Shihua Zhao

Transcatheter closure of patent ductus arteriosus with severe pulmonary arterial hypertension in adults

Background: Surgical closure of patent ductus arteriosus (PDA) with severe pulmonary arterial hypertension in adults carries higher risk than in children. Objectives: To investigate the application of self-expandable occluders for transcatheter closure of PDA associated with severe pulmonary arterial hypertension in adults, and the assessment of immediate and short-term results. Methods: 29 adult patients (6 men, 23 women) underwent attempted transcatheter closure of PDA at a mean (standard deviation (SD)) age of 31.1 (11.4) years (range 18–58 years) and a mean (SD) weight of 54.1 (7.1) kg (range 42–71 kg). On the basis of haemodynamic and clinical data obtained before and after trial occlusion, the final duct occlusion was determined and carried out. Radiographs of the chest, electrocardiograms and echocardiograms were used for follow-up evaluation of the treatment within 1 day, 1 month and 3–6 months after successful closure. Results: 20 of the 29 patients had successful occlusion (group 1), and 9 patients failed (named group 2). In group 1, in which occlusion was successful, mean (SD) pulmonary arterial pressures decreased markedly after trial occlusion: 78 (19.3) mm Hg (range 50–125 mm Hg) before occlusion and 41 (13.8) mm Hg (range 23–77 mm Hg) after occlusion. Systemic arterial oxygen saturation was found to be >90% in 19 patients and <90% in the remaining patient before inhalation of oxygen, and >95% during inhalation of oxygen or after occlusion in all 20 patients. In group 2, the occlusion was not successful, because in two patients the device was not available; another two patients showed worsening of symptoms. The other five patients showed increased pulmonary arterial pressures after trial closure; their mean (SD) pulmonary arterial pressures increased by 10.3 (6) mm Hg (4–16 mm Hg) after trial occlusion, and systemic arterial oxygen saturation was 85.5% (2.6%) (range 82.6–88%) before inhalation of oxygen and 94.7% (1.7%) (range 90.7–99.1%) during inhalation of oxygen. In group 1, the dimensions of the left atrium, left ventricle and pulmonary artery increased considerably in 3–6-months of follow-up compared with those of preocclusion. Conclusions: Transcatheter closure is an effective treatment for adults with PDA associated with reversible severe pulmonary arterial hypertension. Further research is needed for the evaluation of long-term results.

The relative atrial volume ratio and late gadolinium enhancement provide additive information to differentiate constrictive pericarditis from restrictive cardiomyopathy

BackgroundThe differentiation of constrictive pericarditis (CP) from restrictive cariomyopathy (RCM) is often difficult. This study sought to determine the clinical utility of cardiovascular magnetic resonance imaging (CMR) for differentiating both these disorders.MethodsTwenty-three patients with surgically documented CP, 22 patients with RCM and 25 normal subjects were included in the study. CMR yielded information about cardiac morphology, function and tissue characteristics. The left (LA) and right atrial (RA) volume was calculated using the area-length method. The relative atrial volume ratio (RAR) was defined as the LA volume divided by RA volume. Receiver operating characteristic curve analysis was used to test the ability of different variables in differentiating CP from RCM.ResultsThe maximal pericardial thickness in CP patients was significantly larger than in normal subjects and RCM patients. The RA volume index in RCM patients (90.5 ± 35.3 mL/m2) was significantly larger than in CP patients (71.4 ± 15.7 mL/m2, p = 0.006) and normal subjects (38.1 ± 9.0 mL/m2, p < 0.001). The LA volume index in RCM (96.0 ± 37.0 mL/m2) and CP patients (105.6 ± 25.1 mL/m2) was significantly larger than in normal subjects (39.5 ± 9.5 mL/m2, p < 0.001 for all). The RAR in CP patients (1.50 ± 0.29) was significantly larger than in RCM patients (1.12 ± 0.33, p < 0.001) and normal subjects (1.06 ± 0.20, p < 0.001). There were no differences between RCM patients and normal subjects in the RAR (p = 0.452). At a cut-off value of 1.32 for the RAR, the sensitivity was 82.6%, and the specificity was 86.4% in the detection of CP. Septal bounce was identified in 95.7% CP patients, in none of RCM patients and normal subjects. Late gadolinium enhancement (LGE) was present in 31.8% RCM patients and absence in all CP patients and normal subjects.ConclusionsCMR with LGE and RAR can facilitate differentiation of CP from RCM.

Varied distributions of late gadolinium enhancement found among patients meeting cardiovascular magnetic resonance criteria for isolated left ventricular non-compaction

BackgroundLate gadolinium enhancement (LGE) is identified frequently in LVNC. However, the features of this findings are limited. The purpose of the present study was to describe the frequency and distribution of LGE in patients meeting criteria for left ventricular non-compaction (LVNC), as assessed by cardiovascular magnetic resonance (CMR).MethodsForty-seven patients (37 males and 10 females; mean age, 39 ± 18 years) considered to meet standard CMR criteria for LVNC were studied. The LGE images were obtained 15 ± 5 min after the injection of 0.2 mmol/kg of gadolinium-DTPA using an inversion-recovery sequence, and analyzed using a 17-segment model.ResultsMean number of non-compacted segments per patient was 7.4 ± 2.5 and the NC:C was 3.2 ± 0.7. Non-compaction was most commonly noted in the apical segments in all patients. LGE was present in 19 of the 47 patients (40%), and most often located in the ventricular septum. The distribution of LGE was subendocardial (n = 5; 6%), mid-myocardial (n = 61; 68%), subepicardial (n = 10; 11%), and transmural (n = 14; 15%) in total of 90 LGE (+) segments.ConclusionsIn patients considered to meet criteria for LVNC, LGE distributions visible were strikingly heterogeneous with appearances potentially attributable to three or more distinct cardiomyopathic processes. This may be in keeping with previous suggestions that the criteria may be of low specificity. Further work is needed to determine whether conditions such as dilated cardiomyopathy, previous myocardidtis or ischaemic heart disease increase the apparent depth of non-compact relative to compact myocardium.

A pilot trial of autologous bone marrow mononuclear cell transplantation through grafting artery: A sub-study focused on segmental left ventricular function recovery and scar reduction

BACKGROUND Our preliminary study suggested that patients with chronic myocardial infarction (MI) and heart failure could potentially benefit from CABG combined with aBM-MNC by improving global left ventricular (LV) function. The purpose of this sub-study was to quantitatively evaluate the effectiveness of aBM-MNC transplantation during CABG in patients with chronic MI by intensively analyzing the global and segmental LV function, the scar, and the relationships between the function recovery and the scar transmural extent. METHODS A randomized, double-blinded, placebo-controlled study was performed in 50 patients with chronic MI. The patients were randomly allocated into CABG with stem cell transplantation (group A) and CABG only (group B) groups. CMR assessments of global and segmental left ventricular function and scar tissue were performed before surgery and repeated at 12 months after CABG and aBM-MNC transplantation. RESULTS The left ventricular ejection fraction (LVEF) improved by 13.5% and 8.0% in group A and B respectively (P=0.04). Segmental analysis of regional LV function recovery indicated that more improvement in contractility was found in group A within the same degree of the infarct transmurality (P=0.017) and showed a predominant interaction in the most severely affected segments (76-100%, P=0.016). Decrease in infarct size between the two groups did not reach statistical difference (9.4% vs. 6.0%, P=0.100). CONCLUSIONS CMR assessments revealed reversed ventricular remodeling and improved systolic function and scar reduction in patients who underwent aBM-MNC transplantation during CABG. And the conjunctional use of CABG and stem cell therapy could improve the left ventricular function in patients with chronic MI.

Evaluation of Left and Right Ventricular Ejection Fraction and Volumes from Gated Blood-Pool SPECT in Patients with Dilated Cardiomyopathy: Comparison with Cardiac MRI

This prospective study evaluated the accuracy of electrocardiogram-gated blood-pool SPECT (GBPS) for the assessment of left ventricular (LV) and right ventricular (RV) ejection fraction (EF), end-diastolic volume (EDV), and end-systolic volume (ESV) in patients with dilated cardiomyopathy (DCM), using cardiac magnetic resonance (CMR) imaging as the reference standard. Methods: Thirty-two patients (24 men and 8 women; mean age, 51 y) with a diagnosis of idiopathic DCM underwent GBPS and CMR. LV and RV parameters including EDV, ESV, and EF from GBPS were calculated using fully automated gradient software and compared with those obtained by CMR. Results: Biventricular volumes were underestimated by GBPS, compared with CMR (P < 0.001). We found no statistical difference between these 2 methods in the assessment of LV EF (P = 0.23), whereas RV EF was overestimated by GBPS (P < 0.001 vs. CMR). Regression analysis yielded significant correlations between GBPS and CMR in the assessments of biventricular parameters (r = 0.83 for LV EDV, 0.88 for LV ESV, 0.89 for LV EF, 0.86 for RV EDV, 0.86 for RV ESV, and 0.62 for RV EF; all P < 0.001). Comparison of the deviations of RV indices between GBPS and CMR with the ratio of RV EDV to LV EDV showed that there was a statistically significant trend for RV volumes to be underestimated and for RV EF to be overestimated as the biventricular volumetric ratio decreased (r = 0.61 for RV EDV, 0.68 for RV ESV, and −0.55 for RV EF; all P < 0.001). Conclusion: For patients with DCM, GBPS correlated well with CMR for the assessment of biventricular parameters, but RV indices should be cautiously interpreted.

Magnetic Resonance Imaging with Superparamagnetic Iron Oxide Fails to Track the Long-term Fate of Mesenchymal Stem Cells Transplanted into Heart

MRI for in vivo stem cell tracking remains controversial. Here we tested the hypothesis that MRI can track the long-term fate of the superparamagnetic iron oxide (SPIO) nanoparticles labelled mesenchymal stem cells (MSCs) following intramyocardially injection in AMI rats. MSCs (1 × 106) from male rats doubly labeled with SPIO and DAPI were injected 2 weeks after myocardial infarction. The control group received cell-free media injection. In vivo serial MRI was performed at 24 hours before cell delivery (baseline), 3 days, 1, 2, and 4 weeks after cell delivery, respectively. Serial follow-up MRI demonstrated large persistent intramyocardial signal-voids representing SPIO during the follow-up of 4 weeks, and MSCs did not moderate the left ventricular dysfunction. The TUNEL analysis confirmed that MSCs engrafted underwent apoptosis. The histopathological studies revealed that the site of cell injection was infiltrated by inflammatory cells progressively and the iron-positive cells were macrophages identified by CD68 staining, but very few or no DAPI-positive stem cells at 4 weeks after cells transplantation. The presence of engrafted cells was confirmed by real-time PCR, which showed that the amount of Y-chromosome-specific SRY gene was consistent with the results. MRI may not reliably track the long-term fate of SPIO-labeled MSCs engraftment in heart.

Fat Deposition in Dilated Cardiomyopathy Assessed by CMR

OBJECTIVES The aim of this study was to prospectively investigate the prevalence of fat deposition in idiopathic dilated cardiomyopathy (DCM) by fat-water separation imaging. An auxiliary aim was to determine the relationship between left ventricular (LV) fat deposition and characteristic myocardial fibrosis, as well as cardiac functional parameters. BACKGROUND Idiopathic DCM remains the most common cause of heart failure in young people referred for cardiac transplantation; little is known about the clinical value of fat deposition in DCM. METHODS A total of 124 patients with DCM were studied after written informed consent was obtained. The magnetic resonance imaging scan protocols included a series of short-axis LV cine imaging for functional analysis, fat-water separation imaging, and late gadolinium enhancement (LGE) imaging. Fat deposition and fibrosis location were compared to the scar regions on LGE images using a 17-segment model. Statistical comparisons of LV global functional parameters, fibrosis volumes, and fat deposition were carried out using the Pearson correlation, Student t test, and multiple regressions. RESULTS The patients had a 41.9% (52 of 124) prevalence of positive LGE, and 12.9% (16 of 124) fat deposition prevalence was found in this DCM cohort. The patients with fat deposition had larger LV end-diastolic volume (LVEDV) index (140.8 ± 20.2 ml/m(2) vs. 123.4 ± 15.8 ml/m(2); p < 0.01), larger LV end-systolic volume (LVESV) index (111.3 ± 19.2 ml/m(2) vs. 87.0 ± 20.3 ml/m(2); p < 0.01), and decreased LV ejection fraction (LVEF) (21.1 ± 7.1% vs. 30.0 ± 10.7%; p < 0.01). Higher volumes of LGE were found in the group with myocardial fat deposition (18.39 ± 9.0 ml vs. 13.40 ± 6.54 ml; p = 0.001), as well as a higher percentage of LGE/LV mass (19.11 ± 7.78% vs. 13.60 ± 4.58%; p = 0.000). The volume of fat deposition was correlated with scar volume, LVEF, LVEDV index, and LVESV index. CONCLUSIONS Fat deposition is a common phenomenon in DCM, and it is associated with DCM characteristics such as fibrosis volume and LV function.

Comparison of 99mTc-MIBI SPECT/18F-FDG PET Imaging and Cardiac Magnetic Resonance Imaging in Patients With Idiopathic Dilated Cardiomyopathy: Assessment of Cardiac Function and Myocardial Injury.

Objective The aim of this study is to evaluate the agreement between myocardial 18F-FDG PET imaging and cardiac magnetic resonance imaging (cMRI) in assessing cardiac function and relationship of cMRI late gadolinium enhancement (cMRI-LGE) and myocardial perfusion/metabolism pattern in patients with idiopathic dilated cardiomyopathy (IDCM). Methods Forty-two consecutive patients diagnosed with IDCM were enrolled. All patients underwent 99mTc-MIBI SPECT, gated 18F-FDG PET imaging, and cMRI within 3–7 days. Cardiac function parameters were calculated using PET and cMRI. The segments analysis was performed using a 17-segment model. Patterns of perfusion/metabolism were classified as normal, mismatch, mild-to-moderate match, and severe match, and cMRI-LGE was classified into 3 categories (non-LGE, mid-wall LGE, and transmural LGE). Results The correlation between gated PET and cMRI was excellent for end-diastolic volume (EDV; r = 0.948, P < 0.001), end-systolic volume (ESV; r = 0.939, P < 0.001), and left ventricular ejection fraction (LVEF; r = 0.685, P < 0.001). EDV and ESV were underestimated, whereas LVEF was slightly overestimated by gated PET in comparison to cMRI. Perfusion/metabolism patterns varied in 3 different categories of non-LGE, mid-wall LGE, and transmural LGE (&khgr;2 = 14.276, P < 0.001). Also, 71.0% (44/62) segments with mid-wall LGE had normal perfusion/metabolism patterns, and 75.9% (63/83) perfusion/metabolism mismatch segments were shown as non-LGE. The incidence of LGE was significantly higher in segments with severe match than the other 3 segment groups (&khgr;2 = 112.53, P < 0.001). Conclusion There is an excellent agreement between gated PET and cMRI in assessment of cardiac function. LGE-cMRI is much more sensitive in detecting moderate fibrosis, while PET could detect more impaired but viable myocardium. Combining the 2 imaging modalities is useful for providing more comprehensive evaluations of myocardial injury in patients with IDCM.

Comparison of cardiac magnetic resonance imaging features of isolated left ventricular non-compaction in adults versus dilated cardiomyopathy in adults

AIM To compare cardiac magnetic resonance imaging (MRI) features between isolated left ventricular non-compaction (IVNC) and dilated cardiomyopathy (DCM) in adults. MATERIALS AND METHODS A consecutive series of 50 patients with IVNC from a single institution were reviewed. During the same period, 50 patients with DCM who had prominent trabeculations, who were matched for age, gender, and body surface area, were prospectively included. Left ventricular (LV) morphology and function were assessed using cardiac MRI. RESULTS Compared with patients with DCM, patients with IVNC had a significantly lower LV sphericity index and end-diastolic volume index (LVEDVI) and a greater LV ejection fraction (LVEF), number of trabeculated segments, and ratio of non-compacted to compacted myocardium (NC/C ratio). There were no significant differences in stroke volume index, cardiac output, and cardiac index between the two patient groups. In patients with IVNC, the number of trabeculated segments and the NC/C ratio correlated positively with LVEDVI (r=0.626 and r=0.559, respectively) and negatively with LVEF (r=-0.647 and r=-0.521, respectively, p<0.001 for all). In patients with DCM, the number of non-compacted segments and the NC/C ratio had no correlation with either the LVEDVI (r=-0.082 and r=-0.135, respectively) or the LVEF (r=0.097 and r=0.205, respectively). CONCLUSION There are demonstrable morphological and functional differences between IVNC and DCM at LV assessment using cardiac MRI. The occurrence of trabeculated myocardium might be due to a different pathophysiological mechanism.

Assessment of left ventricular myocardial scar in coronary artery disease by a three-dimensional MR imaging technique

To evaluate the feasibility of free‐breathing three‐dimensional (3D) phase sensitive inversion recovery (PSIR) Turbo FLASH late gadolinium enhancement (LGE) magnetic resonance images (MRI) on left ventricular scar in patients with coronary artery disease (CAD) compared with clinically established breathhold two‐dimensional (2D) PSIR Turbo FLASH images.