Prediction, prevention, and management of right ventricular failure after left ventricular assist device implantation: A comprehensive review

Structural Heart Interventions in Patients with Left Ventricular Assist Devices

Left ventricular assist devices (LVADs) have changed the landscape for patients with advanced heart failure (HF). With advances in pump design and management, patients with LVADs are living longer with improved quality of life despite having more comorbidities and complex structural heart disease. As such, HF cardiologists and surgeons collaborate more frequently with structural heart interventionalists to address the complex problems of patients with LVADs who present at different points of failure in their circuits. Unlike heart transplants and total artificial heart recipients, the native heart and its components must function to maintain successful circulatory support from these assist devices. Multiple points of potential failure of the native heart and the LVAD circuit exist that can result in significant morbidity and mortality. These include regurgitant valve lesions, interatrial shunts, outflow cannula obstruction, and pump thrombosis. Transcatheter interventions can be applied and tailored specifically to the anatomy of the individual in these situations to improve the lives and outcomes of our LVAD patients. This review provides a comprehensive approach for diagnosing and treating structural heart disease associated with patients who have LVADs, focusing on multidisciplinary collaboration and individualized interventional strategies.

Impact of early CVP monitoring on 1-year mortality in patients with congestive heart failure in the ICU: a retrospective analysis based on the MIMIC-IV2.2 database

BACKGROUND

Central venous pressure (CVP) monitoring is critical for fluid management in critically ill patients. This study evaluated the impact of CVP monitoring on 1-year mortality in intensive care unit (ICU) patients with congestive heart failure (CHF).

METHODS

Data from the Medical Information for Critical Care IV (MIMIC-IV) database were analyzed for ICU patients admitted for the first time with a stay > 24 h. Patients were categorized into CVP and no-CVP groups based on CVP measurement. Logistic regression analyses were performed, with propensity score matching (PSM) and overlap weighting (OW) to minimize confounding. Inflection point analysis using logistic regression was conducted in the CVP group. Patients were further stratified into early (≤ 24 h) and late (> 24 h) CVP monitoring groups for additional analysis.

RESULTS

Among 4,479 patients, 919 were in the CVP group and 3,560 in the no-CVP group. CVP monitoring was associated with lower 1-year mortality (odds ratio [OR] = 0.75, 95% confidence interval [CI] = 0.62-0.91, p = 0.003). Early CVP monitoring (≤ 24 h) independently reduced 1-year mortality (OR = 0.68, 95% CI = 0.47-0.97, p = 0.032). Predictors of mortality included the lowest diastolic blood pressure, lowest blood glucose, highest blood chloride, and Acute Physiology Score III (APSIII) score within 24 h of admission.

CONCLUSION

Early CVP monitoring significantly improves 1-year survival in ICU patients with congestive heart failure. These findings underscore the value of timely hemodynamic assessments in critical care and warrant further prospective validation in diverse settings.

Mitigating Post-operative Right Ventricular Dysfunction After Left Ventricular Assist Device: The RV Protection Study

BACKGROUND

Despite improvements in hemocompatibility-related adverse events (HRAEs) with the HeartMate 3 left ventricular assist device (LVAD), hemodynamic-related events (HDREs), such as right ventricular failure (RVF) and aortic insufficiency, still result in considerable morbidity and mortality. We investigated a comprehensive, upfront RV protection strategy combining hemodynamic, ventilatory and pharmaceutical optimization to mitigate the risk of RVF.

METHODS/RESULTS

Participants were prospectively randomized in a 1:1 fashion to either the RV-protection strategy or usual care for post-operative LVAD management. The RV-protection strategy targeted RV afterload (inhaled NO ≥ 48 hrs, PCWP < 18), RV preload (CVP 8-14), RV perfusion (MAP 70-90, Hgb > 8), RV contractility (IV inotropes), rate/rhythm control (HR >100, normal sinus), ventilatory management (SpO2 >95, PaCO2 < 50, plateau pressure < 30, PEEP ≤ 5), and RV geometry (echo-guided septal position). The primary outcome was survival free from any HDREs or HRAEs at 24 weeks. Secondary outcomes included severe RVF, according to INTERMACS and ARC definitions. Twenty participants were randomized: 10 to the RV-protection strategy and 10 to usual care. The median age was 60 years (IQR 54-69), 50% were Black, and 50% had ischemia. At 24 weeks, the RV-protection strategy showed significantly greater survival rates free from HDREs or HRAEs compared to usual care (80% vs 40%; P = 0.04). Event-free survival for HRAEs resulted in similar findings. No HDREs occurred with the RV protection strategy vs 3 (30%) with usual care (P = 0.067). Similarly, severe RVF according to INTERMACS or ARC did not occur in the RV protection strategy vs 3 (30%) in the usual-care cohort (P = 0.20).

CONCLUSIONS

Participants receiving a novel, comprehensive, upfront RV protection strategy post-LVAD implantation had significantly greater survival rates free from HDREs or HRAEs at 24 weeks.

The association of right ventricular function with outcomes after cardiac surgery: a systematic review

PURPOSE

Assessment of right ventricular (RV) function is recommended as part of a comprehensive echocardiography exam, including before and after cardiac surgery. Nevertheless, the prognostic implications of various measures of RV function in patients undergoing cardiac surgery are not well characterized. Our goal was to conduct a focused systematic review to assess the association of quantitative parameters of RV function with postoperative outcomes in patients undergoing cardiac surgery.

METHODS

We conducted a systematic review of randomized controlled trials or observational studies in adult (≥ 18 yr) patients undergoing cardiac surgery with a reported echocardiogram within six months of surgery, intraoperatively, or shortly after surgery. We excluded case reports and case series. Databases included PubMed® and MEDLINE, and papers published from 1 January 1990 to 22 April 2024 were searched for. The primary predictors of interest were quantitative RV function parameters. The primary outcome of interest was postoperative mortality up to five years. The secondary outcome was all major adverse cardiac events (MACE).

RESULTS

We identified 7,187 potentially relevant studies, 27 of which were included; all of these were observational studies. Right ventricular fractional area change (RVFAC) was the most commonly reported parameter, but was inconsistently associated with mortality and MACE. Tricuspid annular plane systolic excursion (TAPSE) and strain were consistently associated with mortality. The most consistent predictor of MACE was RV myocardial performance index (MPI) across studies.

CONCLUSION

Pre- and perioperative assessment of RV function using at least two quantitative echocardiographic parameters may offer prognostic information in patients undergoing cardiac surgery. Right ventricular FAC, TAPSE, strain, and RV MPI have been frequently studied; however, further research is needed to delineate the role of echocardiographic RV quantification for perioperative prognostication.

STUDY REGISTRATION

PROSPERO ( CRD42023387383 ); first submitted 23 December 2022.

Patient-specific hemodynamic modeling to optimize LVAD speed and right heart health

Background

Left ventricular assist device (LVAD) speed optimization and right heart failure post device implantation are major clinical challenges. Right heart catheterization (RHC)-guided speed titration studies are often performed to optimize LVAD settings, which are unknown and must be optimized for each patient. A virtual hemodynamic model (VHM) that can be tailored to each patient may provide useful guidance and reduce repeated studies.

Methods

We conducted a retrospective analysis on 16 patients implanted with HeartMate 3 (HM3) who underwent RHC speed titration study as an outpatient. A custom-designed VHM was built and customized for each patient based on RHC measurements. VHM predictions were obtained for multiple scenarios: (1) population-based pulmonary system parameters, (2) patient-specific systemic and pulmonary resistance and capacitance parameters, (3) clinical optimization-based patient-specific mean arterial pressure (MAP), and (4) several MAP targets ranging from 70 to 90 mm Hg.

Results

All patients who underwent RHC speed titration had a clinician-guided speed increase, with a median increase of 300 revolutions per minute (rpm). Using each patient's customized VHM, virtual speed optimization demonstrated congruence with clinician-guided optimization, with a median predicted speed increase of 321 rpm. After virtual optimization, there was a decrease in the pulmonary artery pressure for 13 patients (81.25%), indicating a predicted improvement in pulmonary parameters.

Conclusions

For our cohort of 16 patients, there was an overall congruence between clinician-guided and patient-specific VHM-predicted optimal LVAD speeds. The magnitude of speed change varied depending on individual patient targets. This may provide individualized speed titration goals and lessen the need for repeat invasive studies.

The Prognostic Role of Pulmonary Arterial Elastance in Patients Undergoing Left Ventricular Assist Device Implantation: A Pilot Study

Background: Pulmonary arterial elastance (Ea) is a helpful parameter to predict the risk of acute postoperative right ventricular failure (RVF) after left ventricular assist device (LVAD) implantation. A new method for calculating Ea, obtained by the ratio between transpulmonary gradient and stroke volume (EaB), has been proposed as a more accurate measure than the Ea obtained as the ratio between pulmonary artery systolic pressure and stroke volume (EaC). However, the role of EaB in predicting acute RVF post-LVAD implantation remains unclear. Methods and Results: A total of 35 patients who underwent LVAD implantation from 2018 to 2021 were reviewed in this retrospective analysis. Acute RVF after LVAD implantation occurred in 12 patients (34%): 5 patients with moderate RVF (14% of total) and 7 patients with severe RVF. The EaB was not significantly different between the "severe RVF" vs. "not-severe RVF" groups (0.27 ± 0.04 vs 0.23 ± 0.1, p < 0.403). However, the combination of arterial elastance and central venous pressure was significantly different between the "not-severe RVF" group (central venous pressure < 14 mmHg and EaC < 0.88 mmHg/mL or EaB < 0.24 mmHg/mL; p < 0.005) and the "severe RVF" group (central venous pressure > 14 mmHg and EaC > 0.88 mmHg/mL or EaB > 0.24 mmHg/mL; p < 0.005). Conclusions: Ea is a reliable parameter of right ventricular afterload and helps discriminate the risk of acute RVF after LVAD implantation. The combined analysis of Ea and central venous pressure can also risk stratify patients undergoing LVAD implantation for the development of RVF.

Durable left ventricular assist devices as a bridge to transplantation: what to expect along the way?

INTRODUCTION

The scarcity of donors coupled with the improvements in left ventricular assist devices (LVAD) technology has led to the use of LVAD as a bridge to transplantation (BTT).

AREAS COVERED

The authors provide an overview of the current status of LVAD BTT implantation with special focus ranging from patient selection and pre-implantation optimization to post-transplant outcomes.

EXPERT OPINION

The United Network for Organ Sharing 2018 policy amendment resulted in a significant reduction in the number of LVADs used for BTT in the US. To overcome this issue, modifications in the US allocation policy to consider factors such as days on device support, age, and type of complications may be necessary to potentially increase implantation rates.

Serum Uric Acid as an Indicator of Right Ventricular Dysfunction in LVAD Patients: A Preliminary Study

(1) Background: Left ventricular assist devices (LVADs) represent mechanical support in end-stage congestive heart failure and are characterized by satisfactory long-term results. Uric acid (UA) represents one of the early heart failure markers whose usefulness was postulated in clinical practice. (2) Methods: Twenty-nine male patients with a median age of 58 (51-62) years were referred for LVAD implantation due to end-stage congestive heart failure in the mean (SD) New York Heart Association (NYHA) status class 3.3 (0.6). Preoperative and postoperative right ventricular (RV) characteristics were compared with serum uric acid concentration within 12 (8-15) months following the implantation. (3) Results: Significant correlations between postoperative uric acid concentration and right ventricular dimension (r = 0.604, p = 0.005), tricuspid annulus plane systolic excursion (TAPSE) (r = -0.496, p = 0.022), left ventricular ejection fraction (r = -0.463, p = 0.046), and N-terminal pro-B-type natriuretic peptide (NT-pro-BNP) (r = 0.505, p = 0.041) were noted. (4) Conclusions: The analysis shows the association between the postoperative RV diameter and TAPSE results in LVAD patients and uric acid concentration. Serum uric acid can be regarded as a possible right ventricular dysfunction marker in LVAD patients.

Monitoring of the right ventricular responses to pressure overload: prognostic value and usefulness of echocardiography for clinical decision-making

Regardless of whether pulmonary hypertension (PH) results from increased pulmonary venous pressure in left-sided heart diseases or from vascular remodeling and/or obstructions in pre-capillary pulmonary vessels, overload-induced right ventricular (RV) dysfunction and its final transition into right-sided heart failure is a major cause of death in PH patients. Being particularly suited for non-invasive monitoring of the right-sided heart, echocardiography has become a useful tool for optimizing the therapeutic decision-making and evaluation of therapy results in PH. The review provides an updated overview on the pathophysiological insights of heart-lung interactions in PH of different etiology, as well as on the diagnostic and prognostic value of echocardiography for monitoring RV responses to pressure overload. The article focuses particularly on the usefulness of echocardiography for predicting life-threatening aggravation of RV dysfunction in transplant candidates with precapillary PH, as well as for preoperative prediction of post-operative RV failure in patients with primary end-stage left ventricular (LV) failure necessitating heart transplantation or a LV assist device implantation. In transplant candidates with refractory pulmonary arterial hypertension, a timely prediction of impending RV decompensation can contribute to reduce both the mortality risk on the transplant list and the early post-transplant complications caused by severe RV dysfunction, and also to avoid combined heart-lung transplantation. The review also focuses on the usefulness of echocardiography for monitoring the right-sided heart in patients with acute respiratory distress syndrome, particularly in those with refractory respiratory failure requiring extracorporeal membrane oxygenation support. Given the pathophysiologic particularity of severe acute respiratory syndrome coronavirus (SARS-CoV-2) infection to be associated with a high incidence of thrombotic microangiopathy-induced increase in the pulmonary resistance, echocardiography can improve the selection of temporary mechanical cardio-respiratory support strategies and can therefore contribute to the reduction of mortality rates. On the whole, the review aims to provide a theoretical and practical basis for those who are or intend in the future to be engaged in this highly demanding field.

PERSUADE Survey-PERioperative AnestheSia and Intensive Care Management of Left VentricUlar Assist DevicE Implantation in Europe and the United States

OBJECTIVE

To comprehensively assess relevant institutional variations in anesthesia and intensive care management during left ventricular assist device (LVAD) implantation.

DESIGN

The authors used a prospective data analysis.

SETTING

This was an online survey.

PARTICIPANTS

Participants were from LVAD centers in Europe and the US.

INTERVENTIONS

After investigating initial interest, 91 of 202 European and 93 of 195 US centers received a link to the survey targeting institutional organization and experience, perioperative hemodynamic monitoring, medical management, and postoperative intensive care aspects.

MEASUREMENTS AND MAIN RESULTS

The survey was completed by 73 (36.1%) European and 60 (30.8%) US centers. Although most LVAD implantations were performed in university hospitals (>5 years of experience), significant differences were observed in the composition of the preoperative multidisciplinary team and provision of intraoperative care. No significant differences in monitoring or induction agents were observed. Propofol was used more often for maintenance in Europe (p < 0.001). The choice for inotropes changed significantly from preoperatively (more levosimendan in Europe) to intraoperatively (more use of epinephrine in both Europe and the US). The use of quantitative methods for defining right ventricular (RV) function was reported more often from European centers than from US centers (p < 0.05). Temporary mechanical circulatory support for the treatment of RV failure was more often used in Europe. Nitric oxide appeared to play a major role only intraoperatively. There were no significant differences in early postoperative complications reported from European versus US centers.

CONCLUSIONS

Although the perioperative practice of care for patients undergoing LVAD implantation differs in several aspects between Europe and the US, there were no perceived differences in early postoperative complications.

Left ventricular assist device implantation and concomitant mitral valve surgery: A systematic review and meta-analysis

BACKGROUND

The management of concomitant valvular lesions in patients undergoing left ventricular assist device (LVAD) implantation remains a topic of debate. This systematic review and meta-analysis aimed to evaluate the existing evidence on postoperative outcomes following LVAD implantation, with and without concomitant MV surgery.

METHODS

A systematic database search was conducted as per PRISMA guidelines, of original articles comparing LVAD alone to LVAD plus concomitant MV surgery up to February 2023. The primary outcomes assessed were overall mortality and early mortality, while secondary outcomes included stroke, need for right ventricular assist device (RVAD) implantation, postoperative mitral valve regurgitation, major bleeding, and renal dysfunction.

RESULTS

The meta-analysis included 10 studies comprising 32 184 patients. It revealed that concomitant MV surgery during LVAD implantation did not significantly affect overall mortality (OR:0.83; 95% CI: 0.53 to 1.29; p = 0.40), early mortality (OR:1.17; 95% CI: 0.63 to 2.17; p = 0.63), stroke, need for RVAD implantation, postoperative mitral valve regurgitation, major bleeding, or renal dysfunction. These findings suggest that concomitant MV surgery appears not to confer additional benefits in terms of these clinical outcomes.

CONCLUSION

Based on the available evidence, concomitant MV surgery during LVAD implantation does not appear to have a significant impact on postoperative outcomes. However, decision-making regarding MV surgery should be individualized, considering patient-specific factors and characteristics. Further research with prospective studies focusing on specific patient populations and newer LVAD devices is warranted to provide more robust evidence and guide clinical practice in the management of valvular lesions in LVAD recipients.

Value of Invasive Hemodynamic Assessments in Patients Supported by Continuous-Flow Left Ventricular Assist Devices

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.

Left Ventricular Assist Device Emergencies: Diagnosis and Management

Durable left ventricular assist devices (LVADs) are a virtually limitless advanced therapy option for an increasingly growing population of patients with end-stage advanced heart failure. As of 2019, 30% to 40% of all patients diagnosed with heart failure were categorized as New York Heart Association class III or IV. In 2018 more than 3.2 million office visits and 1.4 million emergency department visits carried a primary diagnosis of heart failure. Given the rapid growth of the LVAD population, facility in the diagnosis and management of common perioperative and outpatient LVAD emergencies has become of paramount importance in a variety of clinical settings.

Postoperative Pulmonary Artery Pulsatility Index Improves Prediction of Right Ventricular Failure After Left Ventricular Assist Device Implantation

OBJECTIVES

This study evaluated whether the postoperative pulmonary artery pulsatility index (PAPi) is associated with postoperative right ventricular dysfunction after durable left ventricular assist device (LVAD) implantation.

DESIGN

Single-center retrospective observational cohort study.

SETTING

The University of Kansas Medical Center, a tertiary-care academic medical center.

PARTICIPANTS

Sixty-seven adult patients who underwent durable LVAD implantation between 2017 and 2019.

INTERVENTIONS

All patients underwent open cardiac surgery with cardiopulmonary bypass under general anesthesia with pulmonary artery catheter insertion.

MEASUREMENTS AND MAIN RESULTS

Clinical and hemodynamic data were collected before and after surgery. The Michigan right ventricular failure risk score and the European Registry for Patients with Mechanical Circulatory Support score were calculated for each patient. The primary outcome was right ventricular failure, defined as a composite of right ventricular mechanical circulatory support, inhaled pulmonary vasodilator therapy for 48 hours or greater, or inotrope use for 14 days or greater or at discharge. Thirty percent of this cohort (n = 20) met the primary outcome. Preoperative transpulmonary gradient (odds ratio [OR] 1.15, 95% CI 1.02-1.28), cardiac index (OR 0.83, 95% CI 0.71-0.98), and postoperative PAPi (OR 0.85, 95% CI 0.75-0.97) were the only hemodynamic variables associated with the primary outcome. The addition of postoperative PAPi was associated with improvement in the predictive model performance of the Michigan score (area under the receiver operating characteristic curve 0.73 v 0.56, p = 0.03). An optimal cutoff point for postoperative PAPi of 1.56 was found.

CONCLUSIONS

The inclusion of postoperative PAPi offers more robust predictive power for right ventricular failure in patients undergoing durable LVAD implantation, compared with the use of existing risk scores alone.

How to Select Patients for Left Ventricular Assist Devices? A Guide for Clinical Practice

In recent years, a significant improvement in left ventricular assist device (LVAD) technology has occurred, and the continuous-flow devices currently used can last more than 10 years in a patient. Current studies report that the 5-year survival rate after LVAD implantation approaches that after a heart transplant. However, the outcome is influenced by the correct selection of the patients, as well as the choice of the optimal time for implantation. This review summarizes the indications, the red flags for prompt initiation of LVAD evaluation, and the principles for appropriate patient screening.