Platelet mass cytometry reveals dysregulation of prothrombotic pathways in essential thrombocythemia.

Thromboembolic events are common in patients with essential thrombocythemia (ET). However, the pathophysiological mechanisms underlying the increased thrombotic risk remain to be determined. Here, we perform the first phenotypical characterization of platelet expression using single-cell mass cytometry in six ET patients and six age- and sex-matched healthy individuals. A large panel of 18 transmembrane regulators of platelet function and activation were analyzed, at baseline and after ex-vivo stimulation with thrombin receptor-activating peptide (TRAP). We detected a significant overexpression of the activation marker CD62P (p-Selectin) (p = .049) and the collagen receptor GPVI (p = .044) in non-stimulated ET platelets. In contrast, ET platelets had a lower expression of the integrin subunits of the fibrinogen receptor GPIIb/IIIa CD41 (p = .036) and CD61 (p = .044) and of the von Willebrand factor receptor CD42b (p = .044). Using the FlowSOM algorithm, we identified 2 subclusters of ET platelets with a prothrombotic expression profile, one of them (cluster 3) significantly overrepresented in ET (22.13% of the total platelets in ET, 2.94% in controls, p = .035). Platelet counts were significantly increased in ET compared to controls (p = .0123). In ET, MPV inversely correlated with platelet count (r=-0.96). These data highlight the prothrombotic phenotype of ET and postulate GPVI as a potential target to prevent thrombosis in these patients.

Essential thrombocythemia (ET) is a rare disease characterized by an increased number of platelets in the blood. As a complication, many of these patients develop a blood clot, which can be life-threatening. So far, the reason behind the higher risk of blood clots is unclear. In this study, we analyzed platelet surface markers that play a critical role in platelet function and platelet activation using a modern technology called mass cytometry. For this purpose, blood samples from 6 patients with ET and 6 healthy control individuals were analyzed. We found significant differences between ET platelets and healthy platelets. ET platelets had higher expression levels of p-Selectin (CD62P), a key marker of platelet activation, and of the collagen receptor GPVI, which is important for clot formation. These results may be driven by a specific platelet subcluster overrepresented in ET. Other surface markers, such as the fibrinogen receptor GPIIb/IIIa CD41, CD61, and the von Willebrand factor receptor CD42b, were lower expressed in ET platelets. When ET platelets were treated with the clotting factor thrombin (thrombin receptor-activating peptide, TRAP), we found a differential response in platelet activation compared to healthy platelets. In conclusion, our results show an increased activation and clotting potential of ET platelets. The platelet surface protein GPVI may be a potential drug target to prevent abnormal blood clotting in ET patients.

Ligand-activated RXFP1 gene therapy ameliorates pressure overload-induced cardiac dysfunction.

Recurrent episodes of decompensated heart failure (HF) represent an emerging cause of hospitalizations in developed countries with an urgent need for effective therapies. Recently, the pregnancy-related hormone relaxin (RLN) was found to mediate cardio-protective effects and act as a positive inotrope in the cardiovascular system. RLN binds to the RLN family peptide receptor 1 (RXFP1), which is predominantly expressed in atrial cardiomyocytes. We therefore hypothesized that ventricular RXFP1 expression might exert potential therapeutic effects in an in vivo model of cardiac dysfunction. Thus, mice were exposed to pressure overload by transverse aortic constriction and treated with AAV9 to ectopically express RXFP1. To activate RXFP1 signaling, RLN was supplemented subcutaneously. Ventricular RXFP1 expression was well tolerated. Additional RLN administration not only abrogated HF progression but restored left ventricular systolic function. In accordance, upregulation of fetal genes and pathological remodeling markers were significantly reduced. In vitro, RLN stimulation of RXFP1-expressing cardiomyocytes induced downstream signaling, resulting in protein kinase A (PKA)-specific phosphorylation of phospholamban (PLB), which was distinguishable from ß-adrenergic activation. PLB phosphorylation corresponded to increased calcium amplitude and contractility. In conclusion, our results demonstrate that ligand-activated cardiac RXFP1 gene therapy represents a therapeutic approach to attenuate HF with the potential to adjust therapy by exogenous RLN supplementation.

[Drop in oxygen saturation and blood pressure as well as increase in central venous pressure during mitral valve clipping in an 81-year-old female patient]. / Abfall von Sauerstoffsättigung und Blutdruck sowie Anstieg des zentralen Venendrucks im Rahmen eines Mitralklappenclippings bei einer 81-Jährigen.

BACKGROUND: Atrial septal defects (ASD) following endovascular mitral valve clipping are potentially hemodynamically relevant complications. Immediate closure with an occluder can represent a safe and effective treatment. An 81-year-old female patient suffering from severe dyspnea due to previously known severe mitral valve regurgitation was scheduled for elective mitral valve clipping. The clip was successfully implanted. Removal of the transseptal cannula resulted in a sudden drop in oxygen saturation and systolic blood pressure as well as an immediate increase in central venous pressure. An iatrogenic left-right shunt was observed at the atrial level with a relevant shunt volume. Immediate closure using an atrial septal occluder successfully restored the oxygen saturation and hemodynamic parameters. CONCLUSION: An increase in central venous pressure, reduction of systolic blood pressure or oxygen saturation after withdrawal of the transseptal cannula during mitral valve clipping should always be further investigated regarding a possible ASD.

Initial experience with percutaneous mitral valve repair in patients with cardiac amyloidosis.

BACKGROUND: Percutaneous mitral valve repair (PMVR) is a therapeutic option for severe mitral regurgitation (MR) in patients with heart failure due to differential aetiologies. However, only little is known about the safety and efficacy of this procedure in patients with amyloid cardiomyopathy. METHODS: Five patients with cardiac amyloidosis and moderate to severe or severe MR undergoing PMVR were analysed retrospectively and compared to seven patients with cardiac amyloidosis and severe MR without intervention. Clinical and functional data, renal function and cardiac biomarkers as well as established risk scores for cardiac amyloidosis were assessed. Primary endpoint was the reduction in MR one year after PMVR. Secondary endpoints were safety, overall mortality after 12 months compared with the control group, as well as changes in clinical and functional parameters. RESULTS: Amyloidosis risk assessment documented amyloid cardiomyopathy at an advanced stage in all patients. Procedural, technical and device success of PMVR were all 100% and residual MR remained mild to moderate at 12 months follow-up (P = .038 vs before PMVR). Differences in survival compared with the control (no PMVR) group pointed to a possible survival benefit in the PMVR group (P = .02). CONCLUSION: PMVR is a feasible and safe procedure in patients with cardiac amyloidosis and might carry a possible survival benefit in this patient group.

Percutaneous mitral valve repair in recurrent severe mitral valve regurgitation after mitral annuloplasty : MitraClip-in-the-ring as a complementary strategy.

BACKGROUND: Patients with reduced left ventricular (LV) function undergoing coronary artery bypass graft surgery or/and aortic valve replacement occasionally show severe mitral valve (MV) regurgitation and thus also undergo surgical mitral annuloplasty. Over time, further deterioration of LV function and additional ischemic events cause recurrence of severe MV regurgitation due to the Carpentier IIIb morphology of the MV that is not adequately addressed by the previously implanted annuloplasty ring. METHODS: Seven patients (Society of Thoracic Surgeons score: 7.5 ± 1.5%) with Carpentier type-IIIb recurrent severe MV regurgitation, having undergone prior cardiothoracic surgery (median: 40 months) including mitral annuloplasty, were treated with the MitraClip device. RESULTS: MitraClip implantation resulted in significantly reduced MV regurgitation and improved New York Heart Association functional state, translating into an increased exercise capability and improved cardiac biomarkers. The morphology of the MV was adequately addressed without causing relevant MV stenosis, while the MV annulus area remained unaltered. The procedure was safe with a 30-day mortality rate of 0%. CONCLUSION: MitraClip-in-the-ring is feasible and in principle safe for treating Carpentier type IIIb severe MV regurgitation after surgical MV repair using mitral annuloplasty. MitraClip-in-the-ring resulted in immediate amelioration of clinical symptoms and increased physical exercise capacity.

ECPELLA 2.0-Minimally invasive biventricular groin-free full mechanical circulatory support with Impella 5.0/5.5 pump and ProtekDuo cannula as a bridge-to-bridge concept: A first-in-man method description.

BACKGROUND: Cardiogenic shock (CS) from biventricular heart failure that requires acute mechanical circulatory support (MCS) is associated with high mortality. Different MCS methods and techniques have emerged as a standard of care in CS. Nevertheless, the routine MCS approach carries multiple limitations such as limb ischemia, missing of left ventricular unloading and immobilization. We describe a method to establish a groin-free full support MCS in patients with CS without the need for thoracotomy. This is the first report of the ECPELLA 2.0 concept, a peripheral groin-free biventricular MCS in patients with acute CS. METHODS AND RESULTS: We discuss two patients in acute CS (INTERMACS I) treated with two peripheral MCS devices (Impella 5.0 or 5.5 surgically via an axillary artery and ProtekDuo cannula percutaneously via a right internal jugular vein) as a bridge before the implantation of a durable left ventricular assist device (LVAD). Biventricular assist device (BIVAD)-support duration was 9 and 15 days and both of the patients were successfully bridged to a durable LVAD. As our BIVAD-concept is groin-free, the patients started full mobilization as early as they were weaned from the respirator 2 days after the BIVAD-implantation. ECPELLA 2.0 provides a high cardiac output, right and left ventricular unloading with end-organ recovery and a possibility of administration of a membrane oxygenator. There were no device-related complications. CONCLUSION: The ECPELLA 2.0 biventricular support concept for patients suffering from an acute CS. Allows for rapid extubation, mobilization, and physical exercise while on full support. Additional application of a membrane oxygenator is easily feasible if required.

AAV6.ßARKct cardiac gene therapy ameliorates cardiac function and normalizes the catecholaminergic axis in a clinically relevant large animal heart failure model.

AIMS: G protein-coupled receptor kinase 2 (GRK2), which is markedly upregulated in failing human myocardium, has been implicated as a contributing factor or consequence of heart failure (HF). Importantly, cardiac-specific GRK2 knockout mice have recently proved the pathological nature of GRK2 in HF. Targeted inhibition of GRK2 is possible using a peptide inhibitor known as the ßARKct, which has rescued several disparate small animal HF models. This study was designed to evaluate long-term ßARKct expression in a clinically relevant large animal HF model, using stable myocardial gene delivery with adeno-associated virus serotype 6 (AAV6). METHODS AND RESULTS: A porcine model of HF subsequent to left ventricular (LV) myocardial infarction (MI) was used to study the effects of retrograde injection into the anterior interventricular vein of either AAV6.ßARKct or AAV6.luciferase as a control 2 weeks after MI. Echocardiography and LV hemodynamics were performed before and 6 weeks after gene transfer. Robust and long-term ßARKct expression was found after AAV6-mediated delivery, leading to significant amelioration of LV haemodynamics and contractile function in HF pigs compared with AAV6.luciferase-treated control animals that showed a continued decline in cardiac function. Interestingly, the neurohormonal axis was virtually normalized in AVV6.ßARKct-treated HF animals, represented by reductions in plasma norepinephrine levels, whereas AAV6.luciferase-treated pigs showed further increases in plasma catecholamine levels. As a result, LV remodelling and foetal gene expression was reversed by AVV6.ßARKct gene therapy. CONCLUSION: These data--showing sustained amelioration of cardiac function in a post-MI pig HF model--demonstrate the therapeutic potential of ßARKct gene therapy for HF.

Reticulated Platelets Predict Cardiovascular Death and Adverse Events in Coronary Artery Disease: A Systematic Review and Meta-analysis.

BACKGROUND: The pro-thrombotic immature or reticulated platelets (RPs) are known to be elevated in high-risk patients and in different pathological settings. It has been shown that RPs correlate with an insufficient antiplatelet response to antiplatelet agents. RPs are emerging novel predictors of adverse cardiovascular events in cardiovascular disease. This study, using the totality of existing evidence, evaluated the prognostic role of RPs in patients with coronary artery disease. METHODS: We performed a systematic review and meta-analysis including trials of acute and chronic coronary syndrome reporting clinical outcomes according to RPs levels in the peripheral blood. We compared patients with elevated RPs (RPshigh) to patients without elevated RPs (RPslow). Odds ratios (ORs) and 95% CIs were used as metric of choice for treatment effects with random-effects models. The primary endpoint was major adverse cardiovascular and cerebrovascular events (MACCE). Secondary endpoints were cardiovascular death, myocardial infarction, ischemic stroke, urgent coronary revascularization and bleedings. RESULTS: A total of 7 studies, including 2213 patients, were included. The risk for MACCE was significantly higher in RPshigh compared to RPslow patients (OR 2.67 [1.87; 3.81], I2 = 43.8%). RPshigh were associated with cardiovascular death (OR 2.09 [1.36; 3.22], I2 = 40.4%). No associations for RPshigh were detected with the other singular components of MACCE: myocardial infarction (OR 1.73 [0.89; 3.38] I2 = 60.5%) and stroke (OR 1.72 [0.59; 4.96] I2 = 21%). The risk of bleeding did not differ between groups(OR 0.58 [0.15; 2.22] I2 = 86.1%). CONCLUSION: Elevated RPs are significantly associated with increased risk of cardiovascular events and cardiovascular death.

Cardiac G-protein-coupled receptor kinase 2 ablation induces a novel Ca2+ handling phenotype resistant to adverse alterations and remodeling after myocardial infarction.

BACKGROUND: G-protein-coupled receptor kinase 2 (GRK2) is a primary regulator of ß-adrenergic signaling in the heart. G-protein-coupled receptor kinase 2 ablation impedes heart failure development, but elucidation of the cellular mechanisms has not been achieved, and such elucidation is the aim of this study. METHODS AND RESULTS: Myocyte contractility, Ca(2+) handling and excitation-contraction coupling were studied in isolated cardiomyocytes from wild-type and GRK2 knockout (GRK2KO) mice without (sham) or with myocardial infarction (MI). In cardiac myocytes isolated from unstressed wild-type and GRK2KO hearts, myocyte contractions and Ca(2+) transients were similar, but GRK2KO myocytes had lower sarcoplasmic reticulum (SR) Ca(2+) content because of increased sodium-Ca(2+) exchanger activity and inhibited SR Ca(2+) ATPase by local protein kinase A-mediated activation of phosphodiesterase 4 resulting in hypophosphorylated phospholamban. This Ca(2+) handling phenotype is explained by a higher fractional SR Ca(2+) release induced by increased L-type Ca(2+) channel currents. After ß-adrenergic stimulation, GRK2KO myocytes revealed significant increases in contractility and Ca(2+) transients, which were not mediated through cardiac L-type Ca(2+) channels but through an increased SR Ca(2+). Interestingly, post-MI GRK2KO mice showed better cardiac function than post-MI control mice, which is explained by an improved Ca(2+) handling phenotype. The SR Ca(2+) content was better maintained in post-MI GRK2KO myocytes than in post-MI control myocytes because of better-maintained L-type Ca(2+) channel current density and no increase in sodium-Ca(2+) exchanger in GRK2KO myocytes. An L-type Ca(2+) channel blocker, verapamil, reversed some beneficial effects of GRK2KO. CONCLUSIONS: These data argue for novel differential regulation of L-type Ca(2+) channel currents and SR load by GRK2. G-protein-coupled receptor kinase 2 ablation represents a novel beneficial Ca(2+) handling phenotype resisting adverse remodeling after MI.

Initial experience with transcatheter tricuspid valve repair in patients with cardiac amyloidosis.

AIMS: Wildtype transthyretin amyloid cardiomyopathy is an under-recognized cause of heart failure in elderly patients. Transcatheter tricuspid valve repair is a newly emerging therapeutic option for severe tricuspid regurgitation (TR). We present first insights into safety and possible benefits of this procedure in patients with cardiac amyloidosis. METHODS AND RESULTS: Eight patients with cardiac non-hereditary (wildtype) transthyretin (ATTRwt) amyloidosis and severe to torrential TR, undergoing successful transcatheter tricuspid valve repair, were included in the analysis and compared to a control group of 21 patients without cardiac amyloidosis. All patients presented with an advanced stage of amyloid cardiomyopathy. Primary endpoint was reduction in TR at 3 months follow-up. Secondary endpoints were feasibility, safety, hospitalization or death, clinical improvement, cardiac biomarkers, and structural and functional right heart parameter obtained by echocardiography. Transcatheter tricuspid valve repair resulted in a significant reduction of TR (IV to II, P = 0.008) in all eight patients with cardiac amyloidosis (100%). Device success (amyloidosis 75% vs. control group 86%, P = 0.597) and overall probability of hospitalization or death (amyloidosis 13% vs. control group 25%, P = 0.646) were similar compared with those in the control group at 3 months follow-up. Transcatheter tricuspid valve repair led to an improvement of New York Heart Association functional class (P = 0.031) and 6 min walking distance (from 313 ± 118 to 337 ± 106, P = 0.012). TR reduction in amyloidosis patients was less extensive compared with that in control group (TR-reduction 1.6 ± 0.3, P = 0.008 vs. control group 2.3 ± 0.3, P < 0.0001). Furthermore, these patients showed no significant improvement of structural right heart parameters. CONCLUSIONS: Transcatheter tricuspid valve repair is a safe and feasible new treatment option in patients with amyloid cardiomyopathy and has the potential to improve TR-grade and clinical status. However, the benefit appears to be less pronounced compared with patients without cardiac amyloidosis.

Outcomes in patients with cardiac amyloidosis undergoing heart transplantation: the eurotransplant experience.

BACKGROUND: When advanced heart failure occurs in cardiac amyloidosis, prognosis is poor. In this setting heart transplantation (HTX) is a treatment option for selected patients. We here present the results of post-transplantation outcomes in cardiac amyloidosis within the Eurotransplant area, investigating possible predictors of survival. METHODS: Of 115 patients undergoing HTX due to cardiac amyloidosis in the Eurotransplant region between November 1987 and May 2020, detailed assessment prior to transplantation was available in 85 patients. The present study was conducted in a retrospective approach. Primary endpoint was mortality after HTX. Baseline variables were entered in a Cox proportional hazards model with the primary endpoint as a dependent variable. RESULTS: Median overall survival following HTX was 6.3 years in the overall collective and the subgroup. Univariate Cox proportional hazards model revealed a significant relationship between overall survival and the transplantation period (2008 to 2020 vs 1987 to 2007; median survival 9.7 years vs 1.8 years, hazard ratio 0.45, p = 0.01). Further predictors were albumin concentration (hazard ratio 0.92, p < 0.001), and systolic blood pressure (hazard ratio 0.96, p < 0.001). The transplant period as well as albumin concentration remained significant independent predictors in the AL sub cohort in a multivariate Cox proportional hazards model. CONCLUSIONS: HTX is a viable treatment option for patients at an advanced stage of cardiac amyloidosis as overall survival after transplantation has improved in the modern age. Patients at a very advanced stage of the disease, indicated by low serum albumin and blood pressure, show worse outcomes following HTX. Optimal timing and careful patient selection may therefore be particularly important to further improve post-HTX survival in amyloidosis patients.

Level of G protein-coupled receptor kinase-2 determines myocardial ischemia/reperfusion injury via pro- and anti-apoptotic mechanisms.

RATIONALE: Activation of prosurvival kinases and subsequent nitric oxide (NO) production by certain G protein-coupled receptors (GPCRs) protects myocardium in ischemia/reperfusion injury (I/R) models. GPCR signaling pathways are regulated by GPCR kinases (GRKs), and GRK2 has been shown to be a critical molecule in normal and pathological cardiac function. OBJECTIVE: A loss of cardiac GRK2 activity is known to arrest progression of heart failure (HF), at least in part by normalization of cardiac ß-adrenergic receptor (ßAR) signaling. Chronic HF studies have been performed with GRK2 knockout mice, as well as expression of the ßARKct, a peptide inhibitor of GRK2 activity. This study was conducted to examine the role of GRK2 and its activity during acute myocardial ischemic injury using an I/R model. METHODS AND RESULTS: We demonstrate, using cardiac-specific GRK2 and ßARKct-expressing transgenic mice, a deleterious effect of GRK2 on in vivo myocardial I/R injury with ßARKct imparting cardioprotection. Post-I/R infarct size was greater in GRK2-overexpressing mice (45.0±2.8% versus 31.3±2.3% in controls) and significantly smaller in ßARKct mice (16.8±1.3%, P<0.05). Importantly, in vivo apoptosis was found to be consistent with these reciprocal effects on post-I/R myocardial injury when levels of GRK2 activity were altered. Moreover, these results were reflected by higher Akt activation and induction of NO production via ßARKct, and these antiapoptotic/survival effects could be recapitulated in vitro. Interestingly, selective antagonism of ß(2)ARs abolished ßARKct-mediated cardioprotection, suggesting that enhanced GRK2 activity on this GPCR is deleterious to cardiac myocyte survival. CONCLUSION: The novel effect of reducing acute ischemic myocardial injury via increased Akt activity and NO production adds significantly to the therapeutic potential of GRK2 inhibition with the ßARKct not only in chronic HF but also potentially in acute ischemic injury conditions.

Cardiac Gene Delivery in Large Animal Models: Selective Retrograde Venous Injection.

Delivery of viral vectors to the heart represents a challenging endeavor. Besides vector design, the route of substrate administration is significantly influencing gene delivery success. The selective retrograde venous injection (SRVI) represents one of the most efficient percutaneous delivery strategies for transduction of the anterior left ventricular myocardium. In this chapter, we discuss the advantages and limitations of this vector delivery approach and provide a protocol for selective retrograde venous injection in a preclinical large animal model. As limited transgene expression frequently hampers generation of reliable proof-of-principle data and thus translation, this technique provides a valuable tool to ensure high myocardial transduction in preclinical research.

One-year results following PASCAL-based or MitraClip-based mitral valve transcatheter edge-to-edge repair.

AIMS: Mitral valve transcatheter edge-to-edge repair (TEER) has been established as a suitable alternative to mitral valve surgery in patients with severe mitral regurgitation (MR) and high surgical risk. The PASCAL system represents a novel device, potentially augmenting the toolkit for TEER. The aim of this study was to assess and compare short and 1 year safety and efficacy of the PASCAL and MitraClip systems for TEER. METHODS AND RESULTS: Procedural, short, and 1 year outcomes of a 1:2 propensity-matched cohort including 41 PASCAL and 82 MitraClip cases were investigated. Matching was based on clinical, laboratory, echocardiographic, and functional characteristics. The primary endpoints assessed were procedural success [as defined by the Mitral Valve Academy Research Consortium (MVARC)], residual MR, functional class, and a composite endpoint comprising death, heart failure hospitalization, and mitral valve re-intervention. We found for the PASCAL and the matched MitraClip cohort no significant differences in MVARC defined technical (90.2% vs. 95.1%, P = 0.44), device (90.2% vs. 89.0%, P = 1.0), or procedural (87.8% vs. 80.5%, P = 0.45) success rates. Accordingly, the overall MR reduction and improvement in New York Heart Association (NYHA) class were comparable (1 year follow-up: MR ≤ 2 95% vs. 93.6%, P = 1.0; NYHA ≤ 2 57.1% vs. 66.7%, P = 0.59). The composite outcome revealed no statistically significant difference between both devices (1 year follow-up: 31.7% vs. 37.8%, P = 0.55). Interestingly, we found at both short and 1 year follow-up a significantly higher rate of patients with none or trace MR in the PASCAL-treated cohort (short follow-up: 17.9% vs. 0%, P = 0.0081; 1 year follow-up: 25% vs. 0%, P = 0.0016). Conversely, the rate of aborted device implantations due to an elevated transmitral gradient was higher in PASCAL interventions (9.8% vs. 1.2%, P = 0.04). CONCLUSIONS: Transcatheter edge-to-edge repair using the PASCAL or MitraClip device results in favourable and comparable outcomes regarding safety, efficacy, and clinical improvement after 1 year.

Impact of Percutaneous Mitral Valve Repair Using the MitraClipTM System on Ventricular Arrhythmias and ICD Therapies.

Transcatheter edge-to-edge repair (TEER) using the MitraClip™ device has been established as a suitable alternative to mitral valve surgery in patients with severe mitral regurgitation (MR) and high or prohibitive surgical risk. Only limited information regarding the impact of TEER on ventricular arrhythmias (VA) has been reported. The aim of the present study was to assess the impact of TEER using the MitraClipTM device on the burden of VA and ICD (Implantable Cardioverter Defibrillator) therapies. Among 600 MitraClipTM implantations performed in our clinic between September 2009 and October 2018, we identified 86 patients with successful TEER and an active implantable cardiac device (pacemaker, ICD, CRT-P/D (Cardiac Resynchronization Therapy-Pacemaker/Defibrillator)) eligible for retrospective VA analyses. These patients presented with mainly functional MR (81.4%) and severely reduced left ventricular ejection fraction (mean LVEF 22.1% ± 10.3%). The observation period comprised 456 ± 313 days before and 424 ± 287 days after TEER. The burden of ventricular arrhythmias (sustained ventricular tachycardia (sVT) and ventricular fibrillation (VF)) was significantly reduced after TEER (0.85 ± 3.47 vs. 0.43 ± 2.03 events per patient per month, p = 0.01). Furthermore, the rate of ICD therapies (anti-tachycardia pacing (ATP) and ICD shock) decreased significantly after MitraClipTM implantation (1.0 ± 3.87 vs. 0.32 ± 1.41, p = 0.014). However, reduction of VA burden did not result in improved two-year survival in this patient cohort with severely reduced LVEF. Mitral valve TEER using the MitraClip™ device was associated with a significant reduction of ventricular arrhythmias and ICD therapies.

Functional improvement following direct interventional leaflet repair of severe tricuspid regurgitation.

AIMS: Several new percutaneous tricuspid repair systems have recently been introduced as new treatment options for severe tricuspid regurgitation (TR). Clinical improvement following percutaneous tricuspid valve leaflet repair has been demonstrated by recent studies. A possible impact on exercise capacity has not yet been reported. METHODS AND RESULTS: Eleven patients with at least severe TR and successful tricuspid leaflet repair using the PASCAL Ace implant at our cardiology department were included in this analysis. All patients suffered from symptomatic right-sided heart failure with compromised exercise capacity. Cardiopulmonary exercise testing (CPET), clinical, laboratory, and echocardiographic parameters were assessed at baseline and 3 months follow-up. The primary endpoint was the change in maximal oxygen consumption [VO2 max (mL/(min*kg))] at 3 months follow-up. Secondary endpoints included improvement in TR, cardiac biomarkers, and other clinical outcomes. TR severity at 3 months follow-up post-PASCAL Ace implantation was significantly lower than at baseline (P = 0.004). Cardiac biomarkers including high-sensitivity troponin T and N-terminal pro-brain natriuretic peptide as well as right ventricular diameter improved slightly without reaching statistical significance (P = 0.89, P = 0.32, and P = 0.06, respectively). PASCAL Ace implantation resulted in a significant improvement in cardiopulmonary exercise capacity at 3 months follow-up compared with baseline. Mean VO2 max improved from 9.5 ± 2.8 to 11.4 ± 3.4 mL/(min*kg) (P = 0.006), VO2 max per cent predicted from 42 ± 12% to 50 ± 15% (P = 0.004), peak oxygen uptake from 703 ± 175 to 826 ± 198 mL/min (P = 0.004), and O2 pulse per cent predicted from 67 ± 21% to 81 ± 25% (P = 0.011). Other CPET-related outcomes did not show any significant change over time. CONCLUSIONS: In this single-centre retrospective analysis, direct tricuspid valve leaflet repair using the transcatheter PASCAL Ace implant system was associated with a reduced TR severity and improved cardiopulmonary exercise capacity.

Initial Experience With the PASCAL Ace Implant System for Treatment of Severe Tricuspid Regurgitation.

[Figure: see text].

PASCAL-based mitral valve repair in an all-comer population: acute and mid-term clinical results.

AIMS: We investigated short and mid-term safety and efficacy of the PASCAL system for percutaneous mitral valve repair (PMVr) in severe mitral regurgitation (MR) in an all-comer population. METHODS AND RESULTS: In the first consecutive 41 patients undergoing PMVr using the PASCAL system in our centre, procedural success and safety were assessed. Efficacy in improving MR and functional class were evaluated. Median patient age was 74 years, 58.5% were male patients, and median European System for Cardiac Operative Risk Evaluation Score II was 5.1%. All patients suffered from severe MR with 59% functional MR, 29% degenerative MR, and 12% of mixed aetiology MR. The technical success rate was 90%, limited by four cases where PASCAL implantation was aborted due to a prohibitive mitral gradient. On average, 1.16 PASCAL devices per patient were implanted. All patients successfully implanted with a PASCAL device were discharged with MR grade ≤ 2 and 79% with MR grade ≤ 1. Mean follow-up was 8.7 ± 4.9 months. Ninety-seven per cent of patients remained at MR ≤ 2 at follow-up, which translated into a significantly improved New York Heart Association functional class as well as a significant reduction of systolic pulmonary artery pressure and brain natriuretic peptide levels. The procedure-related rate for major adverse events was 3%. Neither early nor late single-leaflet detachment was found. In one patient, air embolism occurred, resulting in modification of the PASCAL instructions for use. CONCLUSIONS: Percutaneous mitral valve repair using PASCAL in a real-world, all-comer population was feasible and safe, resulting in a significant mid-term reduction of MR with persistent clinical improvement.

Re-do MitraClip in patients with functional mitral valve regurgitation and advanced heart failure.

AIM: Percutaneous mitral valve repair (PMVR) via MitraClip implantation is a therapeutic option for severe mitral regurgitation (MR) in advanced stages of heart failure (HF). However, progressive left ventricular dilation in these patients may lead to recurrent MR after PMVR and consequent re-do MitraClip implantation. Here, we describe the characteristics and outcomes of this clinical scenario. METHODS AND RESULTS: Patients with systolic HF and functional MR undergoing a re-do MitraClip procedure were retrospectively analysed. Inclusion criteria were age ≥18 years, technical, device and procedural success at first MitraClip procedure, functional MR and systolic HF with an ejection fraction (EF) of <45%. Seventeen out of 684 patients undergoing PMVR with the MitraClip device at our institution between September 2009 and July 2019 were included. All patients displayed advanced HF with an EF of 20% (±9.9) and highly elevated N-terminal pro-brain natriuretic peptide. Technical success of the re-do MitraClip procedure was 100%, whereas procedural and device success were only achieved in 11 patients (65%). Unsuccessful re-do procedures were related to lower EF and implantation of more than one clip at initial procedure. However, despite reduction in MR grade and no occurrence of significant mitral stenosis after the procedure, the mortality during 12 months follow-up remained high (8 of 17; 47%). CONCLUSIONS: In a cohort of patients with advanced HF undergoing PMVR, re-do MitraClip procedure was feasible, but procedural success was unsatisfactory and morbidity and mortality remained high, possibly reflecting the advanced stage of HF in these patients.

Gene therapy in heart failure.

With increasing knowledge of basic molecular mechanisms governing the development of heart failure (HF), the possibility of specifically targeting key pathological players is evolving. Technology allowing for efficient in vivo transduction of myocardial tissue with long-term expression of a transgene enables translation of basic mechanistic knowledge into potential gene therapy approaches. Gene therapy in HF is in its infancy clinically with the predominant amount of experience being from animal models. Nevertheless, this challenging and promising field is gaining momentum as recent preclinical studies in larger animals have been carried out and, importantly, there are 2 newly initiated phase I clinical trials for HF gene therapy. To put it simply, 2 parameters are needed for achieving success with HF gene therapy: (1) clearly identified detrimental/beneficial molecular targets; and (2) the means to manipulate these targets at a molecular level in a sufficient number of cardiac cells. However, several obstacles do exist on our way to efficient and safe gene transfer to human myocardium. Some of these obstacles are discussed in this review; however, it primarily focuses on the molecular target systems that have been subjected to intense investigation over the last decade in an attempt to make gene therapy for human HF a reality.