Minimally invasive delivery of a hydrogel-based exosome patch to prevent heart failure.

Coronary heart disease (CHD) has been the number one killer in the United States for decades and causes millions of deaths each year. Clinical treatment of heart ischemic injury relieves symptoms in the acute stage of CHD; however, patients with an infarcted heart muscle can develop heart failure (HF) due to chronic maladaptive remodeling. Regenerative therapy has been studied as a potential treatment option for myocardial infarction (MI) and HF. Cardiac patches have been designed and tested to increase therapeutic retention and integration. However, the delivery usually requires invasive surgical techniques, including open-chest surgeries and heart manipulation. Those procedures may cause chronic adhesions between the heart anterior wall and the chest wall. This study created and tested an injectable ExoGel by embedding mesenchymal stem cell (MSC) -derived exosomes into a hyaluronic acid (HA) hydrogel. ExoGel was injected into the pericardial cavity of rats with transverse aortic constriction (TAC) induced heart failure. ExoGel therapy reduced LV chamber size and preserved wall thickness. The feasibility and safety of ExoGel injection were further confirmed in a pig model.

Comparative differences of mitral valve-in-valve implantation: A new mitral bioprosthesis versus current mosaic and epic valves.

OBJECTIVE: Evaluate transcatheter mitral valve replacement (TMVR) valve-in-valve (VIV) outcomes in three different mitral bioprostheses (of comparable measured internal diameters) under stable hemodynamic and surgical conditions by bench, echocardiographic, computerized tomography (CT), and autopsy comparisons pre- and post-valve implantation in a porcine model under matched controlled conditions. BACKGROUND: Impact of surgical bioprosthesis design on TMVR VIV procedures is unknown. METHODS: Fifteen similar-sized Yorkshire pigs underwent pre-procedural CT screening. Twelve had consistent anatomic features and underwent implantation of mitral bioprostheses. Four valves from each of three manufacturers were implanted in randomized fashion: 27-mm Epic, 27-mm Mosaic, and 25-mm Mitris, followed by TMVR VIV with 26 Edwards Sapien3. Post-VIV, suprasternal TEE studies were performed to assess hemodynamic function, followed by a gated contrast CT. After euthanasia, animals underwent necropsy for anatomic evaluation. RESULTS: All 12 animals had successful VIV implantation with no study deaths. The post vivMitris (3.77 ± 0.36)/(2.2 ± 0.25 mmHg) had the lowest peak/mean trans-mitral gradient and the vivEpic the highest (15.5 ± 2.55)/(7.09 ± 1.13 mmHg). All THVs (transcatheter heart valves) had greatest deformation within the center of the THV frame; with the smallest waist opening area in the vivEpic (329 ± 35.8 mm2 ) and greatest in the vivMitris (414 ± 33.12 mm2 ). Bioprosthetic frames without obvious radiopaque markers resulted in the most ventricular implantation of the THV's anteroseptal frame (Epic: -4.52 ± 0.76 mm), versus the most radiopaque bioprosthesis (Mitris: -1.18 ± 2.95 mm), and higher peak LVOT gradients (Epic: 4.82 ± 1.61 mmHg; Mitris: 2.91 ± 1.47 mmHg). CONCLUSIONS: The current study demonstrates marked variations in hemodynamics, THV opening area, and anatomic dimensions among measured similarly sized mitral bioprostheses. These data suggest a critical need for understanding the potential impact of variations in bioprosthesis design on TMVR VIV clinical outcomes.

Initial in-human experience with the conveyor cardiovascular system for the delivery of large profile transcatheter valve devices.

OBJECTIVES: To determine the safety and efficacy of the conveyor cardiovascular system (CCS) to facilitate the delivery of large profile transcatheter valve devices. BACKGROUND: Transcatheter valve devices rely on force provided by the operator to be delivered to their intended position. This delivery may be challenging in a variety of anatomic scenarios. The ability to provide steering from the tip of the device by forming an arterial venous loop may help overcome these challenges. METHODS: Between May, 2019 and October, 2020, five patients were recruited for delivery of transcatheter valve devices with the CCS. These patients were deemed by the operators to have challenging anatomy which could make conventional valve delivery difficult or impossible. These patients were recruited as part of an FDA approved early feasibility study or through an institutional review board approved compassionate use protocol. RESULTS: Three patients underwent transcatheter mitral valve replacement with a SAPIEN-3 valve. One patient each underwent transcatheter aortic valve (TAVR) implantation with a SAPIEN 3 and 1 patient underwent TAVR implantation with a Lotus valve. All patients underwent successful implantation of the valve and removal of the CCS and valve delivery systems. There was no more than trivial mitral regurgitation post procedure in any patient and there was no more than trivial paravavular leak. There were no major in-hospital complications. CONCLUSIONS: The CCS facilitates the delivery of large profile transcatheter valve devices in challenging anatomic scenarios. Further studies are needed with additional valve technologies.

Adrenomedullin Induces Cardiac Lymphangiogenesis After Myocardial Infarction and Regulates Cardiac Edema Via Connexin 43.

RATIONALE: Cardiac lymphangiogenesis contributes to the reparative process post-myocardial infarction, but the factors and mechanisms regulating it are not well understood. OBJECTIVE: To determine if epicardial-secreted factor AM (adrenomedullin; Adm=gene) improves cardiac lymphangiogenesis post-myocardial infarction via lateralization of Cx43 (connexin 43) in cardiac lymphatic vasculature. METHODS AND RESULTS: Firstly, we identified sex-dependent differences in cardiac lymphatic numbers in uninjured mice using light-sheet microscopy. Using a mouse model of Adm hi/hi ( Adm overexpression) and permanent left anterior descending ligation to induce myocardial infarction, we investigated cardiac lymphatic structure, growth, and function in injured murine hearts. Overexpression of Adm increased lymphangiogenesis and cardiac function post-myocardial infarction while suppressing cardiac edema and correlated with changes in Cx43 localization. Lymphatic function in response to AM treatment was attenuated in mice with a lymphatic-specific Cx43 deletion. In vitro experiments in cultured human lymphatic endothelial cells identified a novel mechanism to improve gap junction coupling by pharmaceutically targeting Cx43 with verapamil. Finally, we show that connexin protein expression in cardiac lymphatics is conserved between mouse and human. CONCLUSIONS: AM is an endogenous, epicardial-derived factor that drives reparative cardiac lymphangiogenesis and function via Cx43, and this represents a new therapeutic pathway for improving myocardial edema after injury.

Comparison of a new bioprosthetic mitral valve to other commercially available devices under controlled conditions in a porcine model.

BACKGROUND/AIM: To evaluate three mitral bioprostheses (of comparable measured internal diameters) under controlled, stable, hemodynamic and surgical conditions by bench, echocardiographic, computerized tomography and autopsy comparisons pre- and postvalve implantation. METHODS: Fifteen similar-sized Yorkshire pigs underwent preprocedural computerized tomography anatomic screening. Of these, 12 had consistent anatomic features and underwent implantation of a mitral bioprosthesis via thoracotomy on cardiopulmonary bypass (CPB). Four valves from each of three manufacturers were implanted in randomized fashion: 27-mm Epic, 27-mm Mosaic, and 25-mm Mitris bioprostheses. After CPB, epicardial echocardiographic studies were performed to assess hemodynamic function and define any paravalvular leaks, followed by postoperative gated contrast computerized tomography. After euthanasia, animals underwent necropsy for anatomic evaluation. RESULTS: All 12 animals had successful valve implantation with no study deaths. Postoperative echocardiographic trans-valve gradients varied among bioprosthesis manufacturers. The 25-mm Mitris (5.1 ± 2.7)/(2.6 ± 1.3 torr) had the lowest peak/mean gradient and the 27-mm Epic bioprosthesis had the highest (9.2 ± 3.7)/(4.6 ± 1.9 torr). Surgical valve opening area (SOA) varied with the 25-mm Mitris having the largest SOA (2.4 ± 0.15 cm2 ) followed by the 27-mm Mosaic (2.04 ± 0.23 cm2 ) and the 27-mm Epic (1.8 ± 0.27 cm2 ) valve. Bench device orthogonal internal diameter measurements did not match manufacturer device size labeling: 25-mm Mitris (23 × 23 mm), 27-mm Mosaic (23 × 22 mm), 27-mm Epic (21 × 21 mm). CONCLUSIONS: Current advertisement/packaging of commercial surgical mitral valves is not uniform. This study demonstrates marked variations in hemodynamics, valve opening area and anatomic dimensions between similar sized mitral bioprostheses. These data suggest a critical need for standardization and close scientific evaluation of surgical mitral bioprostheses to ensure optimal clinical outcomes.

Platelet-Inspired Nanocells for Targeted Heart Repair After Ischemia/Reperfusion Injury.

Cardiovascular disease is the leading cause of mortality worldwide. While reperfusion therapy is vital for patient survival post-heart attack, it also causes further tissue injury, known as myocardial ischemia/reperfusion (I/R) injury in clinical practice. Exploring ways to attenuate I/R injury is of clinical interest for improving post-ischemic recovery. A platelet-inspired nanocell (PINC) that incorporates both prostaglandin E2 (PGE2)-modified platelet membrane and cardiac stromal cell-secreted factors to target the heart after I/R injury is introduced. By taking advantage of the natural infarct-homing ability of platelet membrane and the overexpression of PGE2 receptors (EPs) in the pathological cardiac microenvironment after I/R injury, the PINCs can achieve targeted delivery of therapeutic payload to the injured heart. Furthermore, a synergistic treatment efficacy can be achieved by PINC, which combines the paracrine mechanism of cell therapy with the PGE2/EP receptor signaling that is involved in the repair and regeneration of multiple tissues. In a mouse model of myocardial I/R injury, intravenous injection of PINCs results in augmented cardiac function and mitigated heart remodeling, which is accompanied by the increase in cycling cardiomyocytes, activation of endogenous stem/progenitor cells, and promotion of angiogenesis. This approach represents a promising therapeutic delivery platform for treating I/R injury.

Therapeutic benefits of CD90-negative cardiac stromal cells in rats with a 30-day chronic infarct.

Cardiac stromal cells (CSCs) can be derived from explant cultures, and a subgroup of these cells is viewed as cardiac mesenchymal stem cells due to their expression of CD90. Here, we sought to determine the therapeutic potential of CD90-positive and CD90-negative CSCs in a rat model of chronic myocardial infarction. We obtain CD90-positive and CD90-negative fractions of CSCs from rat myocardial tissue explant cultures by magnetically activated cell sorting. In vitro, CD90-negative CSCs outperform CD90-positive CSCs in tube formation and cardiomyocyte functional assays. In rats with a 30-day infarct, injection of CD90-negative CSCs augments cardiac function in the infarct in a way superior to that from CD90-positive CSCs and unsorted CSCs. Histological analysis revealed that CD90-negative CSCs increase vascularization in the infarct. Our results suggest that CD90-negative CSCs could be a development candidate as a new cell therapy product for chronic myocardial infarction.

Meta-analysis of transfemoral TAVR versus surgical aortic valve replacement.

BACKGROUND: In the recently concluded PARTNER 2 trial, TF-TAVR cohort was shown to have lower risks of death or disabling strokes as compared to SAVR, whereas the outcomes with transthoracic TAVR were comparable with SAVR. METHODS: We searched PubMed, EMBASE, Web of Science, and Google Scholar for all comparison studies between TAVR and SAVR and mortality as an outcome, irrespective of surgical risk. Randomized controlled trials and propensity-score-matched cohort studies that used a transfemoral approach exclusively or stratified results by route of access and reported data for TF-TAVR patients were eligible for inclusion. Outcomes of interest included 30-day and 1-year mortality, and 30-day complications. If significant heterogeneity was found in the random effects meta-analyses, a sensitivity analysis which individually removed each study was conducted. RESULTS: Seven studies reported results on TF-TAVR. Compared with SAVR, TF-TAVR had comparable 30-day mortality (RR 0.79, 95% CI 0.58, 1.06), 1-year mortality (RR 0.91, 95% CI 0.78, 1.08) and 30-day risk of bleeding (RR 0.70, 95% CI 0.31, 1.57). However, TF-TAVR was associated with lower 30-day risks of atrial fibrillation (RR 0.28, 95% CI 0.17, 0.45), acute kidney injury (RR 0.38, 95% CI 0.20, 0.71), and myocardial infarction (RR 0.41, 95% CI 0.23, 0.75) at a cost of higher incidences of vascular complications (RR 6.10, 95% CI 2.92, 12.73) and pacemaker implantations (RR 3.29, 95% CI 1.41, 7.65). CONCLUSIONS: TF-TAVR is associated with lower 30-day risks of myocardial infarction compared to SAVR. Further studies are required to investigate the role of myocardial injury on overall TF-TAVR outcomes.

Derivation of therapeutic lung spheroid cells from minimally invasive transbronchial pulmonary biopsies.

BACKGROUND: Resident stem and progenitor cells have been identified in the lung over the last decade, but isolation and culture of these cells remains a challenge. Thus, although these lung stem and progenitor cells provide an ideal source for stem-cell based therapy, mesenchymal stem cells (MSCs) remain the most popular cell therapy product for the treatment of lung diseases. Surgical lung biopsies can be the tissue source but such procedures carry a high risk of mortality. METHODS: In this study we demonstrate that therapeutic lung cells, termed "lung spheroid cells" (LSCs) can be generated from minimally invasive transbronchial lung biopsies using a three-dimensional culture technique. The cells were then characterized by flow cytometry and immunohistochemistry. Angiogenic potential was tested by in-vitro HUVEC tube formation assay. In-vivo bio- distribution of LSCs was examined in athymic nude mice after intravenous delivery. RESULTS: From one lung biopsy, we are able to derive >50 million LSC cells at Passage 2. These cells were characterized by flow cytometry and immunohistochemistry and were shown to represent a mixture of lung stem cells and supporting cells. When introduced systemically into nude mice, LSCs were retained primarily in the lungs for up to 21 days. CONCLUSION: Here, for the first time, we demonstrated that direct culture and expansion of human lung progenitor cells from pulmonary tissues, acquired through a minimally invasive biopsy, is possible and straightforward with a three-dimensional culture technique. These cells could be utilized in long-term expansion of lung progenitor cells and as part of the development of cell-based therapies for the treatment of lung diseases such as chronic obstructive pulmonary disease (COPD) and idiopathic pulmonary fibrosis (IPF).

Transcatheter Versus Surgical Aortic Valve Replacement in Patients With Lower Surgical Risk Scores: A Systematic Review and Meta-Analysis of Early Outcomes.

BACKGROUND: The results from the PARTNER 2 trial showed the feasibility of transcatheter aortic valve replacement (TAVR) in intermediate surgical risk patients. Although low risk clinical trials will take time to conclude, some data has emerged comparing TAVR with surgical aortic valve replacement (SAVR) in lower risk patients. METHODS: A Medline search was conducted using standard methodology to search for studies reporting results comparing TAVR and SAVR. Studies were included if the overall mean Society of Thoracic Surgeons Score was less than 4% (or equivalent Euroscore). A meta-analysis comparing the 30-day risk of clinical outcomes between TAVR and SAVR in the lower surgical risk population was conducted. RESULTS: A total of four studies, including one clinical trial and three propensity-matched cohort studies met the inclusion criteria. Compared to SAVR, TAVR had a lower risk of 30-day mortality (RR 0.67, 95% CI 0.41, 1.10), stroke (RR 0.60, 95% CI 0.30, 1.22), bleeding complications (RR 0.51, 95% CI 0.40, 0.67) and acute kidney injury (RR 0.66, 95% CI 0.47, 0.94). However, a higher risk of vascular complications (RR 11.72, 95% CI 3.75, 36.64), moderate or severe paravalvular leak (RR 5.04, 95% CI 3.01, 8.43), and permanent pacemaker implantations (RR 4.62, 95% CI 2.63, 8.12) was noted for TAVR. CONCLUSION: Among lower risk patients, TAVR and SAVR appear to be comparable in short term outcomes. Additional high quality studies among patients classified as low risk are needed to further explore the feasibility of TAVR in all surgical risk patients.

Transcatheter Mitral Valve-in-Ring for Progressive Mitral Stenosis after Prior Repair with Annuloplasty: A Novel Balloon Sizing Technique.

An 83-year-old man with a previous mitral valve repair using a semi-rigid annuloplasty ring was found to have severe mitral stenosis. A transcatheter approach for mitral valve-in-ring replacement was selected due to the patient's high surgical risk. Pre-procedural computed tomography scans for transcatheter valve size selection were inconsistent with previously published recommendations. To determine the appropriate valve size, a 25 mm compliant balloon was inflated intraoperatively within the stenotic mitral ring, but yielded no resistance to movement and no 'waist'. Thus, a 29 mm balloon-expandable prosthetic valve was selected and deployed with no paravalvular leak. This novel balloon sizing technique helped lead to a successful outcome in this case. Video 1: Angiographic video displaying mitral valve-in-ring balloon sizing technique. The 25 mm compliant balloon was inflated within a stenotic mitral ring to determine which prosthetic transcatheter valve size was appropriate. As shown, this technique yielded no 'waist' and no resistance to movement, suggesting that a 29 mm valve was necessary.

Cardiac regenerative potential of cardiosphere-derived cells from adult dog hearts.

The regenerative potential of cardiosphere-derived cells (CDCs) for ischaemic heart disease has been demonstrated in mice, rats, pigs and a recently completed clinical trial. The regenerative potential of CDCs from dog hearts has yet to be tested. Here, we show that canine CDCs can be produced from adult dog hearts. These cells display similar phenotypes in comparison to previously studied CDCs derived from rodents and human beings. Canine CDCs can differentiate into cardiomyocytes, smooth muscle cells and endothelial cells in vitro. In addition, conditioned media from canine CDCs promote angiogenesis but inhibit cardiomyocyte death. In a doxorubicin-induced mouse model of dilated cardiomyopathy (DCM), intravenous infusion of canine CDCs improves cardiac function and decreases cardiac fibrosis. Histology revealed that injected canine CDCs engraft in the mouse heart and increase capillary density. Out study demonstrates the regenerative potential of canine CDCs in a mouse model of DCM.

An Unusual Culprit: Syncope in an Adolescent With Congenital Left Main Coronary Artery Atresia.

There are fewer than 100 reported cases of congenital left main coronary artery atresia. In this report, we present an adolescent male presenting with exertional syncope in the setting of this rare coronary defect, and review important diagnostic and therapeutic considerations imperative to obtain a favorable outcome.

Late Outcomes of Surgery Versus Medical Therapy in Patients With Type A Aortic Intramural Hematoma: Meta-Analysis of Reconstructed Time-to-Event Data.

The effect of an initial surgical approach (in comparison with initial medical therapy) in acute type A intramural hematoma remains insufficiently explored. We designed a pooled analysis of Kaplan-Meier-derived individual patient data from studies with follow-up for overall survival (all-cause death). Restricted mean survival time was calculated to evaluate lifetime gain or loss. The Risk of Bias in Non-Randomized Studies of Interventions tool (ROBINS-I) was used to assess risk of bias. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) was applied to assess certainty of evidence. Eight studies met our eligibility criteria, including a total of 654 patients (311 patients treated with surgery and 343 patients treated with medical therapy alone). All the studies were non-randomized and observational. The median follow-up was 4.6 years (interquartile range 1.0 to 7.7). Patients who underwent surgery had a significantly lower risk of mortality compared with patients receiving medical therapy alone (hazard ratio 0.51, 95% confidence interval 0.35 to 0.74, p <0.001). The restricted mean survival time was overall 1.1 years greater with surgery compared with medical therapy, and this difference was statistically significant (p <0.001), which means that surgery is associated with lifetime gain. The overall risk of bias (ROBINS-I) was considered moderate-to-serious and the certainty of evidence (GRADE) was deemed to be low. In conclusion, in the overall follow-up, surgery as the initial approach was associated with better late survival and lifetime gain in comparison with medical therapy alone in the setting of acute type A aortic intramural hematoma; however, high-quality randomized trials are warranted to establish the efficacy of the surgical strategy.

An infusible biologically active adhesive for chemotherapy-related heart failure in elderly rats.

Chemotherapy-induced cardiotoxicity with subsequent heart failure (HF) is a major cause of morbidity and mortality in cancer survivors worldwide. Chemotherapy-induced HF is exceptionally challenging as it generally manifests in patients who are typically not eligible for left ventricular device implantation or heart transplantation. To explore alternative treatment strategies for cancer survivors suffering from chemotherapy-induced HF, we developed a minimally invasive infusible cardiac stromal cell secretomes adhesive (MISA) that could be delivered locally through an endoscope-guided intrapericardial injection. To mimic the typical clinical presentation of chemotherapy-induced HF in elder patients, we established an aged rat model in which restrictive cardiomyopathy with sequential HF was induced via consecutive doxorubicin injections. In vitro, we prove that MISA not only enhanced cardiomyocytes proliferation potency and viability, but also inhibited their apoptosis. In vivo, we prove that MISA improved the ventricular contractility indexes and led to beneficial effects on histological and structural features of restrictive cardiomyopathy via promoting cardiomyocyte proliferation, angiogenesis, and mitochondrial respiration. Additionally, we also evaluated the safety and feasibility of MISA intrapericardial delivery in a healthy porcine model with an intact immune system. In general, our data indicates that MISA has a strong potential for translation into large animal models and ultimately clinical applications for chemotherapy-induced HF prior to the final option of heart transplantation.

FlatWire Sternal Closure System technique for median sternotomy closure.

Sternal closure after median sternotomy traditionally uses a stainless steel wire cerclage. Sternal wires are placed through or around the sternum, and the wire ends are twisted together to bring the sternum back together. Complications of this technique include sternal instability, dehiscence, non-union, and increased pain. Compared to traditional wire cerclage, the Figure 8 FlatWire Sternal Closure System has been demonstrated to be stronger and significantly reduce sternal cut-through and postoperative pain. There was no significant difference in hospital length of stay or mean hospitalization cost. Operative time was slightly longer in the FlatWire group, but this difference has been attributed to the learning curve of mastering the FlatWire technique. This article and supplemental video will demonstrate the technique of FlatWire Sternal Closure System. Briefly, the FlatWire is placed around the sternum, and the FlatWire end is fed through the security box. Once all of the wires are placed, the Figure 8 tensioning device is used to tighten each wire through the security box to the appropriate tensile force. Next, the FlatWires are rotated 90 degrees to hold the sternal position temporarily. Once sternal approximation is achieved, each FlatWire is twisted 120 degrees, and any excess length of the FlatWire is clipped.

Long-Term Outcomes of Patients Undergoing Aortic Root Replacement With Mechanical Versus Bioprosthetic Valves: Meta-Analysis of Reconstructed Time-to-Event Data.

Background An aspect not so clear in the scenario of aortic surgery is how patients fare after composite aortic valve graft replacement (CAVGR) depending on the type of valve (bioprosthetic versus mechanical). We performed a study to evaluate the long-term outcomes of both strategies comparatively. Methods and Results Pooled meta-analysis of Kaplan-Meier-derived time-to-event data from studies with follow-up for overall survival (all-cause death), event-free survival (composite end point of cardiac death, valve-related complications, stroke, bleeding, embolic events, and/or endocarditis), and freedom from reintervention. Twenty-three studies met our eligibility criteria, including 11 428 patients (3786 patients with mechanical valves and 7642 patients with bioprosthetic valve). The overall population was mostly composed of men (mean age, 45.5-75.6 years). In comparison with patients who underwent CAVGR with bioprosthetic valves, patients undergoing CAVGR with mechanical valves presented no statistically significant difference in the risk of all-cause death in the first 30 days after the procedure (hazard ratio [HR], 1.24 [95% CI, 0.95-1.60]; P=0.109), but they had a significantly lower risk of all-cause mortality after the 30-day time point (HR, 0.89 [95% CI, 0.81-0.99]; P=0.039) and lower risk of reintervention (HR, 0.33 [95% CI, 0.24-0.45]; P<0.001). Despite its increased risk for the composite end point in the first 6 years of follow-up (HR, 1.41 [95% CI, 1.09-1.82]; P=0.009), CAVGR with mechanical valves is associated with a lower risk for the composite end point after the 6-year time point (HR, 0.46 [95% CI, 0.31-0.67]; P<0.001). Conclusions CAVGR with mechanical valves is associated with better long-term outcomes in comparison with CAVGR with bioprosthetic valves.