Additional prognostic values of strain and strain rate over late gadolinium enhancement in hypertrophic cardiomyopathy patients.

BACKGROUND: Late gadolinium enhancement (LGE) has some shortcomings in the risk stratification in hypertrophic cardiomyopathy (HCM). Myocardial strain/strain rate (SR) can be acquired from unenhanced cardiovascular magnetic resonance (CMR) images and detect cardiac dysfunction sensitively. The present study aimed to evaluate the additional prognostic values of myocardial strain/SR beyond LGE for the risk stratification in patients with HCM. METHODS: 293 patients with HCM who underwent CMR were enrolled in this prospective study. LGE/left ventricular (LV) mass, LV global strain, and SR were acquired based on CMR. Also, conventional clinical, echocardiography, and CMR parameters and established risk factors for HCM were evaluated. RESULTS: 14/293 patients had major adverse cardiovascular events (MACEs) during the median follow-up of 15.0 months, including eight all-cause deaths, four resuscitated cardiac arrests and two cardiac transplantations. Peak systolic (PS)-global longitudinal SR (GLSR) was independently associated with MACEs (hazard ratio: 15.297, P < 0.001) after adjusting for conventional clinical characteristics, echocardiography, and CMR parameters. The model constructed by conventional variables plus PS-GLSR had significantly stronger predictive ability than the model constructed by conventional variables plus LGE/LV mass (C-statistic: 0.850 vs 0.708, P = 0.030). The addition of PS-GLSR to the conventional model also significantly improved the sensitivity (92.9% vs 71.4%) and specificity (71.0% vs 57.3%), and lowered false positives (81 patients vs 119 patients) compared to the addition of LGE/LV mass. CONCLUSION: LV PS-GLSR derived from CMR has the potential to be a novel biomarker for risk stratification of HCM and provide additional prognostic value over LGE/LV mass.

Value of native T1 mapping in the prediction of major adverse cardiovascular events in hemodialysis patients.

OBJECTIVES: This study aimed to evaluate the association of myocardial characterization by native T1 mapping using cardiac MR (CMR) with the incidence of major adverse cardiovascular event (MACE) in end-stage renal dysfunction (ESRD) patients on hemodialysis. METHODS: A total of 52 ESRD patients and 52 healthy individuals were prospectively recruited between June 2017 and June 2018. ESRD patients underwent CMR examinations post-hemodialysis for the evaluation of cardiac function and global native T1 mapping. Demographics, serum biomarkers, and coronary artery calcification were collected. MACE including all-caused death, and new onset of myocardial infarction, heart failure leading to hospitalization, fatal arrhythmia, and cardiac arrest was set as the endpoint. RESULTS: During a median follow-up of 38.0 months, 13 patients (25.0%) reached the endpoints. Global native T1 mapping in patients on hemodialysis was significantly higher compared with that of healthy individuals (1280.3 ms ± 45.3 vs. 1238.2 ms ± 31.1, p < 0.001). In the univariate Cox regression analysis, global native T1 mapping (HR [hazard ratios]: 1.887, 95% CI [confidence interval]: 1.302-2.736, p = 0.001) was associated with the prediction of MACE. Multivariate Cox regression analysis demonstrated that global native T1 mapping (HR: 1.580, 95% CI: 1.112-2.244, p = 0.011) and age (HR: 1.088, 95% CI: 1.032-1.146, p = 0.002) were associated with the incidence of MACE after adjusting for other conventional risk factors. CONCLUSIONS: Global native T1 mapping by CMR can potentially become a novel predictor of MACE in ESRD patients on hemodialysis, providing additional prognostic values over conventional risk factors. However, this conclusion should be validated in a larger sample size of hemodialysis patients. KEY POINTS: • Global native T1 mapping was significantly higher in ESRD patients on hemodialysis compared with that of normal controls. • Global native T1 mapping was associated with myocardial enzymes, myocardial hypertrophy, coronary calcification, and cardiac function. • Global native T1 mapping value was independently predictive of MACE in hemodialysis patients, providing additional prognostic values over conventional risk factors.

Percutaneous Ventricular Restoration Prevents Left Ventricular Remodeling Post Myocardial Infarction: One-Year Evaluation of the Heartech First-in-man Study.

BACKGROUND: This is first-in-man investigation of an implantable Heartech left ventricular partitioning device (LVPD) therapy for chronic heart failure (HF) after a myocardial infarction. METHODS AND RESULTS: Initially, 16 patients were chosen from 3 cardiac centers within China. All patients were treated with percutaneous ventricular restoration involving the Heartech LVPD implantation. Major adverse cardiovascular and cerebrovascular events were documented. Functional status, echocardiograph evaluation, European five-dimensional health scale, 6-minute walk test before the procedure and at postoperative follow-ups were recorded. We demonstrated successful implantation and device function with a success rate of 93.75%. One patient suffered a fatal myocardial infarction within the 12 ± 1 month follow-up. However, other patients did not report any major adverse cardiovascular and cerebrovascular events at their 12 ± 1 month follow-ups. After the operation, the average left ventricular end-systolic volume index decreased dramatically (66.00 mL/m2, interquartile range [IQR] 63.00-89.00 mL/m2 vs 48.00 mL/m2, IQR 32.25-68.25 mL/m2, P = .001), along with the left ventricular end-diastolic volume index (105.00 mL/m2, IQR 90.00-130.00 mL/m2 vs 76.50 mL/m2, IQR 57.75-120.25 mL/m2, P = .002). The left ventricular ejection fraction (35.00%, IQR 27.00-38.00% vs 42.50%, IQR 34.75-50.25%, P = .003), 6-minute walk test (383.13 ± 108.70 m vs 491.17 ± 118.44 m, P = .01), and European five-dimensional health scale (65.93 ± 11.25 vs 82.50 ± 5.44, P < .001), in turn, improved significantly. CONCLUSIONS: In our study, the Heartech LVPD was demonstrated as both safe and effective in reducing LV volume, enhancing LV function after implantation. These results remain constant at least till the 12 month follow-up. (Trial Registration: NCT02938637.).

Incremental Values of T1 Mapping in the Prediction of Sudden Cardiac Death Risk in Hypertrophic Cardiomyopathy: A Comparison With Two Guidelines.

Background: MRI native T1 mapping and extracellular volume fraction (ECV) are quantitative values that could reflect various myocardial tissue characterization. The role of these parameters in predicting the risk of sudden cardiac death (SCD) in hypertrophic cardiomyopathy (HCM) is still poorly understood. Aim: This study aims to investigate the ability of native T1 mapping and ECV values to predict major adverse cardiovascular events (MACE) in HCM, and its incremental values over the 2014 European Society of Cardiology (ESC) and enhanced American College of Cardiology/American Heart Association (ACC/AHA) guidelines. Methods: Between July 2016 and October 2020, HCM patients and healthy individuals with sex and age matched who underwent cardiac MRI were prospectively enrolled. The native T1 and ECV parameters were measured. The SCD risk was evaluated by the 2014 ESC guidelines and enhanced ACC/AHA guidelines. MACE included cardiac death, transplantation, heart failure admission, and implantable cardioverter-defibrillator implantation. Results: A total of 203 HCM patients (54.2 ± 14.9 years) and 101 healthy individuals (53.2 ± 14.7 years) were evaluated. During a median follow-up of 15 months, 25 patients (12.3%) had MACE. In multivariate Cox regression analysis, global native T1 mapping (hazard ratio (HR): 1.446; 95% confidence interval (CI): 1.195-1.749; P < 0.001) and non-sustained ventricular tachycardia (NSVT) (HR: 4.949; 95% CI, 2.033-12.047; P < 0.001) were independently associated with MACE. Ten of 86 patients (11.6%) with low SCD risk assessed by the two guidelines had MACE. In this subgroup of patients, multivariate Cox regression analysis showed that global native T1 mapping was independently associated with MACE (HR: 1.532; 95% CI: 1.221-1.922; P < 0.001). In 85 patients with conflicting results assessed by the two guidelines, end-stage systolic dysfunction was independently associated with MACE (HR: 7.942, 95% CI: 1.322-47.707, P = 0.023). In 32 patients with high SCD risk assessed by the two guidelines, NSVT was independently associated with MACE (HR: 9.779, 95% CI: 1.953-48.964, P = 0.006). Conclusion: The global native T1 mapping could provide incremental values and serve as potential supplements to the current guidelines in the prediction of MACE.

A radiomic approach to predict myocardial fibrosis on coronary CT angiography in hypertrophic cardiomyopathy.

BACKGROUND: Late gadolinium enhancement (LGE) derived from cardiac magnetic resonance (CMR) represents myocardial fibrosis (MF) and is associated with prognosis in hypertrophic cardiomyopathy (HCM). However, it cannot be evaluated when CMR is unavailable. Hence, we aimed to investigate the ability of radiomic features derived from coronary computed tomography angiography (CCTA) to detect the presence and extent of MF in HCM, with LGE as references. METHODS: 161 patients with HCM who underwent CCTA and CMR were retrospectively enrolled and randomly divided into training (107 patients, 1712 segments) and testing cohorts (54 patients, 864 segments). Segments were obtained according to AHA 17-segment method. Radiomic features were extracted from per-segment and entire myocardium regions, and multiple machine-learning algorithms were used for radiomic signatures (Rad-sig) generation and model building. Four models were established by multivariable logistic regression using Rad-sig (R-model), clinical characteristic (C-model), echocardiography parameters (E-model), and all features integrated (Integ-model) to identify LGE/left ventricular mass ≥ 15%. RESULTS: The model achieved good diagnostic accuracy in both training (area under the curve [AUC]:0.81, 95% confidence interval [CI]: 0.78-0.83) and testing cohort (AUC: 0.78, 95%CI: 0.75-0.81) on a per-segment basis for the presence of MF. The Integ-model owned the highest discriminative ability for patients with LGE/left ventricular mass ≥ 15% in both training and testing cohorts with AUC of 0.94 (95%CI: 0.89-0.98) and 0.92 (95%CI: 0.85-0.99), respectively. CONCLUSIONS: Our radiomic models were considered as useful and complementary biomarkers for the evaluation of the presence and extent of MF on CCTA, facilitating clinical decision-making and risk stratification in HCM patients.

Left ventricular myocardial deformation: a study on diastolic function in the Chinese male population and its relationship with fat distribution.

BACKGROUND: Obesity has become an epidemic in China with its increased prevalence, especially in the male population. Disparities in fat distribution rather than increasing body mass index (BMI) confer the risk of different diseases, including cardiac abnormalities. Therefore, early detection of cardiac abnormalities is important for treatment to reverse the progression to heart failure. Nowadays, strain analysis based on cardiac magnetic resonance (CMR) imaging has been established to assess myocardial function in diverse cardiac diseases. We aimed to assess the relationship between fat distribution and subclinical diastolic dysfunction in obese Chinese men assessed by deformation registration algorithm (DRA)-based myocardial strain rate (SR) analysis. METHODS: A total of 115 male participants with different BMI underwent CMR scanning using a 1.5T MAGNETOM Aera (Siemens Healthcare, Erlangen, Germany) and computed tomography (CT) scan. All the participants were enrolled from September 2017 to April 2018. They were classified into 3 groups according to their BMIs with 23 and 27.5 kg/m2 being the cutoff values. A Trufi-Strain prototype software (version 2.0, Siemens Healthcare, Erlangen, Germany) was used to quantify SR in both early and late diastole from CMR cine images. Ratios of early and late SRs were calculated. Areas of epicardial and pericardial adipose tissue (EAT and PAT) were measured on a single 4-chamber-view slice of cine images. Volumes of visceral and subcutaneous adipose tissue (VAT and SAT) were acquired semi-automatically from CT images using the dedicated software Cardiac Risk2.0 (Siemens Healthcare). Waist and hip circumferences were manually measured (WC and HC). Analysis of variance or nonparametric tests, along with correlation and stepwise multivariate regression analysis models, was applied for statistical analysis. RESULTS: Peak late diastolic SRs were higher in obese men compared with their lean counterparts [-36.25±10.46 vs. -29.46±8.17, 66.97±18.58 vs. 45.62 (42.44, 55.96), and 56.81±15.07 vs. 41.40±6.41 for radial, circumferential, and longitudinal SRs, respectively; P<0.05]. All SR ratios in the obese subgroups were lower than those of lean men (3.12±1.14 vs. 4.63±1.24, 2.12±0.58 vs. 2.96±0.62 and 1.63±0.50 vs. 2.20±0.63 for radial, circumferential, and longitudinal directions, respectively; P<0.05). EAT was a significant predictor of diastolic function assessed by radial and circumferential SR ratios (ß=-0.439 and -0.337 respectively; all P<0.001), while VAT was a significant predictor of circumferential and longitudinal SR ratios (ß=-0.216 and -0.355, respectively, P<0.05). CONCLUSIONS: Decreased LV diastolic function assessed by DRA-based SR analysis in obesity is associated with fat distribution. Furthermore, EAT and VAT might be better predictors of a decrease of diastolic function in obese Chinese men than BMI.

The impact of iterative reconstruction algorithms on machine learning-based coronary CT angiography-derived fractional flow reserve (CT-FFRML) values.

To evaluate the impact of an iterative reconstruction (IR) algorithm (advanced modeled iterative reconstruction, ADMIRE) on machine learning-based coronary computed tomography angiography-derived fractional flow reserve (CT-FFRML) measurements compared with filtered back projection (FBP). 170 plaque-containing vessels in 107 patients were included. CT-FFRML values were measured and compared among 5 imaging reconstruction algorithms (FBP and ADMIRE at strength levels of 1, 2, 3 and 5). The plaques were classified as, 'calcified" or "noncalcified" and "≥ 50% stenosis" or "< 50% stenosis', a total of four subgroups by consensus. There were no significant differences of CT-FFRML values among the FBP and ADMIRE 1, 2, 3 and 5 groups wherever comparisons were done at the level of subgroups (P = 0.676, 0.414, 0.849, 0.873, respectively) or overall (P = 0.072). There were 20, 21, 19, 19 and 29 vessels with lesion-specific ischemia (CT-FFRML ≤ 0.80) in FBP and ADMIRE 1, 2, 3 and 5 datasets, respectively, but no statistical differences were found (P = 0.437). Compared with CT-FFRML value of FBP dataset, the CT-FFRML values of 9 (5.3%) vessels from 8 patients (7.5%) in ADMIRE5 dataset switched from above 0.8 to below or equal to 0.8. There were no significant differences of the CT-FFRML values among the FBP and IR image algorithms at different strength levels. However, high iterative strength level (ADMIRE 5) was not recommended, which might have an impact on diagnosis of lesion-specific ischemia, although changes only occurred in a modest number of subjects.

MRI Manufacturer Shift and Adaptation: Increasing the Generalizability of Deep Learning Segmentation for MR Images Acquired with Different Scanners.

PURPOSE: To quantitatively evaluate the generalizability of a deep learning segmentation tool to MRI data from scanners of different MRI manufacturers and to improve the cross-manufacturer performance by using a manufacturer-adaptation strategy. MATERIALS AND METHODS: This retrospective study included 150 cine MRI datasets from three MRI manufacturers, acquired between 2017 and 2018 (n = 50 for manufacturer 1, manufacturer 2, and manufacturer 3). Three convolutional neural networks (CNNs) were trained to segment the left ventricle (LV), using datasets exclusively from images from a single manufacturer. A generative adversarial network (GAN) was trained to adapt the input image before segmentation. The LV segmentation performance, end-diastolic volume (EDV), end-systolic volume (ESV), LV mass, and LV ejection fraction (LVEF) were evaluated before and after manufacturer adaptation. Paired Wilcoxon signed rank tests were performed. RESULTS: The segmentation CNNs exhibited a significant performance drop when applied to datasets from different manufacturers (Dice reduced from 89.7% ± 2.3 [standard deviation] to 68.7% ± 10.8, P < .05, from 90.6% ± 2.1 to 59.5% ± 13.3, P < .05, from 89.2% ± 2.3 to 64.1% ± 12.0, P < .05, for manufacturer 1, 2, and 3, respectively). After manufacturer adaptation, the segmentation performance was significantly improved (from 68.7% ± 10.8 to 84.3% ± 6.2, P < .05, from 72.4% ± 10.2 to 85.7% ± 6.5, P < .05, for manufacturer 2 and 3, respectively). Quantitative LV function parameters were also significantly improved. For LVEF, the manufacturer adaptation increased the Pearson correlation from 0.005 to 0.89 for manufacturer 2 and from 0.77 to 0.94 for manufacturer 3. CONCLUSION: A segmentation CNN well trained on datasets from one MRI manufacturer may not generalize well to datasets from other manufacturers. The proposed manufacturer adaptation can largely improve the generalizability of a deep learning segmentation tool without additional annotation.Supplemental material is available for this article.© RSNA, 2020.

First-in-man study of Heartech® percutaneous left ventricular partitioning device for treatment of heart failure postmyocardial infarction.

OBJECTIVE: This first-in-man (FIM) study aimed to determine the safety and efficacy of the Heartech® left ventricular partitioning device (LVPD) in patients with chronic heart failure (HF) postmyocardial infarction. METHODS: Sixteen patients were enrolled from three cardiac intervention centers in China. All patients underwent percutaneous ventricular restoration (PVR) procedures with implantation of the Heartech® LVPD. Safety and immediate success rates were recorded. Major adverse cardiovascular and cerebrovascular events (MACCEs) including all-cause mortality, myocardial infarction, stroke, emergent or selective surgery or interventional therapy, renal failure requiring hemodialysis, and major bleeding were recorded. Efficacy features included functional status, echocardiographic characteristics, life quality characteristics including peak oxygen consumption of cardiopulmonary exercise testing (CPET), European five-dimensional health scale (EQ-5D), 6-min walk test (6MWT) at baseline and during follow-up (NCT02938637). RESULTS: The device success rate was 93.75% (15 successes in 16 patients) with 100% safety. During follow-up of 36 ± 4.5 days, no MACCEs were found. The left ventricular end-systolic volume index decreased significantly (LVESVi, 72.47 ± 22.77 mL/m2 vs. 50.13 ± 13.36 mL/m2 , p < .001) as did left ventricular end diastolic volume index (LVEDVi, 106.27 ± 28.01 mL/m2 vs. 83.20 ± 16.87 mL/m2 , p = .001). Left ventricular ejection fraction (LVEF, 32.47 ± 6.98% vs. 40.41 ± 6.15, p < .001), 6MWT (383.13 ± 108.70 vs. 453.47 ± 88.24, p < 0.001) and EQ-5D (65.93 ± 11.25 vs. 78.67 ± 8.35, p < .001) improved significantly. CONCLUSIONS: Heartech® LVPD appeared to be safe and effective for treatment of HF postmyocardial infarction.

Contribution of epicardial and abdominopelvic visceral adipose tissues in Chinese adults with impaired glucose regulation and diabetes.

AIMS: To quantify epicardial adipose tissue (EAT) and visceral adipose tissue (VAT) in Chinese adults with impaired glucose regulation (IGR) or diabetes and compare the contributions of EAT and VAT to the occurrence of IGR and diabetes with those of traditional obesity indices. METHODS: Cardiac and abdominopelvic noncontrast computed tomographic images of 668 individuals were used to measure EAT and VAT volume. Multivariable logistic regression and area under the receiver operating characteristic (ROC) curve were used to illustrate the contributions of these tissues. RESULTS: Patients with IGR or diabetes had larger EAT and VAT volumes than did the controls, and the VAT volume was significantly different between the IGR and diabetic groups. In multivariable models, higher EAT or VAT volume was positively associated with the presence of IGR and diabetes. After adjusting further for body mass index (BMI) and waist-to-hip ratio (WHR), a higher EAT volume was still positively associated with IGR (odds ratio (OR) = 1.46; 95% confidence interval (CI), 1.04-2.03), and a higher VAT volume was positively associated with IGR (OR = 1.86; 95% CI, 1.15-3.02) and diabetes (OR = 1.86; 95% CI, 1.16-2.99). The areas under the curve (AUCs) of the association of EAT (AUC = 0.751; 95% CI, 0.712-0.789) and VAT (AUC = 0.752; 95% CI, 0.713-0.792) with dysglycemia (IGR + diabetes) were significantly larger than those of the traditional obesity indices (all P < 0.05). CONCLUSIONS: High EAT or VAT volume is positively associated with IGR and diabetes in Chinese adults. With a given WHR and BMI, such an association still exists to some extent. The correlation may be stronger than those of the traditional obesity indices.

Initial exploration of coronary stent image subtraction using dual-layer spectral CT.

OBJECTIVES: This study aimed to investigate the feasibility of coronary stent image subtraction using spectral tools derived from dual-layer spectral computed tomography (CT). METHODS: Forty-three patients (65 stents) who underwent coronary CT angiography using dual-layer spectral CT were included. Conventional, 50-keV (kilo electron-volt), 100-keV, and virtual non-contrast (VNC) images were reconstructed from the same cardiac phase. Stents were subtracted on VNC images from conventional (convsub), 100-keV (100-keVsub), and 50-keV (50-keVsub) images. The in-stent lumen diameters were measured on subtraction, conventional, and 100-keV images. Subjective evaluation of reader confidence and subtractive quality was evaluated. Friedman tests were performed to compare in-stent lumen diameters and subjective evaluation among different images. Correlation between stent diameter and subjective evaluation was expressed as Spearman's rank correlation coefficient (rs). The diagnostic accuracy was assessed according to invasive coronary angiography (ICA) performed in 11 patients (20 stents). RESULTS: In-stent lumen diameters were significantly larger on subtraction images than those on conventional and 100-keV images (p < 0.05). Higher reader confidence was found on 100-keV, convsub, 100-keVsub, and 50-keVsub images compared with conventional images (p < 0.05). Subtractive quality of 100-keVsub images was better than that of convsub images (p = 0.037). A moderate-to-strong correlation between stent diameter and subjective evaluation was found (rs = 0.527~0.790, p < 0.05). Higher specificity, positive predictive value, and negative predictive value of subtraction images were shown by ICA results. CONCLUSIONS: Subtraction images derived from dual-layer spectral CT enhanced in-stent lumen visibility and could potentially improve diagnostic performance for evaluating coronary stents. KEY POINTS: • Dual-layer spectral CT enabled good subtractive quality of coronary stents without misregistration artifacts. • Subtraction images could improve in-stent lumen visibility. • Reader confidence and diagnostic performance were enhanced with subtraction images.