Cytochrome c Oxidase Inhibition by ATP Decreases Mitochondrial ROS Production

This study addresses the eventual consequence of cytochrome c oxidase (CytOx) inhibition by ATP at high ATP/ADP ratio in isolated rat heart mitochondria. Earlier, it has been demonstrated that the mechanism of allosteric ATP inhibition of CytOx is one of the key regulations of mitochondrial functions. It is relevant that aiming to maintain a high ATP/ADP ratio for the measurement of CytOx activity effectuating the enzymatic inhibition as well as mitochondrial respiration, optimal concentration of mitochondria is critically important. Likewise, only at this concentration, were the differences in ΔΨ(m) and ROS concentrations measured under various conditions significant. Moreover, when CytOx activity was inhibited in the presence of ATP, mitochondrial respiration and ΔΨ(m) both remained static, while the ROS production was markedly decreased. Consubstantial results were found when the electron transport chain was inhibited by antimycin A, letting only CytOx remain functional to support the energy production. This seems to corroborate that the decrease in mitochondrial ROS production is solely the effect of ATP binding to CytOx which results in static respiration as well as membrane potential

Feasibility of the Engager™ aortic transcatheter valve system using a flexible over-the-wire design

OBJECTIVES The aim was to investigate the safety and feasibility of the redesigned Engager™ transcatheter aortic valve implantation (TAVI) system. METHODS Transapical aortic valve implantation with the Engager™ valve prosthesis was intended in 11 patients, and performed in 10. Endpoints were defined according to the valve academic research consortium recommendations for reporting outcomes of TAVI in clinical trials. RESULTS All 10 patients were implanted successfully. No devicerelated or delivery system complications like coronary obstruction or aortic dissection emerged. One patient (10%) died from non-device-related reasons at post-operative day 23 of multi-organ failure. The invasively measured peak-to-peak gradient after valve implantation was 7.1±3.5mmHg. In 90%, there was no or only trivial (≤grad I) aortic regurgitation due to paravalvular leakage. In 10% of the patients, aortic regurgitation grade I-II was observed. At 30-day follow up, the mean gradient was 15.6±4.9mmHg, and no more than a mild transvalvular and paravalvular aortic regurgitation was seen as assessed by transthoracic echocardiography. CONCLUSIONS Application of the Engager™ TAVI system is safe and feasible. Prosthesis deployment in an anatomically correct position was facilitated by the design of the valve prosthesis and was successful in all patients. No device or delivery-system-related complications emerged. Safety and feasibility endpoints were met. Good results concerning the aortic valve performance after implantation and at 30-day follow up were ascertained. These results encouraged the start of a European Pivotal trial including patients to dat

Video-assisted minimal access surgery for complicated mitral valve endocarditis, tricuspid valve insufficiency and progressive coronary disease after previous CABG - in the time of COVID-19: a case report

Background!#!The timing for heart surgery following cerebral embolization after cardiac valve vegetation is vital to postoperative recovery being uneventful, additionally Covid-19 may negatively affect the outcome. Minimally invasive methods and upgraded surgical instruments maximize the benefits of surgery also in complex cardiac revision cases with substantial perioperative risk.!##!Case presentation!#!A 68 y.o. patient, 10 years after previous sternotomy for OPCAB was referred to cardiac surgery on the 10th postoperative day after neurosurgical intervention for intracerebral bleeding with suspected mitral valve endocarditis. Mitral valve vegetation, tricuspid valve insufficiency and coronary stenosis were diagnosed and treated by minimally invasive revision cardiac surgery on the 14th postoperative day after neurosurgery.!##!Conclusion!#!The present clinical case demonstrates for the first time that the minimally invasive approach via right anterior mini-thoracotomy can be safely used for concomitant complex mitral valve reconstruction, tricuspid valve repair and aorto-coronary bypass surgery, even as a revision procedure in the presence of florid endocarditis after recent neurosurgical intervention. The Covid-19 pandemic and prophylactic patient isolation slow down the efficacy of pulmonary weaning and mobilisation and prolong the need for ICU treatment, without adversely affecting long-term outcome

Outcome of patients treated with engager transapical aortic valve implantation: one-year results of the feasibility study

OBJECTIVE: The aim of this study was to investigate the short-term and midterm outcome of the Engager transcatheter aortic valve implantation (TAVI) system, a transapical self-expanding valve device with anatomic orientation. METHODS: Transapical aortic valve implantation with the Engager valve prosthesis was performed in 10 patients. Endpoints were defined according to the Valve Academic Research Consortium recommendations for reporting outcomes of TAVI in clinical trials. Follow-up has been completed after 30 days and 1 year. RESULTS: All patients underwent the implantation procedure successfully. No device-related or delivery system-related complications were observed. One patient died of non-device-related reasons at postoperative day 23 in multiorgan failure. At 30-day follow-up, no more than mild transvalvular and paravalvular aortic regurgitation were seen. After 1 year, no transvalvular regurgitation was observed as assessed by transthoracic echocardiography. None of the patients had more than mild paravalvular leakage. The mean ± SD gradient was 15.3 ± 4.2 mm Hg. New York Heart Association class decreased one degree in mean and sustained until 1-year follow-up. No more patients died until 1-year follow-up. CONCLUSIONS: Application of the Engager TAVI system is safe and reliable. Prosthesis deployment in an anatomically correct position was facilitated by the design of the valve prosthesis and successful in all patients. No device-related or delivery system-related complications occurred. Procedural, short-term, and midterm results up to 1 year concerning the aortic valve performance are promising, with stable mean gradients and low rates of even mild regurgitation

The Role of Matrix Metalloproteinases in Thoracic Aortic Disease: Are They Indicators for the Pathogenesis of Dissections?

The pathogenesis of aortic aneurysm and dissection continues to be under discussion. Extracellular matrix (ECM) remodeling processes in the aortic wall are hypothesized to be involved in the development of the disorders. Therefore, in a histological study, we investigated the expression of metalloproteases 1 and 9 (MMP1 and MMP9) and their inhibitors (TIMP 1 and TIMP 2) in cardiac surgery patients. In parallel, we studied the aortic roots by echocardiography. Clinical reports of 111 patients (30 women and 81 men) who suffered from aortic aneurysms and aortic dissection were evaluated and studied by transesophageal echocardiography. Seven patients who had coronary heart disease served as “healthy controls”. All patients underwent the necessary surgical procedure according to the diagnosed aortic disease in the period from 2007 to 2015. A tissue sample of the aortic biopsies was collected from each patient during surgery. Immunohistochemical staining was performed for MMP1 and MMP9 and TIMP1 and TIMP2 as well. Vascularization was monitored by a CD 31 antibody. In direct comparison, the expressions are not homogeneous. We found the smallest changes in the intima area at all. TIMP 1 and TIMP 2 distribution increases from the lumen of the vessel outward in the wall layers of the aorta. In the case of arteriosclerotic changes, intima had a capillarization, but not in the media. An opposite pattern was found in the dissected aortas. There are differences in the vascularization between the aneurysm and dissection and the different layers, respectively. A different remodeling process of the ECM in comparison to the vascular layers must be hypothesized. Reading the patterns of staining and with regard to the known inhibitory effect of MMP9 on ECM remodeling, but especially TIMP 2 on neoangiogenesis, disturbed nutrition, and dysfunctional vasa vasorum remodeling must be assumed as causes of dissection

Randomized Clinical Trial Comparing a Thermosensitive Polymer (LeGoo) With Conventional Vessel Loops for Temporary Coronary Artery Occlusion During Off-Pump Coronary Artery Bypass Surgery

International audienceBACKGROUND: During off-pump coronary artery bypass graft (OPCABG) surgery, a bloodless surgical field is mandatory for visualization and construction of optimal coronary anastomoses. Presently used temporary vascular occluders are known to cause endothelial dysfunction and vessel injury. The present prospective multicenter randomized clinical trial evaluates safety and efficacy of a novel thermosensitive polymer (LeGoo) as an atraumatic temporary vascular occluder. METHODS: Between July 2008 and February 2010, 110 patients undergoing OPCABG were randomized between LeGoo (LG) and conventional vessel loops (VL) for coronary artery occlusion during construction of the distal anastomosis. A semiquantitative 4-point scale was used to evaluate the degree of bloodless surgical field and surgical comfort. Duration of coronary artery occlusion was also recorded. Safety during the operation and ensuing 30 days was evaluated by a composite endpoint of major adverse cardiac events that consisted of death from all causes, graft occlusion, myocardial infarction, and low cardiac output. RESULTS: Fifty-six patients (117 distal anastomoses) were randomly assigned to LG and 54 patients (122 anastomoses) to VL. There were 2 anastomoses crossed over from LG to the control arm, and 3 from control to LG. Five anastomoses in LG patients were treated with an alternative device (shunts). Satisfactory hemostasis was achieved in 88.0% of LG anastomoses (103 of 117) compared with 60.7% of VL anastomoses (74 of 122; p < 0.001). Mean total anastomotic time was 12.8 minutes in the LG group and 15.1 minutes in the VL group (p < 0.001). This difference was more pronounced for arteries on the posterior and lateral than on the anterior walls of the heart. Composite adverse events were similar in the two groups: 3 of 48 LG patients and 3 of 46 VL patients. There was 1 death in the LG group. One patient in the LG group and 1 in the VL arm had a myocardial infarction. No operation was converted from OPCABG to CABG with cardiopulmonary bypass. CONCLUSIONS: LeGoo is a safe and effective temporary coronary occluder during OPCABG. It provided a dry surgical field for visualization of the anastomotic field and surgical comfort more frequently than conventional vessel loops. In addition, anastomotic times were shorter with LG. Major cardiac adverse events were similar in the LG and VL arms