles identified from 2021 to 2024, 75 were excluded being reviews or meta-analyses. Among the remaining 419 articles, 359 (84.7%) focused on anthracyclines (91.1% evaluated doxorubicin), 17 (4.0%) addressed tyrosine kinase inhibitors (TKI), 10 (2.4%) HER2 inhibitors, 9 (2.1%) alkylating agents, and <1% other cancer therapies (Figure, panel A). In contrast, 165 (24.1%) of 414 phase 3 RCTs assessed immune checkpoint inhibitors (ICI), 106 (15.5%) TKI, and 95 (13.9%) alkylating agents (Figure, panel B). Notably, only 9 (1.3%) RCTs tested therapeutic strategies including anthracyclines. The proportion of pre-clinical studies about anthracyclines, TKI, alkylating agents, and ICI was significantly different than the one of RCTs (P <0.0001 for all), while HER2 inhibitors were investigated with similar frequency (P = 0.24). Information about CTR-CVT was provided only for 25 (6.0%) RCTs. This analysis highlights a significant mismatch between the object of most pre-clinical cardio-oncology research and the cancer treatments that are currently being evaluated in contemporary RCTs. In particular, compared with current clinical oncology studies, pre-clinical cardio-oncology research disproportionately emphasizes anthracyclines. The disconnect between pre-clinical cardio-oncology and clinical oncology research is magnified by the frequent omission of data about CTR-CVT in the reports of RCTs. Bridging this gap is critical to advance the translational impact of basic cardio-oncology research.

AIMS:The necessity of lifelong treatment and polypharmacy in chronic heart failure (HF) patients with improved myocardial function remains debated. This systematic review aims to synthesize current literature regarding this issue. METHODS AND RESULTS:A systematic literature search was performed in MEDLINE, Embase, and Cochrane Central Register of Controlled Trials from the inception to 18 October 2024. Seven studies (n = 552) reporting minimization or withdrawal of pharmacotherapy in chronic HF patients with improved ejection fraction or stable New York Heart Association status were included. Findings were heterogeneous due to variations in study design and protocols. Loop diuretic withdrawal was favoured by one non-randomized study (n = 26) and one randomized controlled trial (RCT) (n = 188). Minimization of angiotensin receptor-neprilysin inhibitors (n = 77) or withdrawal of mineralocorticoid receptor antagonists (MRA) (n = 70) was not favourable. Carvedilol monotherapy was favoured by one small-sample RCT (n = 60). One RCT (n = 51) reported a high overall relapse rate (65%) following multiple drug withdrawal in recovered patients with dilated cardiomyopathy. Another RCT (n = 80) found a low occurrence of cardiac dimensional deterioration (7.5%) following multiple drug withdrawal in post-cardiac resynchronization therapy patients with normalized ejection fraction. However, 28% required drug re-initiation due to cardiac comorbidities. CONCLUSION:The existing evidence on minimizing or withdrawing oral pharmacotherapy in chronic HF patients with improved myocardial function remains very limited and heterogeneous, supporting only loop diuretic withdrawal and possibly carvedilol monotherapy, but not the minimization or withdrawal of renin-angiotensin system inhibitors, MRA, or the combination of HF medications. Large RCTs are needed to determine the appropriate treatment strategy.

Cardio-oncology has rapidly evolved in the past decade. It is a continuous field that was founded on the manifestation of cardiac dysfunction in patients treated with anticancer therapy. Short- and long-term cardiovascular complications became known as cancer therapy-related cardiovascular toxicity (CTR-CVT). These may arise from a plethora of anticancer therapies, including broad classes such as chemotherapy, immunotherapy, and hormonal therapy. Recently, the first European Society of Cardiology guideline on cardio-oncology was published, providing expert consensus on definitions, diagnosis, treatment, and prevention for health-care professionals. This side of cardio-oncology focuses on the classical CTR-CVT, here termed forward cardio-oncology. On the other side is the paradigm of heart failure stimulating tumor growth, coined as reverse cardio-oncology. As cardio-oncology expanded, the knowledge of co-occurrence of these disease entities in the same individuals grew. This raised the question of whether this phenomenon was due to shared risk factors (i.e. diabetes mellitus, obesity, etc.) between cardiovascular disease (CVD) and cancer or because of shared underlying mechanisms, and thus whether the presence of one of the two disease entities could drive the onset or progression of the other. Indeed, mechanistic studies revealed that heart failure can stimulate tumor growth in a multifaceted manner, including through a protumor cardiac secretome, by immune system modulation, or even through the gut microbiome. This review provides an extensive and robust overview of the current knowledge on the entirety of cardio-oncology and highlights future perspectives for research.

Various observational studies have reported that chronic kidney disease (CKD) is associated with cancer development. However, the mechanisms underpinning these associations are still to be addressed. Therefore, the present study aimed to investigate whether CKD can stimulate tumor growth using two experimental models, and to identify pathophysiological pathways that may be involved. An orthotopic model of breast cancer was established by injecting 2.5×105 E0771 breast cancer cells into the mammary fat pad of 10-week-old female C57BL/6J mice. Subsequently, unilateral ureteral obstruction (UUO) was induced in the left kidney 7 days after cancer cell implantation to induce CKD. In a separate study, UUO surgery was performed on the left kidney of 10 to 14-week-old female genetic MMTV-PvVT mice, which are prone to developing breast cancer. Sham surgeries were performed in both models without ureteral ligation. In both models, the percentage of fibrosis in the kidney tissue (C57BL/6JE0771 (C): Fc = 6.88| p < 0.0001; MMTV-PyMT (M): Fc = 12.7 | p < 0.0001) and the plasma levels of creatinine (C: Fc = 1.17 | p = 0.0025; M: Fc = 1.36 | p < 0.0001) were significantly higher in the UUO mice compared to the sham mice. This effect was accompanied by a several fold upregulation in the mRNA expression of fibrotic genes, including α-SMA, TGFβ, Col1α1, Col3α1, Col4α1, Fn1, and CTGF, as well as inflammatory genes including IL-1β, MCP-1 and TNF-α (p <0.05). In Both xenograft and genetic model of breast cancer tumor volume (C: Fc = 1.95 | p = 0.0175; M: Fc = 3.37 | p = 0.0214) and tumor weight (C: Fc = 1.68 | p = 0.026; M: Fc = 2.12 | p = 0.0009) were significantly increased in the UUO mice compared to the sham mice. UUO induced proteomic changes in kidney, plasma and tumor tissues, and several proteomic changes were correlated with tumor size (p <0.05). Subsequent pathway analyses showed that inflammatory and fibrosis pathways were upregulated in the UUO kidneys, and that complement activation was upregulated in the UUO kidneys and plasma (p <0.05). As for tumor tissues, downregulation of apoptotic and aerobic respiration pathways was observed in UUO groups. We demonstrate that CKD leads to increased breast tumor growth in two different mice models, suggesting a causal link between CKD and cancer. Pathway analyses indicate that inflammation and complement activation, extracellular matrix organization and angiogenesis are potential mechanisms explaining this relationship.

- The tyrosine kinase inhibitor (TKI) nilotinib has improved treatment for patients with chronic myeloid leukaemia resistant to conventional therapy with imatinib. Unfortunately, compared to imatinib, nilotinib is linked to a higher incidence of cardiotoxic side effects, ranging from subclinical electrophysiological changes to life-threatening cardiac events. The underlying mechanisms driving these myocardial toxicities remain largely unknown. We assessed the incidence of cardiovascular toxicities and then analysed the direct impact of both drugs on three major cardiac cell types in vitro. – Data from the FDA Adverse Event Reporting System (FEARS) was used to determine the incidence of nilotinib and imatinib-associated cardiovascular events. In vitro, human induced pluripotent stem cell cardiomyocytes (hiPSC-CMs), cardiac fibroblast (CFs) and endothelial cells (ECs) were cultured and treated with 1 µM nilotinib or imatinib for 72 hours. Cell viability was assessed using the CellTiter-Glo® and gene expression analyses were performed to evaluate fibroblast-to-myofibroblast transition and (early) endothelial-to-mesenchymal transition in CFs and ECs, respectively. – Based upon FEARS, we determined a higher incidence (15.6%) of cardiac events in nilotinib-treated patients compared to those treated with imatinib (6.4%). In vitro, cell viability was affected in all three cell types when exposed to nilotinib compared to untreated controls: CFs (27.4%, p < 0.0001; % residual cell viability, p-value), hiPSC-CMs (64.4%, p = 0.02), and ECs (60.4%, p = 0.04). Imatinib affected cell viability in neither of the three cell types. Both drugs led to increased Col3α1 (nilotinib, p = 0.02; imatinib, p = 0.02) expression in CFs, whereas Col1α1 and fibronectin expression showed a discrepancy. Notably, nilotinib significantly increased αSMA expression (p < 0.0001), suggesting the transition to the myofibroblast phenotype. Both drugs did not impair EC integrity. – A current extraction from a medication registry validated that nilotinib is more cardiotoxic than imatinib. Mechanistically, nilotinib exerts a more potent direct cytotoxic effect on cardiac cells in vitro compared to imatinib. Our data underscore the importance of investigating pro-fibrotic responses potentially impairing cardiac function in patients treated with TKIs.

Immune checkpoints are understudied in cardiovascular disease. We investigated the TIM-3 pathway in human serum, peripheral blood mononuclear cells (PBMCs) and cardiac tissue following myocardial infarction (MI). First, TIM-3 ligands in serum, galectin-9 and HMGB-1, were associated with cardiac remodelling 4 months post-MI (n = 357). Next, post-hoc single-cell RNA-sequencing of PBMCs from MI patients (n = 38) and controls (n = 38) revealed acute downregulation of TIM-3 in lymphocytes 24 h post-MI, which occurred after 8 weeks in myeloid cells. In the heart, single-nucleus RNA-sequencing and spatial transcriptomics of MI tissue demonstrated cardiomyocyte HMGB-1 upregulation which could communicate with myeloid TIM-3. Pro-inflammatory macrophages specifically showed significant TIM-3 expression and NLRP3 inflammasome activity. On the protein level, HMGB-1 was also upregulated in the infarcted heart and actively translocated throughout the cells. Finally, in vitro macrophage stimulation with HMGB-1 induced pro-inflammatory polarization (e.g. NLRP3 pathway activation), which was prevented by blocking TIM-3. Thus, TIM-3/HMGB-1 interaction presents as a target in cardiac inflammation following MI.