Cardiovascular magnetic resonance characterization of myocardial tissue injury in a miniature swine model of cancer therapy-related cardiovascular toxicity.

BACKGROUND: Left ventricular ejection fraction (LVEF) is the most commonly clinically used imaging parameter for assessing cancer therapy-related cardiac dysfunction (CTRCD). However, LVEF declines may occur late, after substantial injury. This study sought to investigate cardiovascular magnetic resonance (CMR) imaging markers of subclinical cardiac injury in a miniature swine model. METHODS: Female Yucatan miniature swine (n = 14) received doxorubicin (2 mg/kg) every 3 weeks for 4 cycles. CMR, including cine, tissue characterization via T1 and T2 mapping, and late gadolinium enhancement (LGE) were performed on the same day as doxorubicin administration and 3 weeks after the final chemotherapy cycle. In addition, magnetic resonance spectroscopy (MRS) was performed during the 3 weeks after the final chemotherapy in 7 pigs. A single CMR and MRS exam were also performed in 3 Yucatan miniature swine that were age- and weight-matched to the final imaging exam of the doxorubicin-treated swine to serve as controls. CTRCD was defined as histological early morphologic changes, including cytoplasmic vacuolization and myofibrillar loss of myocytes, based on post-mortem analysis of humanely euthanized pigs after the final CMR exam. RESULTS: Of 13 swine completing 5 serial CMR scans, 10 (77%) had histological evidence of CTRCD. Three animals had neither histological evidence nor changes in LVEF from baseline. No absolute LVEF <40% or LGE was observed. Native T1, extracellular volume (ECV), and T2 at 12 weeks were significantly higher in swine with CTRCD than those without CTRCD (1178 ms vs. 1134 ms, p = 0.002, 27.4% vs. 24.5%, p = 0.03, and 38.1 ms vs. 36.4 ms, p = 0.02, respectively). There were no significant changes in strain parameters. The temporal trajectories in native T1, ECV, and T2 in swine with CTRCD showed similar and statistically significant increases. At the same time, there were no differences in their temporal changes between those with and without CTRCD. MRS myocardial triglyceride content substantially differed among controls, swine with and without CTRCD (0.89%, 0.30%, 0.54%, respectively, analysis of variance, p = 0.01), and associated with the severity of histological findings and incidence of vacuolated cardiomyocytes. CONCLUSION: Serial CMR imaging alone has a limited ability to detect histologic CTRCD beyond LVEF. Integrating MRS myocardial triglyceride content may be useful for detection of early potential CTRCD.

Comparison of DeepStrain and Feature Tracking for Cardiac MRI Strain Analysis.

BACKGROUND: Myocardial feature tracking (FT) provides a comprehensive analysis of myocardial deformation from cine balanced steady-state free-precession images (bSSFP). However, FT remains time-consuming, precluding its clinical adoption. PURPOSE: To compare left-ventricular global radial strain (GRS) and global circumferential strain (GCS) values measured using automated DeepStrain analysis of short-axis cine images to those calculated using manual commercially available FT analysis. STUDY TYPE: Retrospective, single-center. POPULATION: A total of 30 healthy subjects and 120 patients with cardiac disease for DeepStrain development. For evaluation, 47 healthy subjects (36 male, 53 ± 5 years) and 533 patients who had undergone a clinical cardiac MRI (373 male, 59 ± 14 years). FIELD STRENGTH/SEQUENCE: bSSFP sequence at 1.5 T (Phillips) and 3 T (Siemens). ASSESSMENT: Automated DeepStrain measurements of GRS and GCS were compared to commercially available FT (Circle, cvi42) measures obtained by readers with 1 year and 3 years of experience. Comparisons were performed overall and stratified by scanner manufacturer. STATISTICAL TESTS: Paired t-test, linear regression slope, Pearson correlation coefficient (r). RESULTS: Overall, FT and DeepStrain measurements of GCS were not significantly different (P = 0.207), but measures of GRS were significantly different. Measurements of GRS from Philips (slope = 1.06 [1.03 1.08], r = 0.85) and Siemens (slope = 1.04 [0.99 1.09], r = 0.83) data showed a very strong correlation and agreement between techniques. Measurements of GCS from Philips (slope = 0.98 [0.98 1.01], r = 0.91) and Siemens (slope = 1.0 [0.96 1.03], r = 0.88) data similarly showed a very strong correlation. The average analysis time per subject was 4.1 ± 1.2 minutes for FT and 34.7 ± 3.3 seconds for DeepStrain, representing a 7-fold reduction in analysis time. DATA CONCLUSION: This study demonstrated high correlation of myocardial GCS and GRS measurements between freely available fully automated DeepStrain and commercially available manual FT software, with substantial time-saving in the analysis. EVIDENCE LEVEL: 3 TECHNICAL EFFICACY: Stage 3.

Quantification of changes in myocardial T1 * values with exercise cardiac MRI using a free-breathing non-electrocardiograph radial imaging.

PURPOSE: To develop and evaluate a free breathing non-electrocardiograph (ECG) myocardial T1 * mapping sequence using radial imaging to quantify the changes in myocardial T1 * between rest and exercise (T1 *reactivity ) in exercise cardiac MRI (Ex-CMR). METHODS: A free-running T1 * sequence was developed using a saturation pulse followed by three Look-Locker inversion-recovery experiments. Each Look-Locker continuously acquired data as radial trajectory using a low flip-angle spoiled gradient-echo readout. Self-navigation was performed with a temporal resolution of ∼100 ms for retrospectively extracting respiratory motion. The mid-diastole phase for every cardiac cycle was retrospectively detected on the recorded electrocardiogram signal using an empirical model. Multiple measurements were performed to obtain mean value to reduce effects from the free-breathing acquisition. Finally, data acquired at both mid-diastole and end-expiration are picked and reconstructed by a low-rank plus sparsity constraint algorithm. The performance of this sequence was evaluated by simulations, phantoms, and in vivo studies at rest and after physiological exercise. RESULTS: Numerical simulation demonstrated that changes in T1 * are related to the changes in T1 ; however, other factors such as breathing motion could influence T1 * measurements. Phantom T1 * values measured using free-running T1 * mapping sequence had good correlation with spin-echo T1 values and was insensitive to heart rate. In the Ex-CMR study, the measured T1 * reactivity was 10% immediately after exercise and declined over time. CONCLUSION: The free-running T1 * mapping sequence allows free-breathing non-ECG quantification of changes in myocardial T1 * with physiological exercise. Although, absolute myocardial T1 * value is sensitive to various confounders such as B1 and B0 inhomogeneity, quantification of its change may be useful in revealing myocardial tissue properties with exercise.

Noncontrast Cardiac Magnetic Resonance Imaging Predictors of Heart Failure Hospitalization in Heart Failure With Preserved Ejection Fraction.

BACKGROUND: Heart failure patients with preserved ejection fraction (HFpEF) are at increased risk of future hospitalization. Contrast agents are often contra-indicated in HFpEF patients due to the high prevalence of concomitant kidney disease. Therefore, the prognostic value of a noncontrast cardiac magnetic resonance imaging (MRI) for HF-hospitalization is important. PURPOSE: To develop and test an explainable machine learning (ML) model to investigate incremental value of noncontrast cardiac MRI for predicting HF-hospitalization. STUDY TYPE: Retrospective. POPULATION: A total of 203 HFpEF patients (mean, 64 ± 12 years, 48% women) referred for cardiac MRI were randomly split into training validation (143 patients, ~70%) and test sets (60 patients, ~30%). FIELD STRENGTH: A 1.5 T, balanced steady-state free precession (bSSFP) sequence. ASSESSMENT: Two ML models were built based on the tree boosting technique and the eXtreme Gradient Boosting model (XGBoost): 1) basic clinical ML model using clinical and echocardiographic data and 2) cardiac MRI-based ML model that included noncontrast cardiac MRI markers in addition to the basic model. The primary end point was defined as HF-hospitalization. STATISTICAL TESTS: ML tool was used for advanced statistics, and the Elastic Net method for feature selection. Area under the receiver operating characteristic (ROC) curve (AUC) was compared between models using DeLong's test. To gain insight into the ML model, the SHapley Additive exPlanations (SHAP) method was leveraged. A P-value <0.05 was considered statistically significant. RESULTS: During follow-up (mean, 50 ± 39 months), 85 patients (42%) reached the end point. The cardiac MRI-based ML model using the XGBoost algorithm provided a significantly superior prediction of HF-hospitalization (AUC: 0.81) compared to the basic model (AUC: 0.64). The SHAP analysis revealed left atrium (LA) and right atrium (RV) strains as top imaging markers contributing to its performance with cutoff values of 17.5% and -15%, respectively. DATA CONCLUSIONS: Using an ML model, RV and LA strains measured in noncontrast cardiac MRI provide incremental value in predicting future hospitalization in HFpEF. EVIDENCE LEVEL: 3 TECHNICAL EFFICACY: Stage 2.

Free-breathing whole-heart multi-slice myocardial T1 mapping in 2 minutes.

PURPOSE: To develop and validate a saturation-delay-inversion recovery preparation, slice tracking and multi-slice based sequence for measuring whole-heart native T1 . METHOD: The proposed free-breathing sequence performs T1 mapping of multiple left-ventricular slices by slice-interleaved acquisition to collect 10 electrocardiogram-triggered single-shot slice-selective images for each slice. A saturation-delay-inversion recovery pulse is used for T1 preparation. Prospective slice tracking by the diaphragm navigator and retrospective registration are used to reduce through-plane and in-plane motion, respectively. The proposed sequence was validated in both phantom and human subjects (12 healthy subjects and 15 patients who were referred for a clinical cardiac MR exam) and compared with saturation recovery single-shot acquisition (SASHA) and modified Look-Locker inversion recovery (MOLLI). RESULTS: Phantom T1 measured by the proposed sequence had excellent agreement (R2  = 0.99) with the ground-truth T1 and was insensitive to heart rate. In both healthy subjects and patients, the proposed sequence yielded nine left-ventricular T1 maps per volume in less than 2 minutes (healthy volunteers: 1.8 ± 0.4 minutes; patients: 1.9 ± 0.2 minutes). The average T1 of whole left ventricle for all healthy subjects and patients were 1560 ± 61 and 1535 ± 49 ms by SASHA, 1208 ± 42 and 1233 ± 56 ms by MOLLI5(3)3, and 1397 ± 34 and 1433 ± 56 ms by the proposed sequence, respectively. The corresponding coefficient of variation of T1 were 6.2 ± 1.4% and 5.8 ± 1.6%, 5.3 ± 1.1% and 5.1 ± 0.8%, and 4.9 ± 0.8% and 4.5 ± 0.8%, respectively. CONCLUSION: The proposed sequence enables quantification of whole heart T1 with good accuracy and precision in less than 2 minutes during free breathing.

Artifact reduction in free-breathing, free-running myocardial perfusion imaging with interleaved non-selective RF excitations.

PURPOSE: To reduce inflow and motion artifacts in free-breathing, free-running, steady-state spoiled gradient echo T1 -weighted (SPGR) myocardial perfusion imaging. METHOD: Unsaturated spins from inflowing blood or out-of-plane motion cause flashing artifacts in free-running SPGR myocardial perfusion. During free-running SPGR, 1 non-selective RF excitation was added after every 3 slice-selective RF excitations to suppress inflow artifacts by forcing magnetization in neighboring regions to steady-state. Bloch simulations and phantom experiments were performed to evaluate the impact of the flip angle and non-selective RF frequency on inflowing spins and tissue contrast. Free-running perfusion with (n = 11) interleaved non-selective RF or without (n = 11) were studied in 22 subjects (age = 60.2 ± 14.3 years, 11 male). Perfusion images were graded on a 5-point Likert scale for conspicuity of wall enhancement, inflow/motion artifact, and streaking artifact and compared using Wilcoxon sum-rank testing. RESULT: Numeric simulation showed that 1 non-selective RF excitation applied after every 3 slice-selective RF excitations produced superior out-of-plane signal suppression compared to 1 non-selective RF excitation applied after every 6 or 9 slice-selective RF excitations. In vitro experiments showed that a 30° flip angle produced near-optimal myocardial contrast. In vivo experiments demonstrated that the addition of interleaved non-selective RF significantly (P < .01) improved conspicuity of wall enhancement (mean score = 4.4 vs. 3.2) and reduced inflow/motion (mean score = 4.5 vs. 2.5) and streaking (mean score = 3.9 vs. 2.4) artifacts. CONCLUSION: Non-selective RF excitations interleaved between slice-selective excitations can reduce image artifacts in free-breathing, ungated perfusion images. Further studies are warranted to assess the diagnostic accuracy of the proposed solution for evaluating myocardial ischemia.

Free-breathing simultaneous myocardial T1 and T2 mapping with whole left ventricle coverage.

PURPOSE: To develop a free-breathing sequence, that is, Multislice Joint T1 -T2 , for simultaneous measurement of myocardial T1 and T2 for multiple slices to achieve whole left-ventricular coverage. METHODS: Multislice Joint T1 -T2 adopts slice-interleaved acquisition to collect 10 single-shot electrocardiogram-triggered images for each slice prepared by saturation and T2 preparation to simultaneously estimate myocardial T1 and T2 and achieve whole left-ventricular coverage. Prospective slice-tracking using a respiratory navigator and retrospective image registration are used to reduce through-plane and in-plane motion, respectively. Multislice Joint T1 -T2 was validated through numerical simulations and phantom and in vivo experiments, and compared with saturation-recovery single-shot acquisition and T2 -prepared balanced Steady-State Free Precession (T2 -prep SSFP) sequences. RESULTS: Phantom T1 and T2 from Multislice Joint T1 -T2 had good accuracy and precision, and were insensitive to heart rate. Multislice Joint T1 -T2 yielded T1 and T2 maps of nine left-ventricular slices in 1.4 minutes. The mean left-ventricular T1 difference between saturation-recovery single-shot acquisition and Multislice Joint T1 -T2 across healthy subjects and patients was 191 ms (1564 ± 60 ms versus 1373 ± 50 ms; P < .05) and 111 ms (1535 ± 49 ms vs 1423 ± 49 ms; P < .05), respectively. The mean difference in left-ventricular T2 between T2 -prep SSFP and Multislice Joint T1 -T2 across healthy subjects and patients was -6.3 ms (42.4 ± 1.4 ms vs 48.7 ± 2.5; P < .05) and -5.7 ms (41.6 ± 2.5 ms vs 47.3 ± 2.7; P < .05), respectively. CONCLUSION: Multislice Joint T1 -T2 enables quantification of whole left-ventricular T1 and T2 during free breathing within a clinically feasible scan time of less than 2 minutes.

Highly accelerated free-breathing real-time phase contrast cardiovascular MRI via complex-difference deep learning.

PURPOSE: To develop and evaluate a real-time phase contrast (PC) MRI protocol via complex-difference deep learning (DL) framework. METHODS: DL used two 3D U-nets to separately filter aliasing artifact from radial real-time velocity-compensated and complex-difference images. U-nets were trained with synthetic real-time PC generated from electrocardiograph (ECG) -gated, breath-hold, segmented PC (ECG-gated segmented PC) acquired at the ascending aorta of 510 patients. In 21 patients, free-breathing, ungated real-time (acceleration rate = 28.8) and ECG-gated segmented (acceleration rate = 2) PC were prospectively acquired at the ascending aorta. Hemodynamic parameters (cardiac output [CO], stroke volume [SV], and mean velocity at peak systole [peak mean velocity]) were measured for ECG-gated segmented and DL-filtered synthetic real-time PC and compared using Bland-Altman and linear regression analyses. Additionally, hemodynamic parameters were quantified from DL-filtered, compressed-sensing (CS) -reconstructed, and gridding reconstructed prospective real-time PC and compared to ECG-gated segmented PC. RESULTS: Synthetic real-time PC with DL showed strong correlation (R > 0.98) and good agreement with ECG-gated segmented PC for quantified hemodynamic parameters (mean-difference: CO = -0.3 L/min, SV = -4.3 mL, peak mean velocity = -2.3 cm/s). On average, DL required 0.39 s/frame to filter prospective real-time PC, which was 4.6-fold faster than CS. Compared to CS, DL showed superior correlation, tighter limits of agreement (LOAs), better bias for peak mean velocity, and worse bias for CO and SV. Compared to gridding, DL showed similar correlation, tighter LOAs for CO and SV, similar bias for CO, and worse bias for SV and peak mean velocity. CONCLUSION: The complex-difference DL framework accelerated real-time PC-MRI by nearly 28-fold, enabling rapid free-running real-time assessment of flow hemodynamics.

Multi-domain convolutional neural network (MD-CNN) for radial reconstruction of dynamic cardiac MRI.

PURPOSE: Cardiac MR cine imaging allows accurate and reproducible assessment of cardiac function. However, its long scan time not only limits the spatial and temporal resolutions but is challenging in patients with breath-holding difficulty or non-sinus rhythms. To reduce scan time, we propose a multi-domain convolutional neural network (MD-CNN) for fast reconstruction of highly undersampled radial cine images. METHODS: MD-CNN is a complex-valued network that processes MR data in k-space and image domains via k-space interpolation and image-domain subnetworks for residual artifact suppression. MD-CNN exploits spatio-temporal correlations across timeframes and multi-coil redundancies to enable high acceleration. Radial cine data were prospectively collected in 108 subjects (50 ± 17 y, 72 males) using retrospective-gated acquisition with 80%:20% split for training/testing. Images were reconstructed by MD-CNN and k-t Radial Sparse-Sense(kt-RASPS) using an undersampled dataset (14 of 196 acquired views; relative acceleration rate = 14). MD-CNN images were evaluated quantitatively using mean-squared-error (MSE) and structural similarity index (SSIM) relative to reference images, and qualitatively by three independent readers for left ventricular (LV) border sharpness and temporal fidelity using 5-point Likert-scale (1-non-diagnostic, 2-poor, 3-fair, 4-good, and 5-excellent). RESULTS: MD-CNN showed improved MSE and SSIM compared to kt-RASPS (0.11 ± 0.10 vs. 0.61 ± 0.51, and 0.87 ± 0.07 vs. 0.72 ± 0.07, respectively; P < .01). Qualitatively, MD-CCN significantly outperformed kt-RASPS in LV border sharpness (3.87 ± 0.66 vs. 2.71 ± 0.58 at end-diastole, and 3.57 ± 0.6 vs. 2.56 ± 0.6 at end-systole, respectively; P < .01) and temporal fidelity (3.27 ± 0.65 vs. 2.59 ± 0.59; P < .01). CONCLUSION: MD-CNN reduces the scan time of cine imaging by a factor of 23.3 and provides superior image quality compared to kt-RASPS.

Deep complex convolutional network for fast reconstruction of 3D late gadolinium enhancement cardiac MRI.

Several deep-learning models have been proposed to shorten MRI scan time. Prior deep-learning models that utilize real-valued kernels have limited capability to learn rich representations of complex MRI data. In this work, we utilize a complex-valued convolutional network (ℂNet) for fast reconstruction of highly under-sampled MRI data and evaluate its ability to rapidly reconstruct 3D late gadolinium enhancement (LGE) data. ℂNet preserves the complex nature and optimal combination of real and imaginary components of MRI data throughout the reconstruction process by utilizing complex-valued convolution, novel radial batch normalization, and complex activation function layers in a U-Net architecture. A prospectively under-sampled 3D LGE cardiac MRI dataset of 219 patients (17 003 images) at acceleration rates R = 3 through R = 5 was used to evaluate ℂNet. The dataset was further retrospectively under-sampled to a maximum of R = 8 to simulate higher acceleration rates. We created three reconstructions of the 3D LGE dataset using (1) ℂNet, (2) a compressed-sensing-based low-dimensional-structure self-learning and thresholding algorithm (LOST), and (3) a real-valued U-Net (realNet) with the same number of parameters as ℂNet. LOST-reconstructed data were considered the reference for training and evaluation of all models. The reconstructed images were quantitatively evaluated using mean-squared error (MSE) and the structural similarity index measure (SSIM), and subjectively evaluated by three independent readers. Quantitatively, ℂNet-reconstructed images had significantly improved MSE and SSIM values compared with realNet (MSE, 0.077 versus 0.091; SSIM, 0.876 versus 0.733, respectively; p < 0.01). Subjective quality assessment showed that ℂNet-reconstructed image quality was similar to that of compressed sensing and significantly better than that of realNet. ℂNet reconstruction was also more than 300 times faster than compressed sensing. Retrospective under-sampled images demonstrate the potential of ℂNet at higher acceleration rates. ℂNet enables fast reconstruction of highly accelerated 3D MRI with superior performance to real-valued networks, and achieves faster reconstruction than compressed sensing.

Texture signatures of native myocardial T1 as novel imaging markers for identification of hypertrophic cardiomyopathy patients without scar.

BACKGROUND: In patients with suspected or known hypertrophic cardiomyopathy (HCM), late gadolinium enhancement (LGE) provides diagnostic and prognostic value. However, contraindications and long-term retention of gadolinium have raised concern about repeated gadolinium administration in this population. Alternatively, native T1 -mapping enables identification of focal fibrosis, the substrate of LGE. However HCM-specific heterogeneous fibrosis distribution leads to subtle T1 -maps changes that are difficult to identify. PURPOSE: To apply radiomic texture analysis on native T1 -maps to identify patients with a low likelihood of LGE(+), thereby reducing the number of patients exposed to gadolinium administration. STUDY TYPE: Retrospective interpretation of prospectively acquired data. SUBJECTS: In all, 188 (54.7 ± 14.4 years, 71% men) with suspected or known HCM. FIELD STRENGTH/SEQUENCE: A 1.5T scanner; slice-interleaved native T1 -mapping (STONE) sequence and 3D LGE after administration of 0.1 mmol/kg of gadobenate dimeglumine. ASSESSMENT: Left ventricular LGE images were location-matched with native T1 -maps using anatomical landmarks. Using a split-sample validation approach, patients were randomly divided 3:1 (training/internal validation vs. test cohorts). To balance the data during training, 50% of LGE(-) slices were discarded. STATISTICAL TESTS: Four sets of texture descriptors were applied to the training dataset for capture of spatially dependent and independent pixel statistics. Five texture features were sequentially selected with the best discriminatory capacity between LGE(+) and LGE(-) T1 -maps and tested using a decision tree ensemble (DTE) classifier. RESULTS: The selected texture features discriminated between LGE(+) and LGE(-) T1 -maps with a c-statistic of 0.75 (95% confidence interval [CI]: 0.70-0.80) using 10-fold cross-validation during internal validation in the training dataset and 0.74 (95% CI: 0.65-0.83) in the independent test dataset. The DTE classifier provided adequate labeling of all (100%) LGE(+) patients and 37% of LGE(-) patients during testing. DATA CONCLUSION: Radiomic analysis of native T1 -images can identify ~1/3 of LGE(-) patients for whom gadolinium administration can be safely avoided. LEVEL OF EVIDENCE: 2 Technical Efficacy Stage: 2 J. Magn. Reson. Imaging 2020. J. Magn. Reson. Imaging 2020;52:906-919.

Heart Rate Recovery as a Novel Test for Predicting Cardiac Involvement in Beta-Thalassemia Major.

BACKGROUND: Abnormal heart rate recovery (HRR) is predictive of cardiac mortality. Autonomic abnormalities in beta-thalassemia major (TM) patients have been reported in previous studies. However, the importance of low HRR in exercise stress test in TM patients has not yet been ascertained. Therefore, this study will be the first of its kind in the literature. METHODS: Exercise stress test was performed on 56 TM patients who were being treated at the Thalassemia Center of our hospital, along with 46 non-TM iron deficiency anemia (IDA) patients as a control group. Values for HHR were recorded at 1, 2, 3, 4 and 5 min, and HRR was calculated by the difference of heart rate at peak exercise and at a specific time interval following the onset of recovery. RESULTS: All HRR values were found to be lower in TM patients compared to those in the IDA group. Exercise capacity [metabolic equivalents (METs)] was also found to be low in these patients (p < 0.001) as well. Total exercise time was significantly lower in the TM group compared to the IDA group (8.40 ± 1.7 min vs. 11.17 ± 1.51 min, p < 0.001). Exercise capacity (METs) was also lower in the TM group compared to the IDA group. Mean T2* value was 28.3 ± 13.7 ms in TM patients on magnetic resonance imaging (MRI). In addition, there are 18 TM patients with T2* value was < 20 ms. CONCLUSIONS: This study found that TM was independently associated with low HRR. Such a condition is an indicator of autonomic dysfunction in TM patients, since abnormal HRR is related to impaired autonomic response. In addition, impaired HRR may be a marker of early cardiac involvement in patients, whose T2* value is high on MRI. Modifying HRR with a cardiac rehabilitation program in TM patients with impaired HRR is a field open for further investigation.

Assessment of Impact of Weight Loss on Left and Right Ventricular Functions and Value of Tissue Doppler Echocardiography in Obese Patients.

OBJECTIVE: In our study, we aimed to evaluate the effect of weight loss on left and right ventricular functions in obese patients. METHODS: Thirty patients with a BMI greater than 30 kg/m(2) and without any exclusion criteria were included in the study. Left ventricular systolic and diastolic functions were assessed with conventional and tissue Doppler echocardiography (TDE). At the end of 3 months, echocardiographic examination was repeated in patients with weight loss for cardiac function evaluation and it was compared to the baseline echocardiographic parameters. RESULTS: At the end of 3 months of weight loss period, conventional Doppler echocardiography revealed an improvement in diastolic functions with an increase in mitral E-wave, a decrease in mitral A-wave and an increase in E/A ratio. Deceleration time and isovolumetric relaxation time were ascertained shortened and Tei index decreased. TDE showed an increase in left ventricular lateral wall systolic wave (Sm) and E-wave velocity (Em). Mitral septal annular isovolumetric acceleration time (IVA), Sm and Em, were found to be increased, whereas Tei index was ascertained reduced. Right ventricular tissue Doppler examination following weight loss revealed an increase in RV- IVA, RV-Sm, and RV-Em, and a decrease in Tei index. CONCLUSION: We disclosed that left ventricular structural changes and diastolic dysfunction occur in obese patients, and by weight loss, these abnormalities may be reversible which we demonstrated both by conventional and TDE. In addition, obesity might impair RV function as well, and we observed an enhancement in right ventricular functions by weight loss.

The Association between Serum Ferritin Level, Tissue Doppler Echocardiography, Cardiac T2* MRI, and Heart Rate Recovery in Patients with Beta Thalassemia Major.

BACKGROUND: It is generally well-understood that iron-mediated cardiomyopathy is the major complication that can arise from beta thalassemia major (TM). Therefore, early diagnosis, risk stratification, and the effective treatment of beta TM patients are clinically important to optimize long-term positive outcomes. METHODS: This study included 57 beta TM patients with a mean age of 25 ± 7 years. We determined the serum ferritin level, echocardiography, heart rate recovery (HRR), and cardiac magnetic resonance (CMR) T2* in all patients. CMR T2* findings were categorized as normal myocardium (T2* > 20 ms), and myocardial involvement (T2* ≤ 20 ms). HRR values at 1-5 min (HRR1-5) were recorded; Subsequently. HRR was calculated by subtracting the heart rate at each time point from the heart rate at peak exercise. RESULTS: There was a significant negative correlation between the serum ferritin level and the cardiac T2* MRI findings (r = -0.34, p = 0.009). A similar result was found in the negative correlation between serum ferritin and all heart rate recovery values. There was a significant positive correlation between HRR1, HRR2, and HRR3 values, and CMR T2* (T2* heart rate recovery (HRR)1: r = 0.51, p < 0.001; T2* HRR2: r = 0.48, p < 0.001; T2* HRR3: r = 0.47, p < 0.001, respectively). CONCLUSIONS: The serum ferritin level and echocardiography can be used to predict the presence of myocardial iron load in beta TM patients. Therefore, HRR can be used to screen beta TM patients, and the clinical use of HRR can be a predictive marker for autonomic dysfunction in beta TM patients. KEY WORDS: Beta thalassemia major • Cardiac magnetic resonance T2* • Heart rate recovery • Iron overload • Serum ferritin level • Tissue Doppler imaging.

Short and Long-Term Effect of Carotid Artery Stenting on Arterial Blood Pressure Measured through Ambulatory Blood Pressure Monitoring.

BACKGROUND: The aim of this study was to assess the short and long-term effects of carotid artery stenting (CAS) procedure on blood pressure (BP) through ambulatory BP monitoring. METHODS: One hundred fifty three patients who underwent CAS for primary or secondary protection from December 2010 to September 2013 were enrolled to our study. The BP levels of total of 123 patients were monitored for 1 year. Thereafter, the pre-procedure levels of BP were compared with BP levels at the 24-hour and the first year intervals after the procedure. RESULTS: Systolic and diastolic BP levels at the 24-hour and the first year intervals after CAS were significantly lower than the pre-procedure BP levels. The mean 24-hour systolic BP was 113 ± 13 mmHg and diastolic BP was 63 ± 8 mmHg, both of which were significantly lower (p < 0.001 and p < 0.001 respectively), while the pre-procedure mean systolic BP was 133 ± 10 mmHg and the mean diastolic BP was 75 ± 9 mmHg. Moreover, the mean first-year systolic BP was 125 ± 10 mmHg with a decline of 8 ± 8 mmHg and mean diastolic BP was 71 ± 8 mmHg with a decline of 4 ± 7 mmHg, both of which were again significantly lower compared to the pre-procedure levels (p < 0.001 and p < 0.001 respectively). CONCLUSIONS: The results of our study suggested that systolic and diastolic BP levels diminished after CAS. Additionally, BP reduction continued even 1 year after the CAS.

Proximal embolization of Edwards SAPIEN prosthesis in transcatheter aortic valve implantation.

Transcatheter aortic valve implantation (TAVI) is considered an alternative therapy in high-risk patients with severe aortic stenosis (AS). However, this minimally invasive procedure carries potential complications, such as valve embolization at time of TAVI. We present a case of balloon-expandable aortic valve embolization which was managed nonsurgically. Valve embolization was managed conservatively, as the patient refused open heart surgery for definitive treatment. The patient was transferred to the intensive care unit in stable hemodynamic condition and discharged 1 week following the procedure.

Assessment of Left Atrial Function in Patients with Celiac Disease.

BACKGROUND: There is some evidence suggesting increased risk of atrial fibrillation (AF) in patients with celiac disease (CD). Impaired left atrial function plays a significant role in the development of AF. This study aimed at assessing the electrical and mechanical functions of the left atrium in patients with CD. METHODS: A total of 71 patients with biopsy-proven, antibody-positive CD and 52 age-matched healthy controls were included in this prospective study. P-wave dispersion (PWD) was measured to assess the electrical functions of the left atrium through the use of surface electrocardiography. A tissue Doppler echocardiography was performed to determine the atrial conduction and electromechanical delay (EMD) time. To evaluate the mechanical functions of the left atrium, maximum, minimum, and presystolic atrial volumes were estimated to calculate the contractile, conduit, and reservoir functions. RESULTS: In terms of transthoracic echocardiographic parameters, CD and control subjects were not significantly different. However, as compared to controls, patients with CD had significantly increased PWD (median 52 ms [interquartile range 46-58 ms] vs. 38 [36-40], P < 0.001). Also, significantly higher interatrial (49 ms [32-60] vs. 26 ms [22-28], P < 0.001), intra-left atrial (26 ms [17-44] vs. 14 ms [12-18], P < 0.001), and intra-right atrial (15 ms [8-22] vs. 10 ms [8-14], P < 0.001) EMD was found among CD subjects than controls. Despite an increase in the left atrial volume in patients with CD, conduit and reservoir functions were comparable. CONCLUSIONS: Although atrial mechanical functions are preserved in patients with CD, a slower electrical conduction was found, suggesting an increased risk of AF in this group of patients.

Decrease of Urotensin II activity can impact on the volume status in predialysis chronic kidney disease.

Urotensin II (U-II) was thought to be one of the mediators of primary renal sodium retention due to effects on renal sodium excretion. For this purpose, the relationship between U-II and overhydration was investigated. A total of 107 patients were enrolled in the study. According to body compositor monitor analysis, fluid overload up to 1.1 L, was considered normohydration. Patients were divided according to hydration status; overhydrate (n = 42) and normohydrate (n = 65) were studied in both groups. Pulse waveform velocity propagation for arterial stiffness and blood pressure analysis and echocardiographic left ventricular and left atrial indices were performed with known fluid overload-related parameters. U-II levels were measured by using Human ELISA kit. In overhydrated group, U-II levels were significantly lower. All parameters (blood pressure, arterial stiffness parameters, echocardiographic data, age, gender, diabetes, U-II, hemoglobin) correlated with overhydration, were determined by linear regression model (method = enter), when considered together, U-II was found to be an independent predictor from other conventional overhydration-related parameters. Male sex, left ventricular mass index, left atrial volume index, hemoglobin value were found to be independent predictors for overhydration. Considering the association of low U-II levels with adverse cardiovascular events and its role in sodium retention, we think that low U-II levels can be accepted as a potential therapeutic target in patients with hypervolemic cardio-renal syndrome.

Assessment of morphology of patent foramen ovale with transesophageal echocardiography in symptomatic and asymptomatic patients.

BACKGROUND: The frequency of patent foramen ovale (PFO) is greater in patients who have had a stroke and transient ischemic attack (TIA) than that in the general population. However, it is not well defined, which PFO would cause stroke or TIA. In this trial, we aimed to evaluate whether there was a difference regarding morphologic features of PFO in patients who were symptomatic (cryptogenic stroke or history of TIA) or asymptomatic according to the neurologic findings. METHODS: Symptomatic patients with PFO and cryptogenic stroke or TIA and asymptomatic patients with PFO who were symptomatic in terms of neurologic findings as well as patients without any neurologic symptoms in whom PFO was diagnosed incidentally by transesophageal echocardiography were enrolled to this retrospective study on the condition that they were aged younger than 55 years. Not only the clinical and demographic characteristics of 2 groups were compared but also their morphological features were assessed. The morphologic features of PFO that were assessed included the length and height of tunnel, atrial septal excursion distance, thickness of septum primum, and thickness of septum secundum. RESULTS: One hundred fifty-six patients, 64 of whom were symptomatic, were enrolled to this study. The height of PFO (median, 3.0 [interquartile range, 2.0-3.8]mm versus 2.0 [2.0-2.0]mm, P < .001), thickness of septum secundum (5.0 [5.0-7.0] versus 3.0 [2.0-3.0], P < .001), and septal excursion distance (7.0 [6.0-10.5] versus 4.0 [4.0-5.0], P < .001) were found to be greater in the symptomatic group than those in the asymptomatic group. There was no significant difference regarding the length of tunnel and thickness of septum primum. The ratio of length to height of PFO tunnel was less in the symptomatic group (3.0 [3.0-3.23] versus 5.0 [4.0-6.25], P < .001). CONCLUSIONS: Our findings appear to indicate that a higher PFO tunnel, relatively greater interatrial septal mobility, thicker septum pellucidum, and the presence of an atrial septal aneurysm may help identifying the subjects at the age of or younger than 55 years with PFO who are at greater risk for cryptogenic stroke or TIA.