Right Ventricular Pressure–Volume Analysis During Left Ventricular Assist Device Speed Optimization Studies: Insights Into Interventricular Interactions and Right Ventricular Failure

doi:10.1016/j.cardfail.2021.04.019

Journal of Cardiac Failure

Volume 27, Issue 9, September 2021, Pages 991-1001

https://doi.org/10.1016/j.cardfail.2021.04.019 Get rights and content

Abstract

Background

Interventricular interaction, which refers to the impact of left ventricular (LV) function on right ventricular (RV) function and vice versa, has been implicated in the pathogenesis of RV failure in LV assist device (LVAD) recipients. We sought to understand more about interventricular interaction by quantifying changes in the RV systolic and diastolic function with varying LVAD speeds.

Methods and Results

Four patients (ages 22–69 years, 75% male, and 25% with ischemic cardiomyopathy) underwent a protocolized hemodynamic ramp test within 12 months of LVAD implantation where RV pressure–volume loops were recorded with a conductance catheter. The end-systolic PV relationship and end-diastolic PV relationship were compared using the V₂₀ and V₁₀ indices (volumes at which end-systolic PV relationship and end-diastolic PV relationship reach a pressure of 20 and 10 mm Hg, respectively). The ∆V₂₀ and ∆V₁₀ refer to the change in V₂₀ and V₁₀ from the minimum to maximum LVAD speeds. RV PV loops demonstrated variable changes in systolic and diastolic function with increasing LVAD speed. The end-systolic PV relationship changed in 1 patient (patient 2, ∆V₂₀ = 23.5 mL), reflecting a decrease in systolic function with increased speed, and was unchanged in 3 patients (average ∆V₂₀ = 7.4 mL). The end-diastolic PV relationship changed with increasing speed in 3 of 4 patients (average ∆V₁₀ = 12.5 mL), indicating an increase in ventricular compliance, and remained unchanged in one participant (patient 1; ∆V₁₀ = 4.0 mL).

Conclusions

Interventricular interaction can improve RV compliance and impair systolic function, but the overall effect on RV performance in this pilot investigation is heterogeneous. Further research is required to understand which patient characteristics and hemodynamic parameters influence the net impact of interventricular interaction.

Section snippets

Hemodynamic and Echocardiographic Ramp Test

Four patients who received a HeartMate 3 device (Abbott Laboratories, Abbott Park, IL) underwent a combined hemodynamic and echocardiographic speed optimization test within 12 months of LVAD implantation (Figure 1). All participants were stable outpatients and had a clinical indication for a follow-up right heart catheterization with LVAD speed optimization. On the day of the procedure, they consented to participate in the research protocol. To participate in the study, patients had to have an

Hemodynamic and Echocardiographic Ramp Test

Hemodynamic and echocardiographic measurements were obtained in 4 consecutive patients who presented for clinically indicated ramp tests. Patients 1 and 3 underwent ramp tests as part of routine surveillance within 6 months of LVAD implantation, and patients 2 and 4 both were undergoing a workup for recurrent low-flow alarms. Baseline characteristics are provided in Table 1. Age ranged from 22 to 69 years and 1 of the 4 patients was female. The indication for device implantation was ischemic

Discussion

In this pilot study, we performed novel, multimodality ramp studies in HeartMate 3 recipients combining pulmonary arterial catheter-derived hemodynamics, 3-dimensional echocardiography, and invasive PV analysis. Furthermore, we used computational modeling to derive important insights into the complex interplay between interventricular interactions and RV function in LVAD recipients. Our key findings were 3-fold. First, despite the small sample size, we observed 3 patterns of interventricular

Conclusions

Previous investigations implied that increasing LVAD speed had no effect on the RV PV loop,²⁰ but we identified additional patterns that included predominant diastolic interventricular interactions and combined systolic and diastolic interactions. The use of computational modeling put these findings into perspective by helping to identify the contributions of serial and parallel ventricular interactions in the setting of LVAD speed variations. These findings are novel and set the stage for

Disclosures

M.K. Kanwar is on the Advisory board for Abiomed, Bayer, and CareDx. P.C. Colombo reports consulting fees from Abbott. G.T. Sayer reports consulting fees from Abbott. N. Uriel reports consulting fees from Medtronic and honorarium from Abbott. D. Burkhoff reports consulting fees from PVLoops and Cardiodyme, and grant support from Abiomed. The remaining authors have stated that they have no conflicts of interest.

Funding

M.I. Brener is supported by NIH (NHLBI) T32HL007343.

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Cited by (13)

Acute right ventricular geometric change predicts outcomes in HeartMate 3 patients
2024, Journal of Heart and Lung Transplantation
The physiological response of the right ventricle (RV) following left ventricular assist device (LVAD) implantation is difficult to predict. We aimed to investigate RV geometric and functional changes after LVAD insertion and their effects on clinical outcomes.
We retrospectively reviewed 188 patients who underwent HeartMate 3 implantation at our center between November 2014 and September 2021. The RV end-diastolic diameter (RVEDD) and RV end-diastolic area (RVEDA) were measured on preoperative and predischarge transthoracic echocardiography. The nonadapted group included patients with increased RVEDD and RVEDA at discharge. The composite outcome was defined as death or readmission due to worsening right heart failure.
There were 82 patients (44%) who had a nonadapted and 106 patients (56%) who had an adapted RV. Preoperatively, the nonadapted group had smaller RVEDD (46 vs 49 mm, p < 0.001) and RVEDA (27 vs 31 cm², p < 0.001). At discharge, the nonadapted group had larger RVEDD (51 vs 43 mm, p < 0.001) and RVEDA (33 vs 27 cm², p < 0.001). Kaplan-Meier analysis demonstrated worse 3-year survival (77% vs 91%, p = 0.006) and freedom from composite outcome (58% vs 85%, p < 0.001) in the nonadapted group. A multivariable Cox proportional hazards model showed that nonadaption (hazard ratio [HR] 3.09, 95% confidence interval [CI] 1.29-7.40, p = 0.01) and age (HR 3.73, 95% CI 1.42-9.77, p = 0.007) were independent predictors of composite outcome.
Acute RV dimensional changes after LVAD insertion may represent intrinsic RV function and may be a useful prognostic marker.
Occult right ventricular dysfunction and right ventricular-vascular uncoupling in left ventricular assist device recipients
2024, Journal of Heart and Lung Transplantation
Detecting right heart failure post left ventricular assist device (LVAD) is challenging. Sensitive pressure-volume loop assessments of right ventricle (RV) contractility may improve our appreciation of post-LVAD RV dysfunction.
Thirteen LVAD patients and 20 reference (non-LVAD) subjects underwent comparison of echocardiographic, right heart cath hemodynamic, and pressure-volume loop-derived assessments of RV contractility using end-systolic elastance (Ees), RV afterload by effective arterial elastance (Ea), and RV-pulmonary arterial coupling (ratio of Ees/Ea).
LVAD patients had lower RV Ees (0.20 ± 0.08 vs 0.30 ± 0.15 mm Hg/ml, p = 0.01) and lower RV Ees/Ea (0.37 ± 0.14 vs 1.20 ± 0.54, p < 0.001) versus reference subjects. Low RV Ees correlated with reduced RV septal strain, an indicator of septal contractility, in both the entire cohort (r = 0.68, p = 0.004) as well as the LVAD cohort itself (r = 0.78, p = 0.02). LVAD recipients with low RV Ees/Ea (below the median value) demonstrated more clinical heart failure (71% vs 17%, p = 0.048), driven by an inability to augment RV Ees (0.22 ± 0.11 vs 0.19 ± 0.02 mm Hg/ml, p = 0.95) to accommodate higher RV Ea (0.82 ± 0.38 vs 0.39 ± 0.08 mm Hg/ml, p = 0.002). Pulmonary artery pulsatility index (PAPi) best identified low baseline RV Ees/Ea (≤0.35) in LVAD patients ((area under the curve) AUC = 0.80); during the ramp study, change in PAPi also correlated with change in RV Ees/Ea (r = 0.58, p = 0.04).
LVAD patients demonstrate occult intrinsic RV dysfunction. In the setting of excess RV afterload, LVAD patients lack the RV contractile reserve to maintain ventriculo-vascular coupling. Depression in RV contractility may be related to LVAD left ventricular unloading, which reduces septal contractility.
Impact of Interventricular Interaction on Ventricular Function: Insights From Right Ventricular Pressure-Volume Analysis
2024, JACC: Heart Failure
Interventricular interactions may be responsible for the decline in ventricular performance observed in various disease states that primarily affect the contralateral ventricle.
This study sought to quantify the impact of such interactions on right ventricular (RV) size and function using clinically stable individuals with left ventricular assist devices (LVADs) as a model for assessing RV hemodynamics while LV loading conditions were acutely manipulated by changing device speed during hemodynamic optimization studies (ie, ramp tests).
The investigators recorded RV pressure-volume loops with a conductance catheter at various speeds during ramp tests in 20 clinically stable HeartMate3 recipients.
With faster LVAD speeds and greater LV unloading, indexed RV end-diastolic volume increased (72.28 ± 15.07 mL at low speed vs 75.95 ± 16.90 at high speed; P = 0.04) whereas indexed end-systolic volumes remained neutral. This resulted in larger RV stroke volumes and shallower end-diastolic pressure-volume relationships. Concurrently, RV end-systolic pressure decreased (31.58 ± 9.75 mL at low speed vs 29.58 ± 9.41 mL at high speed; P = 0.02), but contractility, as measured by end-systolic elastance, did not change significantly. The reduction in RV end-systolic pressure was associated with a reduction in effective arterial elastance from 0.65 ± 0.43 mm Hg/mL at low speed to 0.54 ± 0.33 mm Hg/mL at high speed (P = 0.02).
Interventricular interactions resulted in improved RV compliance, diminished afterload, and did not reduce RV contractility. These data challenge the prevailing view that interventricular interactions compromise RV function, which has important implications for the understanding of RV-LV interactions in various disease states, including post-LVAD RV dysfunction.
Value of Invasive Hemodynamic Assessments in Patients Supported by Continuous-Flow Left Ventricular Assist Devices
2024, JACC: Heart Failure
Left ventricular assist devices (LVADs) are increasingly used in patients with end-stage heart failure (HF). There is a significant risk of HF admissions and hemocompatibility-related adverse events that can be minimized by optimizing the LVAD support. Invasive hemodynamic assessment, which is currently underutilized, allows personalization of care for patients with LVAD, and may decrease the need for recurrent hospitalizations. It also aids in triaging patients with persistent low-flow alarms, evaluating reversal of pulmonary vasculature remodeling, and assessing right ventricular function. In addition, it can assist in determining the precipitant for residual HF symptoms and physical limitation during exercise and is the cornerstone of the assessment of myocardial recovery. This review provides a comprehensive approach to the use of invasive hemodynamic assessments in patients supported with LVADs.
Late Right Heart Failure After Left Ventricular Assist Device Implantation: Contemporary Insights and Future Perspectives
2023, JACC: Heart Failure
Late right heart failure (RHF) is increasingly recognized in patients with long-term left ventricular assist device (LVAD) support and is associated with decreased survival and increased incidence of adverse events such as gastrointestinal bleeding and stroke. Progression of right ventricular (RV) dysfunction to clinical syndrome of late RHF in patients supported with LVAD is dependent on the severity of pre-existing RV dysfunction, persistent or worsening left- or right-sided valvular heart disease, pulmonary hypertension, inadequate or excessive left ventricular unloading, and/or progression of the underlying cardiac disease. RHF likely represents a continuum of risk with early presentation and progression to late RHF. However, de novo RHF develops in a subset of patients leading to increased diuretic requirement, arrhythmias, renal and hepatic dysfunction, and heart failure hospitalizations. The distinction between isolated late RHF and RHF due to left-sided contributions is lacking in registry studies and should be the focus of future registry data collection. Potential management strategies include optimization of RV preload and afterload, neurohormonal blockade, LVAD speed optimization, and treatment of concomitant valvular disease. In this review, the authors discuss definition, pathophysiology, prevention, and management of late RHF.
Biventricular catheterization combined with pressure-volume loop monitoring provides insight into the dynamic effects of left ventricular assist devices ramp on right ventricular function
2024, Catheterization and Cardiovascular Interventions

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Lay Summary

A left ventricular assist device can be a life-saving treatment for patients with advanced heart failure symptoms. Although the left ventricular assist device offloads the weakened left ventricle by taking blood out from the ventricle and pumping it to the rest of the body, the right ventricle (RV) often suffers and, when it does, this leads to many adverse outcomes. Further complicating matters, physicians have difficulty predicting and treating RV dysfunction. Thus, we used a specialized conductance catheter that measures pressure and volume simultaneously in the RV to understand, at a mechanistic level, how the RV responds to left ventricular assist device implantation.

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Right Ventricular Pressure–Volume Analysis During Left Ventricular Assist Device Speed Optimization Studies: Insights Into Interventricular Interactions and Right Ventricular Failure

Abstract

Background

Methods and Results

Conclusions

Section snippets

Hemodynamic and Echocardiographic Ramp Test

Hemodynamic and Echocardiographic Ramp Test

Discussion

Conclusions

Disclosures

Funding

J Heart Lung Transplant

J Heart Lung Transplant

J Thorac Cardiovasc Surg

JACC Heart Fail

JACC Cardiovasc Imaging

J Am Coll Cardiol

J Heart Lung Transplant

J Heart Lung Transplant

Prog Cardiovasc Dis

Investigating the role of interventricular interdependence in development of right heart dysfunction during LVAD support: a patient-specific methods based approach

Front Physiol