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Jahanyar J, Koerner MM, Ghodsizad A, Loebe M, Noon GP. Heterotopic heart transplantation: the United States experience. Heart Surg Forum 2014; 17:E132-40. [PMID: 25002388 DOI: 10.1532/hsf98.2014328] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
INTRODUCTION More than 3 decades have passed since the first heterotopic heart transplantation (HHT) was reported. Nowadays, this surgical technique is used rarely, and only in patients who do not qualify for standard orthotopic heart transplantation (OHT). Current indications mainly comprise refractory pulmonary hypertension and a donor-recipient size mismatch (>20%). The objective of this study was to analyze the United States experience with HHT. PATIENTS AND METHODS The United Network for Organ Sharing (UNOS) database between 1987 and 2007 was analyzed. Patients who underwent heart transplantation were enrolled in this study. Patients with missing transplant dates or history of retransplantation were excluded. RESULTS A total of 41,379 patients underwent OHT and 178 HHT; 32,361 and 111 patients, respectively, were enrolled. Overall 1-, 5-, and 10-year survival was significantly (P < .001) better in OHT (87.7%, 74.4%, 54.4%) than HHT patients (83.8%, 59%, 35.1%). Survival in patients with transpulmonary gradients (TPG) >15 mmHg was 86.6 %, 73.3%, and 57.4% in the OHT and 93.8%, 64.8%, and 48.6% in the HHT group (P = .35). Pretransplant criteria (HHT versus OHT) with statistically significant differences (P < .05) were as follows (mean + SD): recipient weight, 78.9 + 19.9 versus 74.1 + 23.4 kg; recipient height, 174.9 + 13.9 versus 168 + 25.1 cm; and TPG 12.1 + 7.2 versus 9.6 + 6.3 mmHg. CONCLUSIONS The results show that HHT remains a feasible option in a highly selected patient population, with overall good results.
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Karmonik C, Partovi S, Schmack B, Weymann A, Loebe M, Noon GP, Piontek P, Karck M, Lumsden AB, Ruhparwar A. Comparison of hemodynamics in the ascending aorta between pulsatile and continuous flow left ventricular assist devices using computational fluid dynamics based on computed tomography images. Artif Organs 2013; 38:142-8. [PMID: 23889366 DOI: 10.1111/aor.12132] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
This study aims to investigate differences in hemodynamic conditions in the thoracic aorta for pulsatile and continuous-flow left ventricular assist devices (LVADs) using computational fluid dynamics (CFD). Patient-specific models were reconstructed from three patients with continuous-flow LVAD (HeartMate II, Thoratec Corporation) and three patients with biventricular assist devices (Excor, Berlin Heart) where only the aortic part was included in the simulations. CFD simulations were performed with constant inflow for the continuous-flow LVADs and time-varying inflow for the pulsatile devices. Differences in flow patterns, wall shear stress (WSS), and dynamic pressure in the ascending aorta were compared for both cases. Retrograde flow patterns were observed in all cases proximal to the location of the outflow cannula anastomosis site. On average, dynamic pressures derived from the retrograde flow velocities were higher in the continuous-flow group with large variations dependent on the angle of the cannula anastomosis relative to the ascending aorta (continuous group: 0.14 ± 0.2 mm Hg, pulsatile group: 0.013 ± 0.008 mm Hg). Elevated WSS contralaterally to the anastomosis site was observed in three of the six models with higher values for the continuous cases. Lower WSS and reduced pressure in the ascending aorta, both favorable hemodynamic conditions, were found in pulsatile versus continuous-flow LVADs by means of CFD. These findings indicate, along with clinical observations reported by others, the superior performance of pulsatile LVADs.
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Noon GP, Loebe M, Motomura T. Respect the history and foresee the future: milestones of the International Society for Rotary Blood Pumps with Artificial Organs. Artif Organs 2012; 36:656-8. [PMID: 22882436 DOI: 10.1111/j.1525-1594.2012.01517.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Karmonik C, Partovi S, Davies MG, Bismuth J, Shah DJ, Bilecen D, Staub D, Noon GP, Loebe M, Bongartz G, Lumsden AB. Integration of the computational fluid dynamics technique with MRI in aortic dissections. Magn Reson Med 2012; 69:1438-42. [PMID: 22700326 DOI: 10.1002/mrm.24376] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2012] [Revised: 05/17/2012] [Accepted: 05/23/2012] [Indexed: 11/05/2022]
Abstract
Short-term and long-term prognosis and their determining factors of Type III/Stanford B aortic dissections (TB-AD), which separate the aorta distal at the origin of the subclavian artery into a true lumen and false lumen, have been elusive: One quarter of patients thought to be treated successfully, either by medical or by surgical means, do not survive 3 years. Unfavorable hemodynamic conditions are believed to lead to false lumen pressure increases and complications. A better characterization of TB-AD hemodynamics may therefore impact therapeutic decision making and improve outcome. The large variations in TB-AD morphology and hemodynamics favor a patient-specific approach. Magnetic resonance imaging with its capability to provide high-resolution structural images of the lumen and aortic wall and also to quantify aortic flow and kinetics of an exogenous tracer is a promising clinical modality for developing a deeper understanding of TB-AD hemodynamics in an individual patient. With the information obtained with magnetic resonance imaging, computational fluid dynamics simulations can be performed to augment the image information. Here, an overview of the interplay of magnetic resonance imaging and computational fluid dynamics techniques is given illustrating the synergy of these two approaches toward a comprehensive morphological and hemodynamic characterization of TB-AD.
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Partovi S, Loebe M, Noon GP, Davies MG, Karimi S, Zipp L, Feinstein SB, Staub D. Detection of Adventitial Vasa Vasorum and Intraplaque Neovascularization
in Carotid Atherosclerotic Lesions with Contrastenhanced Ultrasound and
their Role in Atherosclerosis. Methodist Debakey Cardiovasc J 2011. [DOI: 10.14797/mdcvj.305] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
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Partovi S, Loebe M, Noon GP, Davies MG, Karimi S, Zipp L, Feinstein SB, Staub D. Detection Of Adventitial Vasa Vasorum And Intraplaque Neovascularization In Carotid Atherosclerotic Lesions With Contrast-Enhanced Ultrasound And Their Role In Atherosclerosis. Methodist Debakey Cardiovasc J 2011; 7:37-40. [DOI: 10.14797/mdcj-7-4-37] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
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Jones WL, Garcia LJ, Trevino AR, Bruckner BA, Loebe M, Noon GP, Elias B, Orrego CM, Torre-Amione G, Estep JD. LVAD Support as a Bridge to Transplant in the Morbidly Obese Needs a Long-Term Weight Loss Strategy. J Card Fail 2010. [DOI: 10.1016/j.cardfail.2010.06.161] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Aldred MA, Comhair SA, Varella-Garcia M, Asosingh K, Xu W, Noon GP, Thistlethwaite PA, Tuder RM, Erzurum SC, Geraci MW, Coldren CD. Somatic chromosome abnormalities in the lungs of patients with pulmonary arterial hypertension. Am J Respir Crit Care Med 2010; 182:1153-60. [PMID: 20581168 DOI: 10.1164/rccm.201003-0491oc] [Citation(s) in RCA: 118] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
RATIONALE Vascular remodeling in pulmonary arterial hypertension (PAH) involves proliferation and migration of endothelial and smooth muscle cells, leading to obliterative vascular lesions. Previous studies have indicated that the endothelial cell proliferation is quasineoplastic, with evidence of monoclonality and instability of short DNA microsatellite sequences. OBJECTIVES To assess whether there is larger-scale genomic instability. METHODS We performed genome-wide microarray copy number analysis on pulmonary artery endothelial cells and smooth muscle cells isolated from the lungs of patients with PAH. MEASUREMENTS AND MAIN RESULTS Mosaic chromosomal abnormalities were detected in PAEC cultures from five of nine PAH lungs but not in normal (n = 8) or disease control subjects (n = 5). Fluorescent in situ hybridization analysis confirmed the presence of these abnormalities in vivo in two of three cases. One patient harbored a germline mutation of BMPR2, the primary genetic cause of PAH, and somatic loss of chromosome-13, which constitutes a second hit in the same pathway by deleting Smad-8. In two female subjects with mosaic loss of the X chromosome, methylation analysis showed that the active X was deleted. One subject also showed completely skewed X-inactivation in the nondeleted cells, suggesting the pulmonary artery endothelial cell population was clonal before the acquisition of the chromosome abnormality. CONCLUSIONS Our data indicate a high frequency of genetically abnormal subclones within PAH lung vessels and provide the first definitive evidence of a second genetic hit in a patient with a germline BMPR2 mutation. We propose that these chromosome abnormalities may confer a growth advantage and thus contribute to the progression of PAH.
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Torre-Amione G, Southard RE, Loebe MM, Youker KA, Bruckner B, Estep JD, Tierney M, Noon GP. Reversal of secondary pulmonary hypertension by axial and pulsatile mechanical circulatory support. J Heart Lung Transplant 2010; 29:195-200. [DOI: 10.1016/j.healun.2009.05.030] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2009] [Revised: 05/22/2009] [Accepted: 05/24/2009] [Indexed: 11/17/2022] Open
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Noon GP, Loebe M. Current status of the MicroMed DeBakey Noon Ventricular Assist Device. Tex Heart Inst J 2010; 37:652-653. [PMID: 21224933 PMCID: PMC3014118] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The HeartAttendant programs the controller and sets pump rpm and alarm thresholds. It collects and stores pump parameters when connected to the controller and enables remote monitoring via the Internet. It charges and reconditions the batteries and can provide electrical power from the wall. It eliminates the need for the Clinical Data Acquisition System and the Patient Home Support System. The new controller, in all modes, displays pump flow (L/min), current/amps, power/watts, rpm, and diagnostic and emergency alarms. The HeartAssist 5 is CE-approved in Europe. A new U.S. Food and Drug Administration study of the HeartAssist 5 as a bridge to transplant is being finalized.
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Motomura T, Long JW, Noon GP. Lifelong contributions of Dr. Michael E. DeBakey and the 16th Congress of the International Society for Rotary Blood Pumps. Artif Organs 2009; 33:685-90. [PMID: 19775259 DOI: 10.1111/j.1525-1594.2009.00919.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Nakazawa T, Makinouchi K, Ohara Y, Ohtsubo S, Kawahito K, Tasai K, Shimono T, Benkowski R, Damm G, Takami Y, Glueck J, Noon GP, Nosé Y. Development of a Pivot Bearing Supported Sealless Centrifugal Pump for Ventricular Assist. Artif Organs 2008; 20:485-490. [PMID: 28868689 DOI: 10.1111/j.1525-1594.1996.tb04469.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Since 1991, in our laboratory, a pivot bearing-supported, sealless, centrifugal pump has been developed as an implantable ventricular assist device (VAD). For this application, the configuration of the total pump system should be relatively small. The C1E3 pump developed for this purpose was anatomically compatible with the small-sized patient population. To evaluate an-tithrombogenicity, ex vivo 2-week screening studies were conducted instead of studies involving an intracorpore-ally implanted VADs using calves. Five paracorporeal LVAD studies were performed using calves for longer than 2 weeks. The activated clotting time (ACT) was maintained at approximately 250 s using heparin. All of the devices demonstrated trouble-free performances over 2 weeks. Among these 5 studies, 3 implantations were subjected to 1-month system validation studies. There were no device-induced thrombus formations inside the pump housing, and plasma-free hemoglobin levels in calves were within the normal range throughout the experiment (35, 34, and 31 days). There were no incidents of system malfunction. Subsequently, the mass production model was fabricated and yielded a normalized index of hemolysis of 0.0014, which was comparable to that of clinically available pumps. The wear life of the impeller bearings was estimated at longer than 8 years. In the next series of in vivo studies, an implantable model of the C1E3 pump will be fabricated for longer term implantation. The pump-actuator will be implanted inside the body; thus the design calls for substituting plastic for metallic parts.
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Ohtsubo S, Tayama E, Short D, Noon GP, Nose Y. Clinical Comparative Study of Cardiopulmonary Bypass with Nikkiso and BioMedicus Centrifugal Pumps. Artif Organs 2008; 20:715-720. [PMID: 28868702 DOI: 10.1111/j.1525-1594.1996.tb04510.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The Nikkiso centrifugal pump was evaluated in elective adult open heard surgery in comparison with the BioMedicus pump. Ten patients using the Nikkiso pump (Group N), and 10 patients using the BioMedicus pump (Group B) were examined for (or to determine) hemato-biologic parameters and patient outcome data as well as pump controllability. During cardiopulmonary bypass (CPB), both pumps maintained systemic perfusion satisfactorily without any mechanical adverse event. Rotation speed of the Nikkiso centrifugal pump (3,580 ± 100 rpm) was significantly higher than that of the BioMedicus pump (3,170 ± 100 rpm; p < 0.05) whereas changes in free plasma hemoglobin, platelet count, blood urea nitrogen, and creatinine levels showed no significant differences between the two groups. Urine output in Group N for 30 min after the initiation of CPB (7.10 ± 1.50 ml/kg/h) was significantly higher than that in Group B (3.23 ± 0.46 ml/kg/h; p < 0.05). Patient outcome data were similar in both groups, such as duration of intensive care unit stay, hospital stay, postoperative intubation time, amount of postoperative bleeding, and amount of blood transfused. These equivalent results with the BioMedicus pump suggested that the Nikkiso pump can be used in open heart surgery as a reliable and atraumatic CPB pump.
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Noon GP. Michael Ellis Debakey, M.D. September 7, 1908 – July 11, 2008. Methodist Debakey Cardiovasc J 2008. [DOI: 10.14797/mdcj-4-4-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
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Jahanyar J, Youker KA, Torre-Amione G, Koerner MM, Bruckner B, Noon GP, Loebe M. Increased expression of stem cell factor and its receptor after left ventricular assist device support: a potential novel target for therapeutic interventions in heart failure. J Heart Lung Transplant 2008; 27:701-9. [PMID: 18582797 DOI: 10.1016/j.healun.2008.03.021] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2007] [Revised: 02/08/2008] [Accepted: 03/27/2008] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND Left ventricular assist devices (LVADs) cause an influx of mast cells into the failing heart, but the underlying mechanism is unknown. This study investigates the potential role of stem cell factor (SCF) and its receptor (c-Kit) in promoting the recruitment of mast cells during heart failure and after LVAD support. METHODS Myocardial samples were collected from 10 end-stage heart failure patients undergoing LVAD implantation (pre-LVAD) and paired with samples taken at the time of orthotopic heart transplantation (post-LVAD). Biopsies of normal hearts served as controls. We assessed gene expression of SCF and c-Kit. In addition, we stained for SCF, c-Kit, tryptase and chymase, and utilized in situ hybridization to determine the origin of SCF. RESULTS SCF mRNA and overall mast cell numbers were significantly increased (p < 0.01/p < 0.001) after LVAD support as compared with paired heart failure tissues. c-Kit mRNA was significantly increased post-LVAD compared with normal tissues (p < 0.05). The c-Kit protein was expressed only in cardiac mast cells. SCF mRNA was found in endothelial cells, myocytes and interstitial cells, as confirmed by antibody staining. CONCLUSIONS LVADs cause an increase of SCF and c-Kit gene expression, which coincides with a surge of mast cells after ventricular unloading. This suggests that SCF functions as an important mediator for the recruitment of mast cells to the mechanically unloaded human heart.
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Noon GP. Michael Ellis DeBakey, M.D. September 7, 1908 - July 11, 2008. Methodist Debakey Cardiovasc J 2008. [DOI: 10.14797/mdcvj.143] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
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Busch J, Torre-Amione G, Noon GP, Loebe M. TandemHeart insertion via a femoral arterial GORE-TEX graft conduit in a high-risk patient. Tex Heart Inst J 2008; 35:462-465. [PMID: 19156243 PMCID: PMC2607081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The TandemHeart percutaneous ventricular assist device (pVAD), which provides temporary circulatory support of the left ventricle, can be used in high-risk and hemodynamically unstable patients. The easily inserted TandemHeart provides cardiac support superior to that from the use of intra-aortic balloon pumps. Herein, we discuss TandemHeart implantation via end-to-side femoral arterial grafting in a cardiac patient whose sepsis and multiorgan failure were complicated by coagulopathy and thromboembolism. A 47-year-old woman, on intra-aortic balloon and intravenous inotropic support after an acute myocardial infarction and emergency coronary artery bypass grafting, was transferred to our institution via helicopter. She developed sepsis and multiorgan failure. Her condition was further complicated by coagulopathy and a left-lower-extremity thromboembolism. After 6 weeks of aggressive pharmacologic and intermittent intra-aortic balloon treatment, the patient developed cardiogenic shock and received a TandemHeart pVAD for short-term circulatory support. A GORE-TEX access graft, sewn end-to-side to the femoral artery because of the patient's leg ischemia and very small vessels, served as a conduit for the TandemHeart's femoral arterial inflow cannula. Her difficult circulatory, anatomic, and coagulopathic status stabilized after 2 weeks of TandemHeart support, and she was bridged to the long-term MicroMed DeBakey VAD Child in anticipation of heart transplantation. The case of our patient shows that high-risk patients who have experienced cardiogenic shock with multiorgan failure and coagulopathy can benefit from the TandemHeart pVAD as a bridge to other therapeutic options, even when creative approaches to treatment and to TandemHeart insertion are required.
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Jahanyar J, Youker KA, Loebe M, Assad-Kottner C, Koerner MM, Torre-Amione G, Noon GP. Mast cell-derived cathepsin g: a possible role in the adverse remodeling of the failing human heart. J Surg Res 2007; 140:199-203. [PMID: 17418861 DOI: 10.1016/j.jss.2007.02.040] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2006] [Revised: 02/20/2007] [Accepted: 02/26/2007] [Indexed: 11/19/2022]
Abstract
BACKGROUND The role of cardiac mast cells (MCs) in the progression to heart failure has recently become increasingly evident. Cathepsin g is a neutrophil- and mast cell-derived protease, which can convert angiotensin I to angiotensin II and thereby activate the TGF-beta pathway, resulting in myocyte necrosis, hypertrophy, and increased fibrosis. This study focuses on mast cell-derived cathepsin g in the human heart during heart failure and following mechanical unloading by means of heart-assist devices (LVADs). MATERIALS AND METHODS Myocardial tissue was obtained from 10 patients with end-stage cardiomyopathy at the time of LVAD implantation (pre-LVAD) and following orthotopic heart transplantation (post-LAVD). In addition, biopsies of four normal hearts served as a control group. Paraffin-embedded sections were dual stained for cathepsin g and tryptase, a known marker for mast cells, using standard immunohistochemistry protocols. Total cathepsin g positive mast cells were counted. RESULTS No cathepsin g positive MCs were found in normal hearts. However, we found evidence for cathepsin g in cardiac MCs in heart failure tissues (pre-LVAD). During heart failure, 46% of total MCs were cathepsin g positive as compared to after mechanical unloading, where only 11% of total MCs were cathepsin g positive (P<0.001). CONCLUSION Heart failure causes an increase of myocardial MCs. We have provided evidence that cathepsin g positive MCs accumulate during heart failure and their total percentage decreases after ventricular unloading. This coincides with the decrease in myocyte necrosis, hypertrophy, and fibrosis. Thus, cathepsin g may play a role in the progression to heart failure by activating angiotensin II, leading to detrimental effects on the heart.
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Jahanyar J, Noon GP, Koerner MM, Youker KA, Malaisrie SC, Ngo UQ, Torre-Amione G, Loebe M. Recurrent device thrombi during mechanical circulatory support with an axial-flow pump is a treatable condition and does not preclude successful long-term support. J Heart Lung Transplant 2007; 26:200-3. [PMID: 17258157 DOI: 10.1016/j.healun.2006.11.602] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2006] [Revised: 09/27/2006] [Accepted: 11/21/2006] [Indexed: 11/27/2022] Open
Abstract
The formation of pump thrombus after implantation of axial-flow ventricular assist devices has been described previously. We report a case of recurrent pump thrombus formation in a 63-year-old man who was bridged to heart transplantation with a MicroMed DeBakey ventricular assist device. He was treated with a low, dose-adjusted thrombolytic treatment protocol, and was subsequently successfully bridged to transplantation. Transient pump thrombus formation does not preclude safe long-term support with an axial-flow pump when diagnosed and treated appropriately.
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Jahanyar J, Joyce DL, Southard RE, Loebe M, Noon GP, Koerner MM, Torre-Amione G, Youker KA. Decorin-mediated Transforming Growth Factor-β Inhibition Ameliorates Adverse Cardiac Remodeling. J Heart Lung Transplant 2007; 26:34-40. [PMID: 17234515 DOI: 10.1016/j.healun.2006.10.005] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2006] [Revised: 09/29/2006] [Accepted: 10/17/2006] [Indexed: 11/25/2022] Open
Abstract
BACKGROUND Implantation of a left ventricular assist device (LVAD) has been shown to induce regression of fibrosis in patients with congestive heart failure (CHF) and improve myocardial function. The mechanism of reverse remodeling after mechanical circulatory support (MCS), however, has not been fully characterized. In this study we examined the anti-fibrotic effects of decorin, an extracellular matrix (ECM) proteoglycan, on the transforming growth factor-beta (TGF-beta) pathway. METHODS Human myocardial tissue samples were obtained from patients undergoing LVAD implantation and again following subsequent transplantation after a sustained period of MCS. The specimens were examined by utilizing different molecular and histologic techniques, including human cardiac fibroblast in vitro studies. We assessed gene expression, mRNA and protein levels. RESULTS We found a significant decrease in interstitial fibrosis after MCS, with a decrease in collagen mRNA transcription rates, serving as an indirect measurement of collagen synthesis. Both the mRNA and protein levels of decorin were significantly increased after a period of MCS. Decorin mRNA was up-regulated by 44% after MCS (p < 0.01), which paralleled the increase in interstitial decorin deposition (p < 0.001). In addition, p-SMAD2, a molecular marker downstream of the TGF-beta pathway, was found to be inactivated after MCS (p < 0.02). Moreover, cultured human cardiac fibroblasts exposed to TGF-beta demonstrated decreased collagen production when exogenous decorin was added (p < 0.03). CONCLUSIONS The decorin molecule is potentially involved in reverse cardiac remodeling, by directly inhibiting the TGF-beta pathway and its pro-fibrotic effects on the failing human heart.
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Oliveira GHM, Brann CN, Becker K, Thohan V, Koerner MM, Loebe M, Noon GP, Torre-Amione G. Dynamic expression of the membrane attack complex (MAC) of the complement system in failing human myocardium. Am J Cardiol 2006; 97:1626-9. [PMID: 16728227 DOI: 10.1016/j.amjcard.2005.12.056] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/17/2005] [Revised: 12/20/2005] [Accepted: 12/20/2005] [Indexed: 02/08/2023]
Abstract
Inflammatory cytokine-mediated pathways are activated in heart failure and participate in the pathogenesis and progression of the disease. Another major response to inflammation is mediated through the complement system with the production of the membrane attack complex (MAC), a protein known to cause cell lysis and mediate apoptosis. It was postulated that the complement system is activated in patients with heart failure, and this study investigated whether hemodynamic conditions regulate this pathway. The expression of the MAC was assessed in myocardial biopsy samples of normal and failing hearts by immunohistochemistry and Western blot analysis. Myocardial samples from failing hearts were obtained before and after left ventricular assist device implantation. Immunohistochemical staining and Western blot analysis identified increased MAC expression in failing but not normal myocardium. After hemodynamic unloading with left ventricular assist device support, MAC expression returned to levels found in normal controls. In failing hearts, MAC expression did not differ between ischemic and nonischemic causes of heart failure. In conclusion, increased MAC expression in failing human hearts indicates that the complement system is activated in the heart failure milieu. Its removal after hemodynamic normalization is evidence of dynamic regulation, suggesting a pathogenic role for the MAC. These findings identify the complement system as part of a novel pathophysiologic path in heart failure that can potentially be targeted by future therapy.
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Akgul A, Noon GP. Comparison of mast cell properties and myocardial structure in dilated and ischemic hearts under mechanical circulatory support. Eur J Cardiothorac Surg 2006; 29:637; author reply 638. [PMID: 16497509 DOI: 10.1016/j.ejcts.2006.01.027] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/01/2006] [Revised: 01/01/2006] [Accepted: 01/16/2006] [Indexed: 11/22/2022] Open
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Henao EA, Hodge MD, Felkai DD, McCollum CH, Noon GP, Lin PH, Lumsden AB, Bush RL. Contrast-enhanced Duplex surveillance after endovascular abdominal aortic aneurysm repair: Improved efficacy using a continuous infusion technique. J Vasc Surg 2006; 43:259-64; discussion 264. [PMID: 16476596 DOI: 10.1016/j.jvs.2005.09.045] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2005] [Accepted: 09/26/2005] [Indexed: 11/26/2022]
Abstract
INTRODUCTION Currently, postoperative endoleak surveillance after endovascular aortic aneurysm repair (EVAR) is primarily done by computed tomography (CT). The purpose of this study was to determine the efficacy of contrast-enhanced ultrasonography scans to detect endoleaks by using a novel infusion method and compare these findings with those of CT angiography (CTA). METHODS Twenty male patients (mean age, 70.4 years) underwent surveillance utilizing both CTA and contrast-enhanced color Duplex imaging. One 3-mL vial of Optison (Perfluten Protein A microspheres for injection) and 57 mL normal saline, for a total of 60 mL, were administered to each patient as a continuous infusion at 4 mL/min via a peripheral vein. Each study was optimized with harmonic imaging, and a reduced mechanical index of 0.4 to 0.5, compression of 1 to 3, and a focal zone below the aorta to minimize microsphere rupture. One minute was allowed from the time of infusion to the appearance of contrast in the endograft. Flow was evaluated within the lumen of the graft and its components, as was the presence or absence of endoleaks. Findings were compared with standard color-flow Duplex imaging and CT utilizing CTA reconstruction protocols. RESULTS All patients evaluated had modular endografts implanted for elective aneurysm repair. Contrast-enhanced duplex scans identified nine endoleaks: one type I and eight type II. No additional endoleaks were seen on CTA. However, CTA failed to recognize three type II endoleaks seen by contrast-enhanced ultrasound. The continuous infusion method allowed for longer and more detailed imaging. An average of 46.8 mL of the contrast infusion solution was used per patient. CONCLUSIONS Contrast enhanced Duplex ultrasonography accurately demonstrates endoleaks after EVAR and may be considered as a primary surveillance modality. Continuous infusion permits longer imaging time.
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Schneider N, Joyce D, Southard R, Cross CA, Noon GP, Koerner MM, Loebe M. Rupture of inlet graft of the HeartMate System: a case report. J Heart Lung Transplant 2006; 25:137-9. [PMID: 16399545 DOI: 10.1016/j.healun.2005.06.017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2005] [Revised: 06/07/2005] [Accepted: 06/21/2005] [Indexed: 11/20/2022] Open
Abstract
As the implantation of left ventricular assist devices (LVADs) as destination therapy for patients with heart failure increases in frequency, device durability and malfunction present an increasing concern. Complications such as inflow valve regurgitation, outflow valve distortion, and problems with power cable or pump motors place the LVAD recipient at increased risk for morbidity and mortality. To offset the risk of complications related to the inflow cannula, modifications to the valve conduit were made to the SNAP VE device in November 2002. These modifications were intended to improve durability with cycle performance of up to 6 times longer than the old inflow valve during in vitro testing. We describe here a patient who sustained disruption of the Dacron inlet graft after implantation of the Heart-Mate XVE System as a destination therapy.
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