Native mitral valve fungal endocarditis caused by Aspergillus fumigatus: A case report.

INTRODUCTION: Aspergillus endocarditis is a rare fungal infection associated with a poor prognosis. Most cases of Aspergillus endocarditis involve prosthetic valves, with native valve involvement being rarely reported. CASE PRESENTATION: A 53-year-old asian female patient presented with fever, chills, dyspnea, generalized fatigue, and significant weight loss one month after undergoing left lower lobectomy for a pulmonary abscess. Echocardiogram showed a large mobile vegetation with a broad base on the anterior leaflet of the mitral valve, resembling atrial myxoma. Despite negative blood cultures, circulating DNA of Aspergillus fumigatus was detected by metagenome Next Generation Sequencing, prompting the initiation of empiric antifungal therapy with voriconazole. Emergency surgery, involving thorough debridement and mitral valve replacement, was successfully performed. Indefinite fungal suppression therapy with oral voriconazole is continued to mitigate the risk of recurrence. The patient survived with no signs of Aspergillus disease recurrence for four years. CLINICAL DISCUSSION: Diagnosis of Aspergillus endocarditis requires a high index of suspicion and is often delayed due to consistently negative results from blood cultures. Non-culture-based methods, particularly metagenome Next-Generation Sequencing, play a crucial role in early diagnosis and therapeutic decision-making. Surgical debridement and valve replacement are imperative for survival in cases of Aspergillus endocarditis. Voriconazole should be considered the primary fungicidal agent for its treatment. Moreover, lifelong fungal suppression therapy is strongly recommended for all survivors to ensure long-term survival and minimize the risk of recurrence. CONCLUSION: Despite grim prognosis associated with Aspergillus endocarditis, patients can attain long-term survival through meticulous surgical debridement and lifelong antifungal therapy.

Acetyltransferase p300 regulates atrial fibroblast senescence and age-related atrial fibrosis through p53/Smad3 axis.

Atrial fibrosis induced by aging is one of the main causes of atrial fibrillation (AF), but the potential molecular mechanism is not clear. Acetyltransferase p300 participates in the cellular senescence and fibrosis, which might be involved in the age-related atrial fibrosis. Four microarray datasets generated from atrial tissue of AF patients and sinus rhythm (SR) controls were analyzed to find the possible relationship of p300 (EP300) with senescence and fibrosis. And then, biochemical assays and in vivo electrophysiological examination were performed on older AF patients, aging mice, and senescent atrial fibroblasts. The results showed that (1) the left atrial tissues of older AF patients, aging mouse, and senescence human atrial fibroblasts had more severe atrial fibrosis and higher protein expression levels of p300, p53/acetylated p53 (ac-p53)/p21, Smad3/p-Smads, and fibrosis-related factors. (2) p300 inhibitor curcumin and p300 knockdown treated aging mouse and senescence human atrial fibroblasts reduced the senescence ratio of atrial fibroblasts, ameliorated the atrial fibrosis, and decreased the AF inducibility. In contrast, over-expression of p300 can lead to the senescence of atrial fibroblasts and atrial fibrosis. (3) p53 knockdown decreased the expression of aging and fibrosis-related proteins. (4) Co-immunoprecipitation and immunofluorescence showed that p53 forms a complex with smad3 and directly regulates the expression of smad3 in atrial fibroblasts. Our findings suggest that the mechanism of atrial fibrosis induced by aging is, at least, partially dependent on the regulation of p300, which provides new sights into the AF treatment, especially for the elderly.

Suppression of the Inhibitory Effect of circ_0036176-Translated Myo9a-208 on Cardiac Fibroblast Proliferation by miR-218-5p.

Increasing evidence has shown that circular RNAs (circRNAs) participate in the process of cardiac remodeling. CircRNA circ_0036176 originating from the back-splicing of exon 2 to exon4 of myosin IXA (Myo9a) gene was shown to be increased in the myocardium of patients with heart failure (HF) and riched in exosomes from human AC16 cardiomyocytes with overexpression of circ_0036176. Proliferation activity was inhibited in mCFs subjected to exosomal circ_0036176 treatment and in mCFs with overexpression of circ_0036176. Interestingly, circ_0036176 contains an IRES element and an ORF of 627 nt encoding a 208-amino acid protein (termed as Myo9a-208). Myo9a-208 was shown to mediate the inhibitory effect of circ_0036176 on CFs proliferation, and miR-218-5p could inhibit Myo9a-208 expression by binding to circ_0036176, resulting in abolishing the effect of circ_0036176 on inactivating cyclin/Rb signal and suppressing CFs proliferation. Our findings suggest that circ_0036176 inhibits mCFs proliferation by translating Myo9a-208 protein to suppress cyclin/Rb pathway.

Safety and efficacy of concomitant ablation for atrial fibrillation in rheumatic mitral valve surgery: A meta-analysis.

OBJECTIVES: This review aimed to evaluate the safety and efficacy of concomitant surgical ablation (SA) for patients with atrial fibrillation (AF) undergoing rheumatic mitral valve (MV) surgery. METHODS: A systematic search of relevant studies focusing on SA for patients with AF undergoing rheumatic MV surgery was performed. The primary outcomes included mortality, efficacy, and complications. RESULTS: Four randomized controlled trials (RCTs) and four observational studies covering 1931 patients met the inclusion criteria. In RCTs, no significant differences in reoperation for bleeding, low cardiac output syndrome, thromboembolic events, and early (risk ratio [RR], 2.07; 95% confidence intervals [CI], 0.37-11.40; p = .41) and midterm all-cause death (RR, 1.07; 95% CI, 0.40-2.88; p = .89) were noted between the SA group and the nonablation group. These results were similar to those obtained from observational studies. However, ablation was associated with a higher incidence of permanent pacemaker implantation (RR, 2.44; 95% CI, 1.15-5.18; p = .02) in observational studies but not in RCTs (RR, 2.03; 95% CI, 0.19-21.26; p = .56). Furthermore, additional SA was significantly more effective in sinus rhythm (SR) restoration than MV surgery alone at discharge and at the 12-month and 3-year follow-ups. CONCLUSIONS: Concomitant SA during rheumatic MV surgery does not increase perioperative adverse events. In addition, SA promotes considerable restoration of SR. Although some evidence exists that permanent pacemaker implantation is more common after ablation, not all studies support this notion.

Connexin 43 participates in atrial electrical remodelling through colocalization with calcium channels in atrial myocytes.

Atrial fibrillation (AF) is associated with atrial conduction disturbances caused by electrical and/or structural remodelling. In the present study, we hypothesized that connexin might interact with the calcium channel through forming a protein complex and, then, participates in the pathogenesis of AF. Western blot and whole-cell patch clamp showed that protein levels of Cav1.2 and connexin 43 (Cx43) and basal ICa,L were decreased in AF subjects compared to sinus rhythm (SR) controls. In cultured atrium-derived myocytes (HL-1 cells), knocking-down of Cx43 or incubation with 30 mmol/L glycyrrhetinic acid significantly inhibited protein levels of Cav1.2 and Cav3.1 and the current density of ICa,L and ICa,T . Incubation with nifedipine or mibefradil decreased the protein level of Cx43 in HL-1 cells. Moreover, Cx43 was colocalized with Cav1.2 and Cav3.1 in atrial myocytes. Therefore, Cx43 might regulate the ICa,L and ICa,T through colocalization with calcium channel subunits in atrial myocytes, representing a potential pathogenic mechanism in AF.

Clinical Characteristics and Long-Term Prognosis of Elderly Valvular Heart Disease Patients with Diabetes Mellitus: Five-Year Experience from a Single-Center Study of Southern China.

BACKGROUND: Diabetes mellitus (DM) is a prognostic marker in elderly patients with cardiovascular diseases, but its predictive value in elderly valvular heart disease (VHD) patients is unclear. This study aimed to investigate the effect of DM on the long-term outcome of elderly VHD patients. METHODS: This single-center, observational study enrolled patients aged 65 and older consecutively with confirmed VHD using echocardiography. Patients, divided into the DM group and non-DM group, were followed up for major adverse cardiac and cerebrovascular events (MACCEs), including all-cause death, ischemic stroke, and heart failure rehospitalization. RESULTS: Our study consisted of 532 patients over a median follow-up of 52.9 months. Compared with the non-DM group (n = 377), the DM group (n = 155) had higher incidences of ischemic stroke (25.2% vs. 13.5%, P=0.001), heart failure rehospitalization (37.4% vs. 20.7%, P < 0.001), and MACCEs (60.0% vs. 35.8%, P < 0.001). After adjustment of confounders by the multivariable cox regression, DM appeared as an independent predictor for MACCEs (adjusted hazard ratio, aHR: 1.88; 95% confidence interval 1.42-2.48; P < 0.001). In the subgroup analysis of VHD etiology and functional style, conversely, DM was a protective factor for MACCEs in the patients with rheumatic VHD compared with those without rheumatic VHD (aHR: 0.43 vs. 2.27, P=0.004). CONCLUSIONS: DM was an independent predictor for ischemic stroke and heart failure rehospitalization in elderly VHD patients undergoing conservative treatment.

Activation of PKCα participates in the reduction of Ikur in atrial myocytes induced by tumour necrosis factor-α.

The atrial-specific ultra-rapid delayed rectifier K+ current (Ikur) plays an important role in the progression of atrial fibrillation (AF). Because inflammation is known to lead to the onset of AF, we aimed to investigate whether tumour necrosis factor-α (TNF-α) played a role in regulating Ikur and the potential signalling pathways involved. Whole-cell patch-clamp and biochemical assays were used to study the regulation and expression of Ikur in myocytes and in tissues from left atrial appendages (LAAs) obtained from patients with sinus rhythm (SR) or AF, as well as in rat cardiomyocytes (H9c2 cells) and mouse atrial myocytes (HL-1 cells). Ikur current density was markedly reduced in atrial myocytes from AF patients compared with SR controls. Reduction of Kv1.5 protein levels was accompanied by increased expression of TNF-α and protein kinase C (PKC)α activation in AF patients. Treatment with TNF-α dose-dependently reduced Ikur and protein expression of Kv1.5 but not Kv3.1b in H9c2 cells and HL-1 cells. TNF-α also increased activity of PKCα. Specific PKCα inhibitor Gö6976 alleviated the reduction in Ikur induced by TNF-α, but not the reduction in Kv1.5 protein. TNF-α was involved in the electrical remodelling associated with AF, probably by depressing Ikur in atrial myocytes via activation of PKCα.

Modified unicaval drainage in reoperative isolated tricuspid valve repair via totally thoracoscopic approach.

AIM: The aim of this study was to investigate the feasibility, safety, and clinical effect of modified unicaval drainage for thoracoscopic reoperative isolated tricuspid valve repair, compared with conventional bicaval drainage. METHODS: A total of 45 consecutive cases of patients who underwent thoracoscopic reoperative isolated tricuspid valve repair on beating-heart were enrolled and divided into two groups according to the different venous drainage (Group A: modified unicaval drainage, Group B: conventional bicaval drainage). A retrospective analysis of perioperative data and clinical outcomes were performed and all the surviving cases were followed up. Re-evaluation of echocardiography and electrocardiogram was performed prior to discharge, and at first month, sixth month, and every year follow-up. RESULTS: The overall postoperative 30-day mortality was 4.5% in Group A and 8.7% in Group B. The postoperative tricuspid valve regurgitation grade of both groups decreased significantly from preoperative regurgitation grade, p < 0.001, without intergroup significant difference, p = 0.815. Follow-up duration ranged from 6 to 38 months, there was one death at 24 months in Group A, and another at 9 months in Group B, respectively. Nobody from both groups experienced reintervention for residual tricuspid regurgitation. No significant difference could be identified about the incidence of postoperative morbidities and follow-up adverse events. CONCLUSION: Both strategies of caval venous drainage can provide satisfactory exposure for thoracoscopic reoperative isolated tricuspid valve repair and equivalent favorable postoperative outcome. And the modified unicaval drainage group may even preserve the anesthetic time and decrease the risk of iatrogenic jugular injury, achieving a more simplified procedure with better cosmetic outcome.

High hydrostatic pressure induces atrial electrical remodeling through angiotensin upregulation mediating FAK/Src pathway activation.

Hypertension is an independent risk factor for atrial fibrillation (AF), although its specific mechanisms remain unclear. Previous research has been focused on cyclic stretch, ignoring the role of high hydrostatic pressure. The present study aimed to explore the effect of high hydrostatic pressure stimulation on electrical remodeling in atrial myocytes and its potential signaling pathways. Experiments were performed on left atrial appendages from patients with chronic AF or sinus rhythm, spontaneously hypertensive rats (SHRs) treated with or without valsartan (10 mg/kg/day) and HL-1 cells were exposed to high hydrostatic pressure using a self-developed device. Whole-cell patch-clamp recordings and western blots demonstrated that the amplitudes of ICa,L, Ito, and IKur were reduced in AF patients with corresponding changes in protein expression. Angiotensin protein levels increased and Ang1-7 decreased, while focal adhesion kinase (FAK) and Src kinase were enhanced in atrial tissue from AF patients and SHRs. After rapid atrial pacing, AF inducibility in SHR was significantly higher, accompanied by a decrease in ICa,L, upregulation of Ito and IKur, and a shortened action potential duration. Angiotensin upregulation and FAK/Src activation in SHR were inhibited by angiotensin type 1 receptor inhibitor valsartan, thus, preventing electrical remodeling and reducing AF susceptibility. These results were verified in HL-1 cells treated with high hydrostatic pressure, and demonstrated that electrical remodeling regulated by the FAK-Src pathway could be modulated by valsartan. The present study indicated that high hydrostatic pressure stimulation increases AF susceptibility by activating the renin-angiotensin system and FAK-Src pathway in atrial myocytes.

High hydrostatic pressure induces atrial electrical remodeling through upregulation of inflammatory cytokines.

AIMS: Hypertension is an independent risk factor for atrial fibrillation (AF). However, the direct effect of hydrostatic pressure on atrial electrical remodeling is unclear. The present study investigated whether hydrostatic pressure is responsible for atrial electrical remodeling and addressed a potential role of inflammation in this pathology. MAIN METHODS: Whole-cell patch-clamp recordings and biochemical assays were used to study the regulation and expression of ion channels in left atrial appendages in patients with AF, spontaneously hypertensive rats (SHRs), and atrium-derived cells (HL-1 cells) exposed to standard (0 mmHg) and elevated (20, 40 mmHg) hydrostatic pressure. KEY FINDINGS: Both TNF-α and MIF were highly expressed in patients with AF and SHRs. AF inducibility in SHRs was higher after atrial burst pacing, accompanied by a decrease in the L-type calcium current (ICa,L), an increase in the transient outward K+ current (Ito) and ultra-rapid delayed rectifier K+ current (IKur), and a shortened action potential duration (APD), which could be inhibited by atorvastatin. Furthermore, exposure to elevated pressure was associated with electrical remodeling of the HL-1 cells. The peak current density of ICa,L was reduced, while Ito and IKur were increased. Moreover, the expression levels of Kv4.3, Kv1.5, TNF-α, and MIF were upregulated, while the expression of Cav1.2 was downregulated in HL-1 cells after treatment with high hydrostatic pressure (40 mmHg). Atorvastatin alleviated the electrical remodeling and increased inflammatory markers in HL-1 cells induced by high hydrostatic pressure. SIGNIFICANCE: Elevated hydrostatic pressure led to atrial electrical remodeling and increased AF susceptibility by upregulating inflammation.

Draft genome sequence analysis of a high carbapenem-resistant Klebsiella quasipneumoniae subsp. quasipneumoniae strain isolated from an HIV-positive patient with pneumonia.

OBJECTIVES: The rapid spread of Klebsiella spp. is recognised as a major threat to public health owing to a rise in the number both of healthcare- and community-acquired infections. Here we report the draft genome sequence of a high carbapenem-resistant Klebsiella quasipneumoniae subsp. quasipneumoniae strain (Cln185) isolated from a human immunodeficiency virus (HIV)-positive patient with pneumonia. METHODS: Classical microbiological methods were applied to isolate and identify the strain. Genomic DNA was sequenced using an Illumina HiSeq platform and the reads were de novo assembled into contigs using CLC Genomics Workbench. The assembled contigs was annotated and whole-genome sequencing (WGS) was performed. RESULTS: WGS analysis revealed that the genome comprised a circular chromosome of 5 406 774bp with a GC content of 57.73%. Three important antimicrobial resistance genes (blaIMP-38, blaOKP-B-6 and blaDHA-1) were detected. In addition, genes conferring resistance to aminoglycosides, ß-lactams, fluoroquinolones and tetracycline were also identified. CONCLUSION: The draft genome sequence reported here will lay the foundation for future research on antimicrobial resistance and pathogenic mechanisms in K. quasipneumoniae subsp. quasipneumoniae and also will promote comparative analysis with genomic features among different sources of clinically important multidrug-resistant strains.

Mitral valve replacement via minimally invasive totally thoracoscopic surgery versus traditional median sternotomy: a propensity score matched comparative study.

BACKGROUND: To compare surgical outcomes after mitral valve replacement via either minimally invasive thoracoscopic (MIs) or traditional median sternotomy (MS) surgery and determine the short- and mid-term clinical outcomes of the MI approach. METHODS: All patients who received either MIs (n=405) or MS (n=691) mitral valve replacement surgery at the Guangdong Cardiovascular Institute between January 2012 and July 2015 were analyzed for outcome differences due to surgical approach using propensity score matching. The best 202 matches from the MI group and the MS group were analyzed. The clinical data of the two groups were collected, including preoperative cardiac function, operative data, postoperative complications, and follow-up. RESULTS: A final total of 404 patients were included in this study after propensity score matching; the MIs group and the MS group each contained 202 patients. The two groups were similar in age, weight, pathological changes, and surgical approach. Compared with the MS group, the MIs group had a longer cardiopulmonary bypass time (P<0.001), aortic cross-clamping time (P<0.001), and total procedure time (P<0.001). There were no significant differences between the groups regarding in-hospital mortality, stroke, pneumonia, acute renal failure, arrhythmia, and chylothorax. The MS group had significantly more patients with poor wound healing than the MIs group (P=0.004). The MI group had a lower rate of transfusion (P=0.037), shorter ventilation time (P=0.041), shorter ICU stay (P=0.033), reduced chest tube drainage and length of chest tube stay (P<0.001), and shorter hospital stay (P<0.001). There was no significant difference between the groups in hospital re-admission for bleeding, but the total hospitalization cost was higher in the MIs group (P=0.002). The mean follow-up was 26.59±12.33 months, the 1-year postoperative survival rate was 98.86%, and the overall survival rate was 97.44%. Compared with the MS group, the MIs group recovered earlier (P<0.05), and returned to work or study earlier (P<0.05). More patients in the MIs group were satisfied with the wound (P<0.001). The MS group had a higher incidence of postoperative osteomyelitis than the MIs group (P=0.028). There were no significant differences between groups in rates of mortality, stroke, pacemaker, reoperation, or 36-item Short Form Health Survey score. CONCLUSIONS: Compared with the MS approach, the MIs method of mitral valve replacement has longer cardiopulmonary bypass time and aortic cross-clamp time; however, it does not increase the risk of mortality and complications. Furthermore, MIs causes less trauma, fewer transfusions, less wound infection, faster recovery, faster return to work or study, and greater satisfaction with the incision in the mid-term. MI cardiac surgery is safe, effective, and feasible.

Intraoperative Implantation of Temporary Endocardial Pacing Catheter During Thoracoscopic Redo Tricuspid Surgery.

BACKGROUND: The placement of a temporary epicardial pacing wire is a challenge during a minimally invasive redo cardiac operation. The aim of this study is to assess the application of temporary endocardial pacing in patients who underwent minimally invasive redo tricuspid surgery. METHODS: Perioperative data of consecutive patients who underwent thoracoscopic redo tricuspid surgery were collected. All the tricuspid surgeries and combined procedures were performed under peripheral cardiopulmonary bypass without aortic cross-clamping. A sheath was introduced into the right jugular vein beside the percutaneous superior vena cava cannula and a temporary endocardial pacing catheter was guided into the right ventricle via the sheath prior to the right atrial closure. The pacemaker was connected and run as needed during or after operation. RESULTS: A total of 33 patients who underwent thoracoscopic redo tricuspid surgery were enrolled. Symptomatic tricuspid valve regurgitation (93.9%) and tricuspid valvular prosthesis obstruction (6.1%) after previous cardiac operations were noted as indications for a redo surgery. The mean time from previous cardiac operation to this time redo surgery was 13.3±6.4years. Isolated tricuspid valve replacement was performed in 18 patients (54.5%) and tricuspid valve plasty combined with or without mitral valve replacement was performed in 15 patients (45.5%). A temporary endocardial pacing catheter was successfully placed in the right ventricle for all patients with good sensing and pacing. No temporary pacing related complications occurred from insertion to removal of pacing catheter in the patients. CONCLUSIONS: This application of temporary endocardial pacing provided a safe and effective substitute for epicardial pacing in patients who underwent minimally invasive redo tricuspid surgery.

A comparative study of three-dimensional high-definition and two-dimensional high-definition video systems in totally endoscopic mitral valve replacement.

BACKGROUND: Three-dimensional vision with improved depth perception and spatial orientation has already proved its superiority to the two-dimensional vision in endoscopic surgery. However, those benefits remain unidentified in cardiac surgery. For the first time, we compare performance of a three-dimensional high-definition video system with a two-dimensional high-definition video system in patients undergoing totally endoscopic mitral valve replacement. METHODS: We enrolled 90 patients with mitral valve disease in a single institution, from June 2013 to June 2016. Totally endoscopic mitral valve replacement was performed by the same surgeon using either a three-dimensional high-definition (n=43) or a two-dimensional high-definition (n=47) video system with the same surgical technique. Short-term outcomes were compared between the two groups. All medical records were retrieved from a prospectively maintained database of minimally invasive cardiac surgery. RESULTS: All surgeries were successfully completed under totally endoscopic guidance. There were no intraoperative complications in either group. The use of three-dimensional video system reduced aortic cross-clamp time by approximately 10% (3D vs. 2D: 65.74±14.32 vs. 72.67±14.67 min, P=0.027). No significant differences were observed in cardiopulmonary bypass time, postoperative ventilation duration, length of surgical intensive care unit stay, length of hospital stay, and major complications between the two groups. There were no perioperative deaths in either group. CONCLUSIONS: Compared with the two-dimensional video system, the three-dimensional high-definition video system provided a better surgical experience with the same operative safety for totally endoscopic mitral valve replacement.

Characteristics, Mechanism and Long-Term Ablation Outcome of Atrial Tachycardias After Mitral Valvular Surgery and Concomitant Cox-MAZE IV Procedure.

The incidence of atrial tachycardia (AT) after rheumatic mitral valvular (RMV) surgery has been well described. However, there have been few reports on the characteristics, mechanism, and long-term ablation outcome of ATs after RMV surgery and concomitant Cox-MAZE IV procedure.The present study reviewed consecutive patients who underwent AT ablation between May 2008 and July 2013. All patients were refractory to antiarrhythmic drugs (AADs) and had a history of RMV surgery and Cox-MAZE IV procedure. A total of 34 patients underwent AT ablation after RMV surgery and concomitant Cox-MAZE IV procedure, and presented 57 mappable and 2 unmappable ATs. The 57 mappable ATs included 14 focal-ATs and 43 reentry-ATs. Ten of the 14 focal-like ATs were located at the pulmonary vein (PV) antrum and border of a box lesion. Of the 43 reentry-ATs, 16 were marco-reentrant around the mitral annulus (MA) and 16 around the tricuspid annulus. There were 41 atypical ATs (non-cavotricuspid isthmus related) including 16 ATs related to the box lesion and 21 ATs related to other Cox-MAZE IV lesions. The AT were successfully terminated in 33 (97.1%) patients. After mean follow-up of 46.9 ± 15.7 months, 25 (73.5%) patients maintained sinus rhythm without AADs after a single procedure and 28 (82.4%) patients after repeated procedures.The recurrent ATs after RMV surgery and concomitant Cox-MAZE IV were mainly reentry mechanism, and largely related to LA. An incomplete lesion or re-conductive gaps in a prior lesion might be the predominant mechanisms for these ATs. Catheter-based mapping and ablation of these ATs seems to be effective and safe during a long-term follow-up.

Giant Left Ventricular Myxoma With Obstruction of the Left Ventricular Outflow Tract.

A rare case of giant left ventricular (LV) myxoma with obstruction of the left ventricular outflow tract (LVOT) was found incidentally on echocardiography in an asymptomatic 21-year-old woman. The tumor was successfully resected through transatrial septal access.

The protective effect of trimetazidine on myocardial ischemia/reperfusion injury through activating AMPK and ERK signaling pathway.

INTRODUCTION: Trimetazidine (TMZ) is an anti-anginal drug that has been widely used in Europe and Asia. The TMZ can optimize energy metabolism via inhibition of long-chain 3-ketoacyl CoA thiolase (3-KAT) in the heart, with subsequent decrease in fatty acid oxidation and stimulation of glucose oxidation. However, the mechanism by which TMZ aids in cardioprotection against ischemic injury has not been characterized. AMP-activated protein kinase (AMPK) is an energy sensor that controls ATP supply from substrate metabolism and protects heart from energy stress. TMZ changes the cardiac AMP/ATP ratio by modulating fatty acid oxidation, thereby triggering AMPK signaling cascade that contributes to the protection of the heart from ischemia/reperfusion (I/R) injury. METHODS: The mouse model of in vivo regional ischemia and reperfusion by the ligation of the left anterior descending coronary artery (LAD) was used for determination of myocardial infarction. The infarct size was compared between C57BL/6J WT mice and AMPK kinase dead (KD) transgenic mice with or without TMZ treatment. The ex vivo working heart perfusion system was used to monitor the effect of TMZ on glucose oxidation and fatty acid oxidation in the heart. RESULTS: TMZ treatment significantly stimulates cardiac AMPK and extracellular signal-regulated kinase (ERK) signaling pathways (p<0.05 vs. vehicle group). The administration of TMZ reduces myocardial infarction size in WT C57BL/6J hearts, the reduction of myocardial infarction size by TMZ in AMPK KD hearts was significantly impaired versus WT hearts (p<0.05). Intriguingly, the administration of ERK inhibitor, PD98059, to AMPK KD mice abolished the cardioprotection of TMZ against I/R injury. The ex vivo working heart perfusion data demonstrated that TMZ treatment significantly activates AMPK signaling and modulating the substrate metabolism by shifting fatty acid oxidation to glucose oxidation during reperfusion, leading to reduction of oxidative stress in the I/R hearts. Therefore, both AMPK and ERK signaling pathways mediate the cardioprotection of TMZ against ischemic injury. The metabolic benefits of TMZ for angina patients could be due to the activation of energy sensor AMPK in the heart by TMZ administration.

Bilateral subclavian vein sheaths for superior vena cava drainage during thoracoscopic repair of atrial septal defects: cosmetic outcomes, safety and effectiveness.

OBJECTIVE: To investigate the cosmetic outcomes, safety and effectiveness of using bilateral subclavian vein sheaths for superior vena cava drainage during thoracoscopic repair of atrial septal defects. METHODS: Sixty-one consecutive adults scheduled for thoracoscopic repair of atrial septal defects between July 2012 and June 2013 were randomized into two groups: one group underwent placement of a 16 Fr percutaneous superior vena cava cannula (n = 30) and the other group underwent placement of bilateral 8 Fr subclavian vein sheaths (n = 31) for superior vena cava drainage during peripheral cardiopulmonary bypass. The perioperative data, central venous pressure during cardiopulmonary bypass, complications and the patient satisfaction scale scores for the incisions were compared between the two groups. RESULTS: The theoretical cardiopulmonary bypass flow rate was reached without complications in all patients. The average central venous pressure during cardiopulmonary bypass was not significantly different between the two groups [(6.9 ± 3.1) mmHg vs. (7.0 ± 3.5) mmHg, p=0.92]. The patient satisfaction scale scores for the incisions were significantly higher in the patients who underwent placement of bilateral subclavian vein sheaths than in the patients who underwent placement of a percutaneous superior vena cava cannula [(2.81 ± 0.75) vs. (2.07 ± 0.74), p<0.001]. CONCLUSIONS: Placement of bilateral subclavian vein sheaths is a safe and effective alternative to placement of a percutaneous superior vena cava cannula for superior vena cava drainage during thoracoscopic repair of atrial septal defects and results in greater patient satisfaction with the cosmetic outcome.