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Glycoprotein nonmetastatic melanoma protein B (GPNMB) is a type I transmembrane protein initially identified in nonmetastatic melanomas and has been associated with human heart failure; however, its role in cardiac injury and function remains unclear. Here we show that GPNMB expression is elevated in failing human and mouse hearts after myocardial infarction (MI). Lineage tracing and bone-marrow transplantation reveal that bone-marrow-derived macrophages are the main source of GPNMB in injured hearts. Using genetic loss-of-function models, we demonstrate that GPNMB deficiency leads to increased mortality, cardiac rupture and rapid post-MI left ventricular dysfunction. Conversely, increasing circulating GPNMB levels through viral delivery improves heart function after MI. Single-cell transcriptomics show that GPNMB enhances myocyte contraction and reduces fibroblast activation. Additionally, we identified GPR39 as a receptor for circulating GPNMB, with its absence negating the beneficial effects. These findings highlight a pivotal role of macrophage-derived GPNMBs in post-MI cardiac repair through GPR39 signaling.

BACKGROUND: Aging-associated left ventricular dysfunction promotes cardiopulmonary fibrogenic remodeling, Group 2 pulmonary hypertension (PH), and right ventricular failure. At the time of diagnosis, cardiac function has declined, and cardiopulmonary fibrosis has often developed. Here, we sought to develop a molecular positron emission tomography (PET)-magnetic resonance imaging (MRI) protocol to detect both cardiopulmonary fibrosis and fibrotic disease activity in a left ventricular dysfunction model. METHODS AND RESULTS: Left ventricular dysfunction was induced by transverse aortic constriction (TAC) in 6-month-old senescence-accelerated prone mice, a subset of mice that received sham surgery. Three weeks after surgery, mice underwent simultaneous PET-MRI at 4.7 T. Collagen-targeted PET and fibrogenesis magnetic resonance (MR) probes were intravenously administered. PET signal was computed as myocardium- or lung-to-muscle ratio. Percent signal intensity increase and Δ lung-to-muscle ratio were computed from the pre-/postinjection magnetic resonance images. Elevated allysine in the heart (P=0.02) and lungs (P=0.17) of TAC mice corresponded to an increase in myocardial magnetic resonance imaging percent signal intensity increase (P

BACKGROUND: Abnormal diastolic function is an independent predictor of adverse postoperative outcomes. Mitral annular tissue Doppler velocity (e) is a key parameter for assessing diastolic function. The purpose of this study was to confirm that an acute increase in preload did not significantly impact the intraoperative measurement of e and secondarily evaluate the impact of this acute intravascular volume increase on the clinical assessment of diastolic function using a previously described simplified algorithm. METHODS: This was a prospective, non-randomized study in adult patients undergoing elective cardiac surgeries requiring transesophageal echocardiographic monitoring, arterial pressure and Swan-Ganz catheter placements as part of the surgical procedure. Following baseline echocardiographic and hemodynamic measurements, 500 ml of crystalloid solution was infused over 10 min. Hemodynamic and echocardiographic measurements were repeated 5 min after fluid administration. RESULTS: Complete data sets were available from 84 of the 100 patients who were enrolled in this study. There was no significant change in the values of e. The average baseline was 7.8 ± 2.0 cm/s (95%CI: 7.4, 8.2) and 8.1 ± 2.4 (95%CI: 7.6, 8.6) following the fluid bolus (p = 0.10). All hemodynamic variables associated with increased intravascular volume (central venous pressure, pulmonary arterial pressures and stroke volume variation) changed significantly. The overall distribution of diastolic function grades did not change following fluid administration (p = 0.69). However, there were many individual patient differences. When using this simplified algorithm, functional grading changed in 35 patients. Thirty of these 35 changes were only a single grade shift. 22 patients had worse functional grading after fluid administration while 13 had improved grading. Nine patients with normal diastolic function at baseline demonstrated diastolic dysfunction after fluid administration while 6 patients with baseline dysfunction normalized following the fluid bolus. CONCLUSION: We confirmed that e is a robust measurement that is reproducible in the intraoperative setting despite variable vascular volume loading conditions, however, the clinical assessment of diastolic function was still altered in 42% of the patients following an intravenous fluid bolus.

The Japanese national guidelines recommend significantly lower doses of carvedilol for heart failure with reduced ejection fraction (HFrEF) management than the US guidelines. Using real-world data, we determined whether initial and target doses of carvedilol in Japanese patients (JPNs) differ from those in US patients (USPs), especially in Asian Americans (ASA) and Caucasians (CA), and investigated differences in outcomes. We collected data from the electronic medical records, including demographics, carvedilol dosing, tolerability, cardiac functional indicators like EF, cardiovascular events including all-cause deaths, and laboratory values from the University of California, San Diego Health and Osaka University. JPNs had significantly lower doses (mg/day) of carvedilol initiation (66 USPs composed of 38 CAs and 28 ASAs, 17.1±16.2; 93 JPNs, 4.3±4.2, p

Background: Limited data exists to evaluate the optimal management of outpatient beta blocker therapy when patients with heart failure with reduced ejection fraction (HFrEF) are admitted for acute decompensated heart failure (ADHF). Objective: This study aimed to compare the effects of holding or decreasing the dose of outpatient beta blocker therapy vs continuation of therapy on rates of tachyarrhythmias during admission for ADHF. Methods: This single-center, retrospective cohort study divided patients with HFrEF (left ventricular ejection fraction less than or equal to 40%) admitted for ADHF into two cohorts: one that had their outpatient beta blocker continued at the same dose upon admission and one that had it held or dose decreased. The primary outcome was a composite of non-sustained or sustained ventricular tachycardia, ventricular fibrillation, or atrial fibrillation or flutter with rapid ventricular response during the hospitalization. Secondary outcomes included the individual tachyarrhythmias in the primary outcome, in-hospital mortality, and 90-day re-admission for heart failure. Results: Of the 137 patients included, 82 were in the continuation cohort and 55 in the discontinuation/reduction cohort. The median length of stay was 5.3 days (interquartile range, 3.8-7.6). No significant difference in the primary composite outcome was found between the discontinuation/reduction and continuation cohorts (29.1% vs 22.0%; relative risk [95% confidence interval], 1.33 [.74-2.37]; P =.420). No significant differences were seen between the two cohorts for any of the secondary outcomes. Conclusion: Beta blocker therapy adjustment on admission for ADHF may not affect the occurrence of tachyarrhythmias in patients with HFrEF. [ABSTRACT FROM AUTHOR]

Congenital interventricular septal aneurysms (IVSA) of the muscular septum are rare and can be associated with other familial abnormalities of the ventricular septum, arrhythmias, additional congenital heart disease, and chromosomal abnormalities. IVSA is also linked to ventricular dysfunction and non-compaction, although there are limited reports of this association presenting in utero. We describe a case of fetal ventricular septal aneurysm associated with ventricular dysfunction and pericardial effusion. [ABSTRACT FROM AUTHOR]