Igor D Gregoric

University of Houston, Houston, Texas, United States

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Publications (253)701.71 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Mortality for patients presenting with acute myocardial infarction (AMI) complicated by ventricular septal defect (VSD) and cardiogenic shock is very high even with surgical repair. We report our experience regarding utilization of TandemHeart, a percutaneous ventricular assist device (pVAD) as an adjunct to the treatment of these patients.Retrospective case series study design included a total of 11 patients with post-AMI VSD and severe refractory cardiogenic shock who received pVAD support at our institution. Three patients underwent immediate surgical repair and received pVAD support for postcardiotomy cardiogenic shock for 2, 4 and 7 days, respectively. However, all 3 died. The other 8 patients had pVAD implanted prior to surgical repair in order to rest the myocardium before operation. Hemodynamics improved immediately after pVAD placement and after pVAD support for 7 ± 3 days they underwent surgical VSD repair. Their total pre- and postsurgical pVAD support was 14 ± 4 days. All 8 survived 30 days postoperatively. At 6 months overall survival was 75%.Our small series of these critically ill patients shows a trend toward better survival after immediate pVAD placement to stabilize the patient and allow for myocardial maturation before surgical VSD repair.
    ASAIO journal (American Society for Artificial Internal Organs: 1992) 07/2014; · 1.39 Impact Factor
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    ABSTRACT: Patients who undergo cardiopulmonary bypass (CPB) are at risk for coagulopathy. Suboptimal turnaround time (TAT) of laboratory coagulation testing results in empiric administration of blood products to treat massive bleeding. We describe our initiative in establishing the coagulation-based hemotherapy (CBH) service, a clinical pathology consultation service that uses rapid TAT coagulation testing and provides comprehensive assessment of bleeding in patients undergoing CPB. A transfusion algorithm that treats the underlying cause of coagulopathy was developed.
    Transfusion 06/2014; · 3.57 Impact Factor
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    ABSTRACT: We describe the development of a mobile computing platform (MCP) with a decision support module (DSM) for patients in our coagulation-based hemotherapy service.
    American Journal of Clinical Pathology 06/2014; 141(6):834-40. · 2.88 Impact Factor
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    ABSTRACT: Although survival rates after cardiac arrest remain low, new techniques are improving patients' outcomes. We present the case of a 40-year-old man who survived a cardiac arrest that lasted approximately 3½ hours. Resuscitation was performed with strict adherence to American Heart Association/American College of Cardiology Advanced Cardiac Life Support guidelines until bedside extracorporeal membrane oxygenation could be placed. A hypothermia protocol was initiated immediately afterwards. The patient had a full neurologic recovery and was bridged from dual ventricular assist devices to a total artificial heart. On hospital day 160, he underwent orthotopic heart and cadaveric kidney transplantation. On day 179, he was discharged from the hospital in ambulatory condition. To our knowledge, this is the only reported case in which a patient survived with good neurologic outcomes after a resuscitation that lasted as long as 3½ hours. Documented cases of resuscitation with good recovery after prolonged arrest give hope for improved overall outcomes in the future.
    Texas Heart Institute journal / from the Texas Heart Institute of St. Luke's Episcopal Hospital, Texas Children's Hospital 04/2014; 41(2):222-6. · 0.67 Impact Factor
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    ABSTRACT: Gelatin impregnated non-porous sealed grafts were introduced in the inflow and outflow conduits for use with the HeartMate II (HMII) to eliminate pre-clotting procedures and to reduce operative bleeding.We compared results of 67 patients who received first time LVADs with sealed inflow and outflow grafts (S-graft group) to a preceding 65 patients who received an LVAD with non-sealed grafts (NS-graft group).Overall, the amount of blood product transfusions was less in the S-graft group than in the NS-graft group (red blood cells, 4.9 ± 4.5 vs. 8.0 ± 9.4 units, P=0.022; fresh frozen plasma, 5.0 ± 3.0 vs. 8.7 ± 9.3 units, P=0.004; platelets, 2.9 ± 1.1 vs. 4.5 ± 3.5 units, P=0.001; and cryoprecipitate, 1.2 ± 0.9 vs. 2.01 ± 1.9 units, P=0.002). Within a follow-up period of 6 months, no device-related infections or strokes occurred in the S-group, but the NS-group had 1 (1.5%) driveline infections and 4 (6%) strokes. The 30-day survival rate was not significantly different between groups (P=0.053), but favored the S-group (97%) over the NS-group (88%). Use of a HMII with a sealed graft on the inflow and outflow conduits is associated with less postoperative bleeding, and may have helped to decrease the frequency of postoperative adverse events.
    ASAIO journal (American Society for Artificial Internal Organs: 1992) 03/2014; · 1.39 Impact Factor
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    ABSTRACT: Transcatheter aortic valve replacement (TAVR) is a safe alternative to surgery in patients with severe aortic stenosis. We report a case of balloon rupture during TAVR with successful retrieval of its remnant and review this complication and its management.
    Journal of Cardiac Surgery 01/2014; · 1.35 Impact Factor
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    ABSTRACT: The use of left ventricular assist devices has become common for the treatment of end-stage heart failure, both as a bridge to transplantation and as destination therapy. The nature of these devices and the comorbid conditions of the patients in whom the devices are implanted lead to high rates of device infection that are related directly to mortality. Over 2 years, the senior author (S.A.I.) treated 26 patients with left ventricular assist device infections, ranging from superficial driveline infections to deeper pocket infections and device infections. An algorithm involving the use of repeated débridement and placement of antibiotic beads was used in treatment of these infections. Once cleared of infection, patients were treated with definitive closure or flap coverage of the formerly infected device component. Seventeen of 26 patients with left ventricular assist device-related infections were cleared of their infection using this method. Ten of these patients underwent flap coverage of the device after their infection was cleared. In patients that were cleared of infection, mortality was 29 percent, whereas patients with recalcitrant infections had a mortality of 67 percent over the course of the study. A systematic approach to treating left ventricular assist device-related infections has the potential to treat and clear these infections, with promising overall survival rates. This proposed algorithm led to high infection clearance rates compared with previously published literature. Infection clearance in patients on left ventricular assist device destination therapy may result in mortality rates approaching those of their uninfected peers. Therapeutic, IV.
    Plastic and Reconstructive Surgery 01/2014; 133(1):28e-38e. · 3.33 Impact Factor
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    ABSTRACT: -Vasoactive intestinal polypeptide (VIP) is released from intracardiac neurons during vagal stimulation, ischemia and heart failure which are associated with increased vulnerability to atrial fibrillation (AF). VIP shortens atrial effective refractory periods in dogs. Endogenous VIP contributes to vagally mediated acceleration of atrial electrical remodeling. VIP is also shown to prolong the duration of acetylcholine-induced AF. However, the ionic mechanisms underlying VIP effects are largely unknown. -VIP's effects on transmembrane ion channels were studied in canine atrial cardiomyocytes using patch-clamp techniques. VIP increased delayed rectifier K(+) current and L-type calcium current but decreased the transient outward K(+) current and sodium current. Optical mapping technique was used to assess VIP's effects on action potential durations (APD) in isolated canine left atria. VIP shortened APD and slowed conduction velocity (CV) in a dose-dependent manner. Furthermore, VIP increased spatial heterogeneity of APD and CV, as assessed by the standard deviations of APD and CV, and AF inducibility. -Through its diverse effects on ion channels, VIP shortens APD with increased APD spatial heterogeneity and decreases intra-atrial conduction velocity, which may play an important role in the pathogenesis of atrial arrhythmias in scenarios where VIP release is increased.
    Circulation Arrhythmia and Electrophysiology 09/2013; · 5.95 Impact Factor
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    ABSTRACT: Aortic annular rupture is a rare and much dreaded complication of transcatheter aortic valve replacement. Device oversizing to prevent post-procedural paravalvular leak is the most commonly identified cause of this complication. However, mechanical stress in a heavily calcified non-compliant vessel can also lead to annular rupture in this older population. We describe a case of aortic annular rupture with involvement of right coronary artery ostium leading to cardiac tamponade and cardiac arrest, successfully managed by extracorporeal membrane oxygenation support, open drainage of the pericardial space, pericardial patching of the defect and bypass of the affected vessel with excellent post-procedural results.
    General Thoracic and Cardiovascular Surgery 08/2013;
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    ABSTRACT: Continuous-flow left ventricular assist devices (LVADs) provide durable, reliable, energy-efficient long-term support. However, the biologic effects of continuous flow are not completely known. Therefore, we examined aortic wall morphology in patients with heart failure before and after prolonged circulatory support with a continuous-flow LVAD. After applying a partial aortic occlusion vascular clamp in the lower half of the ascending aorta, we removed samples of aortic wall tissue and then attached the outflow graft of the pump. Samples were obtained from 11 patients (9 men and 2 women, mean age 65 ± 7 years) with severe heart failure at the time of LVAD implantation. We obtained matched specimens at explantation after heart transplantation (n = 5) or autopsy (n = 6). These specimens were removed from the distal ascending aorta, remote from the aortic anastomotic site. Tissue sections were stained with hematoxylin and eosin, Movat's pentachrome and Masson's trichrome. Smooth muscle actin immunohistochemistry was performed on all sections. To evaluate the morphology of the aortic wall media, we quantitatively graded tissue sections for medial thickness, medial degenerative changes, smooth muscle cell (SMC) disorientation and depletion, elastic fiber fragmentation and depletion, medial fibrosis and atherosclerotic changes. The mean duration of support was 140 ± 136 days (range 87 to 580 days). The histologic evaluation and comparison of specimens obtained before and after LVAD support showed significantly increased foci of medial degeneration, SMC depletion, elastic fiber fragmentation, medial fibrosis and atherosclerotic changes after LVAD support. Mean medial thickness was not significantly different after LVAD support. We observed similar changes between samples obtained at transplantation and those obtained at autopsy. After continuous-flow LVAD support, the morphology of the aortic wall media was altered in all of our patients. The clinical relevance of these findings is unknown.
    The Journal of heart and lung transplantation: the official publication of the International Society for Heart Transplantation 08/2013; · 5.61 Impact Factor
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    ABSTRACT: The HeartWare Ventricular Assist System (HeartWare Inc, Framingmam, MA) is a miniaturized implantable, centrifugal design, continuous-flow blood pump. The pivotal bridge to transplant and continued access protocols trials have enrolled patients with advanced heart failure in a bridge-to-transplant indication. The primary outcome, success, was defined as survival on the originally implanted device, transplant, or explant for ventricular recovery at 180 days. Secondary outcomes included an evaluation of survival, functional and quality of life outcomes, and adverse events. A total of 332 patients in the pivotal bridge to transplant and continued access protocols trial have completed their 180-day primary end-point assessment. Survival in patients receiving the HeartWare pump was 91% at 180 days and 84% at 360 days. Quality of life scores improved significantly, and adverse event rates remain low. The use of the HeartWare pump as a bridge to transplant continues to demonstrate a high 180-day survival rate despite a low rate of transplant. Adverse event rates are similar or better than those observed in historical bridge-to-transplant trials, despite longer exposure times due to longer survival and lower transplant rates.
    The Journal of heart and lung transplantation: the official publication of the International Society for Heart Transplantation 07/2013; 32(7):675-683. · 5.61 Impact Factor
  • Interventional Cardiology Clinics. 07/2013; 2(3):457–468.
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    ABSTRACT: Objectives The aim of this study was to characterize levels of serum biomarkers in patients with severe refractory cardiogenic shock (SRCS) and to document temporal changes in these levels during restoration of circulation. Background Patients with SRCS have been challenging to study because of their rapidly changing clinical condition while undergoing multiple simultaneous interventions. Methods Twenty-one patients with SRCS received circulatory support via a percutaneously implanted ventricular assist device (PVAD). Serum samples obtained prior to PVAD support initiation, at 24 h of PVAD support, and at 7 days of PVAD support were assayed for B-type natriuretic peptide (BNP), high-sensitivity C-reactive protein (hsCRP), soluble tumor necrosis factor receptor-1 (sTNFR1), soluble Fas (sFas), soluble Fas ligand (sFasL), endothelin-1, and procollagen III N-terminal peptide (PIIINP). Baseline biomarker levels were qualitatively compared to reference values; levels at 24 h of PVAD support and at 7 days of PVAD support were compared to baseline using 2-tailed Wilcoxon matched pair signed rank tests with Bonferroni correction for multiple comparisons. Results These patients with SRCS had elevated serum levels of BNP, hsCRP, sTNFR1, endothelin-1, and PIIINP. Ventricular unloading and restoration of circulation via PVAD support in patients with SRCS were associated with reductions in serum BNP, sFas, and endothelin-1 levels and increases in serum sFasL and PIIINP levels. Conclusions This study characterizes several important baseline serum biomarker levels in patients with SRCS and introduces a novel PVAD-based protocol with the potential to "reverse"-model the pathophysiology of cardiogenic shock.
    JACC: Heart Failure. 06/2013; 1(3):200–206.
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    ABSTRACT: We describe the case of a 54-year-old woman with a postinfarction ventricular septal defect (VSD) and ventricular free wall rupture who was stabilized with a percutaneous ventricular assist device (pVAD) to allow for myocardial infarct stabilization. Following the rupture of the right ventricular free wall and cardiopulmonary arrest on hospital day 10, pVAD support was promptly converted to extracorporeal membrane oxygenation (ECMO) support for stabilization. After surgical repair was completed, pVAD support was continued for 4 days to allow recovery. The patient was discharged on postoperative day 11 and is alive and well 4 years later. Postinfarction VSD with free wall rupture may be salvaged with pVAD and ECMO support.
    Heart Surgery Forum 06/2013; 16(3):E150-E151. · 0.56 Impact Factor
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    ABSTRACT: Evaluation of: Thiele H, Zeymer U, Neumann FJ et al; IABP-SHOCK II Trial Investigators. Intra-aortic balloon support for myocardial infarction with cardiogenic shock. N. Engl. J. Med. 367(14), 1287-1296 (2012). Cardiogenic shock (CS) in acute myocardial infarction (AMI) is associated with high mortality. Ventricular support devices such as intra-aortic balloon pumps have been used in the acute management of this condition. However, a recent randomized controlled trial conducted by Thiele et al. showed that the use of an intra-aortic balloon pump in CS in AMI does not improve 30-day outcomes in these patients. In the following review, the authors discuss the salient features of the article, how the results of this trial are likely to change the management strategies in CS in the setting of AMI and the future directions.
    Expert Review of Cardiovascular Therapy 02/2013; 11(2):147-9.
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    ABSTRACT: The ductus arteriosus originates from the persistence of the distal portion of the left sixth aortic arch. It connects the descending aorta (immediately distal to the left subclavian artery) to the roof of the main pulmonary artery, near the origin of the left pulmonary artery. Persistence of the duct beyond 48 h after birth is abnormal and results in patent ductus arteriosus (PDA). PDA is rare in adults because it is usually discovered and treated in childhood. Mechanical closure remains the definitive therapy because the patency of ductus arteriosus may lead to multiple complications, depending on the size and flow through the ductus. PDA closure is indicated in patients with symptoms and evidence of left heart enlargement, and in patients with elevated pulmonary pressures when reversal is possible. Transcatheter closure is the preferred technique in adults because it avoids sternotomy, reduces the length of hospital stay and is associated with fewer complications compared with surgery. First demonstrated in 1967, both the technique and the occluder devices used have since evolved. However, designing an ideal PDA occluder has been a challenge due to the variability in size, shape and orientation of PDAs. The present article describes a case involving a 35-year-old woman who presented to the Center for Advanced Heart Failure (Houston, USA) with congestive heart failure due to a large PDA, which was successfully occluded using an Amplatzer (St Jude Medical, USA) muscular ventricular septal defect closure device. The wider waist and dual-retention discs of these ventricular septal defect closure devices may be important factors to consider in the future development of devices for the occlusion of large PDAs.
    Experimental and clinical cardiology 01/2013; 18(1):e50-e54. · 0.76 Impact Factor
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    ABSTRACT: We report the case of a 70-year-old man who presented with a large dissection of the ascending aorta related to coronary artery bypass grafting 3 years earlier. One graft was patent; however, a reverse venous graft to the right coronary artery was occluded, and that artery was substantially stenotic. The patient was a high-risk surgical candidate, so we treated a large dissection successfully by endovascular means with a thoracic endograft. This case suggests that this approach can be applied safely and effectively to other high-surgical-risk patients who have complex ascending aortic disease.
    Texas Heart Institute journal / from the Texas Heart Institute of St. Luke's Episcopal Hospital, Texas Children's Hospital 01/2013; 40(2):182-5. · 0.67 Impact Factor
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    ABSTRACT: Left ventricular assist devices and percutaneous valve interventions have radically changed the treatment of advanced heart disease and minimized surgical morbidity in patients with end-stage heart failure who would not survive conventional surgery. We describe a successful approach to the simultaneous placement of a percutaneous left ventricular assist device and mitral valvuloplasty in a decompensated patient with end-stage ischemic cardiomyopathy, severe peripheral arterial disease, porcelain aorta, and severe mitral and aortic disease.
    Texas Heart Institute journal / from the Texas Heart Institute of St. Luke's Episcopal Hospital, Texas Children's Hospital 01/2013; 40(4):445-448. · 0.67 Impact Factor
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    ABSTRACT: The unique findings on transthoracic echocardiography of the HeartWare left ventricular assist device (LVAD) have not been previously described. HeartWare LVADs were implanted in 19 patients from May 2009 through December 2010; 152 comprehensive transthoracic echocardiograms (TTEs) performed postoperatively on these patients were retrospectively analyzed for device component visualization, inlet cannula/outflow conduit flow velocities, and imaging artifacts. The inlet cannula was adequately visualized in 66% of studies, incompletely visualized in 14%, and not visualized in 20%. Spectral Doppler interrogation of inlet cannula flow velocity was always uninterpretable due to artifact. Standard parasternal long-axis and apical views always included the inlet cannula in the imaging sector, resulting in a prominent "waterfall" color Doppler artifact obscuring the mitral valve. Inclusion of the inlet cannula in the imaging sector also precluded spectral Doppler interrogation of the mitral valve owing to artifact. The outflow conduit was partially visualized and interrogated by spectral Doppler in 68% of studies, and the average measured peak flow velocity was 1.4 m/s (range 1.0-1.9 m/s). The HeartWare LVAD inlet cannula and outflow conduit are both readily visualized by TTE in a majority of patients. However, significant color and spectral Doppler artifacts occur when the inlet cannula is visualized in the imaging sector, necessitating routine off-axis Doppler interrogation of the mitral valve.
    Journal of cardiac failure 09/2012; 18(9):745-8. · 3.07 Impact Factor
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    ABSTRACT: Abstract  Background: In patients with a left ventricular assist device (LVAD), pump-related infection can cause adverse effects that may result in death. Methods: We describe three patients who had infections related to a fistula between the gastrointestinal (GI) tract and the LVAD pocket and who subsequently underwent successful heart transplantation without developing sepsis. In no case did the LVAD-related infection adversely affect the outcome of transplantation. Conclusions: For detecting the fistulas, full upper-GI endoscopy and colonoscopy were superior to other types of diagnostic imaging studies. (J Card Surg 2012;27:643-645).
    Journal of Cardiac Surgery 09/2012; 27(5):643-5. · 1.35 Impact Factor

Publication Stats

2k Citations
701.71 Total Impact Points


  • 2005–2013
    • University of Houston
      Houston, Texas, United States
    • University of Texas MD Anderson Cancer Center
      • Department of Thoracic Cardiovascular Surgery
      Houston, Texas, United States
  • 2002–2013
    • University of Texas Health Science Center at Houston
      • Department of Pathology and Laboratory Medicine
      Houston, Texas, United States
  • 1991–2013
    • Texas Heart Institute
      • Division of Cardiovascular Surgery
      Houston, Texas, United States
  • 2011
    • Universität Heidelberg
      • Department of Cardiac Surgery
      Heidelberg, Baden-Wuerttemberg, Germany
    • Methodist Hospitals
      Gary, Indiana, United States
  • 2008–2011
    • Houston Methodist Hospital
      Houston, Texas, United States
    • University of Cincinnati
      Cincinnati, Ohio, United States
  • 2007–2010
    • Baylor College of Medicine
      • • Department of Medicine
      • • Section of Pulmonary, Critical Care and Sleep Medicine
      Houston, Texas, United States
    • Hannover Medical School
      • Department of Cardiothoracic, Transplantation and Vascular Surgery (HTTG)
      Hannover, Lower Saxony, Germany
    • Università degli Studi di Siena
      Siena, Tuscany, Italy
  • 2007–2009
    • Ljubljana University Medical Centre
      • Department of Cardiovascular Surgery
      Ljubljana, Ljubljana, Slovenia
  • 2003–2006
    • University of Texas Medical School
      • Department of Cardiothoracic and Vascular Surgery
      Houston, Texas, United States
  • 2000
    • University of Lille Nord de France
      Lille, Nord-Pas-de-Calais, France
  • 1993
    • Texas Children's Hospital
      Houston, Texas, United States