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Heart failure (HF) prevalence is rising due to reduced early mortality and demographic change. Relaxin (RLN) mediates protective effects in the cardiovascular system through ...Relaxin-receptor 1 (RXFP1). Cardiac overexpression of RXFP1 with additional RLN supplementation attenuated HF in the pressure-overload transverse aortic constriction (TAC) model. Here, we hypothesized that robust transgenic RXFP1 overexpression in cardiomyocytes (CM) protects from TAC-induced HF even in the absence of RLN.
Hence, transgenic mice with a CM-specific overexpression of human RXFP1 (hRXFP1tg) were generated. Receptor functionality was demonstrated by in vivo hemodynamics, where the administration of RLN induced positive inotropy strictly in hRXFP1tg. An increase in phospholamban-phosphorylation at serine 16 was identified as a molecular correlate. hRXFP1tg were protected from TAC without additional RLN administration, presenting not only less decline in systolic left ventricular (LV) function but also abrogated LV dilation and pulmonary congestion compared to WT mice. Molecularly, transgenic hearts exhibited not only a significantly attenuated fetal and fibrotic gene activation but also demonstrated less fibrotic tissue and CM hypertrophy in histological sections. These protective effects were evident in both sexes. Similar cardioprotective effects of hRXFP1tg were detectable in a RLN-knockout model, suggesting an alternative mechanism of receptor activation through intrinsic activity, alternative endogenous ligands or crosstalk with other receptors.
In summary, CM-specific RXFP1 overexpression provides protection against TAC even in the absence of endogenous RLN. This suggests RXFP1 overexpression as a potential therapeutic approach for HF, offering baseline protection with optional RLN supplementation for specific activation.
Heart failure (HF) is a common pathological end point for several cardiac diseases. Despite reasonable achievements in pharmacological, electrophysiological and surgical treatments, prognosis for ...chronic HF remains poor. Modern therapies are generally symptom oriented and do not currently address specific intracellular molecular signaling abnormalities. Therefore, new and innovative therapeutic approaches are warranted and, ideally, these could at least complement established therapeutic options if not replace them. Gene therapy has potential to serve in this regard in HF as vectors can be directed toward diseased myocytes and directly target intracellular signaling abnormalities. Within this review, we will dissect the adrenergic system contributing to HF development and progression with special emphasis on G-protein-coupled receptor kinase 2 (GRK2). The levels and activity of GRK2 are increased in HF and we and others have demonstrated that this kinase is a major molecular culprit in HF. We will cover the evidence supporting gene therapy directed against myocardial as well as adrenal GRK2 to improve the function and structure of the failing heart and how these strategies may offer complementary and synergistic effects with the existing HF mainstay therapy of β-adrenergic receptor antagonism.
Heart failure (HF) is the common end point of cardiac diseases. Despite the optimization of therapeutic strategies and the consequent overall reduction in HF‐related mortality, the key underlying ...intracellular signal transduction abnormalities have not been addressed directly. In this regard, the gaps in modern HF therapy include derangement of β‐adrenergic receptor (β‐AR) signaling, Ca2+ disbalances, cardiac myocyte death, diastolic dysfunction, and monogenetic cardiomyopathies. In this review we discuss the potential of gene therapy to fill these gaps and rectify abnormalities in intracellular signaling. We also examine current vector technology and currently available vector‐delivery strategies, and we delineate promising gene therapy structures. Finally, we analyze potential limitations related to the transfer of successful preclinical gene therapy approaches to HF treatment in the clinic, as well as impending strategies aimed at overcoming these limitations.
Clinical Pharmacology & Therapeutics (2011) 90 4, 542–553. doi:10.1038/clpt.2011.148
Zusammenfassung
Die 2004 eingeführten Kriterien für die Aufnahme eines Patienten auf der Hochdringlichkeits(„High-urgency“-, HU-)Warteliste für eine Herztransplantation waren aufgrund fehlender ...zugrunde liegender Evidenzen sowie zu großem Interpretationsspielraum zunehmend kritisiert worden. Als erster Schritt wurden am 19.12.2019 in Abstimmung mit Eurotransplant die HU-Kriterien für Patienten mit kardialem Hypoperfusionssyndrom und nachgewiesener Abhängigkeit von inotropen Medikamenten publiziert. Zeitgleich wurden die Fristen für die Reevaluierung auf 4 bzw. 8 Wochen verlängert. Zentrumsintern müssen die Voraussetzungen für den HU-Status alle 14 Tage überprüft und der Wartelistenstatus ggf. zurückgestuft werden. Als weitere Änderung werden HU-Wartezeiten nun akkumuliert. Im zweiten Schritt wurden die Kriterien für Patienten mit Komplikationen am dauerhaften Kreislaufunterstützungssystem („durable mechanical circulatory support“, dMCS) angepasst. Hier wurden die einzelnen Kriterien wesentlich deutlicher definiert. Diese Richtlinienänderung trat zum 07.09.2021 in Kraft. Es wurden gleichzeitig HU-Kriterien für Spezialfälle veröffentlicht, wie z. B. angeborene Herzfehler oder unkontrollierbare ventrikuläre Arrhythmien etc.
Different ST-segment elevation myocardial infarction (STEMI) localizations go along with dissimilarities in the size of the affected myocardium, the causing coronary vessel occlusion, and the right ...ventricular participation. Therefore, this study aims to clarify if there is any difference in long-term survival between anterior- and non-anterior-wall STEMI.
This study included 2,195 incident STEMI cases that occurred between 2009 and 2017, recorded by the population-based Augsburg Myocardial Infarction Registry, Germany. The study population comprised 1.570 men and 625 women aged 25-84 years at acute myocardial infarction. The patients were observed from the day of their first acute event with an average follow-up period of 4.3 years, (standard deviation: 3.0). Survival analyses and multivariable Cox regression analyses were performed to examine the association between infarction localizations and long-term all-cause mortality.
Of the 2,195 patients, 1,118 had an anterior (AWS)- and 1,077 a non-anterior-wall-STEMI (NAWS). No significant associations of the STEMI localization with long-term mortality were found. When comparing AWS with NAWS, a hazard ratio of 0.91 95% confidence interval: 0.75-1.10 could be calculated after multivariable adjustment. In contrast to NAWS, AWS was associated with a greater <28 day mortality, less current or former smoking and higher creatine kinase-myocardial band levels (CK-MB) and went along with a higher frequency of impaired left ventricular ejection fraction (<30%).
Despite pathophysiological differences between AWS and NAWS, and identified differences in multiple clinical characteristics, no significant differences in long-term mortality between both groups were observed.
Low levels of the molecular inotrope S100A1 are sufficient to rescue post-ischemic heart failure (HF). As a prerequisite to clinical application and to determine the safety of myocardial S100A1 ...DNA-based therapy, we investigated the effects of high myocardial S100A1 expression levels on the cardiac contractile function and occurrence of arrhythmia in a preclinical large animal HF model. At 2 weeks after myocardial infarction domestic pigs presented significant left ventricular (LV) contractile dysfunction. Retrograde application of AAV6-S100A1 (1.5 × 10(13) tvp) via the anterior cardiac vein (ACV) resulted in high-level myocardial S100A1 protein peak expression of up to 95-fold above control. At 14 weeks, pigs with high-level myocardial S100A1 protein overexpression did not show abnormalities in the electrocardiogram. Electrophysiological right ventricular stimulation ruled out an increased susceptibility to monomorphic ventricular arrhythmia. High-level S100A1 protein overexpression in the LV myocardium resulted in a significant increase in LV ejection fraction (LVEF), albeit to a lesser extent than previously reported with low S100A1 protein overexpression. Cardiac remodeling was, however, equally reversed. High myocardial S100A1 protein overexpression neither increases the occurrence of cardiac arrhythmia nor causes detrimental effects on myocardial contractile function in vivo. In contrast, this study demonstrates a broad therapeutic range of S100A1 gene therapy in post-ischemic HF using a preclinical large animal model.
Cornerstone for an efficient cardiac gene therapy is the need for a vector system, which enables selective and long-term expression of the gene of interest. In rodent animal models adeno-associated ...viral (AAV) vectors like AAV-6 have been shown to efficiently transduce cardiomyocytes. However, since significant species-dependent differences in transduction characteristics exist, large animal models are of imminent need for preclinical evaluations. We compared gene transfer efficiencies of AAV-6 and heparin binding site-deleted AAV-2 vectors in a porcine model. Application of the AAVs was performed by pressure-regulated retroinfusion of the anterior interventricular cardiac vein, which has been previously shown to efficiently deliver genes to the myocardium (3.5 x 10(10) viral genomes per animal; n=5 animals per group). All vectors harbored a luciferase reporter gene under control of a cytomegalovirus (CMV)-enhanced 1.5 kb rat myosin light chain promoter (CMV-MLC2v). Expression levels were evaluated 4 weeks after gene transfer by determining luciferase activities. To rule out a systemic spillover peripheral tissue was analyzed by PCR for the presence of vector genomes. Selective retroinfusion of AAV serotype 6 vectors into the anterior cardiac vein substantially increased reporter gene expression in the targeted distal left anterior descending (LAD) territory (65 943+/-31 122 vs control territory 294+/-69, P<0.05). Retroinfusion of AAV-2 vectors showed lower transgene expression, which could be increased with coadministration of recombinant human vascular endothelial growth factor (1365+/-707 no vascular endothelial growth factor (VEGF) vs 38 760+/-2448 with VEGF, P<0.05). Significant transgene expression was not detected in other organs than the heart, although vector genomes were detected also in the lung and liver. Thus, selective retroinfusion of AAV-6 into the coronary vein led to efficient long-term myocardial reporter gene expression in the targeted LAD area of the porcine heart. Coapplication of VEGF significantly increased transduction efficiency of AAV-2.
Background
The Cardioband system enables percutaneous surgical-like direct mitral valve annuloplasty and, thereby, repair of severe functional mitral valve regurgitation (MR) in patients with ...advanced systolic heart failure (HF) and dilation of the left ventricular (LV) annulus. Since the device is anchored by screws in the LV annulus, limited myocardial injury is likely to occur.
Methods and results
Five patients (Society of Thoracic Surgeons score: 2.7 ± 0.7%) with severe HF (LV ejection fraction LVEF: 17 ± 1%; LV end-diastolic diameter LVEDD: 71 ± 3 mm) were treated with the Cardioband (sizes C–F) receiving 14–17 screws in the LV annulus region. Myocardial injury was monitored by measuring high-sensitive cardiac troponin T (hsTnT) levels and by echocardiography. All patients showed significant periprocedural increase in hsTnT levels. Peak hsTnT concentration was reached between day 1 and day 6 (593 ± 141 pg/ml). None of the patients showed clinical signs of myocardial infarction, ST-segment elevation, new onset of deteriorated myocardial wall motion, or new ventricular tachycardia. hsTnT levels normalized in all patients after 14 days (hsTnT on day 0: 34 ± 6 pg/ml vs. hsTnT on day 14: 36 ± 6 pg/ml;
p
= 0.604). This nonischemic hsTnT kinetics was compared to a sixth patient who experienced proximal damage of the left circumflex artery (LCX) and ST-segment elevation during the Cardioband procedure, followed by immediate repair of the LCX, avoiding structural damage of the LV.
Conclusion
Cardioband implantation is accompanied by significant elevation of hsTnT without causing structural myocardial damage or clinical symptoms such as worsening of LV function, new-onset LV regions exhibiting reduced wall motion, or ventricular tachycardia.
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