Prognostic Implications of Residual Tricuspid Regurgitation Grading After Transcatheter Tricuspid Valve Repair.

BACKGROUND: The safety profile of transcatheter tricuspid valve (TTV) repair techniques is well established, but residual tricuspid regurgitation (TR) remains a concern. OBJECTIVES: The authors sought to assess the impact of residual TR severity post-TTV repair on survival. METHODS: We evaluated the survival rate at 2 years of 613 patients with severe isolated functional TR who underwent TTV repair in TRIGISTRY according to the severity of residual TR at discharge using a 3-grade (mild, moderate, and severe) or 4-grade scheme (mild, mild to moderate, moderate to severe, and severe). RESULTS: Residual TR was none/mild in 33%, moderate in 52%, and severe in 15%. The 2-year adjusted survival rates significantly differed between the 3 groups (85%, 70%, and 44%, respectively; restricted mean survival time [RMST]: P = 0.0001). When the 319 patients with moderate residual TR were subdivided into mild to moderate (n = 201, 33%) and moderate to severe (n = 118, 19%), the adjusted survival rate was also significantly different between groups (85%, 80%, 55%, and 44%, respectively; RMST: P = 0.001). Survival was significantly lower in patients with moderate to severe residual TR compared to patients with mild to moderate residual TR (P = 0.006). No difference in survival rates was observed between patients with no/mild and mild to moderate residual TR (P = 0.67) or between patients with moderate to severe and severe residual TR (P = 0.96). CONCLUSIONS: The moderate residual TR group was heterogeneous and encompassed patients with markedly different clinical outcomes. Refining TR grade classification with a more granular 4-grade scheme improved outcome prediction. Our results highlight the importance of achieving a mild to moderate or lower residual TR grade during TTV repair, which could define a successful intervention.

Understanding transcatheter edge-to-edge repair "knobology": Advanced catheter steering for different scenarios of transseptal puncture.

Following the introduction in the latest European and American guidelines, transcatheter edge-to-edge repair has become a valid alternative to surgery for ineligible patients. Among the available technologies, MitraClip (Abbott) was the first to be introduced for the percutaneous treatment of mitral regurgitation with the edge-to-edge technique. Although its safety and effectiveness has been widely demonstrated, the optimal procedural results are highly dependent from operators' experience. In this manuscript, we provide a full guide of advanced steering maneuvers of MitraClip in different scenarios of transseptal puncture.

Prediction of Mortality and Heart Failure Hospitalization After Transcatheter Tricuspid Valve Interventions: Validation of TRISCORE.

BACKGROUND: Data on the prognostic role of the TRI-SCORE in patients undergoing transcatheter tricuspid valve intervention (TTVI) are limited. OBJECTIVES: The aim of this study was to evaluate the performance of the TRI-SCORE in predicting outcomes of patients undergoing TTVI. METHODS: TriValve (Transcatheter Tricuspid Valve Therapies) is a large multicenter multinational registry including patients undergoing TTVI. The TRI-SCORE is a risk model recently proposed to predict in-hospital mortality after tricuspid valve surgery. The TriValve population was stratified based on the TRI-SCORE tertiles. The outcomes of interest were all-cause death and all-cause death or heart failure hospitalization. Procedural complications and changes in NYHA functional class were also reported. RESULTS: Among the 634 patients included, 223 patients (35.2%) had a TRI-SCORE between 0 and 5, 221 (34.8%) had 6 or 7, and 190 (30%) had ≥8 points. Postprocedural blood transfusion, acute kidney injury, new atrial fibrillation, and in-hospital mortality were more frequent in the highest TRI-SCORE tertile. Postprocedure length of stay increased with a TRI-SCORE increase. A TRI-SCORE ≥8 was associated with an increased risk of 30-day all-cause mortality and all-cause mortality and the composite endpoint assessed at a median follow-up of 186 days (OR: 3.00; 95% CI: 1.38-6.55; HR: 2.17; 95% CI: 1.78-4.13; HR: 2.08, 95% CI: 1.57-2.74, respectively) even after adjustment for procedural success and EuroSCORE II or Society of Thoracic Surgeons Predicted Risk of Mortality. The NYHA functional class improved across all TRI-SCORE values. CONCLUSIONS: In the TriValve registry, the TRI-SCORE has a suboptimal performance in predicting clinical outcomes. However, a TRISCORE ≥8 is associated with an increased risk of clinical events and a lack of prognostic benefit after successful TTVI.

Effects of tricuspid transcatheter edge-to-edge repair on tricuspid annulus diameter - Data from the TriValve registry.

AIMS: T-TEER is an effective therapy for the treatment of tricuspid regurgitation (TR). However, the effects of leaflets clipping on tricuspid valve annulus (TA) have not been investigated in detail. The aim of this study is to investigate the effects of tricuspid transcatheter edge-to-edge repair (T-TEER) on TA diameter. METHODS AND RESULTS: The TriValve registry (Transcatheter Tricuspid Valve Therapies, NCT03416166) collected 556 patients from 22 European and North American centres undergoing transcatheter tricuspid valve interventions from 2016 to 2022. Patients undergoing T-TEER with available pre- and post-procedural data on TA diameter measured in the apical 4-chamber view on transthoracic echocardiography were selected for this study. Primary end-point was the reduction of TA diameter after T-TEER. A total of 186 patients were included in the study. In 115 patients (62%) TA diameter was reduced by at least 1 mm as compared to baseline. A significant reduction of TA dimension was observed following T-TEER (mean 2.3 mm [from pre-procedural diameter 46.7 mm to post-procedural diameter 44.4 mm], p < 0.001). In particular, the greatest reduction was observed in those with T-TEER in antero-septal commissure (mean 2.7 mm [from 47.1 mm to 44.4 mm], p < 0.001) as compared to those combining both antero-septal and postero-septal commissures (mean 1.4, from 46.0 mm to 44.6 mm, P = 0.06). A significant reduction of TA dimension was recorded in patients with 1 or 2 clips implanted but not in those patients with ≥3 clips implanted. CONCLUSIONS: In almost two third of patients T-TEER reduces TA diameter in addition to leaflet approximation. CONDENSED ABSTRACT: The effects of tricuspid transcatheter edge-to-edge repair (T-TEER) on tricuspid valve annulus (TA) have not been studied in details. This study investigates TA diameter as measured in apical 4-chamber view on transthoracic echocardiography before and after T-TEER. A total of 186 patients from the TriValve registry were included in the study. The study results show that 62% of patients have a TA reduction after T-TEER, especially in those receiving 1 or 2 clips in the antero-septal commissure. These suggest that T-TEER reduces tricuspid regurgitation not only by approximation of leaflets, but also by TA diameter reduction.

Temporal trends of frame expansion and paravalvular leak reduction after transcatheter aortic valve replacement with self-expandable prostheses.

BACKGROUND: Paravalvular leakage (PVL) is a common finding after transcatheter aortic valve replacement (TAVR) and affects late clinical outcome. It is more frequent with self-expandable (SE) transcatheter-heart-valve (THV). Few is known about SE-THV expansion after implantation. The purpose is to assess SE-THV frame expansion and its possible influence on PVL. METHODS: We designed a prospective pilot study to assess the time-course of SE-THV frame dimensions and PVL after TAVR. Consecutive patients undergoing TAVR with SE-THV were enrolled. Prosthesis fluoroscopy and echocardiography were prospectively performed immediately after TAVR (T0) and before discharge (T1) to grade PVL. Prosthesis diameters were assessed in 2 fluoroscopic orthogonal views. PVL reduction ≥1+ from T0 to T1 at echocardiography was the primary study endpoint. RESULTS: Twenty-five patients were enrolled. Mean interval between T0 and T1 evaluations was 5 days. Grade 1 or 2 was present in 76% of patients at T0 and in 68% at T1 (P=0.034). A total of 7 patients (28%) improved PVL ≥1 grade from T0 to T1. Differences between T0 and T1 fluoroscopic diameters were not statistically significant. When comparing the diameter changes according to PVL evolution, patients with PVL improvement (as compared with those without) had significantly larger minimum diameter increase at both annulus/inflow (P=0.016) and outflow/distal edge (P=0.027). CONCLUSIONS: PVL may improve in the early days after SE-THV and those patients with PVL improvement may have THV frame expansion. Further studies are needed to confirm such preliminary observations and to establish the clinical relevance of this phenomenon.

TRI-SCORE and benefit of intervention in patients with severe tricuspid regurgitation.

BACKGROUND AND AIMS: Benefit of tricuspid regurgitation (TR) correction and timing of intervention are unclear. This study aimed to compare survival rates after surgical or transcatheter intervention to conservative management according to a TR clinical stage as assessed using the TRI-SCORE. METHODS: A total of 2,413 patients with severe isolated functional TR were enrolled in TRIGISTRY (1217 conservatively managed, 551 isolated tricuspid valve surgery, and 645 transcatheter valve repair). The primary endpoint was survival at 2 years. RESULTS: The TRI-SCORE was low (≤3) in 32%, intermediate (4-5) in 33%, and high (≥6) in 35%. A successful correction was achieved in 97% and 65% of patients in the surgical and transcatheter groups, respectively. Survival rates decreased with the TRI-SCORE in the three treatment groups (all P < .0001). In the low TRI-SCORE category, survival rates were higher in the surgical and transcatheter groups than in the conservative management group (93%, 87%, and 79%, respectively, P = .0002). In the intermediate category, no significant difference between groups was observed overall (80%, 71%, and 71%, respectively, P = .13) but benefit of the intervention became significant when the analysis was restricted to patients with successful correction (80%, 81%, and 71%, respectively, P = .009). In the high TRI-SCORE category, survival was not different to conservative management in the surgical and successful repair group (61% and 68% vs 58%, P = .26 and P = .18 respectively). CONCLUSIONS: Survival progressively decreased with the TRI-SCORE irrespective of treatment modality. Compared to conservative management, an early and successful surgical or transcatheter intervention improved 2-year survival in patients at low and, to a lower extent, intermediate TRI-SCORE, while no benefit was observed in the high TRI-SCORE category.

Characteristics and outcomes of patients with atrial versus ventricular secondary tricuspid regurgitation undergoing tricuspid transcatheter edge-to-edge repair - Results from the TriValve registry.

AIM: Functional or secondary tricuspid regurgitation (STR) is the most common phenotype of tricuspid regurgitation (TR) with atrial STR (ASTR) and ventricular STR (VSTR) being recently identified as two distinct entities. Data on tricuspid transcatheter edge-to-edge repair (T-TEER) in patients with STR according to phenotype (i.e. ASTR vs. VSTR) are lacking. The aim of this study was to assess characteristics and outcomes of patients with ASTR versus VSTR undergoing T-TEER. METHODS AND RESULTS: Patients with STR undergoing T-TEER were selected from the Transcatheter Tricuspid Valve Therapies (TriValve) registry. ASTR was defined by (i) left ventricular ejection fraction ≥50%, (ii) atrial fibrillation, and (iii) systolic pulmonary artery pressure <50 mmHg. Patients not matching these criteria were classified as VSTR. Patients with primary TR and cardiac implantable electronic device were excluded. Key endpoints included procedural success and survival at follow-up. A total of 298 patients were enrolled in the study: 65 (22%) with ASTR and 233 (78%) with VSTR. Procedural success was similar in the two groups (80% vs. 83% for ASTR vs. VSTR, p = 0.56) and TEER was effective in reducing TR in both groups (from 97% of patients with baseline TR ≥3+ to 23% in ASTR and to 15% in VSTR, all p = 0.001). At 12-month follow-up, survival was significantly higher in the ASTR versus VSTR cohort (91% vs. 72%, log-rank p = 0.02), with VSTR being an independent predictor of mortality at multivariable analysis (hazard ratio 4.75). CONCLUSIONS: In a real-world, multicentre registry, T-TEER was effective in reducing TR grade in both ASTR and VSTR. At 12-month follow-up, ASTR showed better survival than VSTR.

Antibody Selection via Phage Display in Microtiter Plates.

The most common and robust in vitro technology to generate monoclonal human antibodies is phage display. This technology is a widely used and powerful key technology for recombinant antibody selection. Phage display-derived antibodies are used as research tools, in diagnostic assays, and by 2022, 14 phage display-derived therapeutic antibodies were approved. In this review, we describe a fast high-throughput antibody (scFv) selection procedure in 96-well microtiter plates. The given detailed protocol allows the antibody selection ("panning"), screening, and identification of monoclonal antibodies in less than 2 weeks. Furthermore, we describe an on-rate panning approach for the selection of monoclonal antibodies with fast on-rates.

Biomarker Discovery by ORFeome Phage Display.

Phage display is an efficient and robust method for protein-protein interaction studies. Although it is mostly used for antibody generation, it can be also utilized for the discovery of immunogenic proteins that could be used as biomarkers. Through this technique, a genome or metagenome is fragmented and cloned into a phagemid vector. The resulting protein fragments from this genetic material are displayed on M13 phage surface, while the corresponding gene fragments are packaged. This packaging process uses the pIII deficient helperphage, called Hyperphage (M13KO7 ΔpIII), so open reading frames (ORFs) are enriched in these libraries, giving the name to this method: ORFeome phage display. After conducting a selection procedure, called "bio-panning," relevant immunogenic peptides or protein fragments are selected using purified antibodies or serum samples, and can be used as potential biomarkers. As ORFeome phage display is an in vitro method, only the DNA or cDNA of the species of interest is needed. Therefore, this approach is also suitable for organisms that are hard to cultivate, or metagenomic samples, for example. An additional advantage is that the biomarker discovery is not limited to surface proteins due to the presentation of virtually every kind of peptide or protein fragment encoded by the ORFeome on the phage surface. At last, the selected biomarkers can be the start for the development of diagnostic assays, vaccines, or protein interaction studies.

Mapping Epitopes by Phage Display.

Monoclonal antibodies (mAbs) are valuable biological molecules, serving for many applications. Therefore, it is advantageous to know the interaction pattern between antibodies and their antigens. Regions on the antigen which are recognized by the antibodies are called epitopes, and the respective molecular counterpart of the epitope on the mAbs is called paratope. These epitopes can have many different compositions and/or structures. Knowing the epitope is a valuable information for the development or improvement of biological products, e.g., diagnostic assays, therapeutic mAbs, and vaccines, as well as for the elucidation of immune responses. Most of the techniques for epitope mapping rely on the presentation of the target, or parts of it, in a way that it can interact with a certain mAb. Among the techniques used for epitope mapping, phage display is a versatile technology that allows the display of a library of oligopeptides or fragments from a single gene product on the phage surface, which then can interact with several antibodies to define epitopes. In this chapter, a protocol for the construction of a single-target oligopeptide phage library, as well as for the panning procedure for epitope mapping using phage display is given.

Immunomodulation Therapies for Atherosclerosis: The Past, the Present, and the Future.

Atherosclerotic cardiovascular disease is the most common cause of morbidity and death worldwide. Recent studies have demonstrated that this chronic inflammatory disease of the arterial wall can be controlled through the modulation of immune system activity. Many patients with cardiovascular disease remain at elevated risk of recurrent events despite receiving current, state-of-the-art preventive medical treatment. Much of this residual risk is attributed to inflammation. Therefore, finding new treatment strategies for this category of patients became of common interest. This review will discuss the experimental and clinical data supporting the possibility of developing immune-based therapies for lowering cardiovascular risk, explicitly focusing on vaccination strategies.

Impact of Impella protected-percutaneous coronary intervention on left ventricle function recovery of patients with extensive coronary disease and poor left ventricular function.

BACKGROUND: The use of Impella support is increasingly adopted to "protect" patients with severe coronary artery disease (CAD) and left ventricle (LV) dysfunction undergoing percutaneous coronary intervention (PCI). AIMS: To evaluate the impact of Impella-protected (Abiomed, Danvers, Massachusetts, USA) PCIs on myocardial function recovery. METHODS: Patients with significant LV dysfunction undergoing multi-vessel PCIs with pre-intervention Impella implantation were evaluated by echocardiography before PCI and at median follow up of 6 months: global and segmental LV contractile function were assessed by LV ejection fraction (LVEF) and wall motion score index (WMSI), respectively. Extent of revascularization was graded using the British Cardiovascular Intervention Society Jeopardy score (BCIS-JS). Study endpoints were LVEF and WMSI improvement, and its correlation with revascularization. RESULTS: A total of 48 high surgical risk (mean EuroSCORE II 8) patients with median LVEF value of 30%, extensive wall motion abnormalities (median WMSI 2.16), and severe multi-vessel CAD (mean SYNTAX score 35) were included. PCIs brought a significant reduction of ischemic myocardium burden with BCIS-JS decrease from mean value of 12 to 4 (p < 0.001). At follow-up, WMSI reduced from 2.2 to 2.0 (p = 0.004) and LVEF increased from 30% to 35% (p = 0.016). WMSI improvement was proportional to the baseline impairment (R - 0.50, p < 0.001), and confined to revascularized segments (from 2.1 to 1.9, p < 0.001). CONCLUSIONS: In patients with extensive CAD and severe LV dysfunction, multi-vessel Impella-protected PCI was associated to an appreciable contractile recovery, mainly determined by regional wall motion improvement in revascularized segments.

Lectin histochemistry reveals two cytotrophoblast differentiation pathways during placental development in the feline (Feliscatus).

INTRODUCTION: Placental glycosylation has been examined on eight feline placentae ranging from approximately 15 to 60 days post-conception as little is known about changes in glycan distribution in this species. METHODS: Specimens were resin embedded and lectin histochemistry was applied to semi-thin sections using a panel of 24 lectins and an avidin-biotin revealing system. RESULTS: Abundant tri-tetraantennary complex N-glycan and α-galactosyl residues found in the syncytium in early pregnancy were greatly reduced in mid-pregnancy, though retained at the invasion front in the syncytium (N-glycan) or cytotrophoblast layer (αGal). Some other glycans were also uniquely present in invading cells. Abundant polylactosamine was found in the infolding basal lamina of syncytiotrophoblast and the apical villous cytotrophoblast membrane. Syncytial secretory granules often clustered near the apical membrane abutting maternal vessels. Decidual cells selectively expressed ß-galactosyl residues throughout pregnancy and highly branched N-glycan levels increased over time. DISCUSSION: Glycan distribution changes significantly over pregnancy, probably relating to the development of transport and invasive properties of trophoblast which in the endotheliochorial placenta reaches the level of the maternal vessels. Highly branched complex N-glycans, often associated with invasive cells, N-Acetylgalactosamine and terminal α-galactosyl residues are present at the invasion front abutting the junctional zone of the endometrium. Abundant polylactosamine on the syncytiotrophoblast basal lamina may reflect the presence of specialised adhesive interactions, while clustering of glycosylated granules apically is probably associated with secretion and absorption of material via maternal vasculature. It is suggested that lamellar and invasive cytotrophoblast represent distinct differentiation pathways. 246 words.

Sex-related characteristics and short-term outcomes of patients undergoing transcatheter tricuspid valve intervention for tricuspid regurgitation.

AIMS: The impact of sexuality in patients with significant tricuspid regurgitation (TR) undergoing transcatheter tricuspid valve intervention (TTVI) is unknown. The aim of this study was to investigate sex-specific outcomes in patients with significant TR treated with TTVI vs. medical therapy alone. METHODS AND RESULTS: The Transcatheter Tricuspid Valve Therapies (TriValve) registry collected data on patients with significant TR from 24 centres who underwent TTVI from 2016 to 2021. A control cohort was formed by medically managed patients with ≥severe isolated TR diagnosed in 2015-18. The primary endpoint was freedom from all-cause mortality. Secondary endpoints were heart failure (HF) hospitalization, New York Heart Association (NYHA) functional status, and TR severity. One-year outcomes were assessed for the TriValve cohort and compared with the control cohort with the inverse probability of treatment weighting (IPTW). A total of 556 and 2072 patients were included from the TriValve and control groups, respectively. After TTVI, there was no difference between women and men in 1-year freedom from all-cause mortality 80.9% vs. 77.9%, P = 0.56, nor in HF hospitalization (P = 0.36), NYHA Functional Classes III and IV (P = 0.17), and TR severity >2+ at last follow-up (P = 0.42). Multivariable Cox-regression weighted by IPTW showed improved 1-year survival after TTVI compared with medical therapy alone in both women (adjusted hazard ratio 0.45, 95% confidence interval 0.23-0.83, P = 0.01) and men (adjusted hazard ratio 0.42, 95% confidence interval 0.18-0.89, P = 0.03). CONCLUSION: After TTVI in high-risk patients, there were no sex-related differences in terms of survival, HF hospitalization, functional status, and TR reduction up to 1 year. The IPTW analysis shows a survival benefit of TTVI over medical therapy alone in both women and men.

Coronary artery plaque rupture and erosion: Role of wall shear stress profiling and biological patterns in acute coronary syndromes.

AIMS: Wall shear stress (WSS) is involved in coronary artery plaque pathological mechanisms and modulation of gene expression. This study aims to provide a comprehensive haemodynamic and biological description of unstable (intact-fibrous-cap, IFC, and ruptured-fibrous-cap, RFC) and stable (chronic coronary syndrome, CCS) plaques and investigate any correlation between WSS and molecular pathways. METHODS AND RESULTS: We enrolled 24 CCS and 25 Non-ST Elevation Myocardial Infarction-ACS patients with IFC (n = 11) and RFC (n = 14) culprit lesions according to optical coherence tomography analysis. A real-time PCR primer array was performed on peripheral blood mononuclear cells for 17 different molecules whose expression is linked to WSS. Computational fluid dynamics simulations were performed in high-fidelity 3D-coronary artery anatomical models for three patients per group. A total of nine genes were significantly overexpressed in the unstable patients as compared to CCS patients, with no differences between IFC and RFC groups (GPX1, MMP1, MMP9, NOS3, PLA2G7, PI16, SOD1, TIMP1, and TFRC) while four displayed different levels between IFC and RFC groups (TNFα, ADAMTS13, EDN1, and LGALS8). A significantly higher WSS was observed in the RFC group (p < 0.001) compared to the two other groups. A significant correlation was observed between TNFα (p < 0.001), EDN1 (p = 0.036), and MMP9 (p = 0.005) and WSS values in the RFC group. CONCLUSIONS: Our data demonstrate that IFC and RFC plaques are subject to different WSS conditions and gene expressions, suggesting that WSS profiling may play an essential role in the plaque instability characterization with relevant diagnostic and therapeutic implications in the era of precision medicine.

Rationale and design of the sirolimus eluting balloon utilization for treatment of vasculogenic erectile dysfunction: the SUASION Registry.

BACKGROUND: Conventional angioplasty balloon catheter, drug coated balloon (DCB), or angioplasty with drug eluting stent (DES) have been used on the percutaneous treatment of erectile dysfunction (ED). Currently available DCBs are paclitaxel eluting balloon (PEB), very recently, sirolimus eluting balloon (SEB). Although endovascular revascularization with balloon resulted in improvement of ED, there have been no prior reports on the feasibility of SEB treatment for ED. METHODS: We present an observational, retrospective-prospective multicentre registry in patients evaluating the use of SEB for the treatment of de novo stenosis in native internal pudendal arteries. We will include 100 patients affected by vasculogenic ED non responder to PDE5i with up to two lesions requiring treatment. ED patients should present a IIEF-5 Score<15, positive dynamic doppler (PSV <25 cm/s) and/or evidence at basal CT angiography. At 30 days, 180, 240, and 365 days following the index procedure, IIEF-5 score will be assessed, and medication regimen and adverse event monitoring will be assessed. At 8 months a dynamic Doppler will be performed. Patients will be followed up for 2 years. The primary endpoints are the Delta IIEF-5 Score and a Delta PSV between basal and 8 months follow-up. The secondary endpoint is the incidence of major adverse event (MAE), binary restenosis and late loss in patients who will repeat control angiography if clinically indicated. CONCLUSIONS: Considering the limitations and safety concerns of PEB, POBA and DES used so far in ED clinical investigations, we hypothesize that sirolimus nanocarriers-coated balloon can potentially be an improved next-generation treatment for ED patients.

Methylation of the Hippo effector YAP by the methyltransferase SETD7 drives myocardial ischaemic injury: a translational study.

AIMS: Methylation of non-histone proteins is emerging as a central regulatory mechanism in health and disease. The methyltransferase SETD7 has shown to methylate and alter the function of a variety of proteins in vitro; however, its function in the heart is poorly understood. The present study investigates the role of SETD7 in myocardial ischaemic injury. METHODS AND RESULTS: Experiments were performed in neonatal rat ventricular myocytes (NRVMs), SETD7 knockout mice (SETD7-/-) undergoing myocardial ischaemia/reperfusion (I/R) injury, left ventricular (LV) myocardial samples from patients with ischaemic cardiomyopathy (ICM), and peripheral blood mononuclear cells (PBMCs) from patients with ST-elevation MI (STEMI). We show that SETD7 is activated upon energy deprivation in cultured NRVMs and methylates the Hippo pathway effector YAP, leading to its cytosolic retention and impaired transcription of antioxidant genes manganese superoxide dismutase (MnSOD) and catalase (CAT). Such impairment of antioxidant defence was associated with mitochondrial reactive oxygen species (mtROS), organelle swelling, and apoptosis. Selective pharmacological inhibition of SETD7 by (R)-PFI-2 restored YAP nuclear localization, thus preventing mtROS, mitochondrial damage, and apoptosis in NRVMs. In mice, genetic deletion of SETD7 attenuated myocardial I/R injury, mtROS, and LV dysfunction by restoring YAP-dependent transcription of MnSOD and CAT. Moreover, in cardiomyocytes isolated from I/R mice and ICM patients, (R)-PFI-2 prevented mtROS accumulation, while improving Ca2+-activated tension. Finally, SETD7 was up-regulated in PBMCs from STEMI patients and negatively correlated with MnSOD and CAT. CONCLUSION: We show a methylation-dependent checkpoint regulating oxidative stress during myocardial ischaemia. SETD7 inhibition may represent a valid therapeutic strategy in this setting.