Dynamic Arterial Elastance Is Associated With the Vascular Waterfall in Patients Treated With Norepinephrine: An Observational Study

Introduction: It has been suggested that dynamic arterial elastance (Eadyn) can predict decreases in arterial pressure in response to changing norepinephrine levels. The objective of this study was to determine whether Eadyn is correlated with determinants of the vascular waterfall [critical closing pressure (CCP) and systemic arterial resistance (SARi)] in patients treated with norepinephrine.Materials and Methods: Patients treated with norepinephrine for vasoplegia following cardiac surgery were studied. Vascular and flow parameters were recorded immediately before the norepinephrine infusion and then again once hemodynamic parameters had been stable for 15 min. The primary outcomes were Eadyn and its associations with CCP and SARi. The secondary outcomes were the associations between Eadyn and vascular/flow parameters.Results: At baseline, all patients were hypotensive with Eadyn of 0.93 [0.47;1.27]. Norepinephrine increased the arterial blood pressure, cardiac index, CCP, total peripheral resistance (TPRi), arterial elastance, and ventricular elastance and decreased Eadyn [0.40 (0.30;0.60)] and SARi. Eadyn was significantly associated with arterial compliance (CA), CCP, and TPRi (p < 0.05).Conclusion: In patients with vasoplegic syndrome, Eadyn was correlated with determinants of the vascular waterfall. Eadyn is an easy-to-read functional index of arterial load that can be used to assess the patient’s macro/microcirculatory status.Clinical Trial Registration:ClinicalTrials.gov #NCT03478709.

Abstract P481: Early Recognition of Heart Failure With Preserved Ejection Fraction (HFpEF): Ventricular Elastance as a Predictive Marker for Prevention and Treatment

Introduction: Heart failure with preserved ejection fraction (HFpEF) is the most common type of heart failure, carries a 50% mortality rate within 3 years of diagnosis with evidence to support early lifestyle behavioral modification as beneficial. Developing an understanding of markers that identify patients early, promotes early recognition and treatment. Objective: Use of a predictive marker, ventricular elastance, enables early identification of patients at-risk for HFpEF. Methods: Patients previously diagnosed with HFpEF were retrospectively identified. Through case-control and hierarchical linear regression modeling, biomarkers were identified that preceded the onset of HFpEF. Using Cox regression, we conducted a survival analysis to determine time to onset of HFpEF for each biomarker. Using repeated measures logistic regression, continuous variables were tested for interval progression toward disease onset, controlling for co-variates: age, race and sex. Results: Through retrospective analysis, 251 patients and 775 echocardiograms spanning nearly 20 years were identified. Through mixed linear regression, for the entire model, 7 biomarkers were identified as statistically significant and 1 biomarker, ventricular elastance (Ees), progressively increased leading to the time of HFpEF hospitalization. Conclusion: This study provides the methodology for testing a predictive marker, ventricular elastance, that enables early recognition of HFpEF.

P1405 3D echocardiographic assessment of right ventriculo-arterial coupling in mitral valve prolapse

Background Both pulmonary artery pressure (PAP) and right ventricular (RV) function have shown their value in the prognostic evaluation of patients with mitral valve prolapse (MVP). Echocardiography which allows simultaneous pressure estimation and volume measurement by 3D allows an approach of arterial (Ea) and ventricular elastance (Emx) and of right ventriculo-arterial coupling (RVAC), usually derived from pressure-volume loops, and could be of interest in the assessment of the RV-PA unit. Methods Thirty normal patients (group Nl, mean age 52.7 ± 15.9) and 75 patients with stable MVP (mean age 52.4 ± 15.4 (ns for age), 39 (group MVP1) with no or mild mitral regurgitation (MR) and 36 (group MVP2) with moderate to severe MR) underwent echocardiography including 3D RV acquisition. RV end-systolic volume (ESV), end-diastolic volume (EDV), stroke volume (SV) (mL) and ejection fraction (EF) (%) were obtained 3D echo (3DE) volumetric analysis (GE, EchoPac). mPAP was estimated from echo using Chemla’s formula (mPAP = 0.61 x sPAP + 2mmHg). Pulmonary artery effective elastance (Ea) was estimated as mPAP/SV (mmHg/mL), RV maximal end-systolic elastance (Emax) as mPAP/ESV (mmHg/mL), and RVAC as Ea/Emax. Ea, Emax and RVAC were compared between the 3 groups of patients using ANOVA. Results Mean LVEF was similar in the 3 groups. There was a significant differences in mPAP (Nl: 15.6 ± 3.0; MVP1: 16.3 ± 3.3; MVP2: 22.9 ± 11.1, p = 0.001). RVEDV (Nl: 81.3 ± 19.2; MVP1: 80.1 ± 22.0; MVP2: 96.1 ± 28.6, p = 0.09), RVEF (Nl: 50.4 ± 4.4; MVP1: 49.3 ± 5.5; MVP2: 46.6 ± 6.6, p = 0.02) and RVESV (Nl: 39.9 ± 9.8; MVP1: 40.8 ± 12.8; MVP2: 52.0 ± 19.5, p = 0.01) were significantly different among the 3 groups. There was a non significant trend toward progressive increase in Ea (Nl: 0.41 ± 0.12; MVP1: 0.45 ± 0.15; MVP2: 0.53 ± 0.30, p = 0.07) and E max (Nl: 0.42 ± 0.11; MVP1: 0.45 ± 0.17; MVP2: 0.53 ± 0.31, p = 0.11) among the 3 groups but RVAC was not significantly different (Nl: 0.99 ± 0.17; MVP1: 1.04 ± 0.22; MVP2: 1.05 ± 0.37, ns). Conclusion 3D echocardiography allows a complete analysis of the RV-PA unit and is able to reveal subtle changes in its equilibrium. Together with an increase in RV volumes and decrease in RVEF, our study reveals a progressive increase in arterial elastance in parallel with the severity of MR, compensated by an increase in ventricular elastance to maintain RV – PA coupling in those stable patients with MVP.

415 Comparison between two methods for assessing ventricular-arterial coupling: the Chen single-beat method and carotid artery wave intensity

Background Ventricular arterial coupling (VAC) can be defined as the ratio of the arterial elastance (Ea) to the ventricular elastance (Ees). . The Ea/Ees ratio has been consistently demonstrated to be a reliable and effective measure of cardiovascular performance. The Chen single-beat method is the most used non-invasive method for this measurement. Carotid artery wave intensity (WI) is also considered a index of VAC, as the first peak (W1) represents the forward compression wave, reflecting left ventricle (LV) contractile function. However, data about the relationship between the two methods are nowadays scarce. Purpose Aim of the study was to compare carotid WI and Ventricular-Arterial Coupling (VAC) in a population of patient with heart failure. Methods We examined 50 consecutive patients with heart failure (9 females, 41 males, mean age 67 + 12 years, range 29-97 years, 34 ischemic, 16 not ischemic). Carotid artery wave intensity was achieved merging the echo-tracking of the vessel with its doppler signal. Simultaneous not-invasive oscillometric blood pressure was obtained. The VAC was assessed by the ratio between the arterial elastance (Ea) and the end-systolic ventricular elastance (Ees). Ea was calculated from stroke volume (SV) and end-systolic pressure (Ea=(Systolic BP x 0.9)/SV) and Ees was calculated by the modified single-beat Chen method, using an estimated normalized ventricular elastance at arterial end-diastole (ENd) Ees = [Diastolic BP-(ENd(est) x Systolic BP x 0.9)]/(ENd(est) x SV). Three subgroups were created according to the left ventricle ejection fraction values (LVEF ≤ 35%, LVEF >35% <50%, LVEF ≥ 50%, with 26, 14, 10 patients respectively). Results The correlation between Ea/Ees and W1 was significant (Pearson’s correlation r= -0.35, p 0.01). The W1 and VAC values of the three LVEF-sorted subgroups were processed with ANOVA test (p 0.054 and p 0.0002 respectively). W1 values resulted to be, as expected, reduced especially in the group of severe ventricular dysfunction (mean 4,97+- 3,29), as well as the ventricular-arterial coupling was increased (mean 2.04 +- 1.04). Interestingly W1 shows to be correlated with the Left atrial volume index (Pearson’s correlation r= -0,30 p = 0,037). Conclusions Carotid WI technique seems to be a reliable method to estimate the ventricular-arterial interplay. Larger studies are needed to evaluate the respective role of W1 and Ea/Ees in the prognostic evaluation. Results EF ≤ 35 (n = 10) 35 < EF < 50 (n = 14) EF≥ 50 (n = 26) p value W1 4.97 ± 3.29 8.05 ± 3.79 7.85 ± 3.12 0.054 Ea/Ees 2.04 ± 1.04 1.39 ± 0.31 1.16 ± 0.3 0.0002 Abstract 415 Figure.

P6470Ventriculo-arterial coupling in severe aortic stenosis: does the flow-gradient pattern play a role?

Background Ventriculo-arterial coupling (VAC) assesses the interplay between ventricular contractility and afterload and it is calculated as the ratio between arterial elastance (Ea) and end-systolic left ventricular elastance (EES). Severe aortic stenosis (AS) carries different configurations according to transvalvular flow rates and pressure gradients and each of these entities has its particularities in terms of physiology and clinical outcome. Little has been studied so far regarding the changes of VAC in severe AS. Purpose We sought to assess the VAC non-invasively in patients (pts) with severe AS and to characterize it according to the flow-gradient pattern. Methods We included 61 consecutive pts with severe AS (78±13 years, 30 men, indexed aortic valve area <0.6 cm2/m2), for whom we performed a comprehensive echocardiography. VAC was determined as the ratio between Ea and EES. Patients were divided in 4 groups, depending on stroke volume index (low-flow [LF] vs. normal-flow [NF]: 35 ml/m2) and mean transaortic pressure gradient (low-gradient [LG] vs. normal gradient [NG]: 40 mm Hg). This resulted in the following flow-gradient patterns: LFLG, LFNG, NFLG, NFNG. Data were compared between groups with one-way analysis of variance and then with a Tukey test. Results There were 11 pts (18%) in the LFLG group, 20 pts (32.8%) in the LFNG group, 8 pts (13.2%) in the NFLG group and 22 pts (36%) in the NGNG group. The arterial elastance was highest in the LFLG group: 3.37±1.49 vs. 2.79±0.92 in the LFNG, 2.05±0.57 in the NFLG and 1.54±0.49 in the NFNG group (p<0.001). The ventricular elastance was also highest in the LFLG group (4.03±2.46) vs. 3.16±1.33 in the LFNG, 2.21±1.22 in the NFLG and 2.29±0.78 in the NFNG group (p=0.007). VAC was most impaired in the NFLG group (1.35±1.08), followed by LFNG group (1.00±0.47), LFLG group (0.93±0.27) and NFNG group (0.70±0.14) (p=0.01). Valvulo-arterial impedance (ZVA) was highest in the LFNG group: 7.78±2.15, followed by 7.38±2.17 in the LFLG group, 4.93±1.17 in the NFLG group and 4.33±1.23 in the NFNG group (p<0.001). VAC and ZVA showed no significant correlation (p=0.27), with VAC being significantly more impaired in patients with abnormal ZVA (>4.5 mm Hg/ml/m2): 0.99±0.60 vs. 0.73±0.20 (p=0.02). Conclusion The ventriculo-vascular interaction in severe AS varies noticeably according to the flow-gradient pattern. Low-gradient states, particularly NFLG, have the most impaired VAC. This study supports the idea that these 4 configurations are different clinical entities and it highlights the importance of integrating the flow-gradient pattern for a comprehensive evaluation of AS severity. Acknowledgement/Funding This work was supported by CREDO Project - ID: 49182, financed through the SOP IEC -A2-0.2.2.1-2013-1 cofinanced by the ERDF