Evaluation of myocardial function by strain echocardiography in cats with hypertrophic cardiomyopathy phenotypes

The value of CMR-derived left atrial strain parameters in differential diagnosis of cardiac amyloidosis and hypertrophic cardiomyopathy

Background Differentiating cardiac amyloidosis (CA) from hypertrophic cardiomyopathy (HCM) is clinically challenging due to overlapping phenotypes of left ventricular hypertrophy. This study aimed to evaluate the diagnostic value of cardiac magnetic resonance (CMR)-derived left atrial strain parameters in differentiating CA from HCM. Methods A retrospective analysis was performed on CMR data obtained from 37 patients with HCM, 41 patients with CA, and 29 individuals in the normal control group. Left ventricular and left atrial functions were quantified using CVI42 software (version 5.14.2). Left atrial strain parameters were assessed using the tissue tracking module, including left atrial reservoir strain (εs) and strain rate (SRs), conduit strain (εe) and strain rate (SRe), and booster strain (εa) and strain rate (SRa). Differences in left ventricular and left atrial functional parameters, as well as left atrial strain parameters among the three groups, were analyzed using the Kruskal-Wallis test. Pairwise comparisons were conducted using the Mann-Whitney U test. Receiver operating characteristic (ROC) curve analysis was performed using MedCalc (version 15.2.2) to determine the diagnostic efficacy of left atrial strain parameters in differentiating CA from HCM. Results The absolute values of εs, εe, εa, SRs, SRe, and SRa were significantly lower in both the HCM and CA groups compared with the normal control group (P<0.05). Furthermore, the absolute values of these parameters were markedly lower in CA compared with HCM (P<0.05). Among these parameters, εs demonstrated the highest diagnostic performance for distinguishing CA from HCM, with an area under the ROC curve of 0.921. Conclusions CMR-derived left atrial strain parameters, particularly εs, might serve as a reliable means for differentiating between HCM and CA, which need further prospective study including patients with all HCM types and conducting internal and external validation to confirm credibility and expand generalizability.

Relationships Between Regional Left Ventricular Myocardial Strain and Tissue Characteristics in Hypertrophic Cardiomyopathy

Both fibrosis and hypertrophy contribute to abnormal myocardial mechanics in hypertrophic cardiomyopathy (HCM). We sought to assess the relationships between regional structural and functional parameters in HCM by cardiac magnetic resonance (CMR). This was a retrospective single-center study of HCM patients and age-matched controls with either hypertensive heart disease (HHD) or normal CMRs. CMR feature tracking was performed to assess global and segmental 2D-radial, circumferential, and longitudinal LV strain, while native and post-contrast T1 parametric mapping analysis was performed to assess the global and regional T1 values and ECV fraction. Of 100 patients (age 56 ± 15 years; 66% male), 62 were in the HCM group and 38 in the control group (19 healthy individuals and 19 with HHD). Compared to the control group, global circumferential strain (−16.1 ± 5.9% vs. −20.8 ± 3.6%, p < 0.001) and radial strain (45.2 ± 14.1% vs. 32.1 ± 14.0%, p < 0.001) were worse in the HCM group. Among the HCM patients, there were significant correlations between segmental native T1 values at the most hypertrophied segment and global longitudinal strain (r = 0.27, p = 0.031), global circumferential strain (r = 0.34, p = 0.006), global radial strain (r = −0.29, p = 0.024), and left ventricular ejection fraction (LVEF) (r = −0.31, p = 0.014). In HCM, higher myocardial T1 at the most hypertrophied segment correlated with worse global LV myocardial strain and LVEF by CMR.

Prognostic Value of Strain Imaging Measurements in Patients with Non-ischemic Cardiomyopathy: A Scoping Review.

Strain parameters, particularly LVGLS, remained independently associated with outcomes in 34 of 36 studies after multivariable adjustment, often providing incremental value beyond LVEF and late gadolinium enhancement, and support strain imaging, especially LVGLS, as an adjunct to conventional risk stratification in diverse NICM populations.

An Alternative Biventricular Tracking Approach for Assessment of Right Ventricular Strain in Cardiac Amyloidosis

Background: Cardiac amyloidosis is characterized by progressive myocardial infiltration leading to ventricular dysfunction. While left ventricular strain assessment is well established, evaluation of right ventricular (RV) mechanics remains challenging because of the ventricle’s complex geometry and limitations of conventional speckle-tracking methods. We aimed to evaluate an alternative approach for RV strain assessment based on a continuous biventricular tracking pathway within the apical four-chamber view. Methods: We retrospectively studied 32 patients with cardiac amyloidosis and 32 age-, sex-, rhythm-, and ejection fraction–matched controls. RV free-wall longitudinal strain was measured using a novel investigational biventricular tracking approach from the basal RV free wall through the apex to the basal lateral left ventricular wall and compared with conventional RV strain. Investigational biventricular strain (BVS) was also obtained automatically as a surrogate marker of global ventricular function. Reproducibility was assessed in a subset of 20 patients using intraclass correlation coefficients (ICC), coefficient of variation (CV), and Bland–Altman analysis. Results: Investigational RV free-wall strain was significantly reduced in patients with cardiac amyloidosis compared with controls (−15.3 ± 4.1% vs. −21.2 ± 5.4%, p < 0.001). Compared with conventional RV strain, the investigational biventricular tracking approach yielded more negative global RV strain values in both patients with amyloidosis (−15.3 ± 4.1% vs. −13.8 ± 4.8%, p = 0.003) and controls (−21.2 ± 5.4% vs. −17.4 ± 5.8%, p < 0.001). The greatest differences were observed at the apical RV segment. Bland–Altman analysis demonstrated a mean bias of −2.64 percentage points with 95% limits of agreement from −8.41 to +3.12 percentage points. A significant regional deformation pattern along the investigational tracking contour was observed in patients with cardiac amyloidosis (p < 0.001), whereas no significant regional variation was observed in controls. BVS correlated strongly with LV global longitudinal strain (r = 0.83 in amyloidosis; r = 0.58 in controls; r = 0.84 overall; all p < 0.001). Inter- and intra-observer reproducibility of investigational RV free-wall strain was excellent (ICC 0.976 and 0.985, respectively). Conclusions: The investigational biventricular tracking approach is a feasible and highly reproducible method for assessing ventricular longitudinal deformation using a single continuous contour. It provides complementary information while remaining an exploratory investigational technique. Further studies are required to validate its anatomical specificity, clinical applicability, and prognostic value.

Left ventricular systolic dysfunction detected by speckle tracking in hypertensive patients with preserved ejection fraction (cid:2)

Left Atrium Myocardial Remodeling and Prognostic Marker Derived from CMR Feature Tracking in Pediatric Hypertrophic Cardiomyopathy.

BACKGROUND The left atrium is an early sensor of left ventricular (LV) dysfunction. The prognostic value of left atrial (LA) strain derived from CMR Feature-Tracking has been demonstrated in adult patients with hypertrophic cardiomyopathy (HCM); however, its significance in pediatric patients with HCM remains unknown. Our study aims to assess LA myocardial function using multi-parametric CMR and to explore the relationship between LA strains with adverse outcomes in pediatric patients with HCM. METHODS This retrospective study included pediatric patients with HCM who underwent CMR from January 2011 to December 2020. Strain parameters were assessed using CMR -FT analysis. Cox regression analysis was performed to assess the associations between variables and clinical outcomes which included sudden cardiac death (SCD) or equivalent events and heart failure-related events. RESULTS The cohort comprised 284 patients (median age, 15.0 years [interquartile range (IQR) 13.0-18.0]; 184 men) and 42 age- and sex-matched normal controls. Compare with normal controls, pediatric patients with HCM had impaired LA reservoir and conduit strains (all P<0.001), with no evidence of a difference in LA booster strain. After a median follow-up period of 62.8 months, a total of 41 (14.4%) patients reached composite outcomes. After adjusting clinical and imaging parameters in multivariable cox analysis, LA reservoir strain (HR: 0.95, 95% CI: 0.91-0.98, P = 0.007), and conduit strain (HR: 0.92, 95% CI: 0.87-0.97, P = 0.002) remained significantly independent predictors of composite outcomes, but not showed in booster strain. Adding LA reservoir strain or conduit strain in turn to the clinical and imaging model resulted in significant improvements in model performance for both composite outcomes and SCD events, respectively (all p < 0.001). CONCLUSION LA reservoir and conduit strains derived from CMR -FT were impaired in pediatric patients with HCM and showed important prognostic value for adverse clinical outcomes, providing incremental prognostic value when combined in a model with clinical and conventional risk factors.