Left Ventricular End-systolic Elastance Research Articles

Combined 3D left ventricular-arterial coupling and 3D left atrial-ventricular coupling indices could better predict MACE in young patients with STEMI

Abstract Background Left ventricular arterial coupling index (VAC) proved to be a key determinant of cardiovascular performance. Previous trials also emphasized the prognostic value of left atrial-ventricular coupling index (LACI) that was independently associated with cardiovascular death and all-cause mortality. Both indices have been associated with disease severity and adverse outcomes. Purpose We aimed to evaluate the prognostic role of 3D VAC, 3D LACI and their combination assessed by 3D echocardiography in a cohort of young patients with STEMI. Patients and methods In this prospective study we enrolled 76 young consecutive patients (under 50 years old) with STEMI treated by primary PCI who underwent both 2D and 3D echocardiography. 3D VAC was calculated as the ratio between arterial elastance (EA) and end-systolic left ventricular elastance (EES), based on a formula proposed by Chen. 3D LACI was determined as the ratio between 3D left atrial end-diastolic volume (minimal atrial volume) and 3D left ventricular end-diastolic volume. Patients were followed up for one year after STEMI and the primary endpoint was the occurrence of MACE defined as death from cardiovascular causes, heart failure requiring hospital admission, or repeat revascularisation. Results Out of 76 patients, 15.8% had an adverse event during the 12 months follow up period. We divided the patients in two groups according to the presence or absence of MACE. Patients with MACE had higher VAC (2.15±0.62 vs. 1.25±0.29%, p<0.0001) and higher LACI (25.1±7.17% vs. 18.3±6.58%, p=0.002). In ROC analysis VAC and LACI combined had the best AUC for MACE prediction (AUC 0.961, p<0.0001), followed by VAC (AUC 0.922, P<0.0001), and then, LACI (AUC 0.772, P<0.001). For each variable we determined a cut off value. A value over 1.7 for VAC and 23.83% for LACI can predict unfavourable outcome with 83.3% sensitivity and 97.1% specificity for VAC and 67% sensitivity and 80% specificity for LACI. In both univariate and multivariate COX regression analysis, both VAC and LACI remained independent predictors for MACE. Moreover, their combination proved to have better predictive value for adverse events compared to each taken separately. We divided the study population into 4 groups: Group 1: VAC < 1.7 and LACI < 23.83%. Group 2: VAC <1.7 and LACI > 23.83%. Group 3: VAC > 1.7 and LACI < 23.83% and Group 4: VAC > 1.7 and LACI >0.23.83%. Kaplan Meier analysis shows significant differences among groups (log rank χ2 = 35.48, p < 0.0001). Calculation of Kaplan-Meier curves for the four groups indicated that the combination of the VAC > 1.7 and LACI > 23.83% had the strongest predictive power for MACE. Conclusion In conclusion 3D VAC and 3D LACI combined are better at predicting adverse events than each variable taken separately and could be used for a more accurate risk stratification in young patients with STEMI.

Left ventricular end-systolic and diastolic elastance as predictors of cardiac events in patients who underwent mitral valve surgery for severe mitral regurgitation

Abstract Background/Introduction In severe mitral regurgitation (MR), the prognostic significance of left ventricular ejection fraction (LVEF) and LV dimensions is well-established. However, the assessment of diastolic function in this patient presents a notable challenge, and its impact on postoperative outcomes remains unclear. Purpose This study was designed to explore the potential of LV end-systolic (Ees) and diastolic elastance (Eed) as novel predictors for cardiac events following surgery. Methods A retrospective cohort study was performed on 199 patients (53% male, average age 60 years, mean LVEF 60.0%) with severe MR and undergoing surgery. Preoperative Ees and Eed were calculated using established formulas: Ees = (systolic blood pressure x 0.9) / LV end-systolic volume, and Eed = left atrial pressure / stroke volume, with left atrial pressure estimated from mitral Doppler flow parameters as SBP – (4 x peak MR velocity²). The primary outcome was defined as either cardiac death or hospitalization due to heart failure. Results Average values for Ees and Eed were 2.61 (IQR: 1.67-3.20) and 0.32 (IQR: 0.05-0.57), respectively. Univariate analysis indicated Ees (HR: 1.24, 95% CI: 0.99-1.57, p = 0.066) and Eed (HR: 5.93, 95% CI: 2.87-12.26) as potential predictors. Adjusting for age, LVEF, and LV dimensions, Eed remained an independent predictor of cardiac events (HR: 5.89, 95% CI: 2.81-12.28). Stratifying Eed at a threshold of 0.31—identified as best sum of sensitivity and specificity—revealed that Eed > 0.31 were associated with a 3.9-fold increase in cardiac events compared to those with Eed ≤ 0.31 (p = 0.008). (Fig.) Conclusions The assessment of Eed is a straightforward and readily available parameter in routine clinical practice. Our findings advocate for the inclusion of preoperative Eed evaluation as an independent prognostic indicator for patients undergoing surgery for severe MR.Event free survival by Eed

Angiotensin receptor-neprilysin inhibition and improved ventricular-arterial coupling in heart failure with reduced ejection fraction.

Sacubitril/valsartan improves outcome in chronic heart failure (HF) with reduced ejection fraction (EF). The underlying mechanisms on left ventricular (LV) myocardial function are incompletely understood. In this study, 117 patients with symptomatic HF and LV-EF ≤ 40% were enrolled prospectively. Non-invasive pressure-volume analysis was calculated from transthoracic echocardiography with simultaneous arm-cuff blood pressure measurements. Primary outcome parameters were LV end-systolic elastance (Ees; a measure of LV contractility), effective arterial elastance (Ea; a measure of afterload), and the ventricular-arterial coupling ratio (Ea/Ees). Mean age was 65±13 years, 30% were female, and 54.7% had ischemic heart disease. During six months of follow-up, eight patients died, three withdrew their consent, and four were lost to follow-up. 102 patients were included in pressure-volume analyses. After six months of sacubitril/valsartan treatment, Ees increased (0.66mmHg/ml [IQR 0.45-0.94] vs. 0.78mmHg/ml [IQR 0.57-1.10], p=0.001), Ea decreased (1.76mmHg/ml [IQR 1.48-2.13] vs. 1.62mmHg/ml [IQR 1.36-1.96], p=0.014), and the Ea/Ees ratio improved (2.52 [IQR 1.88-4.05] vs. 1.93 [IQR 1.50-2.63], p<0.001). LV end-diastolic pressure and LV volumes were reduced, and LVEF increased from 33% to 43% (both p<0.001). Clinical improvement occurred in NYHA functional class, NT-proBNP level, and 6-minute walking distance. Change in LVEF correlated with change in Ees (r=0.33, p=0.0008), while change in NT-proBNP was associated with change in LVEDP (r=0.42, p<0.0001). In conclusion, sacubitril/valsartan is associated with improved ventricular-arterial coupling by enhancing LV contractility and reducing afterload. Beyond LV reverse remodeling, optimized ventricular-arterial interaction may contribute to the favorable outcome of sacubitril/valsartan treatment in HF with reduced EF.

Physiological control for left ventricular assist devices based on deep reinforcement learning.

The improvement of controllers of left ventricular assist device (LVAD) technology supporting heart failure (HF) patients has enormous impact, given the high prevalence and mortality of HF in the population. The use of reinforcement learning for control applications in LVAD remains minimally explored. This work introduces a preload-based deep reinforcement learning control for LVAD based on the proximal policy optimization algorithm. The deep reinforcement learning control is built upon data derived from a deterministic high-fidelity cardiorespiratory simulator exposed to variations of total blood volume, heart rate, systemic vascular resistance, pulmonary vascular resistance, right ventricular end-systolic elastance, and left ventricular end-systolic elastance, to replicate realistic inter- and intra-patient variability of patients with a severe HF supported by LVAD. The deep reinforcement learning control obtained in this work is trained to avoid ventricular suction and allow aortic valve opening by using left ventricular pressure signals: end-diastolic pressure, maximum pressure in the left ventricle (LV), and maximum pressure in the aorta. The results show controller obtained in this work, compared to the constant speed LVAD alternative, assures a more stable end-diastolic volume (EDV), with a standard deviation of 5 mL and 9 mL, respectively, and a higher degree of aortic flow, with an average flow of 1.1 L/min and 0.9 L/min, respectively. This work implements a deep reinforcement learning controller in a high-fidelity cardiorespiratory simulator, resulting in increases of flow through the aortic valve and increases of EDV stability, when compared to a constant speed LVAD strategy.

U-shaped prognostic value of left ventricular-arterial coupling in septic patients: a prospective study

BackgroundVentricular-arterial coupling (VAC) has garnered increasing interest in critical care. The prognostic significance of left ventricular-arterial coupling (LVAC) in this context remains a topic of debate.ObjectiveThis study aimed to explore the association between LVAC and patient outcomes in sepsis.MethodsPatients with sepsis or septic shock admitted to the intensive care unit (ICU) were included. LVAC was evaluated using the arterial elastance (Ea)/left ventricular end-systolic elastance (Ees) ratio. Prognostic indicators, including 30-day mortality, length of ICU stay, mechanical ventilation (MV), changes in delta lactate levels, and oxygen index were also collected.ResultsA total of 388 patients were enrolled in this study. A U-shaped relationship was observed between LVAC and 30-day mortality, with an optimal LVAC value of 1.19 identified. For LVAC values above 1.19, the odds ratio (OR) for 30-day mortality was 1.07 (95% confidence interval [CI] 1.01–1.14). Below this threshold, OR was 0.85 (95% CI 0.73, 0.99). Similarly, in the curve for ICU-free days, a β value of − 8.64 (95% CI − 16.53, − 0.76) was noted for LVAC values over 1.26. For ventilator-free time, the kink point was 1.24, with significant β values on both sides of this threshold [− 226.49 (95% CI − 411.59, − 41.38) and 147.67 (95% CI 12.40, 282.93), respectively].ConclusionsThis study established U-shaped associations between LVAC and various clinical outcomes in septic patients. Optimizing LVAC could potentially enhance patient prognosis. Given the slight variations in optimal LVAC values across different patient populations, individualized LVAC titration may be beneficial in improving clinical outcomes.

Analysis of ventricular-vascular properties during preeclampsia: an echocardiography study.

The aim of the study is to analyze ventricular-vascular properties with different ventricular-arterial coupling (VAC) ratio in the preeclamptic women. Seventy-seven pregnant women with preeclampsia and eighty-nine with normal pregnancy were performed echocardiography. VAC was defined as the ratio between aortic elastance (Ea) and left ventricular (LV) end-systolic elastance (Ees). Using the VAC value of 0.8 as the cut-off near uncoupling, the preeclampsia cases were divided into two subgroups: VAC ratio ≥ 0.8 and <0.8. Cardiac structure and function, VAC properties, as well as four components of the LV pressure-strain loop, including global myocardial work index (GWI), constructive work (GCW), wasted work (GWW), and work efficiency (GWE) were determined. The preeclampsia with VAC ≥ 0.8 had an enlarger indexed ventricular volume and a thicker relative ventricular wall than the VAC < 0.8. The Ees significantly increased in the subgroup with VAC < 0.8 and decreased in the VAC ≥ 0.8, while the Ea increased in both of them. The preeclampsia with VAC ≥ 0.8 showed an obvious augmentation in GWI, GCW and GWE, along with a similar GWW compared to those with VAC < 0.8. There were variable relationships between the LV pressure-strain components and VAC properties. Thus, the preeclampsia with VAC ≥ 0.8 undergoes a more adverse remodeling and a greater impact on cardiac contractility. The increased stiffness of the heart and arterial system, and increased resistance of peripheral vessels net lead to the deteriorative ventricular efficiency with elevated myocardial oxygen consumption during a preeclampsia pregnancy.

NON-INVASIVE ASSESSMENT OF HEMODYNAMIC FORCES AND PRESSURE-VOLUME RELATION ANALYSIS IN TWIN PREGNANCY

Objective: This aim of the study was to prospectively investigate pattern of intraventricular Hemo-Dynamic Forces (HDF) associated with Left Ventricular (LV) function and remodeling in women with uncomplicated twin pregnancy. Design and method: Prospective, cohort study. Transthoracic echocardiography was performed on 35 women (aged 35.9±4.7 years) during gestation (&lt;14 w, T1; 14–27 w, T2; &gt;28 w, T3), and 6–7 months after delivery (T0). LV HDF were computed from echocardiography long axis data sets using a novel technique based on endocardial boundary tracking, both in apex-base (A-B) and latero-septal (L-S) directions. HDF distribution was evaluated by L-S over A-B HDF ratio (L-S/A-B HDF ratio). Results: At T1, L-S/A-B HDF ratio was higher than in T0 (p&lt;0.05) indicating HDF misalignment. At T2, a slight impairment of cardiac function was then recorded with a reduction of Global Longitudinal Strain (GLS) and left ventricular End-Systolic Elastance (Ees) at pressure-volume relationship analysis versus T1 (both p&lt;0.05). Finally, at T3, when HDF misalignment and LV contractility reduction (GLS and Ees) were all restored, a rightward shift of the End Diastolic Pressure-Volume Relationship (EDPVR) with an increase of ventricular capacitance were documented. Conclusions: In twin pregnancy, HDF misalignment in the first trimester precedes the slight temporary decrease in left ventricular systolic function in the second trimester; at the third trimester a rightward shift of the EDPVR was associated with a realignment of HDF and normalization of ventricular contractility indexes. These coordinated changes that occur in the maternal heart during twin pregnancy suggests the role of HDF in cardiac remodelling.

GENDER DIFFERENCES IN THE IMPACT OF VENTRICULAR-ARTERIAL COUPLING ON LEFT VENTRICULAR FUNCTION IN PATIENTS WITH HYPERTENSION

Objective: Increased arterial stiffness elevates aortic load, which can have adverse impacts on left ventricular (LV) function and contribute to the onset of heart failure. This impact is known to be more pronounced in women. Optimal coordination between ventricular contraction and the arterial system is required to maintain efficient cardiac function. This study aimed to investigate gender differences in the impact of ventricular-arterial coupling (VAC) on LV function in patients with hypertension at rest and after handgrip exercise. Design and method: Echocardiographic indexes of LV volumes, systolic function, and diastolic function were obtained in the usual way. Effective arterial elastance (EA) and index (EAI) were calculated from stroke volume measured using LV outflow waveform. Effective LV end-systolic elastance (ELV) and index (ELVI) were obtained using the single-beat method. Central aortic pressure waveform was recorded using the applanation tonometry. Characteristic impedance (Zc) of aortic root and reflection magnitude (RM) was calculated after Fourier transformation of both aortic pressure and flow waveforms. Results: Sixty-four patients (31 women and 33 men) with hypertension were enrolled. Women showed higher ELVI (1.33±0.34 vs. 1.10±0.29 mmHg/ml/m2, P=0.004) and EAI (1.14±0.25 vs. 0.93±0.26 mmHg/ml/m2, P=0.001), but VAC was not different (women: 0.88±0.17 vs. men: 0.85±0.11, P=0.431). Zc and RM were not different between women and men. After handgrip exercise, an increase in ELVI (P=0.021) and a decrease in VAC (P=0.035) were observed specifically in men, with no corresponding changes noted in women. In women, VAC was significantly associated with E’ velocity (beta -0.344, P=0.029) and left ventricular global longitudinal strain (beta 0.470, P=0.012) after adjustment, but in men, no association was found. Conclusions: Hypertensive women demonstrated greater stiffness in both the left ventricle and arterial systems, along with impaired LV contractile reserve in response to handgrip exercise, as compared to men. The ventricular-arterial mismatch had a notable impact on LV diastolic and systolic dysfunction only in women, but not in men.

Impact of cardiac rehabilitation on ventricular-arterial coupling and left ventricular function in patients with acute myocardial infarction.

To maintain efficient myocardial function, optimal coordination between ventricular contraction and the arterial system is required. Exercise-based cardiac rehabilitation (CR) has been demonstrated to improve left ventricular (LV) function. This study aimed to investigate the impact of CR on ventricular-arterial coupling (VAC) and its components, as well as their associations with changes in LV function in patients with acute myocardial infarction (AMI) and preserved or mildly reduced ejection fraction (EF). Effective arterial elastance (EA) and index (EAI) were calculated from the stroke volume and brachial systolic blood pressure. Effective LV end-systolic elastance (ELV) and index (ELVI) were obtained using the single-beat method. The characteristic impedance (Zc) of the aortic root was calculated after Fourier transformation of both aortic pressure and flow waveforms. Pulse wave separation analysis was performed to obtain the reflection magnitude (RM). An exercise-based, outpatient cardiac rehabilitation (CR) program was administered for up to 6 months. Twenty-nine patients were studied. However, eight patients declined to participate in the CR program and were subsequently classified as the non-CR group. At baseline, E' velocity showed significant associations with EAI (beta -0.393; P = 0.027) and VAC (beta -0.375; P = 0.037). There were also significant associations of LV global longitudinal strain (LV GLS) with EAI (beta 0.467; P = 0.011). Follow-up studies after a minimum of 6 months demonstrated a significant increase in E' velocity (P = 0.035), improved EF (P = 0.010), and LV GLS (P = 0.001), and a decreased EAI (P = 0.025) only in the CR group. Changes in E' velocity were significantly associated with changes in EAI (beta -0.424; P = 0.033). Increased aortic afterload and VA mismatch were associated with a negative impact on both LV diastolic and systolic function. The outpatient CR program effectively decreased aortic afterload and improved LV diastolic and systolic dysfunction in patients with AMI and preserved or mildly reduced EF.

Effect of age and gender on ventricular-arterial coupling estimated using a non-invasive technique

BackgroundLeft ventricular-arterial coupling is assessed as the ratio of left ventricular end-systolic elastance (Ees) to arterial elastance (Ea). Previous studies have introduced non-invasive estimations of Ees/Ea. It requires only four variables, namely pre-ejection period, ejection time, end-systolic pressure and diastolic pressure. The aims of the present study were to clarify the reference values of Ees/Ea estimated using the noninvasive technique, and to investigate the effects of age and gender on Ees/Ea in healthy subjects.MethodsThis retrospective study utilized data from healthy, 30-79-year-old subjects. We recorded electrocardiogram, phonocardiogram, and brachial arterial pulse waves simultaneously using the vascular screening system, and used the observed variables to calculate Ees/Ea. We separated subjects into five groups according to their age and compared Ees/Ea among the different age groups.ResultsThe study included 2114 males and 2292 females. Ees/Ea ranged from 1.87 to 2.04 in males, and 1.98 to 2.32 in females. We observed no age-related differences in Ees/Ea in males (p = 0.10), and significant differences in females (p < 0.001). Ees/Ea in males was not different compared to those in females in 60-69-year-old group (p = 0.92). Whereas Ees/Ea was higher in females compared to those in males in the other age groups. The differences between medians of Ees/Ea in males and those in females were 0.45 (p < 0.001), 0.24 (p < 0.001), 0.13 (p = 0.01), and 0.13 (p = 0.03) in 30–39, 40–49, 50–59, and 70-79-year-old age groups, respectively.ConclusionsWe clarified the reference values of Ees/Ea in healthy subjects. The effect of age on Ees/Ea is different in males and females, although Ees/Ea is maintained within a relatively narrow range in all subjects.

Distinctive left ventricular-arterial and right ventricular-pulmonary arterial coupling observed in patients with heart failure and a higher left ventricular ejection fraction range.

Higher left ventricular (LV) ejection fraction (EF) is related to unfavourable prognosis in patients with heart failure (HF) with preserved ejection fraction (HFpEF). The cause of this finding needs to be haemodynamically explained. Thus, we investigated this crucial issue from the perspective of LV-arterial (A) and right ventricular (RV)-pulmonary arterial (PA) coupling. Study patients were derived from our prospective cohort study of patients hospitalized due to acute decompensated HF and LVEF > 40%. We divided the 255 patients into three groups: HF with mildly reduced EF (HFmrEF), HFpEF with 50% ≤ LVEF < 60%, and HFpEF with LVEF ≥ 60%. We compared LV end-systolic elastance (Ees), effective arterial elastance (Ea), and Ees/Ea as a representative of LV-A coupling among groups and compared the ratio of tricuspid annular plane excursion to peak pulmonary arterial systolic pressure (TAPSE/PASP) as a representative of RV-PA coupling. All-cause death and readmission due to HF-free survival was worse in the group with a higher LVEF range. Ees/Ea was greater in HFpEF patients with LVEF ≥ 60% (2.12 ± 0.57) than in those with 50% ≤ LVEF < 60% (1.20 ± 0.14) and those with HFmrEF (0.82 ± 0.09) (P < 0.001). PASP was increased in the groups with higher LVEF; however, TAPSE/PASP did not differ among groups (n = 168, P = 0.17). In a multivariate Cox proportional hazard model, TAPSE/PASP but not PASP was significantly related to event-free survival independent of LVEF. HFpEF patients with higher LVEF have unfavourable prognosis and distinctive LV-A coupling: Ees/Ea is elevated up to 2.0 or more. Impaired RV-PA coupling also worsens prognosis in such patients. URL: https://www.umin.ac.jp/ctr/index.htm Unique identifier: UMIN000017725.

Left Ventricular-Arterial Coupling as an Independent Predictor of Adverse Events in Young Patients with ST Elevation Myocardial Infarction-A 3D Echocardiographic Study.

Left ventricular-arterial coupling (VAC) is a key determinant of global cardiovascular performance, calculated as the ratio between arterial elastance (EA) and left ventricular end-systolic elastance (EES). Over the years, acute myocardial infarction (STEMI) has remained an important cause of morbidity and mortality worldwide. Although, until recently, it was considered a disease occurring mostly in older patients, its prevalence in the young population is continuously rising. In this study, we aimed to investigate the role of 3D VAC and its derived indices in predicting adverse outcomes in young patients with STEMI. We prospectively enrolled 84 young patients (18-51 years) with STEMI who underwent primary PCI and 28 healthy age and sex-matched controls. A 3D echocardiography was used for non-invasive measurements of end-systolic elastance (EES), arterial elastance (EA), and VAC (EA/EES). The occurrence of major adverse cardiac events (MACE) was assessed one year after the index STEMI. Out of 84 patients, 15.4% had adverse events at 12 months follow-up. Patients were divided into two groups according to the presence or absence of MACE. There were no significant differences in arterial elastance between the two groups. EA was higher in the MACE group but without statistical significance (2.65 vs. 2.33; p = 0.09). EES was significantly lower in the MACE group (1.25 ± 0.34 vs. 1.91 ± 0.56. p < 0.0001) and VAC was higher (2.2 ± 0.62 vs. 1.24 ± 0.29, p < 0.0001). ROC analysis showed that VAC has a better predictive value for MACE (AUC 0.927) compared with EA or EEA but also compared with a classical determinant of LV function (LVEF and LVGLS). A VAC value over 1.71 predicts unfavourable outcome with 83.3% sensitivity and 97.1% specificity. In both univariate and multivariate COX regression analysis, VAC remained an independent predictor for MACE and demonstrated incremental prognostic value over LVEF and LVGLS in the proposed statistical models. In conclusion, 3D VAC is an independent predictor of adverse events in young patients with STEMI at a 12 month follow-ups and could be used for a more accurate risk stratification in the acute phase.

Left ventricular remodeling in twin pregnancy, noninvasively assessed using hemodynamic forces and pressure-volume relation analysis: prospective, cohort study.

This study was designed to prospectively investigate the pattern of intraventricular hemodynamic forces (HDFs) associated with left ventricular (LV) function and remodeling in women with uncomplicated twin pregnancy. Transthoracic echocardiography was performed on 35 women (aged 35.9 ± 4.7-yr old) during gestation (T1, <14 wk; T2, 14-27 wk; T3, >28 wk) and 6-7 mo after delivery (T0). LV HDFs were computed from echocardiography long-axis data sets using a novel technique based on endocardial boundary tracking, both in apex-base (A-B) and latero-septal (L-S) directions. HDF distribution was evaluated by L-S over A-B HDF ratio (L-S:A-B HDF ratio). At T1, L-S:A-B HDF ratio was higher than in T0 (P < 0.05) indicating HDF misalignment. At T2, a slight impairment of cardiac function was then recorded with a reduction of global longitudinal strain (GLS) and left ventricular end-systolic elastance (Ees) at pressure-volume relationship analysis versus T1 (both P < 0.05). Finally, at T3, when HDF misalignment and LV contractility reduction (GLS and Ees) were all restored, a rightward shift of the end-diastolic pressure-volume relationship (EDPVR) with an increase of ventricular capacitance was documented. In twin pregnancy, HDF misalignment in the first trimester precedes the slight temporary decrease in left ventricular systolic function in the second trimester; at the third trimester, a rightward shift of the EDPVR was associated with a realignment of HDF and normalization of ventricular contractility indexes. These coordinated changes that occur in the maternal heart during twin pregnancy suggest the role of HDFs in cardiac remodeling.NEW & NOTEWORTHY These changes indicate that 1) the misalignment of hemodynamic forces (HDFs) precedes a mild reduction in systolic function in twin pregnancy and 2) the positive left ventricular (LV) response to hemodynamic stress is mainly due to an improved diastolic function with enhanced LV cavity compliance.

The effect of intra-aortic balloon pumping on hemodynamics and left ventricular load in Impella-supported condition: A simulation study

Abstract Introduction Intra-aortic balloon pumping (IABP) is a commonly used percutaneous mechanical circulatory support device. Although IABP combined with Impella, a percutaneous left ventricular assist device, has shown positive outcomes in a few case reports of acute heart failure, its hemodynamic and left ventricular (LV) unloading effects remain unclear. Purpose We conducted a simulation study to clarify the clinical benefits of adding IABP to Impella-supported conditions. Methods We used SimulinkⓇ for cardiovascular simulation. The systemic and pulmonary circulation were modelled by using a 5-element resistance-capacitance network with four ventricles represented by time-varying elastance and unidirectional valves (Figure 1A). We compared total systemic flow, coronary perfusion pressure (CPP), and pressure-volume relationships (PV loop) in severe LV dysfunction (LV end-systolic elastance: 0.2 mmHg/mL) under three scenarios: IABP with a 40 mL balloon volume added to baseline, IABP added to Impella CP support at P2 (partial support) and P8 (total support) (Figure 1B). Results As shown in Figure 2A, IABP increased total systemic flow and CPP, and shifted the PV loop to the left. In P2-Impella condition, the addition of IABP increased native cardiac output (0.3 to 0.7 L/min) and total systemic flow (2.7 to 2.9 L/min), while decreased Impella pump flow due to increased afterload of Impella during diastole. IABP further moved PV loop leftward and reduced LV pressure-volume area (PVA) by -3.8% from Impella only and -7.8% from baseline (Figure 2B). In P8-Impella condition, IABP did not change total systemic flow, CPP, or PV loop (Figure 2C). Conclusions The addition of IABP to Impella could increase CPP while increasing Impella pump afterload and decreasing Impella flow. Overall, IABP slightly increased total systemic flow and decreased LV workload in Impella partial support condition. In specific clinical situations, IABP has the potential to be used as adjuvant therapy alongside Impella partial support.Figure 1

Treatment with sacubitril/valsartan and improvement of ventricular-arterial coupling in heart failure with reduced ejection fraction

Abstract Background Treatment with the angiotensin receptor-neprilysin inhibitor sacubitril/valsartan (S/V) in patients with heart failure and reduced ejection fraction (HFrEF) reduces mortality and heart failure (HF) hospitalizations. The specific hemodynamic mechanisms underlying these beneficial effects are currently unclear. Purpose This study aimed to assess the effects of S/V treatment on left ventricular (LV) end-systolic elastance (Ees), effective arterial elastance (Ea), and the ventricular-arterial coupling ratio (Ea/Ees) in patients with HFrEF using non-invasive pressure-volume analysis. Methods 117 patients with symptomatic HF and LVEF &amp;lt;40% in whom treatment with S/V was initiated were enrolled in this multicenter German prospective study. We used transthoracic echocardiography with simultaneous arm-cuff blood pressure measurements for non-invasive pressure-volume loop analyses. Primary endpoints were changes in Ees, Ea, and Ea/Ees ratio after six months of S/V treatment. Results The mean age was 65 (±13) years and 30% were female. In 54.7% of the patients, the etiology of HF was ischemic, and 45.3% was non-ischemic. 58.4% had first HF diagnosis at baseline. 102 patients with complete clinical and echocardiographic data at baseline and after six months of follow-up were analyzed. Among those, 62% were on target dose of S/V. Six months of S/V treatment resulted in a significant increase of Ees (0.66 mmHg/ml, IQR [0.45;0.94] vs. 0.78 mmHg/ml [0.57;1.10], p=0.001) and decrease of Ea (1.76 mmHg/ml [1.48;2.13] vs. 1.62 mmHg/ml [1.36;1.96], p=0.014). Hence, the Ea/Ees ratio significantly improved (2.52 [1.88;4.05] vs. 1.93 [1.50;2.63], p&amp;lt;0.001). In addition, LV volumes and pressure improved significantly with a regression of the LV end-systolic volume (LVESV: 142 ml [115;180] vs. 96 ml [65;124]), end-diastolic volume (LVEDV: 216 ml [179;247] vs. 165 ml [132;200]) and LV end-diastolic pressure (LVEDP: 19.6 mmHg [18.2;22.4] vs. 17.8 mmHg [16.6;19.9]), p&amp;lt;0.001 respectively. The LVEF increased from a median of 33% (27;37) to 43% (36;49), p&amp;lt;0.001. NT-proBNP level decreased from (median) 1771 pg/ml [838;5211] to 724 pg/ml [300;1575] and mean 6-minute walking distance increased from 371m (±125) to 423 m (±122), p&amp;lt;0.001 respectively. The percentage of patients with NYHA class III changed from 25.6% to 5.9%. Conclusion In a 6-months treatment period, initiation of sacubitril/valsartan in patients with heart failure and reduced ejection fraction was associated with reduction of LV volumes, improved LV function, reduction in afterload and fewer heart failure symptoms. These new data indicate that beyond reverse LV remodeling, improvement of LV contractility and ventricular-arterial coupling may contribute to the favorable clinical outcomes on treatment with sacubitril/valsartan in chronic heart failure.

A Novel Index System for Assessing Ventricular-Vascular Coupling.

To explore the value of a novel ventricular-vascular coupling index (VVI) system in relation to age, gender and body mass index (BMI). A total of 239 volunteers with single-center and cross-sectional health screening were enrolled in the study. Subjects were divided according to age (young [18-44 years], middle-age [45-59 years], old [60-80 years]), gender (male, female), and BMI (overweight/obese [BMI 24], control [BMI 24]). The left ventricle end-diastolic volume (LVEDV) and left ventricle end-systolic volume (LVESV) provided the left ventricular structure index, while the TDI provided the functional index. Also derived from routine echocardiography were the effective arterial elastance (Ea), left ventricular end-systolic elastance (Ees), and VVI. The novel VVI systems were arterial velocity pulse index (AVI), left ventricular global longitudinal strain (LVGLS), and the AVI to LVGLS ratio (AVI/LVGLS). (1) Middle-age and elderly subjects had higher Ea and lower LVGLS compared to young subjects. AVI and AVI/LVGLS increased progressively from young to middle-age to old subjects. (2) Females had higher Ea, Ees and LVGLS than male subjects. No significant differences in AVI and AVI/LVGLS were observed between males and females. (3) No significant differences in Ea, Ees, VVI, AVI, LVGLS and AVI/LVGLS were observed between the overweight/obese and control groups. (4) AVI/LVGLS was negatively correlated with LVEDV and LVESV and with TDI . LVEDV, LVESV and TDI were independent predictors of AVI/LVGLS. (5) The diagnostic performance of AVI/LVGLS was higher than that of VVI in the young and middle-age groups. The diagnostic efficacy of AVI/LVGLS was higher than that of VVI in the young and old groups, and the diagnostic efficacy of AVI was higher than that of Ea. The difference in diagnostic efficacy between LVGLS and Ees was not statistically significant. The differences in diagnostic efficacy between AVI/LVGLS and VVI, AVI and Ea, and LVGLS and Ees were not statistically significant in the middle-age and old groups. The novel index system of ventricular-vascular coupling described here (AVI, LVGLS, and AVI/LVGLS) was more effective than traditional indexes in detecting differences in cardiovascular function between different ages groups. The study protocol was registered on the official website of China Clinical Trial Registration Center (ChiCTR2000035937).

Inverse ESPVR Estimation with Singularity Avoidance via Constrained EDPVR Parameter Optimization.

Left ventricular end-systolic elastance Ees, as an index of cardiac contractility, can play a key role in continuous patient monitoring during cardiac treatment scenarios such as drug therapies. The clinical feasibility of Ees estimation remains challenging because most techniques have been built on left ventricular pressure and volume, which are difficult to measure or estimate in the regular ICU/CCU setting. The purpose of this paper is to propose and validate a novel approach to estimate Ees, which is independent of left ventricular pressure and volume. Our methods first derive an analytical representation of Ees as the inverse function of the gradient of the Frank-Starling Curve based on cardiac mechanics. Second, elucidating the mechanism of singularities in the inverse function, we derive multiple conditions in both end-systolic pressure-volume relationship (ESPVR) and end-diastolic pressure-volume relationship (EDPVR) parameters to avoid these singularities analytically. Third, we formulate a constrained nonlinear least squares problem to optimize both ESPVR and EDPVR parameters simultaneously to avoid singularities. The effectiveness of the proposed method in avoiding singularities was evaluated in an animal experiment. Compared to the conventional Ees estimation by linear regression, our proposed method reproduced in-vivo hemodynamics more accurately when simulating the estimated Ees variation during drug administration. Our method can be applied using the available data in the regular ICU/CCU setting. The improved clinical feasibility can support not only physicians' decision-making, including adjusting drug dosages in current clinical treatment, but also a closed-loop hemodynamic control system requiring accurate continuous Ees estimation.

MATERNAL LEFT VENTRICULAR ADAPTATION IN TWIN PREGNANCY

Objective: During pregnancy, a maternal left ventricular (LV) remodeling occurs to face significant hemodynamic changes. Although twin pregnancy can require greater modifications than in singleton, limited data are currently available. The aim of the study was to longitudinally investigate maternal changes of LV function and compliance in twin pregnancy. Design and method: 35 uncomplicated twin pregnancy women underwent transthoracic echocardiography at first (T1, 10-15 weeks) and third trimester (T3, 30-35 weeks) of gestation. Left atrial (LA) and LV dimensions, LV volumes, systolic and diastolic function were measured, LV mass was calculated. Speckle-tracking imaging was used to evaluate global longitudinal strain (GLS). Non-invasive pressure-volume curves (PV loops) were reconstructed using a dedicated software. Results: Maternal LA and LV dimensions, LV volumes and mass increased from T1 to T3. Ejection fraction and GLS showed no changes between visits. Assessment of diastolic function (at pulsed wave Doppler and tissue Doppler) showed no changes in E/A ratio, while E/e’ ratio was higher at T3. At PV loops analysis, ventricular-arterial coupling (VAC) was stable due to the reduction of both LV end-systolic elastance (Ees) and arterial elastance (Ea). An increase in stroke work was observed. The increase in LV end-diastolic volumes from T1 to T3 with no changes in LV end-diastolic filling pressure suggested enhanced LV cavity compliance (rightward shift of the end-diastolic pressure-volume relationship, EDPVR). Conclusions: Maternal heart in uncomplicated twin pregnancy adapts to the increased hemodynamic load with an increase in stroke work and enhancement of LV volumes without altering ventricular filling pressure.

Enhancement of left ventricular compliance in twin pregnancy

Abstract Funding Acknowledgements Type of funding sources: None. Background The knowledge of maternal left ventricular adaptation in twin pregnancies is incomplete. Purpose The objective of this study was to longitudinally investigate maternal changes of left ventricular (LV) function and compliance in twin pregnancies. Methods Thirty-five women (age 35.3±4.8 years) with uncomplicated twin pregnancy were enrolled to undergo transthoracic echocardiography at 10-15 (T1) and 30-38 (T3) week’s gestation. Left atrial (LA) and LV dimensions, LV volumes and mass, diastolic parameters (at pulsed wave Doppler and tissue Doppler), global longitudinal strain (GLS) at speckle-tracking imaging, and non-invasive pressure-volume curves (PV loops) were measured and calculated. Results Maternal LA and LV dimensions, LV volumes and mass had an increasing trend from T1 to T3 (p&amp;lt;0.001 for all). E/A remained stable, while E/e’ ratio slightly increased during gestation. GLS showed no changes between the two visits. At PV loops analysis (Figure 1), LV end-systolic elastance (Ees) and arterial elastance (Ea) both decreased, with no changes in ventricular-arterial coupling (VAC). LV end-diastolic volumes increased from T1 to T3 with no changes in LV end-diastolic filling pressure; the rightward shift of the end-diastolic pressure-volume relationship (EDPVR) suggested enhanced LV cavity compliance (Figure 2). An increase in stroke work was observed. Conclusions During twin pregnancy GLS and VAC were not modified showing functional adaptation to enhanced haemodynamic load. Importantly, stroke work increase was sustained by enhancement in LV end-diastolic volume with unaltered filling pressure.

Ascending aorta dilatation reduces the influence of elevated pulse pressure on left ventricular hypertrophy: findings from a Chinese elderly hypertensive population.

To determine the role of ascending aorta dilatation in the relationship between pulse pressure (PP) and left ventricular (LV) hypertrophy. A total of 1556 Chinese elderly hypertensive patients were retrospectively studied. Transthoracic echocardiography was used to obtain the aortic and cardiac structure measurements. In addition, brachial blood pressure was measured, and total arterial compliance, systemic vascular resistance, arterial elastance, and end-systolic LV elastance were calculated. The participants were divided into four groups according to the status of ascending aortic diameter and PP. LV mass index increased in succession in the four groups, i.e., the group with the normal aorta and lower PP, with the normal aorta and higher PP, with aortic dilatation and lower PP, and with aortic dilatation and higher PP (P trend < 0.001). Total arterial compliance-1, arterial elastance, and end-systolic LV elastance were slightly higher in the individuals with normal aorta compared to those with aortic dilatation, regardless of PP being lower or higher (P < 0.01). Compared to the group with the normal aorta and lower PP, individuals with aortic dilatation had a significantly increased multivariable adjusted risk of LV hypertrophy, and higher PP further exacerbated this risk [aortic dilatation with lower PP (OR = 1.75, 95% CI: 1.01-3.04) and aortic dilatation with higher PP (OR = 3.42, 95% CI: 2.03-5.77)]. In the relation between PP and LV mass index (β = 0.095, P < 0.001), -41.3% of the total effect was attributable to mediation by ascending aortic diameter (P < 0.0001). In Chinese elderly patients with hypertension, ascending aorta dilatation could reduce the influence of elevated PP on LV hypertrophy.