Introduction: Mechanisms underlying bioprosthetic valve deterioration (BVD) are multifactorial and incompletely elucidated. Reparative circulating progenitor cells (CPCs), and conversely calcification-associated osteocalcin expressing CPCs (CPC-OCN), have been linked to native aortic valve deterioration. However, their role in BVD remains elusive. This study sought to evaluate the contribution of different subpopulations of CPCs in BVD. Methods: This prospective study enrolled 121 patients who had peripheral blood mononuclear cells (PBMC) isolated prior to bioprosthetic aortic valve replacement (surgical 104, transcatheter 17) and had an echocardiographic follow-up ≥2 years after the procedure. Using flow cytometry, fresh PBMC were analyzed for the surface markers CD34, CD133, and osteocalcin (OCN). BVD was evaluated by hemodynamic valve deterioration (HVD) using echocardiography, which was defined as an elevated mean transprosthetic gradient ≥30mmHg and/or at least moderate intraprosthetic regurgitation. Multivariable models were constructed to evaluate the association of each subpopulation of CPCs and other clinical characteristics with HVD. Results: Sixteen patients (13.2%) developed HVD during follow-up for a median of 5.9 years. Patients with HVD showed significantly lower levels of reparative CD34 + CD133 + cells and higher levels of OCN + cells than those without HVD (CD34 + CD133 + cells: 125 [80, 210] vs 270 [130, 420], P=0.002; OCN + cells: 3060 [523, 5528] vs 670 [180, 1930], P=0.005 respectively). Decreased level of CD34 + CD133 + cells was a significant predictor of HVD. Conclusions: Circulating levels of CD34 + CD133 + cells and OCN + cells were significantly associated with the subsequent occurrence of HVD in patients undergoing bioprosthetic aortic valve replacement. CPCs might play a vital role in the mechanism, risk stratification and a potential therapeutic target for patients with bioprosthetic valve deterioration.
Abstract 12824: Predictive Value of Artificial Intelligence-Enabled Electrocardiography in Patients with Takotsubo Cardiomyopathy
Introduction: Recent studies have indicated high rates of future major adverse cardiovascular events in patients with Takotsubo cardiomyopathy (TTC). This study sought to evaluate the prognostic value of our institutional artificial intelligence-augmented electrocardiography (AI-ECG) algorithms in patients with TTC. Methods: This study enrolled consecutive patients in the prospective and observational Mayo Clinic Takotsubo syndrome registry. TTC was diagnosed according to the Mayo Clinic diagnostic. Our clinic’s previously developed and validated AI-ECG algorithms were used for detection of ECG-Age, probability of low ejection fraction, and probability of atrial fibrillation.Multivariable models were constructed to evaluate the association of AI-ECG and other clinical characteristics with major adverse cardiac events (MACE), defined as cardiac death, recurrence of TTC, nonfatal myocardial infarction, hospitalization for congestive heart failure, and stroke. Results: In the final analysis, 305 patients were studied over a median follow-up of 4.8 years. Patients with MACE were more likely to be older, have history of hypertension and chronic heart failure (CHF), worse renal function as well as having high-risk AI-ECG findings compared to those without. In the multivariate Cox proportional hazard analysis, the presence of 3 or 4 high-risk findings detected by AI-ECG, remained a significant predictor of MACE in the patients with TTC after adjusted by conventional risk factors (hazard ratio (HR) 2.17, 95% CI [1.33, 3.53], P=0.002; HR 2.44, 95% CI [1.38, 4.29], P=0.002, respectively). Conclusions: The combined use of developed AI-ECG algorithms derived from a single 12-lead ECG might identify ECG correlates of underlying non-transient myocardial dysfunction and detect subtle underlying patterns associated with worse outcomes in patients with TTC. This approach might be beneficial for stratifying high-risk patients with TTC.
#4623 A NOVEL ELECTRO-HYDRAULIC ACOUSTIC THERAPY REDUCES BLOOD PRESSURE IN HYPERTENSIVE PATIENTS WITH CHRONIC KIDNEY DISEASE: PRELIMINARY RESULTS
Abstract Background and Aims Arterial hypertension (HTN) in association with chronic kidney disease (CKD) is a global healthcare burden, yet clinically proven treatments are limited. electro-Hydraulic Acoustic Therapy (eHAT), using ∼10% of the energy used in shockwave lithotripsy, is a promising technique to ameliorate ischemia and regenerate tissues. eHAT has been demonstrated to enhance healing in tissues such as bone, muscle, and myocardium, via several mechanisms, particularly by promoting neovascularization. Furthermore, previous animal studies demonstrated that eHAT reduces blood pressure (BP) and preserves renal function after ischemic kidney injury. The present pilot study explored the clinical safety and efficacy of eHAT and tested the hypothesis that eHAT would reduce BP and preserve renal function in patients with medically-treated hypertension and CKD. Method So far, a total of 15 patients with HTN and Stage III a/b CKD were enrolled in this prospective, single-arm study. The patients were treated with six sessions of eHAT during a 3-week period. At each session, 2400 shockwaves were applied to each kidney with 0.09 mJ/mm2 at 2.66Hz (NephrospecTM by Curespec LTD, Yehud, Israel). Follow-up (FU) visits were performed at 1, 3, and 6 months. Results The treatment was well tolerated with no major adverse events or need for analgesic treatment. Average Automated Office BP (AOBP) showed a strong tendency for a decrease in diastolic BP from baseline to the Primary Efficacy Objective at FU II (3 months post last treatment), which progressively decreased further at FU III (6 months) (Table 1). Similarly, average Office BP (OBP) detected a strong trend for a progressive decrease in systolic BP from baseline to the Primary Efficacy Objective (Table 1). Levels of eGFR appeared to slightly rise throughout the study, but this change has not reached statistical significance levels (Table 1). Conclusion The current study demonstrates that the eHAT procedure is tolerable and safe in this cohort. Moreover, a 3-week regimen tended to reduce BP and preserve eGFR in patients with controlled HTN and CKD. Therefore, electro-Hydraulic Acoustic Therapy may emerge as a novel, safe, and non-invasive alternative therapeutic approach in the management of HTN in the context of CKD.
#4067 HYPOXIC PRECONDITIONING FOR THE IMPROVEMENT OF THE REGENERATIVE CAPACITY OF MESENCHYMAL STEM CELLS AND ITS APPLICATION IN HYPERTENSIVE KIDNEY DISEASE
Abstract Background and Aims Autologous mesenchymal stem/stromal cells (MSCs) have emerged as a therapeutic option for many chronic diseases. Hypertensive kidney disease (HKD) might impair MSCs’ reparative ability by altering important biomolecular properties of the cell, but the characteristics of this impairment are unclear. In our previous pre-clinical studies, hypoxic preconditioning (HPC) enhanced MSC angiogenesis and reduced senescence through global gene and protein expression. Thus, we hypothesize that HPC would improve human MSCs by enhancing their functionality and angiogenesis, creating an anti-inflammatory and anti-senescence environment in MSCs from healthy control (HC), hypertensive patients (HTN), and hypertensive kidney disease patients (HKD). Method Human MSCs were collected from abdominal subcutaneous fat tissue biopsy of HC, HTN, and HKD patients (n=12 each). Samples were collected from healthy volunteers with no history of hypertension or kidney disease (HC), patients diagnosed with hypertension controlled with antihypertensive drugs (HTN), and hypertensive patients with eGFR<60 mL/min/1.73 m2 (HKD). MSCs were harvested and cultured in Normoxic (20% O2) or Hypoxic (1% O2) conditions for 24-48 hours. MSC functionality was measured by migration and proliferation. Angiogenic and inflammatory secretome in conditioned media was assessed along with MSC senescence by senescence-associated beta-galactosidase (SA-beta-gal) activity. In addition, transcriptome analysis using RNA-sequencing (n=3/group) and quantitative PCR (qPCR) were performed to evaluate gene expression. Results At baseline, Normoxic HTN-MSCs interestingly had higher proliferation compared to HC. HC-MSC subjected to HPC showed increased proliferation (Figure 1A). SA-β-gal activity tended to decrease after HPC, particularly in the HC group (P = .06). HPC did not affect the release of the pro-angiogenic protein VEGF from MSCs, but increased EGF in HC-MSC, and decreased HGF in HC and HKD MSCs. HPC upregulated the pro-angiogenetic genes, inflammatory gene, and a few senescence genes (Figure 1F). Conclusion HPC has a more favorable functional effect on HC- than on HKD-MSC, reflected in increased proliferation and EGF release, and tends to decrease senescence, whereas it has little effect on HTN or HKD MSCs. These observations may assist in developing novel therapeutic strategies to improve the regenerative capacity of MSCs in patients with hypertensive kidney disease.
Obesity blunts amelioration of cardiac hypertrophy and fibrosis by human mesenchymal stem/stromal cell-derived extracellular vesicles
Injection of A-MSC-derived EVs harvested from patients who are lean can resolve myocardial injury in mice with experimental renovascular hypertension more effectively than A-MSC-derived EVs from patients with obesity. These observations underscore and might have important ramifications for the self-healing capacity of patients with obesity and for the use of autologous EVs as a regenerative tool.
A NOVEL ELECTRO-HYDRAULIC ACOUSTIC THERAPY REDUCES BLOOD PRESSURE IN HYPERTENSIVE PATIENTS WITH CHRONIC KIDNEY DISEASE: PRELIMINARY RESULTS
Objective: Electro-Hydraulic Acoustic Therapy (eHAT), using ∼10% of the energy used in shockwave lithotripsy, is a promising technique to ameliorate ischemia and regenerate tissues. eHAT has been demonstrated to enhance healing in tissues such as bone, muscle, and myocardium, via several mechanisms, particularly by promoting neovascularization. Furthermore, previous animal studies demonstrated that eHAT reduces blood pressure (BP) and preserves renal function after ischemic kidney injury. The present pilot study explored the clinical safety and efficacy of eHAT and tested the hypothesis that eHAT would reduce BP and preserve renal function in patients with medically-treated hypertension and CKD. Design and method: So far, a total of 15 patients with HTN and Stage III a/b CKD were enrolled in this prospective, single-arm study. The patients were treated with six sessions of eHAT during a 3-week period. At each session, 2400 shockwaves were applied to each kidney with 0.09 mJ/mm2 at 2.66Hz (NephrospecTM by Curespec LTD, Yehud, Israel). Follow-up (FU) visits were performed at 1, 3, and 6 months. Results: The treatment was well tolerated with no major adverse events or need for analgesic treatment. Average Automated Office BP (AOBP) showed a strong tendency for a decrease in diastolic BP from baseline to the Primary Efficacy Objective at FU II (3 months post-last treatment), which progressively decreased further at FU III (6 months) (Table 1). Similarly, average Office BP (OBP) detected a strong trend for a progressive decrease in systolic BP from baseline to the Primary Efficacy Objective (Table 1). Levels of eGFR appeared to slightly rise throughout the study, but this change has not reached statistical significance levels (Table 1). Conclusions: The current study demonstrates that the eHAT procedure is tolerable and safe in this cohort. Moreover, a 3-week regimen tended to reduce BP and preserve eGFR in patients with controlled HTN and CKD. Therefore, electro-Hydraulic Acoustic Therapy may emerge as a novel, safe, and non-invasive alternative therapeutic approach in the management of HTN in the context of CKD.
Metabolic Syndrome Induces Epigenetic Alterations in Mitochondria-Related Genes in Swine Mesenchymal Stem Cells
Autologous mesenchymal stem/stromal cells (MSCs) have demonstrated important therapeutic effects in several diseases. Cardiovascular risk factors may impair MSC mitochondrial structure and function, but the underlying mechanisms remain unknown. We hypothesized that metabolic syndrome (MetS) induces epigenetic alterations in mitochondria-related genes in swine MSCs. Pigs were fed a Lean or MetS diet (n = 6 each) for 16 weeks. MSCs were collected from subcutaneous abdominal fat, and DNA hydroxymethylation (5 hmC) profiles of mitochondria-related genes (MitoCarta-2.0) were analyzed by hydroxymethylated DNA immunoprecipitation and next-generation sequencing (hMeDIP-seq) in Lean- and MetS-MSCs untreated or treated with the epigenetic modulator vitamin (Vit)-C (n = 3 each). Functional analysis of genes with differential 5 hmC regions was performed using DAVID6.8. Mitochondrial structure (electron microscopy), oxidative stress, and membrane potential were assessed. hMeDIP-seq identified 172 peaks (associated with 103 mitochondrial genes) with higher and 416 peaks (associated with 165 mitochondrial genes) with lower 5 hmC levels in MetS-MSCs versus Lean-MSCs (≥2-fold, p < 0.05). Genes with higher 5 hmC levels in MetS + MSCs were primarily implicated in fatty acid metabolism, whereas those with lower 5 hmC levels were associated with electron transport chain activity. Vit-C increased 5 hmC levels in mitochondrial antioxidant genes, improved mitochondrial structure and membrane potential, and decreased oxidative stress. MetS alters 5 hmC levels of mitochondria-related genes in swine MSCs. Vit-C modulated 5 hmC levels in these genes and preserved mitochondrial structure and function in MetS-MSCs. These observations may contribute to development of strategies to overcome the deleterious effects of MetS on MSCs.
Evaluation of Renal Fibrosis Using Magnetization Transfer Imaging at 1.5T and 3T in a Porcine Model of Renal Artery Stenosis
Renal fibrosis is an important marker in the progression of chronic kidney disease, and renal biopsy is the current reference standard for detecting its presence. Currently, non-invasive methods have only been partially successful in detecting renal fibrosis. Magnetization transfer imaging (MTI) allows estimates of renal fibrosis but may vary with scanning conditions. We hypothesized that MTI-derived renal fibrosis would be reproducible at 1.5T and 3T MRI and over time in fibrotic kidneys. Fifteen pigs with unilateral renal artery stenosis (RAS, n = 9) or age-matched sham controls (n = 6) underwent MTI-MRI at both 1.5T and 3T 6 weeks post-surgery and again 4 weeks later. Magnetization transfer ratio (MTR) measurements of fibrosis in both kidneys were compared between 1.5T and 3T, and the reproducibility of MTI at the two timepoints was evaluated at 1.5T and 3T. MTR at 3T with 600 Hz offset frequency successfully distinguished between normal, stenotic, and contralateral kidneys. There was excellent reproducibility of MTI at 1.5T and 3T over the two timepoints and no significant differences between MTR measurements at 1.5T and 3T. Therefore, MTI is a highly reproducible technique which is sensitive to detect changes in fibrotic compared to normal kidneys in the RAS porcine model at 3T.
The Role of Shear Stress in Coronary Artery Disease
Abstract:Coronary artery disease is the leading cause of morbidity and mortality worldwide, espe-cially in developed countries, with an increasing incidence in developing countries. Despite the ad-vances in cardiology, there are yet many unanswered questions about the natural history of coronary atherosclerosis. However, it has not been fully explained why some coronary artery plaques remain quiescent over time, whereas others evolve to a high-risk, “vulnerable” plaque with a predisposition to destabilize and induce a cardiac event. Furthermore, approximately half of the patients with acute coronary syndromes demonstrate no prior symptoms of ischemia or angiographically evident dis-ease. Recent findings have indicated that apart from cardiovascular risk factors, genetics, and other unknown factors, local hemodynamic forces, such as endothelial shear stress, blood flow patterns, and endothelial dysfunction of the epicardial and microvascular coronary arteries, are associated with the progression of coronary plaque and the development of cardiovascular complications with complex interactions. In this review article, we summarize the mechanisms that affect coronary ar-tery plaque progression, indicating the importance of endothelial shear stress, endothelial dysfunc-tion of epicardial and microvascular vessels, inflammation, and their complex associations, underly-ing in parallel the clinical perspectives of these findings.
Fraction of Osteocalcin Endothelial Progenitor Cells and Cardiovascular Risk