1
|
Rohde S, Miera O, Sliwka J, Sandica E, Amodeo A, Veen K, de By TMMH, Bogers AJJC, Schweiger M. Durable left ventricular assist device explantation following recovery in paediatric patients: Determinants and outcome after explantation. Eur J Cardiothorac Surg 2024; 65:ezae126. [PMID: 38613845 DOI: 10.1093/ejcts/ezae126] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Revised: 01/31/2024] [Accepted: 04/11/2024] [Indexed: 04/15/2024] Open
Abstract
OBJECTIVES Myocardial recovery in children supported by a durable left ventricular assist device is a rare, but highly desirable outcome because it could potentially eliminate the need for a cardiac transplant and the lifelong need for immunosuppressant therapy and the risk of complications. However, experience with this specific outcome is extremely limited. METHODS All patients < 19 years old supported by a durable left ventricular assist device from the European Registry for Patients with Mechanical Circulatory Support database were included. Participating centres were approached for additional follow-up data after explantation. Associated factors for explantation due to myocardial recovery were explored using Cox proportional hazard models. RESULTS The incidence of recovery in children supported by a durable left ventricular assist device was 11.7% (52/445; median duration of support, 122.0 days). Multivariable analyses showed body surface area (hazard ratio 0.229; confidence interval 0.093-0.565; P = 0.001) and a primary diagnosis of myocarditis (hazard ratio 4.597; confidence interval 2.545-8.303; P < 0.001) to be associated with recovery. Left ventricular end-diastolic diameter in children with myocarditis was not associated with recovery. Follow-up after recovery was obtained for 46 patients (88.5%). Sustained myocardial recovery was reported in 33/46 (71.7%) at the end of the follow-up period (28/33; >2 year). Transplants were performed in 6/46 (11.4%) (in 5 after a ventricular assist device was reimplanted). Death occurred in 7/46 (15.2%). CONCLUSIONS Myocardial recovery occurs in a substantial portion of paediatric patients supported with durable left ventricular assist devices, and sustainable recovery is seen in around three-quarters of them. Even children with severely dilated ventricles due to myocarditis can show recovery. Clinicians should be attentive to (developing) myocardial recovery. These results can be used to develop internationally approved paediatric weaning guidelines.
Collapse
Affiliation(s)
- Sofie Rohde
- Department of Cardio-thoracic surgery, Erasmus University Medical Center, Rotterdam, Netherlands
| | - Oliver Miera
- Department of Congenital Heart Disease and Pediatric Cardiology, Deutsches Herzzentrum der Charité, Berlin, Germany
| | - Joanna Sliwka
- Department of Cardiac Surgery, Transplantology and Vascular Surgery, Silesian Center for Heart Diseases, Zabrze, Poland
| | - Eugen Sandica
- Clinic for Pediatric Cardiac Surgery and Congenital Heart Defects, Heart and Diabetes Centre North Rhine-Westphalia, Ruhr-University of Bochum, Bad Oeynhausen, Germany
| | - Antonio Amodeo
- Heart Failure, Transplant and MCS Unit, Bambino Gesù Children Hospital & Research Institute, Rome, Italy, Catholic University of Sacred Heart, Department of Cardiac Surgery, Rome, Italy
| | - Kevin Veen
- Department of Cardio-thoracic surgery, Erasmus University Medical Center, Rotterdam, Netherlands
| | | | - Ad J J C Bogers
- Department of Cardio-thoracic surgery, Erasmus University Medical Center, Rotterdam, Netherlands
| | - Martin Schweiger
- Children's Hospital Zurich, Pediatric Heart Centre, Department for congenital heart surgery, Zurich, Switzerland
| |
Collapse
|
2
|
Tseliou E, Lavine KJ, Wever-Pinzon O, Topkara VK, Meyns B, Adachi I, Zimpfer D, Birks EJ, Burkhoff D, Drakos SG. Biology of myocardial recovery in advanced heart failure with long-term mechanical support. J Heart Lung Transplant 2022; 41:1309-1323. [PMID: 35965183 DOI: 10.1016/j.healun.2022.07.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Revised: 07/03/2022] [Accepted: 07/07/2022] [Indexed: 10/17/2022] Open
Abstract
Cardiac remodeling is an adaptive, compensatory biological process following an initial insult to the myocardium that gradually becomes maladaptive and causes clinical deterioration and chronic heart failure (HF). This biological process involves several pathophysiological adaptations at the genetic, molecular, cellular, and tissue levels. A growing body of clinical and translational investigations demonstrated that cardiac remodeling and chronic HF does not invariably result in a static, end-stage phenotype but can be at least partially reversed. One of the paradigms which shed some additional light on the breadth and limits of myocardial elasticity and plasticity is long term mechanical circulatory support (MCS) in advanced HF pediatric and adult patients. MCS by providing (a) ventricular mechanical unloading and (b) effective hemodynamic support to the periphery results in functional, structural, cellular and molecular changes, known as cardiac reverse remodeling. Herein, we analyze and synthesize the advances in our understanding of the biology of MCS-mediated reverse remodeling and myocardial recovery. The MCS investigational setting offers access to human tissue, providing an unparalleled opportunity in cardiovascular medicine to perform in-depth characterizations of myocardial biology and the associated molecular, cellular, and structural recovery signatures. These human tissue findings have triggered and effectively fueled a "bedside to bench and back" approach through a variety of knockout, inhibition or overexpression mechanistic investigations in vitro and in vivo using small animal models. These follow-up translational and basic science studies leveraging human tissue findings have unveiled mechanistic myocardial recovery pathways which are currently undergoing further testing for potential therapeutic drug development. Essentially, the field is advancing by extending the lessons learned from the MCS cardiac recovery investigational setting to develop therapies applicable to the greater, not end-stage, HF population. This review article focuses on the biological aspects of the MCS-mediated myocardial recovery and together with its companion review article, focused on the clinical aspects, they aim to provide a useful framework for clinicians and investigators.
Collapse
Affiliation(s)
- Eleni Tseliou
- Division of Cardiovascular Medicine, University of Utah Health, Salt Lake City, UT; Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah Health, Salt Lake City, UT
| | - Kory J Lavine
- Division of Cardiology, Washington University School of Medicine, St Louis, MO
| | - Omar Wever-Pinzon
- Division of Cardiovascular Medicine, University of Utah Health, Salt Lake City, UT; Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah Health, Salt Lake City, UT
| | - Veli K Topkara
- Department of Medicine, Division of Cardiology, Columbia University College of Physicians and Surgeons, New York, NY
| | - Bart Meyns
- Department of Cardiology and Department of Cardiac Surgery, University Hospitals Leuven, Leuven, Belgium
| | - Iki Adachi
- Division of Cardiac Surgery, Texas Children's Hospital, Houston, TX
| | - Daniel Zimpfer
- Department of Surgery, Division of Cardiac Surgery, Medical University of Vienna, Vienna, Austria
| | | | - Daniel Burkhoff
- Department of Medicine, Division of Cardiology, Columbia University College of Physicians and Surgeons, New York, NY; Cardiovascular Research Foundation (CRF), New York, NY
| | - Stavros G Drakos
- Division of Cardiovascular Medicine, University of Utah Health, Salt Lake City, UT; Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah Health, Salt Lake City, UT.
| |
Collapse
|
3
|
Shen S, Sewanan LR, Campbell SG. Evidence for synergy between sarcomeres and fibroblasts in an in vitro model of myocardial reverse remodeling. J Mol Cell Cardiol 2021; 158:11-25. [PMID: 33992697 DOI: 10.1016/j.yjmcc.2021.05.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Revised: 05/07/2021] [Accepted: 05/10/2021] [Indexed: 12/22/2022]
Abstract
We have created a novel in-vitro platform to study reverse remodeling of engineered heart tissue (EHT) after mechanical unloading. EHTs were created by seeding decellularized porcine myocardial sections with a mixture of primary neonatal rat ventricular myocytes and cardiac fibroblasts. Each end of the ribbon-like constructs was fixed to a plastic clip, allowing the tissues to be statically stretched or slackened. Inelastic deformation was introduced by stretching tissues by 20% of their original length. EHTs were subsequently unloaded by returning tissues to their original, shorter length. Mechanical characterization of EHTs immediately after unloading and at subsequent time points confirmed the presence of a reverse-remodeling process, through which stress-free tissue length was increased after chronic stretch but gradually decreased back to its original value within 9 days. When a cardiac myosin inhibitor was applied to tissues after unloading, EHTs failed to completely recover their passive and active mechanical properties, suggesting a role for actomyosin contraction in reverse remodeling. Selectively inhibiting cardiomyocyte contraction or fibroblast activity after mechanical unloading showed that contractile activity of both cell types was required to achieve full remodeling. Similar tests with EHTs formed from human induced pluripotent stem cell-derived cardiomyocytes also showed reverse remodeling that was enhanced when treated with omecamtiv mecarbil, a myosin activator. These experiments suggest essential roles for active sarcomeric contraction and fibroblast activity in reverse remodeling of myocardium after mechanical unloading. Our findings provide a mechanistic rationale for designing potential therapies to encourage reverse remodeling in patient hearts.
Collapse
Affiliation(s)
- Shi Shen
- Department of Biomedical Engineering, Yale University, New Haven, CT, USA
| | - Lorenzo R Sewanan
- Department of Biomedical Engineering, Yale University, New Haven, CT, USA
| | - Stuart G Campbell
- Department of Biomedical Engineering, Yale University, New Haven, CT, USA; Department of Cellular and Molecular Physiology, Yale School of Medicine, New Haven, CT, USA.
| |
Collapse
|
4
|
Das BB, Moskowitz WB, Butler J. Current and Future Drug and Device Therapies for Pediatric Heart Failure Patients: Potential Lessons from Adult Trials. CHILDREN-BASEL 2021; 8:children8050322. [PMID: 33922085 PMCID: PMC8143500 DOI: 10.3390/children8050322] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/27/2021] [Revised: 04/19/2021] [Accepted: 04/20/2021] [Indexed: 12/11/2022]
Abstract
This review discusses the potential drug and device therapies for pediatric heart failure (HF) due to reduced systolic function. It is important to realize that most drugs that are used in pediatric HF are extrapolated from adult cardiology practices or consensus guidelines based on expert opinion rather than on evidence from controlled clinical trials. It is difficult to conclude whether the drugs that are well established in adult HF trials are also beneficial for children because of tremendous heterogeneity in the mechanism of HF in children and variations in the pharmacokinetics and pharmacodynamics of drugs from birth to adolescence. The lessons learned from adult trials can guide pediatric cardiologists to design clinical trials of the newer drugs that are in the pipeline to study their efficacy and safety in children with HF. This paper's focus is that the reader should specifically think through the pathophysiological mechanism of HF and the mode of action of drugs for the selection of appropriate pharmacotherapy. We review the drug and device trials in adults with HF to highlight the knowledge gap that exists in the pediatric HF population.
Collapse
Affiliation(s)
- Bibhuti B. Das
- Heart Center, Department of Pediatrics, Mississippi Children’s Hospital, University of Mississippi Medical Center, Jackson, MS 39212, USA;
- Correspondence: ; Tel.: +601-984-5250; Fax: +601-984-5283
| | - William B. Moskowitz
- Heart Center, Department of Pediatrics, Mississippi Children’s Hospital, University of Mississippi Medical Center, Jackson, MS 39212, USA;
| | - Javed Butler
- Department of Medicine, University of Mississippi Medical Center, Jackson, MS 39212, USA;
| |
Collapse
|
5
|
Haller C. Commentary: Patience is a virtue. JTCVS Tech 2021; 5:95-96. [PMID: 34318120 PMCID: PMC8299982 DOI: 10.1016/j.xjtc.2020.04.027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Revised: 04/21/2020] [Accepted: 04/22/2020] [Indexed: 11/05/2022] Open
Affiliation(s)
- Christoph Haller
- Department of Cardiovascular Surgery, The Labatt Family Heart Centre, The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
| |
Collapse
|
6
|
Javier Delmo EM, Javier MFDM, Böthig D, Rüffer A, Cesnjevar R, Dandel M, Hetzer R. Heart failure in the young: Insights into myocardial recovery with ventricular assist device support. Cardiovasc Diagn Ther 2021; 11:148-163. [PMID: 33708488 DOI: 10.21037/cdt-20-278] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Background Data on ventricular unloading-promoted myocardial recovery and post-weaning outcome in children is scarce. We analyzed the weaning outcome in children with heart failure (HF) supported with ventricular assist device (VAD). Methods A multi-institutional data on VAD implanted in 193 children and adolescents with HF between April 1990 and November 2015 was reviewed. Among them, 25 children (mean age 3.4±3.0, range, 0.058-16.3 years, 15 females) were weaned from VAD. Etiology of HF were myocarditis (n=11), dilated cardiomyopathy (DCMP) (n=7), ischemic HF (n=3), arrhythmogenic CMP (n=1), post-correction of congenital heart disease (CHD) (n=1) and acute graft failure (n=1). Mean duration of HF before VAD implantation was 59.4±3 days. Results Age, duration of HF, DCMP, cardiac arrest and duration of VAD are essential clinical characteristics to delineate who may have the potential to myocardial recovery. Echocardiographic parameters pre-implantation, during the final off-pump trial and during the post-explantation follow-ups revealed that LVEF, LVEDD and relative wall thickness (RWT) showed significant differences (P<0.001) among patients stratified by outcome to assess recovery. Presently, 21 (84.0%) of the weaned patients are alive with their native hearts 1.3-19.1 years after VAD explantation. An additional weaned patient had HF recurrence 3 months post-weaning and was transplanted. Conclusions Post-weaning myocardial recovery and cardiac stability of children with HF from several etiologies supported with a VAD appears sustainable and durable. Young patients with short HF duration are more likely to recover. Absence of cardiac arrest, cardiac size, geometry and function may prospectively identify patients who may be likely to have myocardial recovery.
Collapse
Affiliation(s)
| | | | - Dietmar Böthig
- Department of Cardiothoracic, Transplantation and Vascular Surgery, Hannover Medical School, Hannover, Germany
| | - Andre Rüffer
- Department of Pediatric Cardiology/Pediatric Cardiac Surgery, Universitäres Herzzentrum Hamburg GmbH, Hamburg, Germany
| | - Robert Cesnjevar
- Department of Cardiothoracic and Vascular Surgery, University Medical Center Erlangen, Erlangen, Germany
| | - Michael Dandel
- Department of Cardiology, Cardio Centrum Berlin, Berlin, Germany
| | - Roland Hetzer
- Department of Cardiothoracic and Vascular Surgery, Cardio Centrum Berlin, Berlin, Germany
| |
Collapse
|
7
|
Tominaga Y, Ueno T, Kido T, Kanaya T, Narita J, Ishida H, Toda K, Kuratani T, Sawa Y. Bridge to recovery with Berlin Heart EXCOR in children <10 kg with dilated cardiomyopathy: a histological analysis. Eur J Cardiothorac Surg 2020; 58:253-260. [DOI: 10.1093/ejcts/ezaa033] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/2019] [Revised: 01/07/2020] [Accepted: 01/09/2020] [Indexed: 11/13/2022] Open
Abstract
Abstract
OBJECTIVES
This study aimed to identify the histological characteristics associated with bridge to recovery using Berlin Heart EXCOR® (BHE) in paediatric patients <10 kg with dilated cardiomyopathy.
METHODS
Of the 10 consecutive patients <10 kg with dilated cardiomyopathy who underwent BHE implantation between 2013 and 2018, 4 patients showed improvement in left ventricular (LV) function, resulting in successful BHE explantation (recovery group). The remaining 6 patients showed persistent LV dysfunction and underwent heart transplantation (non-recovery group). The following variables were compared between the 2 groups: (i) histological findings in LV myocardium obtained at BHE implantation and (ii) LV function after BHE implantation assessed with echocardiography and cardiac catheterization.
RESULTS
The degree of myocardial fibrosis was significantly lower, and the capillary vascular density was significantly higher in the recovery group than in the non-recovery group [16% (standard deviation 5.9%) vs 28% (5.9%), P = 0.021, and 65 (11) vs 43 (18) units/high-power field, P = 0.037, respectively]. The changes during 3 months after BHE implantation in LV diastolic dimension (z-score) and ejection fraction were significantly greater in the recovery group than in the non-recovery group [−9.6 (3.5) vs −3.6 (4.5), P = 0.045, and 36% (13%) vs 13% (13%), P = 0.032, respectively].
CONCLUSIONS
In paediatric patients <10 kg with dilated cardiomyopathy, bridge to recovery with BHE implantation was achieved in patients with less injured LV myocardial histology at BHE implantation.
Collapse
Affiliation(s)
- Yuji Tominaga
- Department of Cardiovascular Surgery, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
| | - Takayoshi Ueno
- Department of Cardiovascular Surgery, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
| | - Takashi Kido
- Department of Cardiovascular Surgery, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
| | - Tomomitsu Kanaya
- Department of Cardiovascular Surgery, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
| | - Jun Narita
- Department of Pediatrics, Pediatric Cardiology, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
| | - Hidekazu Ishida
- Department of Pediatrics, Pediatric Cardiology, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
| | - Koichi Toda
- Department of Cardiovascular Surgery, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
| | - Toru Kuratani
- Department of Cardiovascular Surgery, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
| | - Yoshiki Sawa
- Department of Cardiovascular Surgery, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
| |
Collapse
|
8
|
Escamilla D, Dayan J, Butani L. Complete resolution of severe dilated cardiomyopathy in a pediatric hemodialysis patient being considered for a combined heart-kidney transplant. Clin Transplant 2018; 32:e13379. [PMID: 30146781 DOI: 10.1111/ctr.13379] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Daniel Escamilla
- Department of Pediatrics, University of California Davis Medical Center, Sacramento, California
| | - Jonathan Dayan
- Department of Pediatrics, University of California Davis Medical Center, Sacramento, California
| | - Lavjay Butani
- Department of Pediatrics, University of California Davis Medical Center, Sacramento, California
| |
Collapse
|
9
|
Miera O, Germann M, Cho MY, Photiadis J, Delmo Walter EM, Hetzer R, Berger F, Schmitt KRL. Bridge to recovery in children on ventricular assist devices-protocol, predictors of recovery, and long-term follow-up. J Heart Lung Transplant 2018; 37:1459-1466. [PMID: 30292432 DOI: 10.1016/j.healun.2018.08.005] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2018] [Revised: 08/03/2018] [Accepted: 08/04/2018] [Indexed: 11/24/2022] Open
Abstract
BACKGROUND The majority of children supported with ventricular assist devices (VADs) are bridged to heart transplantation. Although bridge to recovery has been reported, low recovery patient numbers has precluded systematic analysis. The aim of this study was to delineate recovery rates and predictors of recovery and to report on long-term follow-up after VAD explantation in children. METHODS Children bridged to recovery at our institution from January 1990 to May 2016 were compared with a non-recovery cohort. Clinical and echocardiographic data before and at pump stoppages and after VAD explantation were analyzed. Kaplan‒Meier estimates of event-free survival, defined as freedom from death or transplantation after VAD removal, were determined. RESULTS One hundred forty-nine children (median age 5.8 years) were identified. Of these, 65.2% had cardiomyopathy, 9.4% had myocarditis, and 24.8% had congenital heart disease. The overall recovery rate was 14.2%, and was 7.1% in patients with dilated cardiomyopathy. Predictors of recovery were age <2 years (recovery rate 27.8%, odds ratio [OR] 5.64, 95% confidence interval [CI] 2.0 to 16.6) and diagnosis of myocarditis (rate 57.1%; OR 17.56, 95% CI 4.6 to 67.4). After a median follow-up of 10.8 years, 15 patients (83.3%) were in Functional Class I and 3 (16.7%) in were in Class II. Mean left ventricular ejection fraction was 53% (range 28% to 64%). Ten- and 15-year event-free survival rates were both 84.1 ± 8.4%. CONCLUSIONS Children <2 years of age and those diagnosed with myocarditis have the highest probability of recovery. Long-term survival after weaning from the VAD was better than after heart transplantation, as demonstrated in the excellent long-term stability of ejection fraction and functional class.
Collapse
Affiliation(s)
- Oliver Miera
- Department of Congenital Heart Disease/Pediatric Cardiology, Deutsches Herzzentrum Berlin, Berlin, Germany.
| | - Matthias Germann
- Department of Congenital Heart Disease/Pediatric Cardiology, Deutsches Herzzentrum Berlin, Berlin, Germany
| | - My Y Cho
- Department of Surgery for Congenital Heart Disease/Pediatric Cardiac Surgery, Deutsches Herzzentrum Berlin, Berlin, Germany
| | - Joachim Photiadis
- Department of Surgery for Congenital Heart Disease/Pediatric Cardiac Surgery, Deutsches Herzzentrum Berlin, Berlin, Germany
| | - Eva M Delmo Walter
- Department of Cardiothoracic, Transplantation and Vascular Surgery/Pediatric and Congenital Heart Disease Surgery, Hannover Medical School, Hannover, Germany; Cardio Centrum Berlin, Berlin, Germany
| | | | - Felix Berger
- Department of Congenital Heart Disease/Pediatric Cardiology, Deutsches Herzzentrum Berlin, Berlin, Germany; German Centre for Cardiovascular Research, Partner Site Berlin, Berlin, Germany; Charité‒Universitätsmedizin Berlin, Berlin, Germany
| | - Katharina R L Schmitt
- Department of Congenital Heart Disease/Pediatric Cardiology, Deutsches Herzzentrum Berlin, Berlin, Germany; German Centre for Cardiovascular Research, Partner Site Berlin, Berlin, Germany
| |
Collapse
|
10
|
Restoration of a denser myocardial capillary network after mechanical unloading of failing hearts in children with dilated cardiomyopathy. J Heart Lung Transplant 2017; 37:175-176. [PMID: 29055601 DOI: 10.1016/j.healun.2017.09.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2017] [Revised: 09/22/2017] [Accepted: 09/26/2017] [Indexed: 11/21/2022] Open
|