Cardiac MRI-derived Myocardial Fibrosis and Ventricular Dyssynchrony Predict Response to Cardiac Resynchronization Therapy in Patients with Nonischemic Dilated Cardiomyopathy.

Purpose: To determine the association of myocardial fibrosis and left ventricular (LV) dyssynchrony measured using cardiac MRI with late gadolinium enhancement (LGE) and feature tracking (FT), respectively, with response to cardiac resynchronization therapy (CRT) for nonischemic dilated cardiomyopathy (DCM). Materials and Methods: This retrospective study included 98 patients (mean age, 59 years ± 10 [SD]; 54 men) who had nonischemic DCM, as assessed with LGE cardiac MRI before CRT. Cardiac MRI FT-derived dyssynchrony was defined as the SD of the time-to-peak strain (TTP-SD) of the LV segments in three directions (longitudinal, radial, and circumferential). CRT response was defined as a 15% increase in LV ejection fraction (LVEF) at echocardiography at 6-month follow-up, and then, long-term cardiovascular events were assessed. The likelihood ratio test was used to evaluate the incremental prognostic value of LGE and dyssynchrony parameters. Results: Seventy-one (72%) patients showed a favorable LVEF response following CRT. LGE presence (odds ratio: 0.14 [95% CI: 0.04, 0.47], P = .002; and hazard ratio: 3.52 [95% CI: 1.37, 9.07], P = .01) and lower circumferential TTP-SD (odds ratio: 1.04 [95% CI: 1.02, 1.07], P = .002; and hazard ratio: 0.98 [95% CI: 0.96, 1.00], P = .03) were independently associated with LVEF nonresponse and long-term outcomes. Combined LGE and circumferential TTP-SD provided the highest discrimination for LVEF nonresponse (area under the receiver operating characteristic curve [AUC]: 0.89 [95% CI: 0.81, 0.94], sensitivity: 84.5% [95% CI: 74.0%, 92.0%], specificity: 85.2% [95% CI: 66.3%, 95.8%]) and long-term outcomes (AUC: 0.84 [95% CI: 0.75, 0.91], sensitivity: 76.9% [95% CI: 56.4%, 91.0%], specificity: 87.0% [95% CI: 76.7%, 93.9%]). Conclusion: Myocardial fibrosis and lower circumferential dyssynchrony assessed with pretherapy cardiac MRI were independently associated with unfavorable LVEF response and long-term events following CRT in patients with nonischemic DCM and may provide incremental value in predicting prognosis.Keywords: MR Imaging, Cardiac, Outcomes Analysis Supplemental material is available for this article. © RSNA, 2023.

T1 Mapping for Identifying the Substrate in Patients With Apparently Idiopathic Premature Ventricular Complexes.

BACKGROUND: Myocardial fibrosis is implicated as a potential substrate responsible for arrhythmias. OBJECTIVES: This study aimed to investigate myocardial fibrosis assessed by T1 mapping in patients with apparently idiopathic premature ventricular complexes (PVCs), and to determine the relationship between this tissue biomarker and PVC features. METHODS: Patients with frequent PVC (>1,000/24 h) who underwent cardiac magnetic resonance imaging (MRI) between 2020 and 2021 were retrospectively evaluated. Patients were included if they had no indicator of known heart diseases on MRI. Sex- and age-matched healthy subjects underwent noncontrast MRI with native T1 mapping. High PVC burden was defined as the percentage of PVC >20%/24 h. RESULTS: A total of 70 patients and 70 healthy controls were included. Global T1 value was significantly higher in patients than in controls (P < 0.001). Extracellular volume was 26.03% ± 2.16% in the patients. Moreover, global T1 value showed a stepwise increase in PVC tertiles (P = 0.03) but not for extracellular volume (P = 0.85). Patients with a non-left bundle branch block (LBBB) inferior axis morphology showed higher global native T1 values than LBBB inferior axis pattern (P = 0.005). In addition, global T1 values correlated significantly with PVC burden (r = 0.28, P = 0.02). In the multivariate analysis, global T1 value independently correlated with high PVC burden (odds ratio: 1.22 per 10-ms increase, P = 0.02). CONCLUSIONS: Increased global T1, a marker of interstitial fibrosis, was detected in patients with apparently idiopathic PVC and was significantly associated with non-LBBB inferior axis morphology and high PVC burden.

Subendocardial Involvement as an Underrecognized LGE Subtype Related to Adverse Outcomes in Hypertrophic Cardiomyopathy.

BACKGROUND: Late gadolinium enhancement (LGE) has been established as an independent predictor for adverse outcomes in hypertrophic cardiomyopathy (HCM). However, the prevalence and clinical significance of some LGE subtypes have not been well demonstrated. OBJECTIVES: In this study, the authors sought to investigate the prognostic value of subendocardium-involved LGE pattern and location of right ventricle insertion points (RVIPs) with LGE in HCM patients. METHODS: In this single-center retrospective study, 497 consecutive HCM patients with LGE confirmed by cardiac magnetic resonance (CMR) were included. Subendocardium-involved LGE was defined as LGE involving subendocardium not corresponding to a coronary vascular distribution. Subjects with ischemic heart disease that would contribute to subendocardial LGE were excluded. Endpoints included a composite of heart failure-related events, arrhythmic events, and stroke. RESULTS: Of the 497 patients, subendocardium-involved LGE and RVIP LGE were observed in 184 (37.0%) and 414 (83.3%), respectively. Extensive LGE (≥15% of left ventricular mass) was detected in 135 patients. During a median follow-up of 57.9 months, 66 patients (13.3%) experienced composite endpoints. Patients with extensive LGE had a significantly higher annual incidence of adverse events (5.1% vs 1.9% per year; P < 0.001). However, spline analysis showed that the association between LGE extent and HRs for adverse outcomes tended to be nonlinear. The risk of composite endpoint increased with percentage increase in LGE extent in patients with extensive LGE, whereas a similar trend was not observed in patients with nonextensive LGE (<15%). In patients with extensive LGE, LGE extent significantly correlated with composite endpoints (HR: 1.05; P = 0.03) after adjusting for left ventricular ejection fraction <50%, atrial fibrillation, and nonsustained ventricular tachycardia, whereas in patients with nonextensive LGE, subendocardium-involved LGE rather than LGE extent was independently associated with adverse outcomes (HR: 2.12; P = 0.03). RVIP LGE was not significantly associated with poor outcomes. CONCLUSIONS: In HCM patients with nonextensive LGE, the presence of subendocardium-involved LGE rather than LGE extent is associated with unfavorable outcomes. Given that the prognostic value of extensive LGE has been broadly recognized, subendocardial involvement as an underrecognized LGE pattern shows the potential to improve risk stratification in HCM patients with nonextensive LGE.

Predictors of Outcome After Alcohol Septal Ablation for Hypertrophic Obstructive Cardiomyopathy: An Echocardiography and Cardiovascular Magnetic Resonance Imaging Study.

BACKGROUND: Alcohol septal ablation (ASA) is used for treatment of medically refractory hypertrophic obstructive cardiomyopathy patients with severe left ventricular outflow tract (LVOT) obstruction. The current recommendations restrict the procedure to adults with favorable anatomy and no other coexisting surgically amenable disease. Some patients remain symptomatic with residual LVOT obstruction, thus better patient selection is required. METHODS AND RESULTS: One-hundred and two consecutive subjects with hypertrophic obstructive cardiomyopathy who underwent cardiovascular magnetic resonance imaging, transthoracic echocardiography, and ASA were enrolled in this study. Successful ASA was defined as reduction of LVOT gradient ≥50% of baseline by echocardiographic follow-up 6 months post ASA. The relationships between segmental thickness assessed by cardiovascular magnetic resonance imaging and echocardiography and outcomes of ASA were compared between the 2 groups. The survival rate after ablation was 100% at 6-month follow-up. The LVOT gradient decreased ≥50% of baseline in 72% (73/102) patients. There were good correlations between the reduction of postoperative LVOT gradient and the thickness of basal anterior segment (r=0.371; P<0.001), basal anteroseptal segment (r=0.527; P<0.001), and total thickness of the above 2 segments (r=0.672; P<0.001). The area under the receiver operating curves were 0.68, 0.79 and 0.89 for predictive analysis (all P<0.001). The cutoff thickness of the segment 1+2 was 50.9 mm, which yielded a sensitivity of 86% and specificity of 77%. CONCLUSIONS: Both echocardiography and cardiovascular magnetic resonance imaging can be used effectively as noninvasive tools for patient selection for ASA procedure. A significantly thickened septum among hypertrophic obstructive cardiomyopathy patients may be associated with a poor outcome after ASA.

Comparison of cardiovascular magnetic resonance characteristics and clinical consequences in children and adolescents with isolated left ventricular non-compaction with and without late gadolinium enhancement.

BACKGROUND: Although cardiovascular magnetic resonance (CMR) is showing increasingly diagnostic potential in left ventricular non-compaction (LVNC), relatively little research relevant to CMR is conducted in children with LVNC. This study was performed to characterize and compare CMR features and clinical outcomes in children with LVNC with and without late gadolinium enhancement (LGE). METHODS: A cohort of 40 consecutive children (age, 13.7 ± 3.3 years; 29 boys and 11 girls) with isolated LVNC underwent a baseline CMR scan with subsequent clinical follow-up. Short-axis cine images were used to calculate left ventricular (LV) ejection fraction (EF), end-diastolic volume (EDV), end-systolic volume (ESV), myocardial mass, ratio of non-compacted-to-compacted myocardial thickness (NC/C ratio), and number of non-compacted segments. The LGE images were analyzed to assess visually presence and patterns of LGE. The primary end point was a composite of cardiac death and heart transplantation. RESULTS: The LGE was present in 10 (25%) children, and 46 (27%) segments were involved, including 23 non-compacted segments and 23 normal segments. Compared with LGE- cohort, LGE+ cohort had significantly lower LVEF (23.8 ± 10.7% vs. 42.9 ± 16.7%, p < 0.001) and greater LVEDV (169.2 ± 65.1 vs. 118.2 ± 48.9 mL/m2, p = 0.010), LVESV (131.3 ± 55.5 vs. 73.3 ± 46.7 mL/m2, p = 0.002), and sphericity indices (0.75 ± 0.19 vs. 0.60 ± 0.20, p = 0.045). There were no differences in terms of number and distribution of non-compacted segments, NC/C ratio, and myocardial mass index between LGE+ and LGE- cohort. In the LGE+ cohort, adverse events occurred in 6 patients compared to 2 events in the LGE- cohort. Kaplan-Meier analysis showed a significant difference in outcome between LGE+ and LGE- cohort for cardiac death and heart transplantation (p = 0.011). CONCLUSIONS: The LGE was present in up to one-fourth of children with LVNC, and the LGE+ children exhibited a more maladaptive LV remodeling and a higher incidence of cardiovascular death and heart transplantation.

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 × 10(6)) 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.

Relation between N-terminal pro-brain natriuretic peptide and cardiac remodeling and function assessed by cardiovascular magnetic resonance imaging in patients with arrhythmogenic right ventricular cardiomyopathy.

Although N-terminal pro-brain natriuretic peptide (NT-proBNP) is a useful screening test of impaired right ventricular (RV) function in conditions affecting the right-sided cardiac muscle, the role of NT-proBNP remains unclear in patients with arrhythmogenic right ventricular cardiomyopathy (ARVC). This study was designed to clarify the relation between the plasma NT-proBNP level and the RV function evaluated by cardiovascular magnetic resonance (CMR) imaging. We selected 56 patients with confirmed ARVC only when their blood specimens for NT-proBNP measurements were collected within 48 hours of a CMR scan. The NT-proBNP level was significantly higher in patients with RV dysfunction than in patients without RV dysfunction (median of 655.3 [interquartile range 556.4 to 870.0] vs 347.0 [interquartile range 308.0 to 456.2] pmol/L, p <0.001). The NT-proBNP levels were positively correlated with RV end-diastolic and end-systolic volume indices (r = 0.49 and 0.70, respectively) and negatively correlated with RV ejection fraction (r = -0.76, all p <0.001), which remained significant after adjustment for age, gender, and body mass index. The area under the receiver-operating characteristic curve for NT-proBNP was 0.91 (95% confidence interval 0.80 to 0.97, p <0.001). The cut-off value of NT-proBNP (458 pmol/L) was associated with sensitivity, specificity, and positive and negative predictive values of 91%, 89%, 67%, and 98%, respectively. In conclusion, NT-proBNP is a useful marker for the detection of RV dysfunction and associated with extent of RV dilatation and dysfunction determined by CMR in patients with ARVC.

Comparative study of CMR characteristics between arrhythmogenic right ventricular cardiomyopathy patients with/without syncope.

To compare cardiovascular magnetic resonance (CMR) characteristics between arrhythmogenic right ventricular cardiomyopathy (ARVC) patients with syncope and without syncope and explore CMR parameters related with syncope. A consecutive series of 80 patients with ARVC were divided in two groups according to history of syncope prior to CMR examinations. The biventricular function and volumes were calculated and indexed by body surface area. Fatty infiltration and late-gadolinium enhancement (LGE) were self-quantitatively analyzed according to segmental model. Patients with syncope had statistically significant greater left ventricular end-diastolic volume index (LVEDVI) (79.6 ± 23.0 vs. 69.0 ± 17.9 mL/m(2), P = 0.030), right ventricular end-diastolic volume index (RVEDVI) (122.0 ± 30.0 vs. 107.4 ± 21.8 mL/m(2), P = 0.017), and LGE incidence (52.2 vs. 21.1 %, P = 0.006) than that of patients without syncope. Patients with syncope had a trend towards greater number of segments with LGE (8.6 ± 4.2 vs. 6.6 ± 3.1, P = 0.199) than that of patients without syncope in subgroup analyses of patients with LGE, but no statistical significance was reached. Multivariate regression analysis showed the presence of LGE was independently associated with syncope in patients with ARVC (odds ratios 8.827, 95 % confidence interval 1.945-40.068, P = 0.005). CMR is helpful in detection and management of the patients with ARVC. Patients with syncope had significantly higher LVEDVI, RVEDVI and LGE incidence, and larger studies with follow-up data are needed to elucidate the relationship between LGE and syncope in patients with ARVC.

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.

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

BACKGROUND: Late 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). METHODS: Forty-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. RESULTS: Mean 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. CONCLUSIONS: In 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.

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

PURPOSE: 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. MATERIALS AND METHODS: In 58 consecutive patients with confirmed CAD, LGE MRI using the two sequences have been acquired. Image quality was graded on a four-point scale according to the image appearance. Qualitative evaluation including the distribution area and the transmural extent of the scar based on the American Heart Association's (AHA's) 17-segment model was performed in both of 2D and 3D images. The scar volumes were compared quantitatively between 2D and 3D images. RESULTS: A total of 51 individuals were used for final statistical analysis. No differences were noted in image quality (P = 0.80), scar distribution area (P = 0.17), and scar transmural extent (P = 0.20) between 3D and 2D images. There was strong correlation in scar volume between the 3D and 2D results (r = 0.940; P < 0.001; Y = 0.298 + 1.251X, R(2) = 0.876). But the scar volume derived from 3D images was significantly larger than that derived from 2D images (2D versus 3D, 20.08 ± 9.41 cm(3) versus 25.41 ± 12.57 cm(3) , t = -7.60; P < 0.001). The trend toward a larger scar volume identified by 3D method was indicated through Bland-Altman analysis. CONCLUSION: Free-breathing 3D PSIR Turbo FLASH imaging is another feasible method to identify left ventricular myocardial scar in patients with CAD and detects more scar volume compared with breathhold 2D PSIR Turbo FLASH imaging.

Cardiac magnetic resonance imaging in arrhythmogenic right ventricular cardiomyopathy: correlation to the QRS dispersion.

The aim of the study was to evaluate the relationship between the presence of right ventricular abnormalities detected by cardiac magnetic resonance (CMR) and QRS dispersion, the strongest independent predictor of sudden death in ARVC. A consecutive series of 40 patients from a single institution were recruited with a clinical diagnosis of ARVC based on the diagnostic criteria. All patients underwent systematic clinical evaluation, including history and examination, electrocardiography, 24-h Holter monitor, chest radiography, echocardiography and CMR examination and were divided into two groups according to the QRS dispersion: group I, QRS dispersion ≥40 ms; group II, QRS dispersion <40 ms. The relationship between the characteristic parameters of CMR image and QRS dispersion were analyzed in two groups. There were significant differences in QRS dispersion (57±14 ms vs. 26±11 ms), right ventricular end-diastolic diameter (57±10 mm vs. 48±11 mm, P=.012), right ventricular end-systolic diameter (52±10 mm vs. 44±11 mm, P=.010), right ventricular end-diastolic volume (260±105 ml vs. 180±66 ml, P=.006), right ventricular end-systolic volume (222±98 ml vs. 148±61 ml, P=.006) and myocardial fibrosis detection rate (74% vs. 38%, P=.024) between two groups. For all patients with ARVC, QRS dispersion and right ventricular end-diastolic volume (r=0.66, P<.001), right ventricular end-systolic volume (r=0.67, P<.001), right ventricular outflow tract area (r=0.68, P<.001) showed a moderate positive correlation. Right ventricular outflow tract area, right ventricular end-diastolic volume and end-systolic volume detected by CMR in patients with ARVC were positively correlated to the extent of QRS dispersion (≥40 ms), the strongest independent predictor of sudden cardiac death.

Transplantation with autologous mesenchymal stem cells after acute myocardial infarction evaluated by magnetic resonance imaging: an experimental study.

PURPOSE: The purpose of this study was to track and investigate the effects of autologous bone marrow-derived mesenchymal stem cells (MSCs) transplantation after acute myocardial infarction in swine assessed by magnetic resonance imaging (MRI). MATERIALS AND METHODS: Twenty-four Chinese mini-pigs (27±3 kg) were divided into 4 groups, including control groups (groups 1 and 3) and MSCs transplantation groups (group 2, super paramagnetic iron oxide labeled and group 4, 4',6-diamidino-2-phenylindole labeled). Super paramagnetic iron oxide-labeled and 4',6-diamidino-2-phenylindole-labeled MSCs (3.0×106 cells/mL) with a volume of 10 mL were injected into the left anterior descending artery by a catheter at 1 week after acute myocardial infarction, respectively. Cell distribution, cardiac functions, and scar tissue were quantitatively assessed by MRI. RESULTS: The reduction of the T2* value in the myocardium, spleen, and liver in group 2 was significantly greater than that in group 1. MRI showed that function and scar size at baseline and 3 days after cell infusion were not significantly different between groups 1 and 2. Six weeks later left ventricular ejection fraction (P<0.0001), end-systolic volume (P<0.05), the number of dyskinetic segments (P<0.0001), left ventricular weight index (P<0.0001), and the infarcted size (P<0.0001) in group 4 were all improved comparing with those in group 3. CONCLUSIONS: The majority of MSCs entrapped by the extracardial organs were mainly in the spleen. Catheter-based delivery of autologous bone marrow-derived MSCs into infarcted myocardium is feasible and effective.

[Incidence of coronary artery disease and outcome of patients with left ventricular noncompaction].

OBJECTIVE: To analyze the incidence of coronary artery disease (CAD) and outcome of patients with left ventricular noncompaction (LVNC). METHODS: Fifty-one patients with LVNC evaluated by echocardiography and/or cardiac magnetic resonance (CMR) from January 2006 to August 2010 were retrospectively reviewed. Coronary angiography or MDCT was performed for detecting coronary artery disease. Predictors of the cardiac events were analyzed by Cox regression analysis. RESULTS: There were 31 LVNC patients without CAD and 20 LVNC patients with CAD including single vessel coronary disease in 9 cases, double vessel coronary disease in 3 cases, three vessel coronary disease in 5 cases and left main coronary disease in 3 cases. Coronary artery bypass graft and percutaneous coronary intervention (PCI) were performed in 4 patients. Compared to LVNC patients without CAD, mean age (P = 0.008), incidence of hypertension (65.0% vs. 19.4%, P = 0.001), diabetes mellitus (40.0% vs. 12.9%, P = 0.026) and hyperlipidemia (55.0% vs. 25.8%, P = 0.035) were significantly higher while NT-proBNP level was significantly lower (P = 0.049) in LVNC patients with CAD. Incidence of major cardiac events was similar in LVNC patients with or without CAD. LogNT-proBNP is the independent prognostic factor for adverse cardiac events in patients with LVNC (HR 3.993, 95%CI 1.140 - 13.988, P = 0.030). CONCLUSIONS: Coronary artery disease is common in patients with LVNC and associated with traditional risk factors for CAD. Poor prognosis is associated with increased NT-proBNP but not with CAD in this patient cohort.

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

BACKGROUND: The differentiation of constrictive pericarditis (CP) from restrictive cardiomyopathy (RCM) is often difficult. This study sought to determine the clinical utility of cardiovascular magnetic resonance imaging (CMR) for differentiating both these disorders. METHODS: Twenty-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. RESULTS: The 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. CONCLUSIONS: CMR with LGE and RAR can facilitate differentiation of CP from RCM.

Cardiac magnetic resonance imaging characteristics of isolated left ventricular noncompaction in a Chinese adult Han population.

To analyze cardiac magnetic resonance imaging (CMR) characteristics in patients with isolated left ventricular noncompaction (IVNC) and assess its value in the diagnosis of IVNC in a Chinese adult Han population. We collected a consecutive series of 30 patients with IVNC from January 1, 2007, to December 31, 2008. During the same period, we prospectively included patients drawn from groups given a potential differential diagnosis for IVNC. All magnetic resonance images were analyzed using 17-segment model. Left ventricular ejection fraction was significantly lower for patients with DCM (16.2 ± 5.2%, P < 0.001) and higher in AR (47.6 ± 16.2%, P = 0.009), AS (54.6 ± 21.1%, P = 0.001) and HHD (62.4 ± 6.8%, P < 0.001) compared with IVNC (33.0 ± 14.1%). The two-layered structure was most frequently seen at the apical segments, followed by the mid-cavity and basal segments in patients with INVC. The anterior and lateral walls were more commonly involved in patients with IVNC. The number of noncompacted segments and end-diastolic ratio of non-compacted to compacted myocardium (NC/C ratio) was greater in patients with IVNC than in other five groups. The end-diastolic NC/C ratio of >2.5 had 96.4% sensitivity and 97.4% specificity for identifying patients with IVNC. CMR provides an accurate and reliable evaluation of the localization and extent of noncompacted myocardium at end-diastole. The end-diastolic NC/C ratio of >2.5 had high diagnostic accuracy for IVNC in a Chinese adult Han population.

[Comparison of clinical and MRI features between dilated cardiomyopathy and left ventricular noncompaction].

OBJECTIVE: To characterize the clinical and cardiac MRI features of dilated cardiomyopathy (DCM) and left ventricular noncompaction (LVNC). METHODS: Compared the clinical and MRI features between 25 patients with LVNC and 21 patients with DCM. The MRI derived diastolic left ventricular wall thickness and the number and degree of noncompaction (NC) were evaluated using the 17-segment model. RESULTS: Chest distress, shortness of breath and abnormal ECG were presented in all DCM patients, abnormal ECG was evidenced in 22 LVNC patients and 21 out of 25 LVNC patients presented similar clinical symptoms as DCM patients while the rest 4 LVNC patients were asymptomatic. Left atrial and ventricular dimensions were significantly smaller in LVNC patients compared to DCM patients. The degree of left ventricular (LV) spherical remodeling was significantly greater in patients with DCM (sphericity index, SI = 0.81 +/- 0.06) than in patients with LVNC (SI = 0.74 +/- 0.11, P < 0.05). The LV ejection fraction (LVEF) was significantly higher in patients with LVNC (32.7% +/- 14.2%) than that in patients with DCM (15.0% +/- 5.1%). The number of NC segments in LVNC patients (9 +/- 1) was significantly higher than the number of hypertrabeculation segment in DCM patients (5 +/- 2). The left ventricular apex (the 17th segment) was unexceptionally involved in all LVNC patients, while hypertrabeculation was absent in the 17th segment of DCM patients. The NC was more common in the apical and mid segments (16th, 12th and 11th segments) than in basal and mid septal segments (2nd, 3rd, 8th and 9th segments) in both LVNC and DCM patients. The thickness of compacted myocardium of the segments associated with noncompaction appeared thin in two groups. The wall thickness of noncompaction myocardium segments was thicker in LVNC patients than in DCM patients. The end-diastolic NC/C ratio was, on average, higher in patients with LVNC (3.3 +/- 0.6) than in patients with DCM (1.9 +/- 0.3). CONCLUSIONS: The clinical manifestation is similar while there are significant differences in the morphology and function of left atria and left ventricle between the LVNC and DCM patients. The different distribution and degree of NC were helpful to differentiate LVNC from DCM.

[In vivo re-distribution of intra-coronary transplanted stem cells into beating and arrested hearts by magnetic resonance imaging in an acute myocardial infarction swine model].

OBJECTIVE: To analyze the stem cell re-distribution after intra-coronary infusion (ICI) into arrested and beating hearts in a swine myocardial infarction (MI) model using magnetic resonance imaging (MRI). METHODS: Bone marrow-derived mesenchymal stem cells were obtained from male swine and labeled with iron oxide during culture. One week after MI in female swine, the survivors were randomly divided into 4 groups. Cardiopulmonary bypass was set up to arrest the heart, and then SPIO labeled male stem cells (1 × 10(8)) were infused through coronary of beating heart (n = 6) and the arrested heart (n = 6). Saline was injected in either the beating or arresting heart as respective controls. Three days later, cell distribution was assessed by T2(*) change with magnetic resonance imaging and Y-chromosome (SRY) was detected with quantitative polymerase chain reaction. RESULTS: The reduction of T2(*) values was significantly different in the hearts, spleens, livers and lung between the transplantation groups and the control groups. Only few transplanted cells were localized in the heart and T2(*) values were similar between beating and arrest heart groups [(-7.81 ± 2.03) ms vs. (-6.56 ± 1.72) ms, P > 0.05], while T2(*) value reduction was more significant in the spleen and liver in arrest heart group than in beating heart group [spleen: (-16.72 ± 2.83) ms vs. (-22.18 ± 3.98) ms, P < 0.01, liver: (-2.40 ± 0.44) ms vs. (-5.32 ± 3.40) ms, P < 0.05]. T2(*) value was similar in kidney among the four groups. qRT-PCR detected SRY gene was similar in the heart, less in the spleen and liver while more in the lung in beating heart group compared to arrested heart group. In vitro Prussian blue stained positively transplanted cells were found in the above organs in transplantation group. CONCLUSIONS: The majority of stem cells transplanted by ICI would be entrapped by the extracardiac organs. Stem cell transplantation via ICI into the arrested heart does not favor more cells retention in the injured myocardium. Further investigation is needed to optimize the approach of stem cell delivery.