John S Ikonomidis

Medical University of South Carolina, Charleston, South Carolina, United States

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Publications (129)552.34 Total impact

  • John S Ikonomidis
    The Journal of thoracic and cardiovascular surgery 07/2015; DOI:10.1016/j.jtcvs.2015.06.085 · 3.99 Impact Factor
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    ABSTRACT: Neonates undergoing repair of the aortic arch are at risk for adverse neurodevelopmental outcomes, including attention deficit/hyperactivity disorder (ADHD). The purpose of this study was to compare the effect of deep hypothermic circulatory arrest versus regional cerebral perfusion on the long-term outcome of ADHD. This study is a cross-sectional observational study of ADHD in children who underwent neonatal aortic arch surgery. Attention Deficit/Hyperactivity Disorder-IV surveys were used to determine the prevalence of ADHD. Review of the medical records was performed to determine the primary method of cerebral protection and to extract related surgical variables. Surveys were sent to parents of 134 children, with 57 surveys completed (43%). The percentage of children classified as having ADHD was 44%. Children with a diagnosis of interrupted aortic arch had the highest prevalence of ADHD (85%). Multivariate analysis demonstrated that interrupted aortic arch was associated with an increased ADHD inattention score (p < 0.01), and a decreased Child Health Questionnaire-50 psychosocial score (p < 0.01). Low Child Health Questionnaire-50 psychosocial summary scores are associated with increased behavioral problems and are lower in patients with ADHD. Attention deficit/hyperactivity disorder is common after neonatal aortic arch surgery and may be primarily related to genetic predisposition. We found insufficient evidence to show that either deep hypothermic circulatory arrest or regional cerebral perfusion decreased the risk of ADHD. Copyright © 2015 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.
    The Annals of thoracic surgery 06/2015; DOI:10.1016/j.athoracsur.2015.04.119 · 3.65 Impact Factor
  • Vinay Badhwar · John S. Ikonomidis · Jeffrey P. Jacobs
    The Journal of thoracic and cardiovascular surgery 03/2015; 149(6). DOI:10.1016/j.jtcvs.2015.03.024 · 3.99 Impact Factor
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    ABSTRACT: Maintenance of the structure and mechanical properties of the thoracic aorta contributes to aortic function and is dependent on the composition of the extracellular matrix and the cellular content within the aortic wall. Age-related alterations in the aorta include changes in cellular content and composition of the extracellular matrix; however, the precise roles of these age-related changes in altering aortic mechanical function are not well understood. Thoracic aortic rings from the descending segment were harvested from C57BL/6 mice aged 6 and 21 months. Thoracic aortic diameter and wall thickness were higher in the old mice. Cellular density was reduced in the medial layer of aortas from the old mice; concomitantly, collagen content was higher in old mice, but elastin content was similar between young and old mice. Stress relaxation, an index of compliance, was reduced in aortas from old mice and correlated with collagen fraction. Contractility of the aortic rings following potassium stimulation was reduced in old versus young mice. Furthermore, collagen gel contraction by aortic smooth muscle cells was reduced with age. These results demonstrate that numerous age-related structural changes occurred in the thoracic aorta and were related to alterations in mechanical properties. Aortic contractility decreased with age, likely because of a reduction in medial cell number in addition to a smooth muscle contractile deficit. Together, these unique findings provide evidence that the age-related changes in structure and mechanical function coalesce to provide an aortic substrate that may be predisposed to aortopathies. © 2015 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.
    Journal of the American Heart Association 02/2015; 4(3). DOI:10.1161/JAHA.114.001744 · 2.88 Impact Factor
  • Circulation 02/2015; 131(10). DOI:10.1161/CIR.0000000000000182 · 14.95 Impact Factor
  • John S Ikonomidis
    Journal of Thoracic and Cardiovascular Surgery 01/2015; 149(1):114-5. DOI:10.1016/j.jtcvs.2014.11.020 · 3.99 Impact Factor
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    ABSTRACT: -The purpose of this study was to determine whether patients with heart failure and a preserved ejection fraction (HFpEF) have an increase in passive myocardial stiffness and the extent to which discovered changes are dependent on changes in extracellular matrix fibrillar collagen and/or cardiomyocyte titin. -Seventy patients undergoing coronary artery bypass grafting underwent an echocardiogram, plasma biomarker determination, and intra-operative left ventricular (LV) epicardial anterior wall biopsy. Patients were divided into 3 groups: referent control (n=17, no hypertension or diabetes), hypertension (HTN) without(-) HFpEF (n=31), and HTN with(+) HFpEF (n=22). One or more of the following studies were performed on the biopsies: passive stiffness measurements to determine total, collagen-dependent and titin-dependent stiffness (differential extraction assay), collagen assays (biochemistry or histology), or titin isoform and phosphorylation assays. Compared with controls, patients with HTN(-)HFpEF had no change in LV end diastolic pressure (LVEDP), myocardial passive stiffness, collagen, or titin phosphorylation but had an increase in biomarkers of inflammation (CRP, sST2, TIMP-1). Compared with both control and HTN(-)HFpEF, patients with HTN(+)HFpEF had increased LVEDP, left atrial volume, NT-proBNP, total, collagen-dependent and titin-dependent stiffness, insoluble collagen, increased titin phosphorylation on PEVK S11878(S26), reduced phosphorylation on N2B S4185(S469), and increased biomarkers of inflammation. -Hypertension in the absence of HFpEF, did not alter passive myocardial stiffness. Patients with HTN(+)HFpEF had a significant increase in passive myocardial stiffness; collagen-dependent and titin-dependent stiffness were increased. These data suggest that the development of HFpEF is dependent on changes in both collagen and titin homeostasis.
    Circulation 01/2015; 131(14). DOI:10.1161/CIRCULATIONAHA.114.013215 · 14.95 Impact Factor
  • Seminars in Thoracic and Cardiovascular Surgery 11/2014; 26(3):255-71. DOI:10.1053/j.semtcvs.2014.10.003
  • John S Ikonomidis
    Journal of Thoracic and Cardiovascular Surgery 10/2014; 149(2). DOI:10.1016/j.jtcvs.2014.10.069 · 3.99 Impact Factor
  • John S Ikonomidis
    Journal of Thoracic and Cardiovascular Surgery 09/2014; 148(6):2466-2467. DOI:10.1016/j.jtcvs.2014.09.085 · 3.99 Impact Factor
  • John S Ikonomidis
    Journal of Thoracic and Cardiovascular Surgery 07/2014; 148(4). DOI:10.1016/j.jtcvs.2014.07.002 · 3.99 Impact Factor
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    ABSTRACT: Valve sparing root replacement (VSRR) is an attractive option for the management of aortic root aneurysms with a normal native aortic valve. Therefore, we reviewed our experience with a modification of the David V VSRR and compared it with stented pericardial bioprosthetic valve conduit (BVC) root replacement in an age-matched cohort of older patients.
    Journal of Thoracic and Cardiovascular Surgery 07/2014; 148(6). DOI:10.1016/j.jtcvs.2014.05.092 · 3.99 Impact Factor
  • Tom P Theruvath · John S Ikonomidis
    Journal of Thoracic and Cardiovascular Surgery 06/2014; 149(3). DOI:10.1016/j.jtcvs.2014.06.032 · 3.99 Impact Factor
  • Tom P. Theruvath · John S. Ikonomidis
    Journal of Thoracic and Cardiovascular Surgery 05/2014; 147(5):1728-1728. · 3.99 Impact Factor
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    ABSTRACT: Objective: We sought to determine the prevalence of attention-deficit/hyperactivity disorder in a population of children who underwent neonatal heart surgery involving repair of the aortic arch for Norwood Stage I, interrupted aortic arch, and combined repair of aortic coarctation with ventricular septal defect. Methods: Children between the ages of 5 and 16 were surveyed using the ADHD-IV and the Child Heath Questionnaire-50. Classification as attention-deficit/hyperactivity disorder was defined for this study as either a parent-reported diagnosis of attention-deficit/hyperactivity disorder or ADHD-IV inattention score of ⩾93 percentile. Results: Of the 134 surveys, 57 (43%) were returned completed. A total of 25 (44%) children either had a diagnosis of attention-deficit/hyperactivity disorder and/or ADHD-IV inattention score ⩾93 percentile. Eleven of the 13 (85%) children with interrupted aortic arch, 3 of the 7 (42.9%) children with combined coarctation/ventricular septal defect repair, and 9 of the 33 (27.3%) children with hypoplastic left-heart syndrome were classified as having attention-deficit/hyperactivity disorder. Only 7 of the 25 (28%) children received medical treatment for this condition. Quality of life indicators in the Child Heath Questionnaire-50 Questionnaire were highly correlated with the ADHD-IV scores. Conclusion: The risks for the development of attention-deficit/hyperactivity disorder are multifactorial but are significantly increased in this post-surgical population. This study revealed a low treatment rate for attention-deficit/hyperactivity disorder, and a significant impact on the quality of life in these children.
    Cardiology in the Young 04/2014; 25(04):1-7. DOI:10.1017/S1047951114000547 · 0.86 Impact Factor
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    ABSTRACT: Children with functional single ventricle heart disease are commonly palliated down a staged clinical pathway toward a Fontan completion procedure (total cavopulmonary connection). The Fontan physiology is fraught with long-term complications associated with lower body systemic venous hypertension, eventually resulting in significant morbidity and mortality. The bidirectional Glenn shunt or superior cavopulmonary connection (SCPC) is commonly the transitional stage in single ventricle surgical management and provides excellent palliation. Some studies have demonstrated lower morbidity and mortality with the SCPC when compared with the Fontan. Unfortunately the durability of the SCPC is significantly limited by the development of pulmonary arteriovenous malformations (PAVMs) which have been commonly attributed to the absence of hepatic venous blood flow and the lack of pulsatile flow to the affected lungs. Abnormal angiogenesis has been suggested as a final common pathway to PAVM development. Understanding these fundamental mechanisms through the investigation of angiogenic pathways associated with the pathogenesis of PAVMs would help to develop medical therapies that could prevent or reverse this complication following SCPC. Such therapies could improve the longevity of the SCPC, potentially eliminate or significantly postpone the Fontan completion with its associated complications, and improve long-term survival in children with single ventricle disease.
    Expert Review of Cardiovascular Therapy 04/2014; 12(6). DOI:10.1586/14779072.2014.912132
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    ABSTRACT: The recently implemented integrated 6-year (I-6) format represents a significant change in cardiothoracic surgical residency training. We report the results of the first nationwide survey assessing I-6 program directors' impressions of this new format. A 28-question web-based survey was distributed to program directors of all 24 Accreditation Council for Graduate Medical Education-accredited I-6 training programs in November 2013. The response rate was a robust 67%. Compared with graduates of traditional residencies, most I-6 program directors with enrolled residents believed that their graduates will be better trained (67%), be better prepared for new technological advances (67%), and have superior comprehension of cardiothoracic disease processes (83%). Just as with traditional program graduates, most respondents believed their I-6 graduates would be able to independently perform routine adult cardiac and general thoracic operations (75%) and were equivocal on whether additional specialty training (eg, minimally invasive, heart failure, aortic) was necessary. Most respondents did not believe that less general surgical training disadvantaged I-6 residents in terms of their career (83%); 67% of respondents would have chosen the I-6 format for themselves if given the choice. The greater challenges in training less mature and experienced trainees and vulnerability to attrition were noted as disadvantages of the I-6 format. Most respondents believed that I-6 programs represent a natural evolution toward improved residency training rather than a response to declining interest among medical school graduates. High satisfaction rates with the I-6 format were prevalent among I-6 program directors. However, concerns with respect to training relatively less experienced, mature trainees were evident.
    The Journal of thoracic and cardiovascular surgery 04/2014; 148(2). DOI:10.1016/j.jtcvs.2014.04.004 · 3.99 Impact Factor
  • Jeffrey M Griffin · John S Ikonomidis
    The Journal of thoracic and cardiovascular surgery 02/2014; 147(6). DOI:10.1016/j.jtcvs.2014.02.065 · 3.99 Impact Factor
  • Daniel Eads · John S Ikonomidis
    The Journal of thoracic and cardiovascular surgery 01/2014; 147(4). DOI:10.1016/j.jtcvs.2013.12.029 · 3.99 Impact Factor
  • Jason B Wheeler · John S Ikonomidis · Jeffrey A Jones
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    ABSTRACT: Marfan Syndrome (MFS) and Loeys-Dietz Syndrome (LDS) represent heritable connective tissue disorders that cosegregate with a similar pattern of cardiovascular defects (thoracic aortic aneurysm, mitral valve prolapse/regurgitation, and aortic root dilatation with regurgitation). This pattern of cardiovascular defects appears to be expressed along a spectrum of severity in many heritable connective tissue disorders and raises suspicion of a relationship between the normal development of connective tissues and the cardiovascular system. Given the evidence of increased transforming growth factor-beta (TGF-β) signaling in MFS and LDS, this signaling pathway may represent the common link in this relationship. To further explore this hypothetical link, this chapter will review the TGF-β signaling pathway, heritable connective tissue syndromes related to TGF-β receptor (TGFBR) mutations, and discuss the pathogenic contribution of TGF-β to these syndromes with a primary focus on the cardiovascular system.
    Advances in Experimental Medicine and Biology 01/2014; 802:107-127. DOI:10.1007/978-94-007-7893-1_8 · 2.01 Impact Factor

Publication Stats

1k Citations
552.34 Total Impact Points

Institutions

  • 2003–2015
    • Medical University of South Carolina
      • • Division of Cardiothoracic Surgery
      • • Department of Surgery
      Charleston, South Carolina, United States
  • 2012
    • University of California, Los Angeles
      Los Ángeles, California, United States
  • 2009
    • University of South Carolina
      Columbia, South Carolina, United States
  • 2001
    • Stanford University
      Palo Alto, California, United States