Agreement between different non-invasive methods of ventricular elastance assessment for the monitoring of ventricular-arterial coupling in intensive care

Cardiac Mechanical Performance Assessment at Different Levels of Exercise in Childhood Acute Lymphoblastic Leukemia Survivors

BACKGROUND

There is a shortage of relevant studies interested in cardiac mechanical performance. Thus, it is clinically relevant to study the impact of cancer treatments on survivors' cardiac mechanical performance to improve our knowledge. The first objective of this study is to assess survivors' cardiac mechanical performance during a cardiopulmonary exercise test (CPET) using both ventricular-arterial coupling (VAC) and cardiac work efficiency (CWE) from cardiac magnetic resonance (CMR) acquisitions. The second objective is to assess the impact of doxorubicin and dexrazoxane (DEX) treatments.

METHODS

A total of 63 childhood acute lymphoblastic leukemia survivors underwent a CMR at rest on a 3T magnetic resonance imaging system, followed by a CPET on ergocycle. The CircAdapt model was used to study cardiac mechanical performance. At different levels of exercise, arterial elastance, end-systolic elastance, VAC, and CWE were estimated.

RESULTS

We observed significant differences between the different levels of exercise for both VAC ( P <0.0001) and CWE parameters ( P =0.001). No significant differences were reported between prognostic risk groups at rest and during the CPET. Nevertheless, we observed that survivors in the SR group had a VAC value slightly lower than heart rate (HR)+DEX and HR groups throughout the CPET. Moreover, survivors in the SR group had a CWE parameter slightly higher than HR+DEX and HR groups throughout the CPET.

CONCLUSIONS

This study reveals that the combination of CPET, CMR acquisitions and CircAdapt model was sensitive enough to observe slight changes in the assessment of VAC and CWE parameters. Our study contributes to improving survivors' follow-up and detection of cardiac problems induced by doxorubicin-related cardiotoxicity.

Diuretics depletion improves cardiac output and ventriculo-arterial coupling in congestive ICU patients during hemodynamic de-escalation

PURPOSE

Congestion was shown to hamper organ perfusion, but the exact timing of diuretic initiation during hemodynamic de-escalation in shock is unclear. The aim of this study was to describe the hemodynamic effects of diuretic initiation in the stabilized shock.

METHODS

We performed a monocentric, retrospective analysis, in a cardiovascular medico-surgical ICU. We included consecutive resuscitated adult patients, for whom the clinician decided to introduce loop diuretic treatment for clinical signs of fluid overload. The patients were hemodynamically evaluated at the moment of diuretic introduction and 24 h later.

RESULTS

Seventy ICU patients were included in this study, with a median duration of ICU stay before diuretic initiation of 2 [1-3] days. 51(73%) patients were classified as congestive (central venous pressure > 12 mmHg). After treatment, the cardiac index increased towards normal values in the congestive group (2.7 ± 0.8 L min^- 1 m^- 2 from 2.5 ± 0.8 L min^- 1 m^- 2, p = 0.042), but not in the non-congestive group (2.7 ± 0.7 L min^- 1 m^- 2 from baseline 2.7 ± 0.8 L min^- 1 m^- 2, p = 0.968). A decrease in arterial lactate concentrations was observed in the congestive group (2.1 ± 2 mmol L^- 1 vs. 1.3 ± 0.6 mmol L^- 1, p < 0.001). The diuretic therapy was associated with an improvement of ventriculo-arterial coupling comparing with baseline values in the congestive group (1.69 ± 1 vs. 1.92 ± 1.5, p = 0.03). The norepinephrine use decreased in congestive patients (p = 0.021), but not in the non-congestive group (p = 0.467).

CONCLUSION

The initiation of diuretics in ICU congestive patients with stabilized shock was associated with improvement of cardiac index, ventriculo-arterial coupling, and tissue perfusion parameter. These effects were not observed in non-congestive patients.

Clinical Usefulness of Right Ventricle-Pulmonary Artery Coupling in Cardiovascular Disease

Right ventricular-pulmonary artery coupling (RV-PA coupling) refers to the relationship between RV contractility and RV afterload. Normal RV-PA coupling is maintained only when RV function and pulmonary vascular resistance are appropriately matched. RV-PA uncoupling occurs when RV contractility cannot increase to match RV afterload, resulting in RV dysfunction and right heart failure. RV-PA coupling plays an important role in the pathophysiology and progression of cardiovascular diseases. Therefore, early and accurate evaluation of RV-PA coupling is of great significance for a patient's condition assessment, clinical decision making, risk stratification, and prognosis judgment. RV-PA coupling can be assessed by using invasive or noninvasive approaches. The aim of this review was to summarize the pathological mechanism and evaluation methods of RV-PA coupling, the advantages and disadvantages of each method, and the application value of RV-PA coupling in various cardiovascular diseases.

Role of Electromechanical Dyssynchrony Assessment During Acute Circulatory Failure and Its Relation to Ventriculo-Arterial Coupling

Introduction

Two parallel paradigms of cardiovascular efficiency and haemodynamic optimisation coexist in haemodynamic research. Targeting ventriculo-arterial (VA) coupling [i.e., the ratio between arterial and ventricular elastance (E_V)] and electromechanical coupling are two promising approaches in acute circulatory failure. However, validation of the parameters of electromechanical coupling in critically ill patients is ongoing. Furthermore, a unifying link between VA and electromechanical coupling may exist, as E_V is correlated with different times of the cardiac cycle.

Materials and Methods

This study was a retrospective analysis of a prospectively collected observational database from one tertiary center ICU. We analyzed the relationship between electromechanical dyssynchrony and acute circulatory failure hemodynamics before and after treatment (i.e., fluid expansion, dobutamine, or norepinephrine infusion). The relationship between electromechanical coupling and VA coupling was also investigated. Adult patients with haemodynamic instability were included. Haemodynamic parameters, including arterial pressure, cardiac index, VA coupling, stroke work index/pressure–volume area (SWI/PVA), t-IVT, and Tei's index, were collected before and after treatment. A t-IVT of >12 s/min was classified as intraventricular dyssynchrony.

Results

We included 54 patients; 39 (72.2%) were classified as having intraventricular dyssynchrony at baseline. These patients with baseline dyssynchrony showed a statistically significant amelioration of t-IVT (from 18 ± 4 s to 14 ± 6 s, p = 0.001), left ventricular E_V [from 1.1 (0.72–1.52) to 1.33 (0.84–1.67) mmHg mL⁻¹, p = 0.001], VA coupling [from 2 (1.67–2.59) to 1.80 (1.40–2.21), p = 0.001], and SWI/PVA [from 0.58 (0.49–0.65) to 0.64 (0.51–0.68), p = 0.007]. Patients without baseline dyssynchrony showed no statistically significant results. The improvement in VA coupling was mediated by an amelioration of E_V. All patients improved their arterial pressure and cardiac index with treatment. The haemodynamic treatment group exhibited no effect on changing t-IVT.

Conclusion

Acute circulatory failure is associated with electromechanical dyssynchrony. Cardiac electromechanical coupling was improved by haemodynamic treatment only if altered at baseline. The improvement of cardiac electromechanical coupling was associated with the improvement of markers of cardiocirculatory efficacy and efficiency (i.e., SWI/PVA and VA coupling). This study was the first to demonstrate a possible link between cardiac electromechanical coupling and VA coupling in patients with acute circulatory failure.

Arterial Hypotension Following Norepinephrine Decrease in Septic Shock Patients Is Not Related to Preload Dependence: A Prospective, Observational Cohort Study

Background

The optimal management of hypotensive patients during norepinephrine weaning is unclear. The primary study aim was to assess the ability of preload dependence to predict hypotension following norepinephrine weaning. The secondary aims were to describe the effect of norepinephrine weaning on preload dependence, and the cardiovascular effects of fluid expansion in hypotensive patients following norepinephrine weaning.

Materials and Methods

This was a prospective observational monocentric study. We included PiCCO®-monitored patients with norepinephrine-treated septic shock, for whom the physician decided to decrease the norepinephrine dosage during the de-escalation phase. Three consecutive steps were evaluated with hemodynamic measurements: baseline, after norepinephrine decrease, and after 500 mL fluid expansion.

Results

Forty-five patients were included. Preload dependence assessed by stroke volume changes following passive leg raising was not predictive of pressure response to norepinephrine weaning [AUC of 0.42 (95%CI: 0.25–0.59, p = 0.395)]. After fluid expansion, there was no difference in the prior preload dependence between pressure-responders and non-pressure-responders (14 vs. 13%, p = 1). The pressure response to norepinephrine decrease was not associated with pressure response after fluid expansion (40 vs. 23%, p = 0.211).

Conclusion

Hypotension following norepinephrine decrease was not predicted by preload dependence, and there was no association between arterial hypotension after norepinephrine decrease and fluid response.

Clinical implication of intraoperative ventricular-arterial coupling in pediatric patients undergoing ventricular septal defects repair: A retrospective cohort study

BACKGROUND

Ventricular-arterial coupling is the ratio of arterial elastance to ventricular end-systolic elastance.

AIMS

The objective of this study was to determine the clinical implication of intraoperative ventricular-arterial coupling derived from the pressure-area relationship using transesophageal echocardiography.

METHODS

This retrospective study reviewed the medical records of 72 pediatric patients with ventricular septal defects who underwent corrective surgery with cardiopulmonary bypass. The single-beat modified method was used to assess ventricular-arterial coupling. Logistic regression analyses were performed to determine the correlation between ventricular-arterial coupling and early postoperative outcomes, including the maximum vasoactive-inotropic score, length of mechanical ventilation, and length of hospital stay.

RESULTS

Ventricular-arterial coupling after cardiopulmonary bypass significantly increased (from 1.0 ± 0.4 to 1.4 ± 0.8, p < .001), indicating a disproportionate increase in the arterial elastance index (from 11.5 ± 5.1 to 19.8 ± 7.5 mmHg/cm² /m² , p < .001) compared with the ventricular end-systolic elastance index (from 13.0 ± 6.9 to 16.9 ± 9.0 mmHg/cm² /m² , p < .001). Logistic regression analyses revealed that high postoperative ventricular-arterial coupling was independently associated with higher postoperative maximum vasoactive-inotropic score (>10; odds ratio [OR], 8.04; 95% confidence interval [CI], 1.38-46.85, p = .020), longer postoperative mechanical ventilation (>15 h; OR: 11.00; 95% CI: 1.26-96.45, p = .030), and longer postoperative hospital stay (>7 days; OR: 2.98; 95% CI: 1.04-8.58, p = .043).

CONCLUSIONS

Ventricular-arterial coupling can be easily obtained from the intraoperative transesophageal echocardiography in pediatric patients undergoing ventricular septal defects repair. High postoperative ventricular-arterial coupling is strongly associated with worse early postoperative outcomes. Ventricular-arterial coupling shows promise as an intraoperative analysis tool that can provide insight into the impact of interventions on cardiovascular performance and identify potential targets for treatment in this population.

Arterial Load and Norepinephrine Are Associated With the Response of the Cardiovascular System to Fluid Expansion

Background

Fluid responsiveness has been extensively studied by using the preload prism. The arterial load might be a factor modulating the fluid responsiveness. The norepinephrine (NE) administration increases the arterial load and modifies the vascular properties. The objective of the present study was to determine the relationship between fluid responsiveness, preload, arterial load, and NE use. We hypothesized that as a preload/arterial load, NE use may affect fluid responsiveness.

Methods

The retrospective multicentered analysis of the pooled data from 446 patients monitored using the transpulmonary thermodilution before and after fluid expansion (FE) was performed. FE was standardized between intensive care units (ICUs). The comparison of patients with and without NE at the time of fluid infusion was performed. Stroke volume (SV) responsiveness was defined as an increase of more than 15% of SV following the FE. Pressure responsiveness was defined as an increase of more than 15% of mean arterial pressure (MAP) following the FE. Arterial elastance was used as a surrogate for the arterial load.

Results

A total of 244 patients were treated with NE and 202 were not treated with NE. By using the univariate analysis, arterial elastance was correlated to SV variations with FE. However, the SV variations were not associated with NE administration (26 [15; 46]% vs. 23 [10; 37]%, p = 0.12). By using the multivariate analysis, high arterial load and NE administration were associated with fluid responsiveness. The association between arterial elastance and fluid responsiveness was less important in patients treated with NE. Arterial compliance increased in the absence of NE, but it did not change in patients treated with NE (6 [−8; 19]% vs. 0 [−13; 15]%, p = 0.03). The changes in total peripheral and arterial elastance were less important in patients treated with NE (−8 [−17; 1]% vs. −11 [−20; 0]%, p < 0.05 and −10 [−19; 0]% vs. −16 [−24; 0]%, p = 0.01).

Conclusion

The arterial load and NE administration were associated with fluid responsiveness. A high arterial load was associated with fluid responsiveness. In patients treated with NE, this association was lower, and the changes of arterial load following FE seemed to be driven mainly by its resistive component.

Vasopressor-Sparing Strategies in Patients with Shock: A Scoping-Review and an Evidence-Based Strategy Proposition

Despite the abundant literature on vasopressor therapy, few studies have focused on vasopressor-sparing strategies in patients with shock. We performed a scoping-review of the published studies evaluating vasopressor-sparing strategies by analyzing the results from randomized controlled trials conducted in patients with shock, with a focus on vasopressor doses and/or duration reduction. We analyzed 143 studies, mainly performed in septic shock. Our analysis demonstrated that several pharmacological and non-pharmacological strategies are associated with a decrease in the duration of vasopressor therapy. These strategies are as follows: implementing a weaning strategy, vasopressin use, systemic glucocorticoid administration, beta-blockers, and normothermia. On the contrary, early goal directed therapies, including fluid therapy, oral vasopressors, vitamin C, and renal replacement therapy, are not associated with an increase in vasopressor-free days. Based on these results, we proposed an evidence-based vasopressor management strategy.

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 (Ea_dyn) can predict decreases in arterial pressure in response to changing norepinephrine levels. The objective of this study was to determine whether Ea_dyn 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 Ea_dyn and its associations with CCP and SARi. The secondary outcomes were the associations between Ea_dyn and vascular/flow parameters.

Results: At baseline, all patients were hypotensive with Ea_dyn 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 Ea_dyn [0.40 (0.30;0.60)] and SARi. Ea_dyn was significantly associated with arterial compliance (C_A), CCP, and TPRi (p < 0.05).

Conclusion: In patients with vasoplegic syndrome, Ea_dyn was correlated with determinants of the vascular waterfall. Ea_dyn 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.

Echocardiographic measure of dynamic arterial elastance predict pressure response during norepinephrine weaning: an observational study

The purpose of this study was to determine whether dynamic elastance E_Adyn derived from echocardiographic measurements of stroke volume variations can predict the success of a one-step decrease of norepinephrine dose. In this prospective single-center study, 39 patients with vasoplegic syndrome treated with norepinephrine and for whom the attending physician had decided to decrease norepinephrine dose and monitored by thermodilution were analyzed. E_Adyn is the ratio of pulse pressure variation to stroke volume variation and was calculated from echocardiography stroke volume variations and from transpulmonary thermodilution. Pulse pressure variation was obtained from invasive arterial monitoring. Responders were defined by a decrease in mean arterial pressure (MAP) > 10% following norepinephrine decrease. The median decrease in norepinephrine was of 0.04 [0.03-0.05] µg kg^-1 min^-1. Twelve patients (31%) were classified as pressure responders with a median decrease in MAP of 13% [12-15%]. E_Adyn was lower in pressure responders (0.40 [0.24-0.57] vs 0.95 [0.77-1.09], p < 0.01). E_Adyn was able to discriminate between pressure responders and non-responders with an area under the curve of 0.86 (CI_95% [0.71 to1.0], p < 0.05). The optimal cut-off was 0.8. E_Adyn calculated from the echocardiographic estimation of the stroke volume variation and the invasive arterial pulse pressure variation can be used to discriminate pressure response to norepinephrine weaning. Agreement between E_Adyn calculated from echocardiography and thermodilution was poor. Echocardiographic E_Adyn might be used at bedside to optimize hemodynamic treatment.

Fluid expansion improve ventriculo-arterial coupling in preload-dependent patients: a prospective observational study

BACKGROUND

The objectives of the present study was to evaluate the effect of fluid challenge (FC) on ventriculo-arterial (V-A) coupling, its determinants: arterial elastance and ventricular elastance, and ability to predict fluid responsiveness.

METHODS

Thirty patients admitted to cardio-thoracic ICU in whom the physician decided to perform FC were included. Arterial pressure, cardiac output, arterial elastance, and ventricular elastance, were measured before and after FC with 500 ml of lactated Ringer's solution. Fluid responders were defined as patients with more than a 15% increase in stroke volume. V-A coupling was evaluated by the arterial elastance to ventricular elastance ratio.

RESULTS

Twenty-three (77%) of the 30 patients included in the study were fluid responders. Before FC, responders had higher arterial elastance and arterial elastance to ventricular elastance ratio. FC significantly increased mean arterial pressure, stroke volume and cardiac output, and significantly decreased systemic vascular resistance, arterial elastance and consequently the arterial elastance to ventricular elastance ratio. Changes in arterial elastance were correlated with changes in stroke volume, systemic vascular resistance, and arterial compliance. Baseline arterial elastance to ventricular elastance ratio over 1.4 predicted fluid responsiveness (area under the curve [95% confidence interval]: 0.84 [0.66-1]; p < 0.0001).

CONCLUSIONS

Fluid responsiveness patients had V-A coupling characterized by increase arterial elastance to ventricular elastance ratio, in relation to an increase arterial elastance. Fc improved the V-A coupling ratio by decreasing arterial elastance without altering ventricular elastance. Arterial elastance changes were related to those of systemic vascular resistance (continue component) and of arterial compliance (pulsatile component).