Aphrodite Tzifa

Replacement therapy for iron deficiency improves exercise capacity and quality of life in patients with cyanotic congenital heart disease and/or the Eisenmenger syndrome

INTRODUCTION Iron deficiency is common in cyanotic congenital heart disease (CHD) and results in reduced exercise tolerance. Currently, iron replacement is advocated with limited evidence in cyanotic CHD. We investigated the safety and efficacy of iron replacement therapy in this population. METHODS Twenty-five iron-deficient cyanotic CHD patients were prospectively studied between August 2008 and January 2009. Oral ferrous fumarate was titrated to a maximum dose of 200mg thrice-daily. The CAMPHOR QoL questionnaire, 6 minute walk test (6MWT) and cardiopulmonary exercise testing were conducted at baseline and after 3 months of treatment. RESULTS Mean age was 39.9 ± 10.9 years, 80% females. Fourteen had Eisenmenger syndrome, 6 complex cyanotic disease and 5 Fontan circulation. There were no adverse effects necessitating termination of treatment. After 3 months of treatment, hemoglobin (19.0 ± 2.9 g/dL to 20.4 ± 2.7 g/dL, p<0.001), ferritin (13.3 ± 4.7 μg/L to 54.1 ± 24.2 μg/L, p<0.001) and transferrin saturation (17.8 ± 9.6% to 34.8 ± 23.4%, p<0.001) significantly increased. Significant improvements were also detected in the total CAMPHOR score (20.7 ± 10.9 to 16.2 ± 10.4, p=0.001) and 6MWT distance (371.7 ± 84.7 m to 402.8.0±74.9m, p=0.001). Peak VO(2) remained unchanged (40.7 ± 9.2% to 43.8 ± 12.4% of predicted, p=0.15). CONCLUSION Three months of iron replacement therapy in iron-deficient cyanotic CHD patients was safe and resulted in significant improvement in exercise tolerance and quality of life. Identification of iron deficiency and appropriate replacement should be advocated in these patients.

Magnetic Resonance–Guided Cardiac Interventions Using Magnetic Resonance–Compatible Devices: A Preclinical Study and First-in-Man Congenital Interventions

Background— Percutaneous cardiac interventions are currently performed under x-ray guidance. Magnetic resonance imaging (MRI) has been used to guide intravascular interventions in the past, but mainly in animals. Translation of MR-guided interventions into humans has been limited by the lack of MR-compatible and safe equipment, such as MR guide wires with mechanical characteristics similar to standard guide wires. The aim of the present study was to evaluate the safety and efficacy of a newly developed MR-safe and compatible passive guide wire in aiding MR-guided cardiac interventions in a swine model and describe the 2 first-in-man solely MR-guided interventions. Methods and Results— In the preclinical trial, the new MR-compatible wire aided the performance of 20 interventions in 5 swine. These consisted of balloon dilation of nondiseased pulmonary and aortic valves, aortic arch, and branch pulmonary arteries. After ethics and regulatory authority approval, the 2 first-in-man MR-guided interventions were performed in a child and an adult, both with elements of valvar pulmonary stenosis. Catheter manipulations were monitored with real-time MRI sequence with interactive modification of imaging plane and slice position. Temporal resolution was 11 to 12 frames/s. Catheterization procedure times were 110 and 80 minutes, respectively. Both patients had successful relief of the valvar stenosis and no procedural complications. Conclusions— The described preclinical study and case reports are encouraging that with the availability of the new MR-compatible and safe guide wire, certain percutaneous cardiac interventions will become feasible to perform solely under MR guidance in the future. A clinical trial is underway in our institution.Background—Percutaneous cardiac interventions are currently performed under x-ray guidance. Magnetic resonance imaging (MRI) has been used to guide intravascular interventions in the past, but mainly in animals. Translation of MR-guided interventions into humans has been limited by the lack of MR-compatible and safe equipment, such as MR guide wires with mechanical characteristics similar to standard guide wires. The aim of the present study was to evaluate the safety and efficacy of a newly developed MR-safe and compatible passive guide wire in aiding MR-guided cardiac interventions in a swine model and describe the 2 first-in-man solely MR-guided interventions. Methods and Results—In the preclinical trial, the new MR-compatible wire aided the performance of 20 interventions in 5 swine. These consisted of balloon dilation of nondiseased pulmonary and aortic valves, aortic arch, and branch pulmonary arteries. After ethics and regulatory authority approval, the 2 first-in-man MR-guided interventions were performed in a child and an adult, both with elements of valvar pulmonary stenosis. Catheter manipulations were monitored with real-time MRI sequence with interactive modification of imaging plane and slice position. Temporal resolution was 11 to 12 frames/s. Catheterization procedure times were 110 and 80 minutes, respectively. Both patients had successful relief of the valvar stenosis and no procedural complications. Conclusions—The described preclinical study and case reports are encouraging that with the availability of the new MR-compatible and safe guide wire, certain percutaneous cardiac interventions will become feasible to perform solely under MR guidance in the future. A clinical trial is underway in our institution.

Magnetic Resonance–Guided Cardiac Interventions Using Magnetic Resonance–Compatible DevicesClinical Perspective

Background— Percutaneous cardiac interventions are currently performed under x-ray guidance. Magnetic resonance imaging (MRI) has been used to guide intravascular interventions in the past, but mainly in animals. Translation of MR-guided interventions into humans has been limited by the lack of MR-compatible and safe equipment, such as MR guide wires with mechanical characteristics similar to standard guide wires. The aim of the present study was to evaluate the safety and efficacy of a newly developed MR-safe and compatible passive guide wire in aiding MR-guided cardiac interventions in a swine model and describe the 2 first-in-man solely MR-guided interventions. Methods and Results— In the preclinical trial, the new MR-compatible wire aided the performance of 20 interventions in 5 swine. These consisted of balloon dilation of nondiseased pulmonary and aortic valves, aortic arch, and branch pulmonary arteries. After ethics and regulatory authority approval, the 2 first-in-man MR-guided interventions were performed in a child and an adult, both with elements of valvar pulmonary stenosis. Catheter manipulations were monitored with real-time MRI sequence with interactive modification of imaging plane and slice position. Temporal resolution was 11 to 12 frames/s. Catheterization procedure times were 110 and 80 minutes, respectively. Both patients had successful relief of the valvar stenosis and no procedural complications. Conclusions— The described preclinical study and case reports are encouraging that with the availability of the new MR-compatible and safe guide wire, certain percutaneous cardiac interventions will become feasible to perform solely under MR guidance in the future. A clinical trial is underway in our institution.Background—Percutaneous cardiac interventions are currently performed under x-ray guidance. Magnetic resonance imaging (MRI) has been used to guide intravascular interventions in the past, but mainly in animals. Translation of MR-guided interventions into humans has been limited by the lack of MR-compatible and safe equipment, such as MR guide wires with mechanical characteristics similar to standard guide wires. The aim of the present study was to evaluate the safety and efficacy of a newly developed MR-safe and compatible passive guide wire in aiding MR-guided cardiac interventions in a swine model and describe the 2 first-in-man solely MR-guided interventions. Methods and Results—In the preclinical trial, the new MR-compatible wire aided the performance of 20 interventions in 5 swine. These consisted of balloon dilation of nondiseased pulmonary and aortic valves, aortic arch, and branch pulmonary arteries. After ethics and regulatory authority approval, the 2 first-in-man MR-guided interventions were performed in a child and an adult, both with elements of valvar pulmonary stenosis. Catheter manipulations were monitored with real-time MRI sequence with interactive modification of imaging plane and slice position. Temporal resolution was 11 to 12 frames/s. Catheterization procedure times were 110 and 80 minutes, respectively. Both patients had successful relief of the valvar stenosis and no procedural complications. Conclusions—The described preclinical study and case reports are encouraging that with the availability of the new MR-compatible and safe guide wire, certain percutaneous cardiac interventions will become feasible to perform solely under MR guidance in the future. A clinical trial is underway in our institution.

In situ endothelialization of intravascular stents from progenitor stem cells coated with nanocomposite and functionalized biomolecules

Owing to their noninvasive nature, coronary artery stents have become popular demand for patients undergoing percutaneous coronary intervention. Late restenosis, in‐stent restenosis, and late thrombosis, all mediated by the denuded endothelium, represent the most recurrent failures of vascular stent induction. Higher patency rates of stents can be achieved by restoring the native internal environment of the vessel—an endothelium monolayer. This active organ inhibits the inflammatory reaction to injury responsible for thrombus and intimal hyperplasia, thereby providing a novel therapeutic option to combat the unacceptably high prevalence of restenosis. As the climax of the nanotechnology era approaches, tissue engineering is being explored by means of exploiting the multipotent abilities of stem cells and their adherence to bioactive surface nanocomposite polymers. The endothelium can be reconstructed from neighboring intact endothelium and adherence of circulating endothelium progenitor cells. The latter takes place via a series of signaling events: mobilization, adhesion, chemoattraction, migration, proliferation, and finally their differentiation in mature endothelial cells. A nanotopography surface can orchestrate endothelium formation, attributable to cellular interactions promoted by its nanosize. This review encompasses the prospect of in situ endothelialization, the mechanisms regulating the process, and the advantages of using a new generation of bioactive nanocomposite materials for coating metal stent scaffolds.

Test occlusion of Fontan fenestration: unique contribution of interventional MRI

A 24-year old lady with fenestrated Fontan circulation was referred for a combined cardiac MRI and catheterisation procedure to assess her anatomy and suitability for fenestration closure. The patient was considering pregnancy; however, due to low saturations of 83%, successful pregnancy was unlikely. Under interactive screening, the balloon of a wedge catheter was inflated in the lateral tunnel to render it visible as a dark spot in the bright surrounding blood. …

MR Imaging-Guided Cardiovascular Interventions in Young Children

Diagnostic cardiac catheterization procedures in children have been largely replaced by magnetic resonance (MR) imaging studies. However, when invasive catheterization is required, MR imaging has a significant role to play, when combined with invasive pressure measurements. Beyond the established reduction to the radiation dose involved, solely MR image-guided or MR image-assisted catheterization procedures can accurately address clinical questions, such as estimation of pulmonary vascular resistance and cardiac output response to stress, without needing to perform laborious measurements that are prone to errors. This article describes MR image-guided or MR image-assisted cardiac catheterization procedures for diagnosis and intervention in children.

Magnetic resonance imaging catheter stress haemodynamics post-Fontan in hypoplastic left heart syndrome

AIMS Exercise limitation is common post-Fontan. Hybrid X-ray and magnetic resonance imaging (XMR) catheterization allows haemodynamic assessment by means of measurement of ventricular volumes and flow in major vessels with simultaneous invasive pressures. We aim to assess haemodynamic response to stress in patients with hypoplastic left heart syndrome (HLHS) post-Fontan. METHODS AND RESULTS Prospective study of 13 symptomatic children (NHYA 2) with HLHS post-Fontan using XMR catheterization. Three conditions were applied: baseline (Stage 1), dobutamine at 10 µg/kg/min (Stage 2), and dobutamine at 20 µg/kg/min (Stage 3). Seven consecutive patients received inhaled nitric oxide (iNO) at peak stress. Control MRI data were from normal healthy adults. In the HLHS patients, baseline mean pulmonary vascular resistance (PVR) was 1.51 ± 0.59 WU m(2) and aortopulmonary collateral flow was 17.7 ± 13.6% of systemic cardiac output. Mean right ventricular end-diastolic pressure was 6.7 ± 2.5 mmHg which did not rise with stress. Cardiac index (CI) increased at Stage 2 in HLHS (40%) and controls (61%) but continued to increase at Stage 3 only in controls (19%) but not in HLHS. The blunted rise in CI in HLHS was due to a continuing fall in end-diastolic volume throughout stress, with no significant change in PVR or CI at peak stress in response to iNO. CONCLUSION Cardiac output post-Fontan in HLHS at peak stress is blunted due to a limitation in preload which is not responsive to inhaled pulmonary vasodilators in the setting of normal PVR.

Cardiovascular MR dobutamine stress in adult tetralogy of Fallot: disparity between CMR volumetry and flow for cardiovascular function.

To evaluate the MR agreement of cardiac function parameters between volumetric (cine SSFP) and phase contrast flow (PC‐flow) assessment in patients with repaired tetralogy of Fallot (r‐TOF) and chronic pulmonary regurgitation (PR) at rest and under dobutamine stress (DS‐MR).

Transcatheter atrial septal defect closure guided by colour flow Doppler

OBJECTIVES To describe and assess the use of the maximum colour flow diameter (CFDmax) in guiding transcatheter closure of atrial septal defects (ASDs) and compare it with the standard balloon sizing method. BACKGROUND Balloon sizing of ASDs has been the standard method of assessing the size of ASDs and selecting a closure device. However, overestimation of the defect by stretching it may result in complications such as erosion of the atrial wall or aortic root, particularly in the presence of a deficient aortic rim and the long-term effects of oversized defects are unknown. METHODS Retrospective and prospective assessment of 115 consecutive patients who underwent ASD closure during three different time periods, when change in local practice occurred. Fifty patients underwent ASD closure with balloon sizing (period A), 15 with the aid of balloon sizing and additional estimation of the CFDmax (period B) and 50 with sole assessment of the CFDmax (period C). RESULTS The mean difference between the device used and the 2D defect size decreased from 6.9 to 5.1mm (p<0.01) and the percentage of device oversizing decreased from 38% to 31%. The complication rate decreased from 14% to 2%, (p=0.03), whilst the procedure and screening times decreased from 70 to 43min, (p<0.001) and 14.2 to 8.4min, (p<0.001), respectively. CONCLUSIONS Transcatheter closure of ASDs guided solely by the CFDmax is feasible and safe and results in decreased procedure and screening times, whilst maintaining a low complication rate.

Predicting hemodynamics in native and residual coarctation: preliminary results of a Rigid-Wall Computational-Fluid-Dynamics model (RW-CFD) validated against clinically invasive pressure measures at rest and during pharmacological stress

Current clinical assessment of borderline aortic coarctation may involve cardiovascular magnetic resonance(CMR) but if inconclusive, invasive catheterization pressure measurements are required to evaluate the pressure gradient at rest and during pharmacological stress(isoprenaline).