Publications by authors named "Chukwuemeka Daniel Iroegbu"

8 Publications

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Cell Death and Exosomes Regulation After Myocardial Infarction and Ischemia-Reperfusion.

Front Cell Dev Biol 2021 9;9:673677. Epub 2021 Jun 9.

Department of Cardiovascular Surgery, The Second Xiangya Hospital, Central South University, Changsha, China.

Cardiovascular disease (CVD) is the leading cause of death in the global population, accounting for about one-third of all deaths each year. Notably, with CVDs, myocardial damages result from myocardial infarction (MI) or cardiac arrhythmias caused by interrupted blood flow. Significantly, in the process of MI or myocardial ischemic-reperfusion (I/R) injury, both regulated and non-regulated cell death methods are involved. The critical factor for patients' prognosis is the infarct area's size, which determines the myocardial cells' survival. Cell therapy for MI has been a research hotspot in recent years; however, exosomes secreted by cells have attracted much attention following shortcomings concerning immunogens. Exosomes are extracellular vesicles containing several biologically active substances such as lipids, nucleic acids, and proteins. New evidence suggests that exosomes play a crucial role in regulating cell death after MI as exosomes of various stem cells can participate in the cell damage process after MI. Hence, in the review herein, we focused on introducing various cell-derived exosomes to reduce cell death after MI by regulating the cell death pathway to understand myocardial repair mechanisms better and provide a reference for clinical treatment.
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http://dx.doi.org/10.3389/fcell.2021.673677DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8220218PMC
June 2021

TMSB4 Overexpression Enhances the Potency of Marrow Mesenchymal Stromal Cells for Myocardial Repair.

Front Cell Dev Biol 2021 9;9:670913. Epub 2021 Jun 9.

Department of the Cardiovascular Surgery, The Second Xiangya Hospital, Central South University, Changsha, China.

Objective: The actin-sequestering proteins, thymosin beta-4 (Tβ4) and hypoxia-inducible factor (HIF)-1α, are known to be associated with angiogenesis after myocardial infarction (MI). Herein, we aimed to identify the mechanism of HIF-1α induction by Tβ4 and investigate the effects of bone marrow mesenchymal stromal cells (BMMSCs) transfected with the Tβ4 gene () in a rat model of MI.

Methods: Rat BMMSCs were isolated, cultured, and transfected with the gene by using the lentivirus-mediated method. Rats with surgically induced MI were randomly divided into three groups ( = 9/group); after 1 week, the rats were injected at the heart infarcted border zone with TMSB4-overexpressed BMMSCs (BMMSC-TMSB4 ), wild-type BMMSCs that expressed normal levels of TMSB4 (BMMSC-TMSB4 ), or medium (MI). The fourth group of animals ( = 9) underwent all surgical procedures necessary for MI induction except for the ligation step (Sham). Four weeks after the injection, heart function was measured using transthoracic echocardiography. Infarct size was calculated by TTC staining, and collagen volume was measured by Masson staining. Angiogenesis in the infarcted heart area was evaluated by CD31 immunofluorescence histochemistry. experiments were carried out to observe the effect of exogenous Tβ4 on HIF-1α and explore the various possible mechanism(s).

Results: experiments showed that vascular density 4 weeks after treatment was about twofold higher in BMMSC-TMSB4 -treated animals than in BMMSC-TMSB4 -treated animals ( < 0.05). The cardiac function and infarct size significantly improved in both cell-treatment groups compared to controls. Notably, the cardiac function and infarct size were most prominent in BMMSC-TMSB4 -treated animals (both < 0.05). HIF-1α and phosphorylated HIF-1α (p-HIF-1α) were significantly enhanced by exogenous Tβ4, which was nonetheless blocked by the factor-inhibiting HIF (FIH) promoter (YC-1). The expression of prolyl hydroxylase domain proteins (PHD) was decreased upon treatment with Tβ4 and further decreased with the combined treatment of Tβ4 and FG-4497 (a specific PHD inhibitor).

Conclusion: TMSB4-transfected BMMSCs might significantly improve recovery from myocardial ischemia and promote the generation of HIF-1α and p-HIF-1α the AKT pathway, and inhibit the degradation of HIF-1α the PHD and FIH pathways.
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http://dx.doi.org/10.3389/fcell.2021.670913DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8221609PMC
June 2021

Case Report: Giant Biatrial Myxoma Mimicking Malignant Cardiac Tumor in a Patient With a Hepatic Angiomatous Mass.

Front Cardiovasc Med 2021 28;8:676807. Epub 2021 May 28.

Department of Cardiovascular Surgery, The Second Xiangya Hospital, Central South University, Changsha, China.

Cardiac myxomas, primarily originating from the left atrium, are the most prevalent types of benign cardiac tumors; however, biatrial myxomas are extremely rare. Herein, we present a rare case of a 55-year old male with exertional dyspnea and intermittent chest discomfort due to a giant biatrial mass with concomitant atrial fibrillation and hepatic hemangioma. The giant tumor with its peduncle at the interatrial septum involved both atria; however, bulging through the tricuspid valve to the right ventricle during systole. Hence, excision of the giant cardiac tumor (which grossly composed of three parts: stiff, fleshy, and soft) and Cox-Maze IV procedure was performed with the resected specimen measuring 100 × 80 × 40 mm. The patient who was in a stable condition was discharged home on the 12th post-operative day. Thus, given the excellent post-operative results achieved, surgical treatment in large multi-cavitary benign cardiac tumors is feasible and should be considered a potentially curative therapy.
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http://dx.doi.org/10.3389/fcvm.2021.676807DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8192690PMC
May 2021

Surgical Management of a Giant Left Sinus of Valsalva Aneurysm with Coronary Artery Abnormality.

Heart Surg Forum 2021 03 25;24(2):E296-E298. Epub 2021 Mar 25.

Department of Cardiovascular Surgery, The Second Xiangya Hospital, Central South University, Changsha, China.

Coronary insufficiency caused by unruptured left sinus of Valsalva aneurysm (SVA) is exceedingly rare in the literature. Herein, we present a successful surgically treated case of giant left SVA with severe aortic regurgitation and coronary insufficiency, thus introducing a tailored valve-sparing aortic root repair technique.
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http://dx.doi.org/10.1532/hsf.3643DOI Listing
March 2021

Individualized Surgical Reconstruction of the Right Ventricle Outflow Tract in Double Outlet Right Ventricle With Mirror Image-Dextrocardia.

Front Pediatr 2021 19;9:611007. Epub 2021 Feb 19.

Department of Cardiovascular Surgery, The Second Xiangya Hospital of Central South University, Changsha, China.

The purpose of this study was to report our experience in the surgical reconstruction of the right ventricular outflow tract in double outlet right ventricle with a major coronary artery crossing the right ventricular outflow tract in the presence of mirror image-dextrocardia. From January 2005 to December 2019, 19 double outlet right ventricle patients (median age 4 years) with mirror image-dextrocardia and a major coronary artery crossing the right ventricular outflow tract received surgical repair. An autologous pericardial patch was used to enlarge the right ventricular outflow tract in four patients without pulmonary stenosis and three patients with mild pulmonary stenosis. A valved bovine jugular venous conduit was added to a hypoplastic native pathway in nine patients, among which six patients with moderate pulmonary stenosis received small-sized bovine jugular venous conduit implantation (diameter ≤ 16 mm). In comparison, a large-sized bovine jugular venous conduit (diameter >16 mm) was adopted in a total of three patients with severe pulmonary stenosis. Finally, three patients with preoperative pulmonary hypertension (mean pulmonary artery pressure ≥40 mmHg) did not undergo further intervention of right ventricular outflow tract due to the adequate outflow tract blood flow. There was no hospital mortality. One patient with sub-pulmonary ventricular septal defect and concomitant severe pulmonary hypertension died from respiratory failure 11 months after the operation. Kaplan-Meier survival was 94% at 5, 10 years. Within a mean echocardiographic follow-up of 6.9 ± 3.6 years, a total of two patients received reintervention due to valvular stenosis of the bovine jugular venous conduit (pressure gradient > 50 mmHg at 4 and 9 years) after surgical operation. Actuarial freedom from reoperation was 90 and 72% at 5 and 10 years, respectively. During the last echocardiographic follow-up phase, all the survivors were in NYHA class I. Double outlet right ventricle with mirror image-dextrocardia is a rare and complicated congenital cardiac malformation. Surgical reconstruction of the right ventricular outflow tract should be individualized based on the degree of pulmonary stenosis and the specific anatomical features of each patient. Reconstructing the pulmonary artery using the various sizes of valved bovine jugular venous conduit is a safe and effective surgical method.
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http://dx.doi.org/10.3389/fped.2021.611007DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7933223PMC
February 2021

Evaluating the cost-effectiveness of catheter ablation of atrial fibrillation.

Cardiovasc Diagn Ther 2020 Oct;10(5):1200-1215

Department of Cardiovascular Surgery, Second Xiangya Hospital, Central South University, Changsha, China.

Background: The pursuit of a clearer understanding of the pathogenesis of atrial fibrillation (AFib) and the development of new technology has resulted in a surge of interest in the surgical ablation for AFib. Here, we report our 8-year experience in the surgical treatment and management of AFib alongside, evaluating the cost-effectiveness in southern Mainland China over a 1-year follow-up.

Methods: Data of 3,068 patients from March 2011 through June 2019 was retrospectively extracted from The Provincial National Cardiac Database of Xiangya Second Hospital. The activities considered (and costs calculated) were outpatient consultations, hospital admissions, and drug treatment. Quality of life (QoL) questionnaires were also carried out to assess whether concomitant AFib correction procedures increase risk in patients, or improve patient's QoL.

Results: A total of 3,068 patients completed the questionnaires at a minimum of one time-point during the follow-up. The total cost was combined to obtain incremental costs per quality-adjusted life-years (QALYs). The total costs of the AFib catheter ablation group were remarkably higher compared to surgery as usual group. The incremental cost-effectiveness ratio was $76,513,227 (¥542,287,667) per QALY, with an acceptability line graph for cost at 43%.

Conclusions: AFib is an extraordinarily costly and worrisome public health problem. Precision medicine is vital as it provides a platform for the clinical translation of targeted interventions that are designed to help treat and prevent AFib. Thus, to improve the QoL expectancy outcome(s), both therapeutic and surgical interventions should be aimed at addressing the underlying heart disease rather than restoring sinus rhythm.
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http://dx.doi.org/10.21037/cdt-20-574DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7666964PMC
October 2020

Application of Modified Sliding Anastomosis in the Repair of Aortic Coarctation.

Biomed Res Int 2020 14;2020:3805385. Epub 2020 May 14.

Department of Cardiovascular Surgery, The Second Xiangya Hospital of Central South University, Middle Renmin Road 139, Changsha 410000, China.

Objectives: To evaluate the early and midterm results of a modified sliding anastomosis technique in patients with aortic coarctation.

Materials And Methods: In this study, we reported a new repair method and compared the early and midterm outcome(s) with a conventional surgical approach for the management of patients with aortic coarctation. Forty-eight aortic coarctation patients with a narrowed segment length longer than 2 cm were operated at our department's pediatric surgical division. Excision of the coarctation and end-to-end anastomosis was carried out in twenty-five patients (control group). In contrast, a modified sliding technique was used for twenty-three cases in the observation group. Other accompanying cardiac anomalies simultaneously repaired included ventricular septal defect and patent ductus arteriosus. All patients received 1.5-10 years of postoperative echocardiographic follow-up.

Results: This is a retrospective study carried out between January 2005 and June 2018. The study population consisted of forty-eight patients, which included twenty-six male and twenty-two female patients, with an average age of 5.2 ± 1.9 months (range, 28 days to 1 year). There was no mortality. The operative time, the number of intercostal artery disconnection, the drainage volume, and arm-leg systolic pressure gradient postoperation were less in the observation group as compared to the control group ( < 0.05). Also, cases with an anastomotic pressure gradient exceeding 10 mmHg during follow-up were less in the observation group as compared to the control group ( < 0.05). The postoperative complications encountered were chylothorax (control group 2 cases vs. observation group 0) and pulmonary atelectasis (control group 4 cases vs. observation group 1). They all, however, recovered after conservative treatment. Three patients in the control group underwent balloon angioplasty (reintervention) postoperative 2-4 years due to an increase in the anastomotic pressure gradient (>20 mmHg). After reintervention, the anastomotic pressure gradient reduced to 14 mmHg, 15 mmHg, and 17 mmHg, respectively.

Conclusions: For long segment aortic coarctation patients (longer than 2 cm), the use of the modified sliding anastomotic technique effectively helps to retain more autologous tissues, enlarge the diameter of the anastomosis, and decrease anastomotic tension and vascular injury. Therefore, this technique provides a new idea for the surgical treatment of aortic coarctations.
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http://dx.doi.org/10.1155/2020/3805385DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7245663PMC
March 2021

Endomyocardial fibrosis.

Cardiovasc Diagn Ther 2020 Apr;10(2):208-222

Department of Cardiovascular Surgery, Second Xiangya Hospital, Central South University, Changsha 410011, China.

Background: Endomyocardial fibrosis (EMF) is a neglected cardiovascular disease of poverty which carries a poor prognosis with no specific treatment affecting mainly children and young adults. Here, we report our 10-year experience in the therapeutic management and surgical treatment for EMF.

Methods: From February 2009 to 2019 March, 55 patients diagnosed with EMF from our cardiology unit underwent surgical repair at our department's pediatric surgical division. There were 35 male, and 20 female patients whose ages varied from 1 year 2 months to 12 years mean age 5.7 (±3.2). We designed the study aimed at assessing the cardio-structural abnormalities and coronary vascular changes faced with EMF patients using echocardiography, and coronary angiography with a detailed and thorough surgical examination of each case.

Results: Of the 55 operated patients, 1 had mild lesions, 26 had moderate lesions, and 28 had severe heart disease. All but one patient was in NYHA functional class III or IV at the time of surgery. All but one female patient with mild ventricular lesions and no valvular involvement had severe atrioventricular valve regurgitation with valves considered suitable for both replacements; 45 patients mean age 6.0 (±3.1) and repair nine patients mean age 3.8 (±2.9). The mean endocardial thickness was 3,000 (±1519) µm.

Conclusions: The echocardiographic changes corresponded well to the findings on surgery and histopathology. The coronary changes seen included a spectrum of fibrin deposition, medial sclerosis and degeneration, and the formation of plexiform lesions. Surgically evaluating the resected cardiac tissue might help improve disease management.
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http://dx.doi.org/10.21037/cdt.2020.02.10DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7225420PMC
April 2020
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