Measures Of Left Ventricular Function Research Articles

Left ventricular diastolic function and cardiotoxic chemotherapy

BackgroundLeft ventricular ejection fraction falls when the myocardium has already lost a significant portion of its functional capacity. There are conflicting data on whether diastolic dysfunction precedes systolic dysfunction after cardiotoxic chemotherapy. We aimed to study systolic and diastolic dysfunction after cardiotoxic chemotherapy and whether diastolic dysfunction can predict subsequent risk of systolic dysfunction. It was an observational prospective cohort study, and patients receiving cardiotoxic chemotherapy were included. Baseline, demographic, and clinical details were recorded. Echocardiographic measurements of left ventricular systolic function, global longitudinal strain, and diastolic function were noted at baseline, three months, and 6 months.ResultsWe included eighty patients. The mean age of the patients was 54.92 ± 7.6 years, predominantly females (80%). The mean left ventricular ejection fraction fell from 64.92 ± 1.96 to 60.97 ± 4.94 at 6 months. Low ejection fraction was seen in 8 (10%) patients at 6 months. The mean global longitudinal strain (GLS) at baseline was − 18.81 ± 0.797 and fell to − 17.65 ± 2.057 at 6 months, with 12 (15%) patients having low GLS (< − 18). Grade 1 diastolic dysfunction was seen in 22 (27.5%) patients, and grade 2 diastolic dysfunction was seen in 3 (3.8%) patients at 6 months. There was a significant decrease in E/A ratio (inflow early diastolic velocity/Inflow late diastolic velocity), mitral tissue Doppler velocity, and an increase in isovolumic relaxation time, mitral valve deceleration time, and E/e′ (inflow early diastolic velocity/tissue Doppler mitral annular velocity), at three months and 6 months. Ejection fraction at 6 months was significantly and negatively correlated with diastolic dysfunction at three months (r = − 0.595, p = 0.02).ConclusionsCardiotoxic chemotherapy is associated with early diastolic dysfunction. Early diastolic dysfunction predicts subsequent left ventricular systolic dysfunction.

Congenital Diaphragmatic Hernia Patients with Left Heart Hypoplasia and Left Ventricular Dysfunction Have Highest Odds of Mortality

To describe the scope of left ventricular (LV) dysfunction and left heart hypoplasia (LHH) in infants with congenital diaphragmatic hernia (CDH), to determine associations with CDH severity, and to evaluate the odds of extracorporeal membrane oxygenation (ECMO) and death with categories of left heart disease. Demographic and clinical variables were collected from a single-center, retrospective cohort of CDH patients from January 2017 through May 2022. Quantitative measures of LV function and LHH were prospectively performed on initial echocardiograms. LHH was defined as ≥2 of the following: Z-score ≤ -2 of any left heart structure or LV end-diastolic volume <3 mL. LV dysfunction was defined as shortening fraction <28%, ejection fraction <60%, or global longitudinal strain <20%. The exposure was operationalized as a four-group categorical variable (LV dysfunction +/-, LHH +/-). Logistic regression models evaluated associations with ECMO and death, adjusting for CDH severity. One-hundred and eight-two patients (80.8% left CDH, 63.2% liver herniation, 23.6% ECMO, 12.1% mortality) were included. Twenty percent demonstrated normal LV function and no LHH (LV dysfunction-/LHH-), 37% normal LV function with LHH (LV dysfunction-/LHH+), 14% LV dysfunction without LHH (LV dysfunction+/LHH-), and 28% both LV dysfunction and LHH (LV dysfunction+/LHH+). There was a dose-response effect between increasing severity of left heart disease, ECMO use, and mortality. LV dysfunction+/LHH+ infants had the highest odds of ECMO use and death, after adjustment for CDH severity [OR (95% CI); 1.76 (1.20,2.62) for ECMO, 2.76 (1.63, 5.17) for death]. In our large single-center cohort, CDH patients with LV dysfunction+/LHH+ had the highest risk of ECMO use and death.

Abstract P489: Intake of Fiber-Rich Foods is Favorably Associated With Cardiac Structure and Function: The Coronary Artery Risk Development in Young Adults (CARDIA) Study

Background: Abnormal cardiac phenotypes, including left ventricular (LV) structure and function, are subclinical characteristics, detectable before experiencing heart failure (HF) symptoms. Identifying lifestyle risk factors of abnormal cardiac phenotypes can help to prevent or slow down the progression to HF and ultimately reduce the burden of the aging heart. Therefore, we aimed to identify the associations of carbohydrate (CHO) quality and fiber-rich foods with LV structure and function. Methods: We studied 3,171 Black and White adults in the Coronary Artery Risk Development in Young Adults (CARDIA) study. Dietary intake was assessed via Diet History and averaged across years 0 (1985-86), 7, and 20. CHO:fiber ratio was created to define CHO quality (greater CHO:fiber ratio representing lower CHO quality). The fiber-rich food score was created based on the servings of whole grains, fruits, vegetables, nuts, and legumes. LV structure and function measures were assessed via echocardiography at years 25 and 30 and were the dependent variables in linear repeated measures models, including random intercepts for individuals. CHO:fiber ratio was treated as a fixed effect. Results: Study participants were 25.1 (range: 18-30, SD: 3.61) years old on average at baseline, 57% (1,807 of 3,171) female, and 53% (1,678 of 3,171) White. Higher CHO quality ratio was favorably associated with global longitudinal strain (GLS); while the fiber-rich food score was favorably associated with LV mass index, GLS, and E/e’ ratio after adjusting for demographic and lifestyle characteristics (see table). Conclusions: Our study finding suggests that higher CHO quality is associated with better systolic function and greater intake of fiber-rich foods is associated with better LV structure and function, which support the Dietary Guidelines for Americans and the Dietary Guidance to Improve Cardiovascular Health by the AHA that recommend intakes of high-quality CHO foods such as whole grains, fruit, and vegetables.

Comparing Strain Assessment in Compressed Sensing and Conventional Cine MRI.

The aim of this study is to assess the feasibility of compressed sensing (CS) acceleration methods compared to conventional segmented cine (Seg) cardiac magnetic resonance (CMR) for evaluating left ventricular (LV) function and strain by feature tracking (FT). In this prospective study, 45 healthy volunteers underwent CMR imaging used Seg, threefold (CS3), fourfold (CS4), and eightfold (CS8) CS acceleration. Cine images were scored for quality (1-5 scale). LV volumetric and functional parameters and global longitudinal (GLS), circumferential (GCS), and radial strains (GRS) were quantified. LV volumetric and functional parameters exhibited no differences between Seg and all CS cines (all P > 0.05). The strains were similar for Seg, CS3, and CS4 (all P > 0.05). Similarly, no significant differences were observed in GRS and GCS between Seg and CS8 (all P > 0.05), but the global longitudinal strain was significantly lower for CS8 versus Seg (P < 0.001). Image quality declined with CS acceleration, especially in long-axis views with CS8. CS cine MRI at acceleration factor 4 maintained good image quality and accurate measurements of LV function and strain, although there was a slight reduction in the quality of long-axis images and GLS with CS8. CS acceleration up to a factor of 4 enabled fast CMR evaluations, making it suitable for clinical use.

Inhaled endotoxin induces a systemic neutrophil response without affecting cardiovascular measures in a randomized cross-over exposure study

Objective The gram-negative bacterial cell wall component endotoxin (lipopolysaccharide, LPS) is a key component of particulate matter (PM). PM exposure is associated with cardiovascular morbidity and mortality. However, the contribution of individual components of PM to acute and chronic cardiovascular measures is not clear. This study examines whether systemic inflammation induced by LPS inhalation causes acute changes in cardiovascular physiology measures. Materials and Methods In this double blinded, placebo-controlled crossover study, fifteen adult volunteers underwent inhalation exposure to 20,000 EU Clinical Center Reference Endotoxin (CCRE). Peripheral blood and induced sputum neutrophils were obtained at baseline and six hours post-exposure. Blood pressure, measures of left ventricular function (ejection fraction (LVEF) and global longitudinal strain (LVGLS)), and indices of endothelial function (flow mediated dilation (FMD) and velocity time integral during hyperemia (VTIhyp)) were measured before and after treatment. Wilcoxon sign-rank tests and linear mixed models were used for statistical analysis. Results In comparison with normal saline, LPS inhalation resulted in significant increases in peripheral blood and sputum neutrophils but was not associated with significant alterations in blood pressure, LVGLS, LVEF, FMD, or VTIhyp. Discussion and Conclusions In healthy adults, systemic inflammation after LPS inhalation was not associated with acute changes in cardiovascular physiology. Larger studies are needed to investigate the effects of other PM components on inflammation induced cardiovascular dysfunction.

Echocardiographic parameters of cardiac structure and function in the diagnosis of acute myocarditis in adult patients: A systematic review and meta-analysis.

Transthoracic echocardiography (TTE) plays a key role in the initial work-up of myocarditis where the identification of pathologic structural and functional changes may assist in its diagnosis and management. The aim of this systematic review was to appraise the evidence for the utility of echocardiographic parameters of cardiac structure and function in the diagnosis of myocarditis in adult populations. A systematic literature search of medical databases was performed using PRISMA principles to identify all relevant studies assessing TTE parameters in adult patients with myocarditis (1995-2020; English only; PROSPERO registration CRD42021243598). Data for a range of structural and functional TTE parameters were individually extracted and those with low heterogeneity were then meta-analyzed using a random-effects model for effect size, and assessed through standardized mean difference (SMD). Available data from six studies (with a pooled total of 269 myocarditis patients and 240 controls) revealed that myocarditis can be reliably differentiated from healthy controls using echocardiographic measures of left ventricular (LV) size and systolic function, in particular LV end-diastolic diameter, LV ejection fraction (LVEF) and LV global longitudinal strain (LV-GLS) (p ≤ .01 for all). LV-GLS demonstrated the highest overall effect size, followed by LVEF and LVEDD (SMD: |0.46-1.98|). Two studies also demonstrated that impairment in LV-GLS was associated with adverse cardiovascular outcomes in this population, irrespective of LVEF. LV-GLS demonstrated the greatest overall effect size and therefore ability to differentiate myocarditis populations from healthy controls. GLS was also shown to be a predictor of adverse cardiovascular outcomes, in this population. What is already known on this subject? Myocarditis is a disease process that is often a diagnosis of exclusion, as it frequently mimics other acute cardiac pathologies. Transthoracic echocardiography is traditionally the initial imaging modality used for noninvasive structural assessment in populations with myocarditis. What might this study add? This study demonstrates that left ventricular (LV) global longitudinal strain, LV ejection fraction and LV end-diastolic diameter can differentiate between myocarditis patients and healthy controls. LV-GLS demonstrated the greatest overall effect size when comparing these two populations, in comparison to the other measures. How might this impact on clinical practice? This study demonstrates that assessment of myocardial deformation indices allows for sensitive discrimination between myocarditis patients from healthy controls. Routine assessment of LV-GLS may serve as an important diagnostic tool in the acute care setting.

S-100β level is closely associated with myocardial work in patients with acute ischemic stroke

BackgroundThe more severe the acute stroke is, the more serious myocardial damage is. This study aimed to determine the relationship between myocardial work and S100β, a quantitative biomarker of active cerebral lesions, in patients with acute ischemic stroke (AIS). MethodsA total of 63 patients with AIS were examined by myocardial work echocardiography, 4D echocardiography with the measurement of left ventricular (LV) myocardial work, volume and function within 24-48 h of symptom onset, respectively. Their plasma S100β was measured from a peripheral blood sample within 2-6 h of symptom onset. ResultsPatients with elevated S-100β level had significantly increased ratios of peak early diastolic transmitral filling velocity to peak early diastolic lateral mitral annulus tissue velocity(E/e’) and global longitudinal strain (GLS), and significantly reduced global work index(GWI) and global constructive work (GCW) compared with those with normal S-100β level (p < 0.05). S-100β positively correlated with E/e’(r = 0.878, p < 0.0001) and GLS (r = 0.511, p = 0.002) but negatively correlated with GWI(r = −0.409, p = 0.034) and GCW(r = −0.353, p = 0.041). S-100β showed an excellent ability to differentiate if a reduced GWI [cut-off value, 120.79 pg/mL; area under receiver operating characteristic curve (AUC), 1.000; sensitivity, 100%; specificity, 100%], GCW (cut-off value, 120.79 pg/mL;AUC,1.000; sensitivity,100%; specificity, 100%) and an increased E/e’ (cut-off value, 91.1 pg/mL;AUC,0.913; sensitivity,80%; specificity, 100%) or not, but poor ability to differentiate if an increased GLS(cut-off value, 91.1 pg/mL; AUC,0.576; sensitivity,63.64%; specificity, 83.33%) or not. ConclusionS-100β level is closely associated with LV function. It is highly competent in determining an impaired myocardial work in patients with AIS.

Kiosk 5R-FB-11 - Utility of Cardiac MRI Scan in Accurate Measurement of Left Ventricular Function: Establishing CMR Service in a Developing Country

Kiosk 5R-FB-11 - Utility of Cardiac MRI Scan in Accurate Measurement of Left Ventricular Function: Establishing CMR Service in a Developing Country

Plasma Ferritin Levels, Incident Heart Failure, and Cardiac Structure and Function: The ARIC Study

BackgroundWhether iron deficiency contributes to incident heart failure (HF) and cardiac dysfunction has important implications given the prevalence of iron deficiency and the availability of several therapeutics for iron repletion. ObjectivesThe aim of this study was to estimate the associations of plasma ferritin level with incident HF overall, HF phenotypes, and cardiac structure and function measures in older adults. MethodsParticipants in the ongoing, longitudinal ARIC (Atherosclerosis Risk In Communities) study who were free of prevalent HF and anemia were studied. The associations of plasma ferritin levels with incident HF overall and heart failure with preserved ejection fraction (HFpEF) and heart failure with reduced ejection fraction (HFrEF) were estimated using Cox proportional hazards regression models. Linear regression models estimated the cross-sectional associations of plasma ferritin with echocardiographic measures of cardiac structure and function. ResultsThe cohort included 3,472 individuals with a mean age of 75 ± 5 years (56% women, 14% Black individuals). In fully adjusted models, lower ferritin was associated with higher risk for incident HF overall (HR: 1.20 [95% CI: 1.08-1.34] per 50% lower ferritin level) and higher risk for incident HFpEF (HR: 1.28 [95% CI: 1.09-1.50]). Associations with incident HFrEF were not statistically significant. Lower ferritin levels were associated with higher E/e′ ratio and higher pulmonary artery systolic pressure after adjustment for demographics and HF risk factors but not with measures of left ventricular structure or systolic function. ConclusionsAmong older adults without prevalent HF or anemia, lower plasma ferritin level is associated with a higher risk for incident HF, HFpEF, and higher measures of left ventricular filling pressure.

Echocardiographic measurements of left ventricular dimensions and function in newborns with omphalocele and pulmonary

PurposeThe purpose of this study was to explore echocardiographic parameters of the left ventricle (LV) in relation to the outcomes of omphalocele neonates with pulmonary hypertension (PH).MethodsThis retrospective study was conducted among omphalocele patients with PH born from 2019 to 2020. Patients in this study did not have additional severe malformations or chromosomal aberrations. Patients who died under palliative care were excluded. The echocardiographic parameters of LV were obtained within 24 h after birth. Clinical and outcomes data were recorded, echocardiograms evaluated for left ventricular internal dimension in end-diastole (LVIDd), end-diastolic volume (EDV), stroke volume (SV) and cardiac output index (CI), among others.ResultsThere were 18 omphalocele newborns with PH, of whom 14 survived and 4 died. Both groups were comparable in the baseline characteristics. Non-survival was associated with a smaller LV [LVIDd (12.2 mm versus15.7 mm, p < 0.05), EDV (3.5 ml versus 6.8 ml, p < 0.05)] and with worse systolic function [SV (2.3 ml versus 4.2 ml, p < 0.05), and CI (1.7 L/min/m2 versus 2.9 L/min/m2, p < 0.01)].ConclusionIn the cohort of omphalocele patients with PH, lower LVIDd, EDV, SV and CI were associated with mortality.Level of evidenceLevel III.

Decline in Left Ventricular Early Systolic Function with Worsening Kidney Function in Children with Chronic Kidney Disease: Insights from the 4C and HOT-KID Studies

Adults with childhood-onset chronic kidney disease (CKD) have an increased risk of cardiovascular disease. First-phase ejection fraction (EF1), a novel measure of early systolic function, may be a more sensitive marker of left ventricular dysfunction than other markers in children with CKD. To examine whether EF1 is reduced in children with CKD. Children from the 4C and HOT-KID studies were stratified according to estimated glomerular filtration rate (eGFR). The EF1 was calculated from the fraction of left ventricular (LV) volume ejected up to the time of peak aortic flow velocity. The EF1 was measured in children ages 10.9±3.7 (mean±SD) years, 312 with CKD and 63 healthy controls. The EF1 was lower, while overall ejection fraction was similar, in those with CKD compared with controls and decreased across stages of CKD (29.3%±3.7%, 23.5%±4.5%, 19.8%±4.0%, 18.5%±5.1%, and 16.7%±6.6% in controls, CKD 1, 2, 3, and≥4, respectively, P<.001). The relationship of EF1 to eGFR persisted after adjustment for relevant confounders (P<.001). The effect size for association of measures of LV structure or function with eGFR (SD change per unit change in eGFR) was greater for EF1 (β=0.365, P<.001) than for other measures: LV mass index (β=-0.311), relative wall thickness (β=-0.223), E/e' (β=-0.147), and e' (β=0.141) after adjustment for confounders in children with CKD. Children with CKD exhibit a marked and progressive decline in EF1 with falling eGFR. This suggests that EF1 is a more sensitive marker of LV dysfunction when compared to other structural or functional measures and that early LV systolic function is a key feature in the pathophysiology of cardiac dysfunction in CKD.

Echocardiographic nomograms for left ventricular parameters in 13,454 infants

Abstract Background Cardiac dimensions and function are key parameters in the management of children with cardiopulmonary abnormalities and are important predictors of clinical outcome. In particular, left ventricular (LV) dimensions and function are important predictors of clinical outcome and prognosis. In pediatric echocardiography, nomograms are essential in the separation of normal variation from pathological conditions and ascertaining normal growth. However, data from cohorts of newborns are limited, and current nomograms remain an insufficient approximation of the range of values that should be considered normal. Purpose We developed nomograms and Z scores for two-dimensional echocardiographic measurements of LV structure and function in a large group of healthy newborns. Methods Our study population included newborns from a large population study of newborns (n &amp;gt;25,000) who were born at term to healthy mothers, had a systematic transthoracic echocardiogram (TTE) performed within 30 days of birth, and with no signs of any major congenital heart diseases. We developed nomograms for 10 LV parameters by modelling these parameters as a function of body surface area (BSA) through joint modelling of the mean, standard deviation, skewness, and kurtosis. We then evaluated the impact of infant sex and age at time of echocardiography on the model fit. Results The 13,454 infants in the study population (48.5% females), had a median age of 12 days at TTE for both boys and girls (interquartile range IQR 8–15 and 8–12 days, respectively), and a median BSA of 0.23 m2 (IQR 0.22 m2 - 0.24 m2). All nomograms had acceptable goodness-of-fit within strata of sex. In contrast, model fit was worse for infants examined &amp;lt;7 days of age, compared with those examined from 7 to 30 days of age, necessitating the creation of separate nomograms for the two age groups. Examples of the plotted Z scores of one of the 10 LV parameters is shown in the figure. Conclusions We provide a large normative dataset and Z scores for echocardiographic measures of LV structure and function in neonates. Normative data is crucial in the management of patients with heart disease and these results provide a needed tool for evaluation of LV size and function in the newborn population.Plotted Z scores of the IVSd

Paradoxical increase in E/e' during severe central hypovolemia in healthy humans

Abstract Introduction The ratio of mitral blood inflow to mitral annular tissue velocity in early diastole (E/e') is widely used as an index of left ventricular (LV) diastolic dysfunction. Theoretically, it is considered that e’ can correct the effect of LV relaxation on E, and thus E/e’ can be applied for the prediction of LV filling pressures in patients with cardiac diseases. However, recent guidelines indicate that E/e’ may not provide a reliable estimate of filling pressures in healthy subjects. Indeed, previous studies have reported that E/e' did not decrease during acute central hypovolemia because both E and e’ are similarly reduced by low preload condtions. However, it is possible that E/e' did not decrease since central hypovolemia are not critical in the previous studies. Purpose The purpose of the present study was to clarify the change of E/e’ during severe central ypovolemia induced by lower body negative pressure. Methods Twelve healthy men (25±5 years old) underwent 2D Doppler and 3D echocardiography during graded lower body negative pressure (LBNP) up to presyncope. We measured LV diastolic function indices by 2D echocardiography including septal and lateral mitral annular early diastolic velocities (e’), and early (E) and late (A) mitral inflow velocities. In addition, we measured LV function indices by 3D echocardiography including end-diastolic volume (EDV), end-systolic volume (ESV), stroke volume (SV), ejection fraction (EF), global longitudinal strain (GLS), global circumferential strain (GCS), twist and peak untwisting rate. We compared echocardiography indices before LBNP (Baseline) with those at maximal LBNP (LBNPmax) and at half of the maximal LBNP (LBNP1/2max). Results E/e’ (Baseline: 5.8±0.8, LBNP1/2max: 5.4±1.0, LBNPmax: 7.8±2.3, mean±SD, p&amp;lt;0.01, ANOVA) did not change at the LBNP1/2max but increased only at the LBNPmax. E (80±11, 59±10, 62±12 cm/sec, p&amp;lt;0.01) and E/A (2.2±0.8, 1.5±0.5, 1.0±0.3, p&amp;lt;0.01) decreased at the LBNP1/2max as compared to baseline but did not change from LBNP1/2max to LBNPmax. e’ (14.1±2.0, 11.1±1.5, 8.2±2.2 cm/sec, p&amp;lt;0.01) decreased in response to LBNP. LV EF (62±3, 55±5, 43±9 %, p&amp;lt;0.01), LV GLS (-20.5±2.8, -17.6±2.7, -13.6±4.7 %, p&amp;lt;0.01), and LV GCS (-31.2±3.7, -26.8±3.3, -19.4±5.3 %, p&amp;lt;0.01) decreased in response to LBNP. LV twist (15.2±5.1, 14.5±5.4, 20.9±7.7 °, p&amp;lt;0.01) and LV peak untwisting rate (-138±42, -164±50, -245±88 °/cm, p&amp;lt;0.01) increased only at the LBNPmax. Conclusion The present study for the first time showed that E/e’ paradoxically increased during acute severe hypovolemia in healthy humans. This paradox was likely caused by well-preserved E, while e’ decreased in response to acute severe central hypovolemia. The present finding also showed that peak untwisting rate was increased only at severe central hypovolemia, suggesting that the well-preserved E may be caused by high pressure gradient from left atrium to LV induced by enhanced LV untwisting suction function.Key results of this study①Key results of this study②

Abstract 18068: Isometric Handgrip Exercise Myocardial Perfusion Reserve Correlates With Coronary Microvascular Dysfunction and Abnormal Left Ventricular Strain: A Report From the Women’s Ischemia Syndrome Evaluation Pre-Heart Failure With Preserved Ejection Fraction Study

Background: Impaired coronary artery response to isometric handgrip exercise (IHE) has previously been demonstrated to reflect endothelial dysfunction, an important contributor to ischemia with no obstructive coronary arteries (INOCA) and coronary microvascular dysfunction (CMD). Stress perfusion cardiac magnetic resonance (CMR) imaging is typically performed with pharmacologic stress using myocardial perfusion reserve index (MPRI) as a measure of CMD. IHE-MPRI has not been comprehensively studied in patients with INOCA, who are at risk for heart failure with preserved ejection fraction (HFpEF). Hypothesis: IHE-MPRI is related to CMD measured by pharm-MPRI and left ventricular (LV) structural and functional abnormalities in INOCA patients at risk for HFpEF. Methods: Participants with INOCA underwent comprehensive CMR with first-pass perfusion with adenosine or regadenoson, rest, and IHE. MPRI was adjusted to rest rate-pressure product (RPP). Lack of a satisfactory IHE response (defined as increase in heart rate≥10 bpm or systolic blood pressure ≥10 mmHg) was excluded. CMR measures of LV structure, function, MPRI, T1 and T2 mapping were analyzed using commercial software, blinded to clinical data. Pearson correlations were performed. Results: Of the participants (n=44) with IHE-MPRI, mean age was 55±11 years, body mass index 27±7 kg/m 2 , and 98% female, 31% hypertension, 12.5% diabetes, 19% hyperlipidemia. IHE-MPRI adjusted for rest RPP significantly correlated positively with pharm-MPRI and inversely with time to peak strain, diastolic strain measures and myocardial T2 ( Figure ). IHE-MPRI was not related to resting or IHE heart rate, systolic strain, LV mass, volumes, mass-volume ratio, native T1 or extracellular volume. Conclusion: IHE-MPRI relates to CMD and LV strain among patients with INOCA. Measurement of IHE-MPRI may improve understanding of CMD and LV structural and functional abnormalities that may contribute to development of HFpEF.

Abstract 17029: Prospective Comparisons and Reference Ranges of Left Ventricular Global Longitudinal Strain by Contemporary Vendor-Neutral Echocardiography Software in Healthy Subjects

Background: Left ventricular global longitudinal strain (LVGLS) by speckle-tracking is an established measure of left ventricular systolic function with many clinical applications. Most strain software traditionally can only analyze strain on scans of the same vendor, however recent advances have allowed them to analyze all scans, although external validation studies are lacking. We aimed to determine the normal ranges and compare two-dimensional LVGLS measurements by contemporary strain software in a healthy prospective cohort. Methods: One-hundred healthy subjects undergoing transthoracic echocardiography during January-April 2023 at our institution were prospectively recruited, 20 per age-group, 50% were female, and 50%GE and 50% Philips scans. TomTec version 51.02 (Autostrain LV), EchoPAC version 206 (AFI) and VVI software were utilized to quantify two-dimensional LVGLS in all patients for comparative and regression analyses. Results: Means (and lower limits of normal)±standard errors LVGLS were -17.1±0.2% (-13.2±0.3%) by TomTec, -17.8±0.3% (-12.7±0.4%) by EchoPAC and -16.3±0.3% (-11.0±0.5%) by VVI, with significant differences on all pairwise T-tests of means (P&lt;0.001-0.017). Means±standard errors LVGLS by strain software for each subgroup are listed in the Table. In multivariable linear regression analyses, factors significantly associated with LVGLS measurements with their beta-coefficients (95%CI) were heart rate (per 1 bpm) 0.05 (0.01-0.07) for TomTec; male sex 1.19 (0.13-2.26) and diastolic blood pressure (per mmHg) 0.06 (0.00-0.12) for EchoPAC; and body mass index (per kg/m 2 ) 0.12 (0.01-0.22) with VVI. Conclusion: All three contemporary strain software demonstrated vendor-neutral properties to measure LVGLS on both GE and Philips scans, with means and lower limits of normal determined, and notably, factors affecting LVGLS values differed by software vendor.

Abstract 16194: Relationship Between Change in Global Longitudinal Strain and Sustained Handgrip Induced Afterload as Assessed Using Invasive Left Ventricular Pressure Measurements and Machine Learning Analytics

Introduction: Global longitudinal strain (GLS) is a sensitive, quantitative measure of left ventricular (LV) systolic function and affected by afterload. We sought to compute the impact of LV systolic pressure (LVP) increase on GLS using handgrip stress during invasive LVP measurements. Methods: Patients undergoing left heart catheterization (n=51; mean age 64+/-11 years; 31% women; Table) for standard of care indications underwent echocardiography during handgrip stress with a catheter in the LV cavity. GLS and LVP were measured simultaneously over 15 seconds of continuous handgrip. GLS and LVP relationships were analyzed using linear regression and machine learning methods. Results: Sustained handgrip (HG) stress significantly increased LVP and reduced GLS. There was no significant correlation between resting and peak HG stress LVP and GLS (p= 0.32 &amp; 0.36, respectively). However, change in GLS was significantly correlated with change in LVP (p&lt;0.0001; Figure) with every 10 unit increase in LVP associated with a 0.6 reduction in GLS. The penalized maximum likelihood machine learning method was used to select key factors associated with the within subject slope of % change in GLS over % change in LVP (median slope -0.53; IQR-0.91 to -0.29). LV ejection fraction was identified as an important predictor of the GLS-LVP slope. LV ejection fraction was significantly associated with the slope (p=0.0005; Figure) with a 10 unit increase in LV ejection fraction corresponding to 0.22 increase in the slope. Conclusions: LV afterload is associated with significant decrements in GLS. LV ejection fraction is an important predictor of the GLS-LVP slope. These data provide the foundation to build models that would account for change in LVP during serial measurements of GLS thus allowing reliable comparison of repeated GLS measurements.

Genome-Wide Association Study of Pericardial Fat Area in 28 161 UK Biobank Participants.

BACKGROUND Pericardial adipose tissue (PAT) is the visceral adipose tissue compartment surrounding the heart. Experimental and observational research has suggested that greater PAT deposition might mediate cardiovascular disease, independent of general or subcutaneous adiposity. We characterize the genetic architecture of adiposity-adjusted PAT and identify causal associations between PAT and adverse cardiac magnetic resonance imaging measures of cardiac structure and function in 28 161 UK Biobank participants. METHODS AND RESULTS The PAT phenotype was extracted from cardiac magnetic resonance images using an automated image analysis tool previously developed and validated in this cohort. A genome-wide association study was performed with PAT area set as the phenotype, adjusting for age, sex, and other measures of obesity. Functional mapping and Bayesian colocalization were used to understand the biologic role of identified variants. Mendelian randomization analysis was used to examine potential causal links between genetically determined PAT and cardiac magnetic resonance-derived measures of left ventricular structure and function. We discovered 12 genome-wide significant variants, with 2 independent sentinel variants (rs6428792, P=4.20×10-9 and rs11992444, P=1.30×10-12) at 2 distinct genomic loci, that were mapped to 3 potentially causal genes: T-box transcription factor 15 (TBX15), tryptophanyl tRNA synthetase 2, mitochondrial (WARS2) and early B-cell factor-2 (EBF2) through functional annotation. Bayesian colocalization additionally suggested a role of RP4-712E4.1. Genetically predicted differences in adiposity-adjusted PAT were causally associated with adverse left ventricular remodeling. CONCLUSIONS This study provides insights into the genetic architecture determining differential PAT deposition, identifies causal links with left structural and functional parameters, and provides novel data about the pathophysiological importance of adiposity distribution.

MMP-2 Associates With Incident Heart Failure and Atrial Fibrillation: The ARIC Study.

MMP (matrix metalloproteinase)-2 participates in extracellular matrix regulation and may be involved in heart failure (HF), atrial fibrillation (AF), and coronary heart disease. Among the 4693 ARIC study (Atherosclerosis Risk in Communities) participants (mean age, 75±5 years; 42% women) without prevalent HF, multivariable Cox proportional hazard models were used to estimate associations of plasma MMP-2 levels with incident HF, HF with preserved ejection fraction (≥50%), HF with reduced ejection fraction (<50%), AF, and coronary heart disease. Mediation of the association between MMP-2 and HF was assessed by censoring participants who developed AF or coronary heart disease before HF. Multivariable linear regression models were used to assess associations of MMP-2 with measures of left ventricular and left atrial structure and function. Compared with the 3 lower quartiles, the highest MMP-2 quartile associated with greater risk of incident HF overall (adjusted hazard ratio, 1.48 [95% CI, 1.21-1.81]), incident HF with preserved ejection fraction (1.44 [95% CI, 1.07-1.94]), incident heart failure with reduced ejection fraction (1.48 [95% CI, 1.08-2.02]), and incident AF (1.44 [95% CI, 1.18-1.77]) but not incident coronary heart disease (0.97 [95% CI, 0.71-1.34]). Censoring AF attenuated the MMP-2 association with HF with preserved ejection fraction. Higher plasma MMP-2 levels were associated with larger left ventricular end-diastolic volume index, greater left ventricular mass index, higher E/e' ratio, larger left atrial volume index, and worse left atrial reservoir and contractile strains (all P<0.001). Higher plasma MMP-2 levels associate with diastolic dysfunction, left atrial dysfunction, and a higher risk of incident HF and AF. AF is a mediator of MMP-2-associated HF with preserved ejection fraction risk.

Characterization of Subclinical Cardiac Dysfunction by Speckle Tracking Echocardiography in Patients With Non-severe Acute-Phase Myocarditis

Subclinical changes in left ventricular (LV) function have been demonstrated in patients with acute-phase myocarditis (AM) despite normal LV ejection fraction. The impact of AM on right ventricular (RV) and left atrial (LA) function has not been well described. This study aimed to assess for subclinical chamber dysfunction by speckle tracking echocardiography and its clinical relevance in this population. Patients with a diagnosis of AM (as per the European Society of Cardiology Working Group on Myocardial and Pericardial Diseases) admitted to our institution from 2013 to 2018 were assessed. Patients with elevated serum troponin, normal coronary assessment, and normal LV ejection fraction on transthoracic echocardiogram were included. Clinical and echocardiographic parameters were compared with healthy age-, gender- and risk-factor matched controls. Global longitudinal strain assessed through speckle tracking echocardiography was performed using vendor independent software (v4.6; TomTec Arena, Munich, Germany). The final cohort consisted of 80 patients (40 AM patients and 40 controls). No significant differences in baseline clinical characteristics were observed between groups. Of the echocardiographic parameters, AM patients had lower LV-global longitudinal strain (p <0.01), lower RV free-wall strain (p=0.02) and lower peak LA strain (p <0.01). There were no differences in traditional echocardiographic measures of LV, RV, and LA function appreciated between groups. The presence of multichamber involvement was associated with peak Troponin levels (p <0.01). In conclusion, our study demonstrates the presence of global subclinical myocardial dysfunction in patients with AM. Additionally, the presence of multichamber involvement was significantly associated with degree of myocardial necrosis.

Absence of long-term structural and functional cardiac abnormalities on multimodality imaging in a multi-ethnic group of COVID-19 survivors from the early stage of the pandemic

Abstract Aims Many patients with coronavirus disease-2019 (COVID-19), particularly from the pandemic’s early phase, have been reported to have evidence of cardiac injury such as cardiac symptoms, troponinaemia, or imaging or ECG abnormalities during their acute course. Cardiac magnetic resonance (CMR) and transthoracic echocardiography (TTE) have been widely used to assess cardiac function and structure and characterize myocardial tissue during COVID-19 with report of numerous abnormalities. Overall, findings have varied, and long-term impact of COVID-19 on the heart needs further elucidation. Methods and results We performed TTE and 3 T CMR in survivors of the initial stage of the pandemic without pre-existing cardiac disease and matched controls at long-term follow-up a median of 308 days after initial infection. Study population consisted of 40 COVID-19 survivors (50% female, 28% Black, and 48% Hispanic) and 12 controls of similar age, sex, and race-ethnicity distribution; 35% had been hospitalized with 28% intubated. We found no difference in echocardiographic characteristics including measures of left and right ventricular structure and systolic function, valvular abnormalities, or diastolic function. Using CMR, we also found no differences in measures of left and right ventricular structure and function and additionally found no significant differences in parameters of tissue structure including T1, T2, extracellular volume mapping, and late gadolinium enhancement. With analysis stratified by patient hospitalization status as an indicator of COVID-19 severity, no differences were uncovered. Conclusion Multimodal imaging of a diverse cohort of COVID-19 survivors indicated no long-lasting damage or inflammation of the myocardium.