Increasing region of interest width reduces neonatal circumferential strain.

OBJECTIVE: There is growing interest in speckle tracking echocardiography-derived strain as a measure of left ventricular function in neonates. However, knowledge gaps remain regarding the effect of image acquisition and processing parameters on circumferential strain measurements. The aim of this study was to evaluate the effect of using different region of interest (ROI) widths on speckle tracking derived circumferential strain in healthy neonates. METHODS: Thirty healthy-term-born neonates were examined with speckle-tracking echocardiography in the short-axis view. Circumferential strain values were acquired and compared using two different ROI widths. Furthermore, strain values in the different vendor-defined wall layers were also compared. RESULTS: Increasing ROI width led to a decrease in global circumferential strain (GCS) in the midwall and epicardial layers, the respective decreases in strain being -23.4 ± .6% to -22.0 ± 1.1%, p < .0001 and 18.5 ± 1.7% to -15.6 ± 2.0%, p < .0001. Segmental analyses were consistent with these results, apart from two segments in the midwall. There was no statistically significant effect on strain for the endocardial layer. A gradient was seen where strain increased from the epicardial to endocardial layers. CONCLUSION: Increasing ROI width led to a decrease in GCS in the midwall and epicardium. There is an increase in circumferential strain when moving from the epicardial toward the endocardial layer. Clinicians wishing to implement circumferential strain into their practice should consider ROI width variation as a potential confounder in their measurements.

Characteristics and prognostic value of cardiac magnetic resonance strain analysis in patients with different phenotypes of heart failure.

Background: Strain analysis of cardiac magnetic resonance imaging (CMR) is important for the prognosis of heart failure (HF). Herein, we aimed to identify the characteristics and prognostic value of strain analysis revealed by CMR in different HF phenotypes. Methods: Participants with HF, including HF with reduced ejection fraction, HF with mildly reduced ejection fraction, and HF with preserved ejection fraction, and controls were enrolled. The baseline information and clinical parameters of participants were collected, and echocardiography and CMR examination were performed. Three-dimensional strain analysis was performed in the left ventricle, right ventricle, left atrium, and right atrium using CMR. A multifactor Cox risk proportional model was established to assess the influencing factors of cardiovascular adverse events in patients with HF. Results: During a median follow-up of 999 days (range: 616-1334), 20.6% of participants (73/354) experienced adverse events (HF readmission and/or cardiovascular death). Univariable Cox regression revealed that a 1% increase in left atrial global longitudinal strain (LAGLS) was associated with a hazard ratio (HR) of 1.21 [95% confidence interval (CI):1.15-1.28; P < 0.001]. Left ventricular global circumferential strain (LVGCS) (HR, 1.18; 95% CI: 1.12-1.24; P < 0.001), and left ventricular global longitudinal strain (LVGLS) (HR, 1.27; 95% CI: 1.20-1.36; P < 0.001) were also associated with HF hospitalizations and cardiovascular deaths. Among clinical variables, hypertension (HR, 2.11; 95% CI: 1.33-13.36; P = 0.002), cardiomyopathy (HR, 2.26; 95% CI: 1.42-3.60; P < 0.001) were associated with outcomes in univariable analysis. Multivariable analyses revealed that LAGLS (95% CI: 1.08-1.29; P < 0.001), LVGLS (95% CI:1.08-1.29; P < 0.001) and LVGCS (95% CI: 1.19-1.51; P < 0.001) were significantly associated with outcomes. Among clinical variables, hypertension (95% CI: 1.09-3.73; P < 0.025) remained a risk factor. Conclusion: CMR plays an obvious role in phenotyping HF. Strain analysis, particularly left atrial and left ventricular strain analysis (LAGLS, LVGLS, and LVGCS) has good value in predicting adverse outcome events.

Mitral regurgitation increases systolic strains in remote zone and worsens left ventricular dyssynchrony in a swine model of ischemic cardiomyopathy.

Background: Ischemic mitral regurgitation (IMR) imposes volume overload on the left ventricle (LV), accelerating adverse LV remodeling. In this study, we sought to investigate the impact of volume overload due to IMR on regional myocardial contractile mechanics. Methods: Ten Yorkshire swine were induced with myocardial infarction (MI) by occluding the left circumflex coronary artery (LCx). Cardiac MRI was performed at baseline (BL) and 2.5 months (2.5M) post-MI. IMR was quantified with epicardial echocardiography 3 months post-MI. The animals were then assigned to 2 groups: no/mild MR (nmMR, n = 4) and moderate/severe MR (msMR, n = 6). MRI images were analyzed to assess infarction size, end-diastolic and end-systolic volume (EDV and ESV, respectively), ejection fraction (EF), longitudinal strain (LS), circumferential strain (CS), and systolic dyssynchrony index (SDI). The myocardial region was divided into infarction, border, and remote zones based on the LCx-supplied region. Results: There was no difference in the infarction size. Group-wise comparison of LS and CS between BL and 2.5M demonstrated that LS and CS in the infarction zone and the border zone decreased at 2.5M in both groups. However, LS and CS in the remote zone were elevated only in the msMR group (LS: -9.81 ± 3.96 vs. -12.58 ± 5.07, p < 0.01; CS; -12.78 ± 3.81 vs. -16.09 ± 3.33, p < 0.01) at 2.5M compared to BL. The SDI of CS was significantly elevated in the msMR group (0.1255 vs. 0.0974, p = 0.015) at 2.5M compared to BL. Conclusions: Elevated LS and CS in the remote zone were observed in moderate/severe MR and ventricular dyssynchrony. These elevated cardiac strains, coupled with ventricular dyssynchrony, may contribute to the progression of MR, thereby accelerating heart failure.

Assessment of new-onset heart failure prediction in a diabetic population using left ventricular global strain: a prospective cohort study based on UK Biobank.

Background: Impaired glucose utilization influences myocardial contractile function. However, the prognostic importance of left ventricular global radial strain (LV-GRS), left ventricular global circumferential strain (LV-GCS), and left ventricular global longitudinal strain (LV-GLS) in predicting new-onset heart failure (HF) in a population with diabetes is unclear. Methods: The study design is prospective cohort from the UK Biobank. Totally 37,899 participants had a complete data of cardiac magnetic resonance (CMR), of which 940 patients with diabetes were included, and all the participants completed follow-up. LV-GRS, LV-GCS, and LV-GLS were measured by completely automated CMR with tissue tagging. Cox proportional hazards regression analysis and C-index was performed to evaluate the association between the strain parameters and the new-onset HF in patients suffering from diabetes. Results: The average age of the 940 participants was 57.67 ± 6.97 years, with males comprising 66.4% of the overall population. With an average follow-up period of 166.82 ± 15.26 months, 35 (3.72%) patients reached the endpoint (emergence of new-onset HF). Significant associations were found for the three strain parameters and the new-onset HF (LV-GRS-hazard ratio [HR]: 0.946, 95% CI: 0.916-0.976; LV-GCS-HR: 1.162, 95% CI: 1.086-1.244; LV-GCS-HR: 1.181, 95% CI: 1.082-1.289). LV-GRS, LV-GCS, and LV-GLS were closely related to the related indicators to HF, and showed a high relationship to new-onset HF in individuals with diabetes at 5 and 10 years: LV-GRS: 0.75 (95% CI, 0.41-0.94) and 0.76 (95% CI, 0.44-0.98), respectively; LV-GCS: 0.80 (95% CI, 0.50-0.96) and 0.75 (95% CI, 0.41-0.98), respectively; LV-GLS: 0.72 (95% CI, 0.40-0.93) and 0.76 (95% CI, 0.48-0.97), respectively. In addition, age, sex, body mass index (BMI), and presence of hypertension or coronary artery disease (CAD) made no impacts on the association between the global strain parameters and the incidence of HF. Conclusion: LV-GRS, LV-GCS, and LV-GLS is significantly related to new-onset HF in patients with diabetes at 5 and 10 years.

Methodology for the induction of myocardial infarction and cardiac function evaluation.

Cardiovascular disease (CVD) is the main cause of death worldwide, with myocardial infarction (MI) being the most prevalent pathology involved in CVD. MI is characterized by a deficiency in oxygen supply to the myocardium, thereby promoting ventricular remodeling of the ischemic and remote zone of the heart. Cardiac remodeling associated with MI could promote the development of heart failure and finally death. For these reasons, it is important to develop animal models that mimic human cardiac disease which could help to identify new mechanisms involved in the pathology and, consequently, develop new therapeutic strategies. We herein describe in detail a protocol for MI induction with low mortality rate (<15%) in rats by ligation of the left anterior descending artery. In addition, we also describe two imaging techniques which allow to evaluate cardiac structure and function-including deformation parameters in rats such as transthoracic echocardiography and cardiac magnetic resonance. This animal model could be useful for acute and chronic studies and for evaluating the potential usefulness of different treatments.

Prognostic Value of Segmental Strain After ST-Elevation Myocardial Infarction: Insights From the EARLY Assessment of MYOcardial Tissue Characteristics by Cardiac Magnetic Resonance (EARLY-MYO-CMR) Study.

BACKGROUND: The prognostic value of left ventricular segmental strain (SS) in ST-elevation myocardial infarction (STEMI) remains unclear. HYPOTHESIS: To assess the prognostic value and application of SS. STUDY TYPE: Retrospective analysis of a prospective registry. POPULATION: Five hundred and forty-four patients after STEMI (500 in Cohort 1, 44 in Cohort 2). FIELD STRENGTH/SEQUENCE: 3 T, balanced steady-state free precession, gradient echo, and gradient echo contrast-enhanced images. ASSESSMENT: Participants underwent cardiac MR during the acute phase after STEMI. Infarct-related artery (IRA) strain was determined based on SS obtained from cine images. The primary endpoint was the composite of major adverse cardiovascular events (MACEs) after 8 years of follow-up. In Cohort 2, SS stability was assessed by MR twice within 8 days. Contrast and non-contrast risk models based on SS were established, leading to the development of an algorithm. STATISTICAL TEST: Student's t-test, Mann-Whitney U-test, Cox and logistic regression, Kaplan-Meier analysis, net reclassification index (NRI). P < 0.05 was considered significant. RESULTS: During a median follow-up of 5.2 years, 83 patients from Cohort 1 experienced a MACE. Among SS, IRA peak circumferential strain (IRA-CS) was an independent factor for MACEs (adjusted hazard ratio 1.099), providing incremental prognostic value (NRI 0.180, P = 0.10). Patients with worse IRA-CS (>-8.64%) demonstrated a heightened susceptibility to MACE. Additionally, IRA-CS was significantly associated with microvascular obstruction (MVO) (adjusted odds ratio 1.084) and infarct size (r = 0.395). IRA-CS showed comparable prognostic effectiveness to global peak circumferential strain (NRI 0.100, P = 0.39), also counterbalancing contrast and non-contrast risk models (NRI 0.205, P = 0.05). In Cohort 2, IRA-CS demonstrated stability between two time points (P = 0.10). Based on risk models incorporating IRA-CS, algorithm "HJKL" was preliminarily proposed for stratification. DATA CONCLUSIONS: IRA-CS is an important prognostic factor, and an algorithm based on it is proposed for stratification. LEVEL OF EVIDENCE: 4 TECHNICAL EFFICACY: Stage 2.

Incremental prognostic value of speckle tracking echocardiography and early follow-up echo assessment in predicting left ventricular recovery after reperfusion for ST-segment elevation myocardial infarction (STEMI).

PURPOSE: Up to 50% of patients do not achieve significant left ventricular ejection fraction (LVEF) recovery after primary percutaneous intervention (PPCI) for STEMI. We aimed to identify the echocardiographic predictors for LVEF recovery and assess the value of early follow-up echocardiography (Echo) in risk assessment of post-myocardial infarction (MI) patients. METHODS: One hundred one STEMI patients undergoing PPCI were enrolled provided EF below 50%. Baseline echocardiography assessed LVEF, volumes, wall motion score index (WMSI), global longitudinal strain (GLS), global circumferential strain (GCS), and E/e'. Follow-up echocardiography after 6 weeks reassessed left ventricular volumes, LVEF and GLS.GCS was not assessed at follow up. Patients were classified into recovery and non-recovery groups. Predictors of LVEF recovery and major adverse cardiovascular events (MACE) at 6 months were analysed. RESULTS: The mean change of EF was 8.04 ± 3.32% in group I versus -.39 ± 5.09 % in group II (p < .001). Recovered patients had better baseline GLS, baseline GCS, E/e', and follow-up GLS. Multivariate regression analysis revealed E/e', GCS, and follow-up GLS after 6 weeks to be strong independent predictors for LVEF recovery. Composite MACE was considerably higher in group II (32.7% vs. 4.1%, p < .001) mainly driven by higher heart failure hospitalisation Multivariate regression analysis revealed baseline GLS, E/e', and ejection fraction (EF) percentage recovery as strong independent predictors for MACE. CONCLUSIONS: Multiparametric echocardiographic approach incorporating LVEF, strain parameters, and diastolic function could allow early optimal risk stratification after STEMI treated with PPCI. Follow-up GLS and LVEF percentage change are the strongest predictors for early LV recovery and long term clinical outcome, respectively.

Clinical study of left ventricular structure and function in patients with Anderson-Fabry disease before and after enzyme replacement therapy.

AIMS: Cardiac left ventricular hypertrophy (LVH) is the most common manifestation of heart involvement in Anderson-Fabry disease (AFD). Conventional cardiac imaging is not sensitive enough to detect early signs of LVH in AFD. It remains uncertain whether enzyme replacement therapy (ERT) can prevent LVH progression and improve myocardial function. This study aimed to assess the effectiveness of two-dimensional speckle tracking echocardiography (2D-STE) in early detection of cardiac involvement in AFD and monitoring the efficacy of agalsidase alfa and agalsidase beta therapy. METHODS AND RESULTS: Thirteen consecutive AFD patients and 12 healthy controls underwent standard transthoracic 2D, color Doppler, tissue Doppler echocardiography, and 2D strain analysis. Global longitudinal strain (GLS) and global circumferential strain (GCS) were measured. Diastolic strain rate (SR) was extracted. Compared to healthy subjects, AFD patients without LVH showed lower levels of GLS (p < 0.001) and SR (p = 0.01), while there was no difference in GCS (p = 0.82). Following treatment, apical circumferential strain (ACS) showed improvement (p = 0.01). CONCLUSION: In AFD patients without LVH, there was a decrease in global and segmental LS. Higher plasma Lyso-GL-3 concentrations were associated with elevated ACS values after ERT, indicating that ACS in AFD patients without LVH, albeit normal, is involved in early LV dysfunction.

MRI Quantification of Left Atrial Circumferential Strain in Mitral Regurgitation: A Feasibility and Reproducibility Study.

BACKGROUND: MRI-derived left atrial (LA) longitudinal strain has been shown to be a marker for mitral regurgitation, but the utility of LA circumferential strain remains unclear. PURPOSE: To assess feasibility and reproducibility of LA circumferential strain, identify changes in mitral regurgitation patients compared to healthy volunteers, and determine strain's association with mitral regurgitation severity and cardiac function. STUDY TYPE: Retrospective. POPULATION: 52 mitral regurgitation patients, 12 healthy volunteers. FIELD STRENGTH/SEQUENCE: Steady-state free precession cine and 2D phase contrast sequences at 1.5T. ASSESSMENT: Peak LA circumferential strain was computed in each of three short-axis slices (superior, mid, and inferior) and longitudinal strain computed from long-axis slices using MRI feature-tracking software. Strain test-retest reproducibility was determined from two repeat studies in healthy volunteers. STATISTICAL TESTS: LA circumferential strain test-retest reproducibility was assessed by intra-class correlation coefficient (ICC). Strain was compared between cohorts using Student's t-test or Mann-Whitney U. Mitral regurgitation severity association with strain and LV function was assessed using Spearman correlation and multivariable regression. Significance was defined as P < 0.05. RESULTS: LA circumferential strain assessment was feasible in all subjects with moderate reproducibility in the superior (ICC = 0.74), mid LA (ICC = 0.71), and inferior LA (ICC = 0.63). In mitral regurgitation patients, LA circumferential strain was significantly lower in the superior (11.86% [6.5%,19.2%] vs. 18.73% ± 6.7%) and mid LA slices (18.41% ± 9.5% vs. 28.7% ± 10.4%) compared to healthy volunteers. Mitral regurgitation severity significantly associated with mid LA circumferential strain (ß = -0.03) and LAV significantly associated with superior LA circumferential strain (ß = -2.09), both independent of LA longitudinal strain and CO. DATA CONCLUSION: LA circumferential strain assessment is feasible with moderate reproducibility. Compared to healthy volunteers, patients had significantly lower LA circumferential strain. Mitral regurgitation severity and LAV were significantly associated with LA circumferential strain independent of LA longitudinal strain. EVIDENCE LEVEL: 3 TECHNICAL EFFICACY: Stage 2.

Association Between Left Ventricular Strains and Cardiovascular Risk Factors in Type 2 Diabetic Patients: a Controlled Cross-sectional Study.

Background: Cardiovascular complications are the leading cause of death in diabetic patients. Speckle tracking echocardiography can early detect left ventricular systolic dysfunction even when normal ejection fraction. Objective: The study aims to evaluate left ventricular systolic function by Speckle tracking echocardiography and its relation with cardiovascular risk factors in type 2 diabetic patients. Methods: A controlled cross-sectional descriptive study was conducted on 150 patients (75 type 2 diabetic patients and 75 controls). Results: Type 2 diabetic patients had global longitudinal strain (-17.02±3.06%), global circumferential strain (-29.04±6.39%) were lower than the control group (p<0.05). Global longitudinal strain was correlated with systolic blood pressure (r=0.3), diastolic blood pressure (r=0.2), fasting plasma glucose (r=0.5), HbA1c (r=0.2), total cholesterol (r=-0.25), (p<0.05). Global circumferential strain was correlated with systolic blood pressure (r=0.2), diastolic blood pressure (r=0.2), HDL (r=-0.3), (p<0.05). Conclusion: Type 2 diabetic patients have reduced global longitudinal strain and global circumferential strain. The reduction of global longitudinal strain, global circumferential strain was correlated with cardiovascular risk factors (hypertension, not good glycemia control, increasing BMI, dyslipidemia).

Role of two-dimensional strain echocardiographic parameters in suspected acute coronary syndrome patients with initial non-diagnostic electrocardiogram and troponins: An observational study.

INTRODUCTION: Diagnosis of acute coronary syndrome (ACS) is often challenging especially in presence of initial normal troponins and non-specific electrocardiogram. The index study aimed at determining the diagnostic value of strain echocardiography in patients with suspected ACS but with non-diagnostic electrocardiogram and echocardiography findings. METHODS: The study was conducted on 42 patients with suspected ACS and non-diagnostic electrocardiograms, normal quantitative troponin-T levels, and left ventricular function. All patients underwent conventional and 2D-strain echocardiography followed by coronary angiography, within 24 h of admission. Patients with regional wall motion abnormalities (RWMA), valvular heart disease, suspected myocarditis, and past coronary artery disease (CAD) were excluded. RESULTS: Amongst the global strains, the global circumferential strain (GCS) was significantly reduced (p = .014) amongst those with significant CAD on angiography as opposed to global longitudinal strain (GLS) which was similar in the two groups (p = .33). The GCS/GLS ratio was also significantly reduced in patients with significant CAD compared to those with normal/mild disease on coronary angiography (p = .025). Both the parameters had good accuracy in predicting significant CAD. GCS displayed a sensitivity of 80% and a specificity of 86% at an optimal cut-off 31.5% (AUROC: .93, 95% CI: .601-1.000; p = .03), and likewise GCS/GLS ratio had a sensitivity of 80% and a specificity and 86% at a cut-off of 1.89% (AUROC: .86, 95% CI: .592-1.000; p = .049). GLS and peak atrial longitudinal strain (PALS) did not differ significantly in patients with/without significant CAD (p = .32 and .58, respectively). CONCLUSION: GCS and GCS/GLS ratio provides incremental value in comparison to GLS, PALS, and tissue Doppler indices (E/e') in patients with suspected ACS and non-diagnostic electrocardiogram and troponins. GCS at cut-off of >31.5% and GCS/GLS ratio >1.89 can reliably exclude patients with significant CAD in this setting.

Early markers of Sepsis Cardiomyopathy in Murine Models by Echocardiography.

BACKGROUND: Strain echocardiography (SE) is a procedure for analyzing myocardial dysfunction that is known to be less dependent on preload and afterload of heart function. Unlike dimension-based parameters, like ejection fraction (EF) and fractional shortening (FS), SE measures cardiac function by tracking cardiac tissue deformation and anomalies throughout the cardiac cycle. Although SE is proven to locate myocardial ailments in various heart diseases, few studies exist regarding using SE relevant to sepsis pathophysiology. OBJECTIVE: The study aimed to calculate the myocardial strain and strain rates, like longitudianl strain (LS), global radial strain (GRS), and global longitudinal strain (GLS), and to show these to be reduced earlier in cecal ligation and puncture (CLP) and lipopolysaccharide (LPS)-induced sepsis in coordination with an elevation of pro-inflammatory cytokines Methodology: Wild-type mice C57BL/6J (WT) were taken in this study and classified as CLP, LPS, and control groups. CLP surgery and LPS injection were given to induce sepsis. Endotoxemic septic shock was induced by intraperitoneal (IP) injection of LPS Escherichia coli. Echocardiography short axis views (SAX), longitudinal strain (LS), global circumferential strain (GCS), and global radial strain (GRS) were measured from the anterior and posterior positions of the septal and lateral walls of the heart. Real-time polymerase chain reaction (RT-PCR) was performed to evaluate post-CLP and LPS to analyze cardiac pro-inflammatory cytokines expressions. Inter- and intra-observer variables were tested by Bland-Altman analyses (BA). All data analysis was performed by GraphPad Prism 6 software. p<0.05 was taken as statistically significant. RESULT: After 48 hours following CLP and LPS-induced sepsis, a significant declination in both longitudinal strain and strain rate (LS and LSR) was identified in the CLP and LPS groups compared to the control group. Strain depression in sepsis was linked with the up-regulation of pro-inflammatory cytokines in RT-PCR analysis. CONCLUSION: In the present study, we found myocardial strain and strain rate parameters, like LS, GRS, and GLS, to be reduced after CLP and LPS-induced sepsis in coordination with the elevation of pro-inflammatory cytokines.

Correlation of myocardial strain by CMR-feature tracking with substrate abnormalities detected by electro-anatomical mapping in patients with nonischemic cardiomyopathy.

BACKGROUND: Late gadolinium enhancement (LGE) detected by cardiac MRI (CMR) has low correlation with low voltage zones (LVZs) detected by electroanatomical mapping (EAM). We aim to study correlation of myocardial strain by CMR- Feature Tracking (FT) alongside LGE with LVZs detected by EAM. METHODS: Nineteen consecutive CMRs of patients with EAM were analyzed offline by CMR-FT. Peak value of circumferential strain (CS), longitudinal strain (LS), and LGE was measured in each segment of the left ventricle (17-segment model). The percentage of myocardial segments with CS and LS > -17% was determined. Percentage area of LGE-scar was calculated. Global and segment-wise bipolar and unipolar voltage was collected. Percentage area of bipolar LVZ (<1.5 mV) and unipolar LVZ (<8.3 mV) was calculated. RESULTS: Mean age was 62±11 years. Mean LVEF was 37±13%. Mean global CS was -11.8±5%. Mean global LS was -11.2±4%. LGE-scar was noted in 74% of the patients. Mean percentage area of LGE-scar was 5%. There was significant correlation between percentage abnormality detected by LS with percentage bipolar LVZ (r = +0.5, p = 0.03) and combined percentage CS+LS abnormality with percentage unipolar LVZ (r = +0.5, p = 0.02). Per-unit increase in CS increased the percentage area of unipolar LVZ by 2.09 (p = 0.07) and per-unit increase in LS increased the percentage area of unipolar LVZ by 2.49 (p = 0.06). The concordance rates between CS and LS to localize segments with bipolar/unipolar LVZ were 79% and 95% compared to 63% with LGE. CONCLUSIONS: Myocardial strain detected by CMR-FT has a better correlation with electrical low voltage zones than the conventional LGE.

Understanding post-surgical decline in left ventricular function in primary mitral regurgitation using regression and machine learning models.

Background: Class I echocardiographic guidelines in primary mitral regurgitation (PMR) risks left ventricular ejection fraction (LVEF) < 50% after mitral valve surgery even with pre-surgical LVEF > 60%. There are no models predicting LVEF < 50% after surgery in the complex interplay of increased preload and facilitated ejection in PMR using cardiac magnetic resonance (CMR). Objective: Use regression and machine learning models to identify a combination of CMR LV remodeling and function parameters that predict LVEF < 50% after mitral valve surgery. Methods: CMR with tissue tagging was performed in 51 pre-surgery PMR patients (median CMR LVEF 64%), 49 asymptomatic (median CMR LVEF 63%), and age-matched controls (median CMR LVEF 64%). To predict post-surgery LVEF < 50%, least absolute shrinkage and selection operator (LASSO), random forest (RF), extreme gradient boosting (XGBoost), and support vector machine (SVM) were developed and validated in pre-surgery PMR patients. Recursive feature elimination and LASSO reduced the number of features and model complexity. Data was split and tested 100 times and models were evaluated via stratified cross validation to avoid overfitting. The final RF model was tested in asymptomatic PMR patients to predict post-surgical LVEF < 50% if they had gone to mitral valve surgery. Results: Thirteen pre-surgery PMR had LVEF < 50% after mitral valve surgery. In addition to LVEF (P = 0.005) and LVESD (P = 0.13), LV sphericity index (P = 0.047) and LV mid systolic circumferential strain rate (P = 0.024) were predictors of post-surgery LVEF < 50%. Using these four parameters, logistic regression achieved 77.92% classification accuracy while RF improved the accuracy to 86.17%. This final RF model was applied to asymptomatic PMR and predicted 14 (28.57%) out of 49 would have post-surgery LVEF < 50% if they had mitral valve surgery. Conclusions: These preliminary findings call for a longitudinal study to determine whether LV sphericity index and circumferential strain rate, or other combination of parameters, accurately predict post-surgical LVEF in PMR.

Prognostic impact of artificial intelligence-based fully automated global circumferential strain in patients undergoing stress CMR.

AIMS: To determine whether fully automated artificial intelligence-based global circumferential strain (GCS) assessed during vasodilator stress cardiovascular (CV) magnetic resonance (CMR) can provide incremental prognostic value. METHODS AND RESULTS: Between 2016 and 2018, a longitudinal study included all consecutive patients with abnormal stress CMR defined by the presence of inducible ischaemia and/or late gadolinium enhancement. Control subjects with normal stress CMR were selected using a propensity score-matching. Stress-GCS was assessed using a fully automatic machine-learning algorithm based on featured-tracking imaging from short-axis cine images. The primary outcome was the occurrence of major adverse clinical events (MACE) defined as CV mortality or nonfatal myocardial infarction. Cox regressions evaluated the association between stress-GCS and the primary outcome after adjustment for traditional prognosticators. In 2152 patients [66 ± 12 years, 77% men, 1:1 matched patients (1076 with normal and 1076 with abnormal CMR)], stress-GCS was associated with MACE [median follow-up 5.2 (4.8-5.5) years] after adjustment for risk factors in the propensity-matched population [adjusted hazard ratio (HR), 1.12 (95% CI, 1.06-1.18)], and patients with normal CMR [adjusted HR, 1.35 (95% CI, 1.19-1.53), both P < 0.001], but not in patients with abnormal CMR (P = 0.058). In patients with normal CMR, an increased stress-GCS showed the best improvement in model discrimination and reclassification above traditional and stress CMR findings (C-statistic improvement: 0.14; NRI = 0.430; IDI = 0.089, all P < 0.001; LR-test P < 0.001). CONCLUSION: Stress-GCS is not a predictor of MACE in patients with ischaemia, but has an incremental prognostic value in those with a normal CMR although the absolute event rate remains low.

Sacubitril/Valsartan Improves Left Atrial and Ventricular Strain and Strain Rate in Patients with Heart Failure with Reduced Ejection Fraction.

BACKGROUND: Data on the impact of sacubitril/valsartan (SV) therapy on phasic left atrial (LA) and left ventricular (LV) strain in heart failure with reduced ejection fraction (HFrEF) are limited. The aim of this study was to evaluate changes in two-dimensional speckle tracking (2D-STE) parameters with SV therapy in HFrEF patients. METHODS: Prospective evaluation of HFrEF patients receiving optimized medical therapy. Two-dimensional speckle tracking (2D-STE) parameters were assessed at baseline and after 6 months of SV therapy. LA strain and strain rate (SR) in reservoir, conduit, and contraction phases were compared with LV longitudinal, radial, and circumferential strain and SR and stratified according to heart rhythm and HFrEF etiology. RESULTS: A total of 35 patients completed the 6-month follow-up, with a mean age of 59 ± 11 years, 40% in atrial fibrillation, 43% with ischemic etiology, and LVEF of 29 ± 6%. There were significant improvements in LA reservoir, conduit, and contractile strain and SR following SV therapy, particularly among patients in sinus rhythm. There were significant improvements in longitudinal, radial, and circumferential LV function indices. CONCLUSION: SV therapy in HFrEF was associated with improved longitudinal, radial, and circumferential function, particularly among patients in sinus rhythm. These findings can provide insights into the mechanisms underlying the improvement of cardiac function and help assess subclinical responses to the treatment.

Link between myocardial deformation phenotyping using longitudinal and circumferential strain and risk of incident heart failure and cardiovascular death.

AIMS: Left ventricular (LV) systolic deformation is altered early in the ventricular disease process despite normal LV ejection fraction (LVEF). These alterations seem to be characterized by decreased global longitudinal strain (GLS) and augmented global circumferential strain (GCS). This study aimed to investigate the link between myocardial deformation phenotyping using longitudinal and circumferential strain and risk of incident heart failure (HF) and cardiovascular death (CD). METHODS AND RESULTS: The study sample was based on the prospective cohort study the 5th Copenhagen City Heart Study (2011-15). All participants were examined with echocardiography following a pre-defined protocol. A total of 2874 participants were included. Mean age was 53±18 years and 60% were female. During a median follow-up of 3.5 years, a total of 73 developed HF/CD. A U-shaped relationship between GCS and HF/CD was observed. LVEF significantly modified the association between GCS and HF/CD (P for interaction <0.001). The optimal transition point for the effect modification was LVEF < 50%. In multivariable Cox regressions, increasing GCS was significantly associated with HF/CD in participants with LVEF ≥ 50% (hazard ratio [HR]=1.12 [95% confidence interval (CI): 1.02; 1.23] per 1% increase), while decreasing GCS was associated with a higher risk of HF/CD in individuals with LVEF < 50% [HR=1.18 (95% CI: 1.05; 1.31) per 1% decrease]. CONCLUSIONS: The prognostic utility of GCS is modified by LVEF. In participants with normal LVEF, higher GCS was associated with increased risk of HF/CD, while the opposite was observed in participants with abnormal LVEF. This observation adds important information to our understanding of the pathophysiological evolution of myocardial deformation in cardiac disease progression.

There is more than just longitudinal strain: Prognostic significance of biventricular circumferential mechanics.

Introduction: Despite the significant contribution of circumferential shortening to the global ventricular function, data are scarce concerning its prognostic value on long-term mortality. Accordingly, our study aimed to assess both left (LV) and right ventricular (RV) global longitudinal (GLS) and global circumferential strain (GCS) using three-dimensional echocardiography (3DE) to determine their prognostic importance. Methods: Three hundred fifty-seven patients with a wide variety of left-sided cardiac diseases were retrospectively identified (64 ± 15 years, 70% males) who underwent clinically indicated 3DE. LV and RV GLS, and GCS were quantified. To determine the prognostic power of the different patterns of biventricular mechanics, we divided the patient population into four groups. Group 1 consisted of patients with both LV GLS and RV GCS above the respective median values; Group 2 was defined as patients with LV GLS below the median while RV GCS above the median, whereas in Group 3, patients had LV GLS values above the median, while RV GCS was below median. Group 4 was defined as patients with both LV GLS and RV GCS below the median. Patients were followed up for a median of 41 months. The primary endpoint was all-cause mortality. Results: Fifty-five patients (15%) met the primary endpoint. Impaired values of both LV GCS (HR, 1.056 [95% CI, 1.027-1.085], p < 0.001) and RV GCS (1.115 [1.068-1.164], p < 0.001) were associated with increased risk of death by univariable Cox regression. Patients with both LV GLS and RV GCS below the median (Group 4) had a more than 5-fold increased risk of death compared with those in Group 1 (5.089 [2.399-10.793], p < 0.001) and more than 3.5-fold compared with those in Group 2 (3.565 [1.256-10.122], p = 0.017). Interestingly, there was no significant difference in mortality between Group 3 (with LV GLS above the median) and Group 4, but being categorized into Group 3 versus Group 1 still held a more than 3-fold risk (3.099 [1.284-7.484], p = 0.012). Discussion: The impaired values of both LV and RV GCS are associated with long-term all-cause mortality, emphasizing the importance of assessing biventricular circumferential mechanics. Reduced RV GCS is associated with significantly increased risk of mortality even if LV GLS is preserved.

Circumferential Strain as a Marker of Vessel Reactivity in Patients with Intradialytic Hypotension.

Background and Objectives: Intradialytic hypotension (IDH) complicates 4 to 39.9% of hemodialysis (HD) sessions. Vessels' reactivity disturbances may be responsible for this complication. Two-dimensional speckle tracking is used to assess arterial circumferential strain (CS) as a marker of the effectiveness of the cardiovascular response to the reduction of circulating plasma. Materials and Methods: The common carotid artery (CCA) and common iliac artery (CIA) CSs were recorded using ultrasonography in 68 chronically dialyzed patients before and after one HD session. Results: In patients with IDH episodes (n = 26), the CCA-CS was significantly lower both before (6.28 ± 2.34 vs. 4.63 ± 1.74 p = 0.003) and after HD (5.00 (3.53-6.78) vs. 3.79 ± 1.47 p = 0.010) than it was in patients without this complication. No relationship was observed between CIA-CS and IDH. IDH patients had a significantly higher UF rate; however, they did not differ compared to complication-free patients either in anthropometric or laboratory parameters. Conclusions: Patients with IDH were characterized by lower pre- and post-HD circumferential strain of the common carotid artery. The lower CCA-CS showed that impaired vascular reactivity is one of the most important risk factors for this complication's occurrence.

The influence of chest wall conformation on myocardial strain parameters in a cohort of mitral valve prolapse patients with and without mitral annular disjunction.

PURPOSE: To evaluate the possible influence of chest wall conformation on myocardial strain parameters in a cohort of mitral valve prolapse (MVP) patients with and without mitral annular disjunction (MAD). METHODS: All consecutive middle-aged patients with MVP referred to our Outpatient Cardiology Clinic for performing two-dimensional (2D) transthoracic echocardiography (TTE) as part of work up for primary cardiovascular prevention between March 2018 and May 2022, were included into the study. All patients underwent clinic visit, physical examination, modified Haller index (MHI) assessment (the ratio of chest transverse diameter over the distance between sternum and spine) and conventional 2D-TTE implemented with speckle tracking analysis of left ventricular (LV) global longitudinal strain (GLS) and global circumferential strain (GCS). Independent predictors of MAD presence on 2D-TTE were assessed. RESULTS: A total of 93 MVP patients (54.2 ± 16.4 yrs, 50.5% females) were prospectively analyzed. On 2D-TTE, 34.4% of MVP patients had MAD (7.3 ± 2.0 mm), whereas 65.6% did not. Compared to patients without MAD, those with MAD had: 1) significantly shorter antero-posterior (A-P) thoracic diameter (13.5 ± 1.2 vs 14.8 ± 1.3 cm, p < 0.001); 2) significantly smaller cardiac chambers dimensions; 3) significantly increased prevalence of classic MVP (84.3 vs 44.3%, p < 0.001); 4) significantly impaired LV-GLS (-17.2 ± 1.4 vs -19.4 ± 3.0%, p < 0.001) and LV-GCS (-16.3 ± 4.1 vs -20.4 ± 4.9, p < 0.001), despite similar LV ejection fraction (63.7 ± 4.2 vs 63.0 ± 3.9%, p = 0.42). A-P thoracic diameter (OR 0.25, 95%CI 0.10-0.82), classic MVP (OR 3.90, 95%CI 1.32-11.5) and mitral annular end-systolic A-P diameter (OR 2.76, 95%CI 1.54-4.92) were the main independent predictors of MAD. An A-P thoracic diameter ≤ 13.5 cm had 59% sensitivity and 84% specificity for predicting MAD presence (AUC = 0.81). In addition, MAD distance was strongly influenced by A-P thoracic diameter (r = - 0.96) and MHI (r = 0.87), but not by L-L thoracic diameter (r = 0.23). Finally, a strong inverse correlation between MHI and both LV-GLS and LV-GCS was demonstrated in MAD patients (r = - 0.94 and - 0.92, respectively), but not in those without (r = - 0.51 and - 0.50, respectively). CONCLUSIONS: A narrow A-P thoracic diameter is strongly associated with MAD presence and is a major determinant of the impairment in myocardial strain parameters in MAD patients, in both longitudinal and circumferential directions.