Significance of Residual Mitral Regurgitation After Continuous Flow Left Ventricular Assist Device Implantation

Intraoperative Echocardiography: Guide to Decision-Making

PURPOSE OF REVIEW

This review aims to provide a concise overview of key recommendations, with a specific focus on common challenges faced by intraoperative echocardiographers when dealing with frequently encountered valvular pathologies and mechanical circulatory support. It offers valuable insights for medical practitioners in this field.

RECENT FINDINGS

The American Society of Echocardiography (ASE) and the American College of Cardiology/American Heart Association (ACC/AHA) have released updated comprehensive guidelines for the use of transesophageal echocardiography (TEE) for the assessment of cardiac structures and implanted devices to help guide intraoperative decision-making. Transesophageal echocardiography (TEE) is a regularly employed intraoperative diagnostic and monitoring tool, offering various modalities for the rapid evaluation of valvular and aortic pathology, hemodynamic disturbances, and cardiac function. It is particularly valuable in assessing and placing mechanical circulatory support (MCS) devices, providing views often challenging to obtain through transthoracic echocardiography. Additionally, intraoperative TEE can be used for decision-making in patients with valvular disease allowing incorporation of patient-specific and situational factors. Echocardiographers can employ this information in real-time to help guide surgical treatment selection such as repair, replacement, or deferral of intervention.

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.

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.

Prognostic value of mitral regurgitation in patients undergoing left ventricular assist device deployment: A systematic review and meta-analysis

BACKGROUND

Left ventricular assist devices (LVADs) represent an important therapeutic option for patients progressing to end-stage heart failure. LVAD has previously been shown to have a promising role in improving mitral regurgitation (MR). Nevertheless, the prognostic value of preoperative uncorrected MR in this population remains unclear.

METHODS

A systematic database search with meta-analysis was conducted of comparative original articles of patients with preoperative mild MR (Grade 0-I) versus moderate-severe MR (Grade II-III) undergoing LVAD implantation, in EMBASE, MEDLINE, Cochrane database, and Google Scholar, from inception to June 2022. Primary outcomes were overall and operative mortality. Secondary outcomes were neurological dysfunction, gastrointestinal bleeding, right heart failure, LVAD thrombosis, and driveline infection.

RESULTS

Our search yielded 2228 relevant studies. A total of 19 studies met the inclusion criteria with a total of 11 873 patients. LVAD caused a statistically significant decrease of 35.9% in the number of patients with moderate-severe MR (grade II-III) postoperatively. No significant difference was observed in terms of overall mortality, operative mortality, GI bleeding, LVAD thrombosis, and driveline infection rates between mild and moderate-severe MR. An increased rate of right heart failure was seen among patients with moderate-severe MR, while lower rates of neurological events were also observed.

CONCLUSION

LVAD improves the haemodynamics of the left ventricle, to promote resolution of MR. Nevertheless, the severity of preoperative mitral regurgitation in patients undergoing LVAD deployment does not seem to affect mortality.

Mitral regurgitation severity at left ventricular assist device implantation is associated with distinct myocardial transcriptomic signatures

OBJECTIVES

We examined for differences in pre-left ventricular assist device (LVAD) implantation myocardial transcriptome signatures among patients with different degrees of mitral regurgitation (MR).

METHODS

Between January 2018 and October 2019, we collected left ventricular (LV) cores during durable LVAD implantation (n = 72). A retrospective chart review was performed. Total RNA was isolated from LV cores and used to construct cDNA sequence libraries. The libraries were sequenced with the NovaSeq system, and data were quantified using Kallisto. Gene Set Enrichment Analysis (GSEA) and Gene Ontology analyses were performed, with a false discovery rate <0.05 considered significant.

RESULTS

Comparing patients with preoperative mild or less MR (n = 30) and those with moderate-severe MR (n = 42), the moderate-severe MR group weighted less (P = .004) and had more tricuspid valve repairs (P = .043), without differences in demographics or comorbidities. We then compared both groups with a group of human donor hearts without heart failure (n = 8). Compared with the donor hearts, there were 3985 differentially expressed genes (DEGs) for mild or less MR and 4587 DEGs for moderate-severe MR. Specifically altered genes included 448 DEGs for specific for mild or less MR and 1050 DEGs for moderate-severe MR. On GSEA, common regulated genes showed increased immune gene expression and reduced expression of contraction and energetic genes. Of the 1050 genes specific for moderate-severe MR, there were additional up-regulated genes related to inflammation and reduced expression of genes related to cellular proliferation.

CONCLUSIONS

Patients undergoing durable LVAD implantation with moderate-severe MR had increased activation of genes related to inflammation and reduction of cellular proliferation genes. This may have important implications for myocardial recovery.

Managing valvular pathology during LVAD implantation

Since the time of their invention, implantable continuous flow left ventricular assist devices (LVADs) have improved the quality of life and extended survival for patients with advanced heart failure. The decision surgeons and their physician colleagues make with these patients to undergo implantation must come with full understanding of the immediate, short-term, and long-term implications of such a life-changing procedure. The presence of pathology regarding the aortic, mitral, and tricuspid valves introduces particularly complex problems for the surgical treatment strategy. Concomitant valve repair or replacement increases cardiopulmonary bypass and cross clamp times, and could potentially lead to worse outcomes in the perioperative setting. Following perioperative recovery, valvular pathology may worsen or arise de novo given the often drastic immediate physiologic changes in blood flow, septal function, and, over time, ventricular remodeling. Over the past two decades, there has been vast improvement in the device manufacturing, surgical techniques, and medical management surrounding LVAD implantation. Yet, addressing concomitant valvular pathology remains a complex question with no perfect solutions. This review aims to briefly describe the evolution of approach to valvular pathology in the LVAD patient and offer our opinion and treatment rationale.

Transcatheter valvular therapies in patients with left ventricular assist devices

Aortic, mitral and tricuspid valve regurgitation are commonly encountered in patients with continuous-flow left ventricular assist devices (CF-LVADs). These valvular heart conditions either develop prior to CF-LVAD implantation or are induced by the pump itself. They can all have significant detrimental effects on patients' survival and quality of life. With the improved durability of CF-LVADs and the overall rise in their volume of implants, an increasing number of patients will likely require a valvular heart intervention at some point during CF-LVAD therapy. However, these patients are often considered poor reoperative candidates. In this context, percutaneous approaches have emerged as an attractive "off-label" option for this patient population. Recent data show promising results, with high device success rates and rapid symptomatic improvements. However, the occurrence of distinct complications such as device migration, valve thrombosis or hemolysis remain of concern. In this review, we will present the pathophysiology of valvular heart disease in the setting of CF-LVAD support to help us understand the underlying rationale of these potential complications. We will then outline the current recommendations for the management of valvular heart disease in patients with CF-LVAD and discuss their limitations. Lastly, we will summarize the evidence related to transcatheter heart valve interventions in this patient population.

HFSA Expert Consensus Statement on the Medical Management of Patients on Durable Mechanical Circulatory Support

The medical management of patients supported with durable continuous flow left ventricular assist device (LVAD) support encompasses pharmacologic therapies administered in the preoperative, intraoperative, postoperative and chronic LVAD support stages. As patients live longer on LVAD support, the risks of LVAD-related complications and progression of cardiovascular and other diseases increase. Using existing data from cohort studies, registries, randomized trials and expert opinion, this Heart Failure Society of America Consensus Document on the Medical Management of Patients on Durable Mechanical Circulatory Support offers best practices on the management of patients on durable MCS, focusing on pharmacological therapies administered to patients on continuous flow LVADs. While quality data in the LVAD population are few, the utilization of guideline directed heart failure medical therapies (GDMT) and the importance of blood pressure management, right ventricular preload and afterload optimization, and antiplatelet and anticoagulation regimens are discussed. Recommended pharmacologic regimens used to mitigate or treat common complications encountered during LVAD support, including arrhythmias, vasoplegia, mucocutaneous bleeding, and infectious complications are addressed. Finally, this document touches on important potential pharmacological interactions from anti-depressants, herbal and nutritional supplements of relevance to providers of patients on LVAD support.

Impact of preoperative mitral regurgitation on left ventricular assist device patients: propensity score-matched analysis of the EUROMACS dataset

OBJECTIVES

Mitral regurgitation (MR) is frequently observed in patients undergoing left ventricular assist device implantation. We investigated the impact of preoperative MR on left ventricular assist device patients.

METHODS

A retrospective propensity score-matched analysis of adult patients enrolled in the EUROMACS registry between 1 January 2011 and 30 November 2021 was performed. Patients were divided into 2 groups according to the grade of preoperative MR: none-to-mild (MR 0-II) or moderate-to-severe (MR III-IV).

RESULTS

Following 1:1 propensity score matching, each group consisted of 914 patients. Incidence of postoperative temporary right ventricular support, reoperation for bleeding and dialysis was similar. MR III-IV demonstrated shorter median intensive care unit stay [14 days (6; 27.8) vs 10 days (5; 22), P = 0.004] and ventilation time [72 h (22, 320) vs 31 h (18, 150), P < 0.001]. Mortality was lower for MR III-IV patients [subdistribution hazard ratio: 0.66, 95% confidence interval (CI): 0.59-0.73, P < 0.001]. The 1-year survival was 68.1% (95% CI: 65.1-71.3%) in MR 0-II and 75% (95% CI: 72.1-78%) in MR III-IV. A lower incidence of total complications [odds ratio (OR): 0.93 (0.89-0.98), P = 0.003] and trend towards a lower risk of neurological dysfunction (subdistribution hazard ratio: 0.79; 95% CI: 0.61-1.01, P = 0.063) and sustained ventricular tachycardia [OR: 0.93 (0.54-1.03), P = 0.074] were demonstrated for MR III-IV. The risk of fatal stroke and pump thrombosis was similar.

CONCLUSIONS

Moderate-to-severe MR in patients undergoing left ventricular assist device implantation is associated with better mid-term survival and lower incidence of total major adverse events and complications. The incidence of severe postoperative complications including fatal stroke and device thrombosis was similar.

Tricuspid surgery at the time of LVAD implant: A critique

Tricuspid regurgitation (TR) is a common finding in patients with end stage heart failure referred for implantation of left ventricular assist devices. While functional TR frequently resolves after left ventricular unloading, patients with residual and progressive TR demonstrate increased rates of RV dysfunction and poor survival. Criteria for intervention on the tricuspid valve have focused on the degree of tricuspid annular dilatation and the severity of tricuspid regurgitant volume. The surgical decision making regarding intervention on the tricuspid valve remains obscure and historical cohort data cannot distinguish cause from effect.

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

Left ventricular assist devices (LVADs) are increasingly common across the heart failure population. Right ventricular failure (RVF) is a feared complication that can occur in the early post-operative phase or during the outpatient follow-up. Multiple tools are available to the clinician to carefully estimate the individual risk of developing RVF after LVAD implantation. This review will provide a comprehensive overview of available tools for RVF prognostication, including patient-specific and right ventricle (RV)-specific echocardiographic and hemodynamic parameters, to provide guidance in patient selection during LVAD candidacy. We also offer a multidisciplinary approach to the management of early RVF, including indications and management of right ventricular assist devices in this setting to provide tools that help managing the failing RV.

Pathophysiology and management of valvular disease in patients with destination left ventricular assist devices

Over the last two decades, implantable continuous flow left ventricular assist devices (LVAD) have proven to be invaluable tools for the management of selected advanced heart failure patients, improving patient longevity and quality of life. The presence of concomitant valvular pathology, including that involving the tricuspid, mitral, and aortic valve, has important implications relating to the decision to move forward with LVAD implantation. Furthermore, the presence of concomitant valvular pathology often influences the surgical strategy for LVAD implantation. Concomitant valve repair or replacement is not uncommonly required in such circumstances, which increases surgical complexity and has demonstrated prognostic implications both short and longer term following LVAD implantation. Beyond the index operation, it is also well established that certain valvular pathologies may develop or worsen over time following LVAD support. The presence of pre-existing valvular pathology or that which develops following LVAD implant is of particular importance to the destination therapy LVAD patient population. As these patients are not expected to have the opportunity for heart transplantation in the future, optimization of LVAD support including ameliorating valvular disease is critical for the maximization of patient longevity and quality of life. As collective experience has grown over time, the ability of clinicians to effectively address concomitant valvular pathology in LVAD patients has improved in the pre-implant, implant, and post-implant phase, through both medical management and procedural optimization. Nevertheless, there remains uncertainty over many facets of concomitant valvular pathology in advanced heart failure patients, and the understanding of how to best approach these conditions in the LVAD patient population continues to evolve. Herein, we present a comprehensive review of the current state of the field relating to the pathophysiology and management of valvular disease in destination LVAD patients.

Role of the mitral valve in left ventricular assist device pathophysiology

Functional mitral regurgitation (MR) in the setting of heart failure results from progressive dilatation of the left ventricle (LV) and mitral annulus. This leads to leaflet tethering with posterior displacement. Contrary to common assumptions, MR often does not resolve with LVAD decompression of the LV alone. The negative impact of significant (moderate-severe) mitral regurgitation in the LVAD setting is becoming better recognized in terms of its harmful effect on right heart function, pulmonary vascular resistance and hospital readmissions. However, controversies remain regarding the threshold for intervention and management. At present, there are no consensus indications for the repair of significant mitral regurgitation at the time of LVAD implantation due to the conflicting data regarding potential adverse effects of MR on clinical outcomes. In this review, we summarize the current understanding of MR pathophysiology in patients supported with LVAD and potential future management strategies.

Outcomes With Phosphodiesterase-5 Inhibitor Use After Left Ventricular Assist Device: An STS-INTERMACS Analysis

BACKGROUND

Elevated right ventricular afterload following continuous-flow left ventricular assist device (CF-LVAD) may contribute to late right heart failure (LRHF). PDE5i (phosphodiesterase-5 inhibitors) are used to treat pulmonary hypertension and right heart dysfunction after CF-LVAD, but their impact on outcomes is uncertain.

METHODS

We queried Interagency Registry for Mechanically Assisted Circulatory Support from 2012 to 2017 for adults receiving a primary CF-LVAD and surviving ≥30 days from index discharge. Patients receiving early PDE5i (ePDE5i) at 1 month were propensity-matched 1:1 with controls. The primary outcome was the cumulative incidence of LRHF, defined using prevailing Interagency Registry for Mechanically Assisted Circulatory Support criteria; secondary outcomes included all-cause mortality and major bleeding.

RESULTS

Among 9627 CF-LVAD recipients analyzed, 2463 (25.6%) received ePDE5i and 1600 were propensity-matched 1:1 with controls. Before implant, ePDE5i patients had more severe RV dysfunction (13.1% versus 9.6%) and higher pulmonary vascular resistance (2.8±2.7 versus 2.2±2.4 WU), both P<0.001, but clinical factors were well-balanced after propensity-matching. In the unmatched cohort, ePDE5i patients had a higher 3-year cumulative incidence of LRHF, mortality, and major bleeding, but these differences were attenuated in the propensity-matched cohort: LRHF 40.8% versus 35.7% (hazard ratio, 1.14 [95% CI, 0.99-1.32]; P=0.07); mortality 38.6% versus 35.8% (hazard ratio, 0.99 [95% CI, 0.86-1.15]; P=0.93); major bleeding 51.2% versus 46.0% (hazard ratio, 1.12 [95% CI, 0.99-1.27]; P=0.06).

CONCLUSIONS

Compared with propensity-matched controls, adult CF-LVAD patients receiving ePDE5i had similar rates of LRHF, mortality, and major bleeding. While intrinsic patient risk factors likely account for more adverse outcomes with ePDE5i in the unmatched cohort, there is no obvious benefit of ePDE5i in the LVAD population.

Ventricular assist devices in transposition and failing systemic right ventricle: role of tricuspid valve replacement

OBJECTIVES

Ventricular assist device (VAD) for systemic right ventricular (RV) failure patients post-atrial switch, for transposition of the great arteries (TGA), and those with congenitally corrected TGA has proven useful to reduce transpulmonary gradient and bridge-to-transplantation. The purpose of this study is to describe our experience of VAD in systemic RV failure and our move towards concomitant tricuspid valve replacement (TVR).

METHODS

This is a single-centre retrospective study of consecutive adult patients receiving HeartWare VAD for systemic RV failure between 2010 and 2019. From 2017, concomitant TVR was performed routinely. Demographic, clinical variables and echocardiographic and haemodynamic measurements pre- and post-VAD implantation were recorded. Complications on support, heart transplantation and survival rates were described.

RESULTS

Eighteen patients underwent VAD implantation. Moderate or severe systemic tricuspid regurgitation was present in 83.3% of patients, and subpulmonic left ventricular impairment in 88.9%. One-year survival was 72.2%. VAD implantation was technically feasible and successful in all but one. Post-VAD, transpulmonary gradient fell from 16 (15-22) to 10 (7-13) mmHg (P = 0.01). Patients with TVR (n = 6) also demonstrated a reduction in mean pulmonary and wedge pressures. Furthermore, subpulmonic left ventricular end-diastolic dimension (44.3 vs 39.6 mm; P = 0.03) and function improved in this group. After 1 year of support, 72.2% of patients were suitable for transplantation.

CONCLUSIONS

VAD is an effective strategy as bridge-to-candidacy and bridge-to-transplantation in patients with end-stage systemic RV failure. Concomitant TVR at the time of implant is associated with better early haemodynamic and echocardiographic results post-VAD.

Prognostic impact of functional mitral regurgitation prior to left ventricular assist device implantation

BACKGROUND

Functional mitral regurgitation (FMR) is a common finding of advanced heart failure with detrimental effects. The prognostic impact of uncorrected FMR prior to left ventricular assist device (LVAD) implantation remains controversial.

METHODS

Between 2016 and 2019 77 patients underwent continuous-flow LVAD implantation at our institution. 34 patients showed FMR ≥ 2 (MR-group), whereas 43 patients showed FMR < 2 (Control-group). Data was retrospectively analyzed. Primary composite endpoint comprised freedom from death, stroke, pump-thrombosis, major bleeding and right heart failure (RHF) after 1 year.

RESULTS

Baseline characteristics, including the severity of left and right ventricular dysfunction, and periprocedural results were comparable. The overall survival during a mean follow up of 24.9 months was 55.9% in the MR-group versus 58.1% in the Control-group (p = 0.963), whereas 1-year event-free survival was 35.3% in the MR-group compared to 44.2% in the Control-group (p = 0.404). RHF within the first postoperative year occurred more frequently in the MR-group (35.3% vs. 11.6%; p = 0.017). Furthermore, RV function was significantly reduced in comparison to baseline values in the MR-group. 12 months after surgery, 74% of patients in the MR-group were classified as NYHA III in comparison to 24% of patients in the Control-group (p < 0.001).

CONCLUSIONS

Preoperative uncorrected FMR prior to LVAD implantation did not affect overall survival, nevertheless it was associated with an impaired RV function and increased incidence of right heart failure during follow-up. Furthermore, preoperative FMR ≥ 2 was associated with persistent symptoms of heart failure.

Physiology of Continuous-Flow Left Ventricular Assist Device Therapy

The expanding use of continuous-flow left ventricular assist devices (CF-LVADs) for end-stage heart failure warrants familiarity with the physiologic interaction of the device with the native circulation. Contemporary devices utilize predominantly centrifugal flow and, to a lesser extent, axial flow rotors that vary with respect to their intrinsic flow characteristics. Flow can be manipulated with adjustments to preload and afterload as in the native heart, and ascertainment of the predicted effects is provided by differential pressure-flow (H-Q) curves or loops. Valvular heart disease, especially aortic regurgitation, may significantly affect adequacy of mechanical support. In contrast, atrioventricular and ventriculoventricular timing is of less certain significance. Although beneficial effects of device therapy are typically seen due to enhanced distal perfusion, unloading of the left ventricle and atrium, and amelioration of secondary pulmonary hypertension, negative effects of CF-LVAD therapy on right ventricular filling and function, through right-sided loading and septal interaction, can make optimization challenging. Additionally, a lack of pulsatile energy provided by CF-LVAD therapy has physiologic consequences for end-organ function and may be responsible for a series of adverse effects. Rheological effects of intravascular pumps, especially shear stress exposure, result in platelet activation and hemolysis, which may result in both thrombotic and hemorrhagic consequences. Development of novel solutions for untoward device-circulatory interactions will facilitate hemodynamic support while mitigating adverse events. © 2021 American Physiological Society. Compr Physiol 12:1-37, 2021.

Impact of severe mitral regurgitation on postoperative outcome after durable left-ventricular assist device implantation

BACKGROUND

Mitral valve regurgitation (MR) is a common finding in patients with end-stage heart failure. The aim of the study was to analyze the impact of preoperative moderate-to-severe MR on postoperative outcomes and survival after durable left-ventricular assist device (LVAD) implantation.

METHODS

From August 2010 to May 2021, 246 patients underwent a durable LVAD implantation. We stratified the patients into two groups: Group A (n = 109) presented with MR 0-I°, and Group B presented with MR II-III° (n = 137). MR II-III° was defined according to the current recommendations (i.e., vena contracta ≥ 7 mm, regurgitation volume ≥ 30 ml or effective regurgitation orifice area ≥ 20 mm² ).

RESULTS

Significantly more patients in Group B suffered from pulmonary hypertension and presented with chronic obstructive lung disease. We observed significantly higher rates of tricuspid regurgitation (TR) II-III° in Group B (76.1%) versus Group A (14.8%) (p < 0.001) and TR III° in Group B (30.4%) versus Group A (3.7%) (p < 0.001). There was no difference in the incidence of right heart failure between the groups. Within our cohort, the in-hospital, 1-year, 3-year, and 5-year mortality was 22.4%, 32.1%, 50.7%, and 64.4%, respectively. Group B showed significantly worse overall survival (p = 0.05). Patients with preoperative TR II-III° had a significantly worse survival than those with TR 0-I° (p = 0.048). In patients presenting with MR II-III°, we discovered that TR III° seems to predict both in-hospital and mid-term mortality.

CONCLUSION

MR II-III° negatively affects the outcomes in patients requiring LVAD implantation. Persisting MR II-III° is an independent predictor of mortality. Patients with concomitant preoperative TR II-III° are at increased risk of developing postoperative major adverse events. Addressing the MR might be considered for these patients.

Right ventricular failure: a comorbidity or a clinical emergency?

There has been ample data providing a convincing perception about the underlying mechanism pertaining to left ventricle (LV) hypertrophy progressing towards LV failure. In comparison, data available on the feedback of right ventricle (RV) due to volume or pressure overload is minimal. Advanced imaging techniques have aided the study of physiology, anatomy, and diseased state of RV. However, the treatment scenario of right ventricular failure (RVF) demands more attention. It is a critical clinical risk in patients with carcinoid syndrome, pulmonary hypertension, atrial septal defect, and several other concomitant diseases. Although the remodeling responses of both ventricles on an increase of end-diastolic pressure are mostly identical, the stressed RV becomes more prone to oxidative stress activating the apoptotic mechanism with diminished angiogenesis. This instigates the advancement of RV towards failure in contrast to LV. Empirical heart failure (HF) therapies have been ineffective in improving the mortality rate and cardiac function in patients, which prompted a difference between the underlying pathophysiology of RVF and LV failure. Treatment strategies should be devised, taking into consideration the anatomical and physiological characteristics of RV. This review would emphasize on the pathophysiology of the RVF and the differences between two ventricles in molecular response to stress. A proper insight into the underlying pathophysiology is required to develop optimized therapeutic management in RV-specific HF.

Left Ventricular Assist Device Implantation in Patients with Preoperative Severe Mitral Regurgitation

We examined cardiac features associated with residual mitral regurgitation (MR) following continuous-flow left ventricular assist device (cfLVAD) implant. From 2003 to 2017, 134 patients with severe MR underwent cfVLAD implant without mitral valve (MV) intervention. Echocardiographic (echo) assessment occurred pre-cfLVAD, early post-cfLVAD, and at last available echo. Ventricular and atrial volumes were calculated from established formulas and normalized to be predicted. Cluster analysis based on preoperative normalized left ventricular and atrial volumes, and MV height identified grades 1, 2, and 3 with progressively larger cardiac chamber sizes. Median early echo follow-up was 0.92 (0.55, 1.45) months and the last follow-up was 15.12 (5.28, 38.28) months. Mitral regurgitation improved early after cfLVAD by 2.10 ± 1.16 grades (p < 0.01). Mitral regurgitation severity at the last echocardiogram positively correlated with the preoperative left ventricular volume (p = 0.014, R = 0.212), left atrial volume (p = 0.007, R = 0.233), MV anteroposterior height (p = 0.032, R = 0.185), and MV mediolateral diameter (p = 0.043, R = 0.175). Morphologically, smaller grade 1 hearts were correlated with MR resolution at the late follow-up (p = 0.023). Late right ventricular failure (RVF) at the last clinical follow-up was less in grade 1 (4/48 [8.3%]) compared with grades 2 and 3 (26/86 [30.2%]), p = 0.004). Grade 1 cardiac dimensions correlates with improvement in severe MR and had less late RVF.

Left Ventricular Assist Device: Indication, Timing, and Management

Left ventricular assist devices (LVADs) are indicated in inotrope-dependent heart failure (HF) patients with pure or predominant LV dysfunction. Survival benefit is less clear in ambulatory, advanced HF. Timing is crucial: early, unnecessary exposure to the risks of surgery, and device-related complications (infections, stroke, and bleeding) should be weighed against the probability of dying or developing irreversible right ventricular and/or end-organ dysfunction while deferring implant. The interplay between LVAD and heart transplantation depends largely on donor availability and allocation rules. Postoperatively, quality of life depends on patients' expectations and is influenced by complications. Patients' preferences, prognosis, and alternative options-including palliation-should be openly discussed and reviewed before and after the operation.

Validation of mitral regurgitation reversibility in patients with HeartMate 3 implantation

The resolution of functional mitral valve regurgitation (MR) in patients awaiting left ventricular assist device (LVAD) implantation is discussed controversially. The present study analyzed MR and echocardiographic parameters of the third-generation LVAD HeartMate 3 (HM3) over 3 years. Of 135 LVAD patients (with severe MR, n = 33; with none, mild, or moderate MR, n = 102), data of transthoracic echocardiography were included preoperatively to LVAD implantation, up to 1 month postoperatively, and at 1, 2, and 3 years after LVAD implantation. Demographic data and clinical characteristics were collected. Severe MR was reduced immediately after LVAD implantation in all patients. The echocardiographic parameters left ventricular end-diastolic diameter (P < .001), right ventricular end-diastolic diameter (P < .001), tricuspid annular plane systolic excursion (P < .001), and estimated pulmonary artery pressure (P < .001) decreased after HM3 implantation independently from the grade of MR prior to implantation and remained low during the 2 years follow-up period. Following LVAD implantation, right heart failure, ventricular arrhythmias, ischemic stroke as well as pump thrombosis and bleeding events were comparable between the groups. The incidences of death and cardiac death did not differ between the patient groups. Furthermore, the Kaplan-Meier analysis showed that survival was comparable between the groups (P = .073). HM3 implantation decreases preoperative severe MR immediately after LVAD implantation. This effect is long-lasting in most patients and reinforces the LVAD implantation without MR surgery. The complication rates and survival were comparable between patients with and without severe MR.

Transcatheter Mitral Valve Repair for Severe,Symptomatic Mitral Regurgitation in Patients with Left Ventricular Assist Devices

Patients with symptomatic stage D heart failure who require left ventricular assist device (LVAD) support and suffer concomitant severe mitral regurgitation are often difficult to manage. One reason is due to cardiac anatomic constraints that limit optimization of the mechanical assist device. Typically, these patients are not candidates for repeat sternotomy with surgical mitral valve repair, and heart transplantation may not be feasible or timely. This case describes two patients with LVAD support who received transcatheter edge-to-edge mitral valve repair for severe, symptomatic mitral regurgitation. We believe this procedure may be a therapeutic option in stable patients with severe mitral regurgitation who require mechanical support.

Inflow Cannula Position Influences Improvement in Mitral Regurgitation After Ventricular Assist Device Implantation

Significant residual mitral regurgitation (MR) after left ventricular assist device (LVAD) implantation has been associated with increased morbidity and mortality. The effect of cannula position on improvement of preexisting MR has yet to be evaluated. Consecutive patients who underwent centrifugal LVAD implantation with >mild preoperative MR and without concomitant mitral repair were reviewed. Left ventricular assist device position was determined by the angle between actual and ideal inflow cannula on computed tomography. The magnitudes of angles (anterior and lateral angle) were added to form an LVAD position assessment (LVADpa). Mitral regurgitation was numerically classified, and improvement in MR was determined by difference in MR preoperatively to MR >1 month postoperatively with a median of 162 (interquartile range: 78-218) days. The primary analysis examined the relationship between LVADpa and postoperative MR. Forty-one patients were identified with >mild preoperative functional MR. Mean age was 51 ± 13 years with an ejection fraction of 16 ± 4%. Overall, MR improved from moderate-severe preoperatively to mild postoperatively (p < 0.001). On multivariable analysis, higher LVADpa deviation was associated with greater postoperative MR (odds ratio [OR] = 2.29, p = 0.005) and higher 1-month pulsatility index was associated with lower postoperative MR (OR = 0.47, p = 0.011). Inflow cannula position during centrifugal LVAD implantation is an important determinant of postoperative MR.

Persistent mitral regurgitation after left ventricular assist device: a clinical conundrum

Aims

Persistent mitral valve regurgitation (MR) after continuous flow left ventricular assist device implantation (cfLVAD) is associated with pulmonary hypertension and right ventricular failure with variable effects on survival across published studies. The aim of this study is to determine the incidence and predictors of persistent MR at 6‐month follow‐up after cfLVAD implantation and its impact on survival, haemodynamics, right ventricular function, and morbidity.

Methods and results

We performed a retrospective review of all adult cfLVAD recipients from January 2012 to June 2017 at a single tertiary university hospital with follow‐up until April 2019. Primary outcome was to compare survival between patients with no‐to‐mild compared with persistent moderate‐to‐severe MR at 6 months. Secondary outcomes included right heart failure (RHF), length of stay, re‐hospitalizations, and composite of death, transplant, and pump exchange during the length of follow‐up. Final analytic sample was 111 patients. The incidence of persistent moderate or severe MR at 6 months was 26%. Significant predictors of persistent MR at 6 months were left atrium dimension and volume. The group with persistent moderate‐to‐severe MR at 6 months had higher incidence of RHF at 6 months (45% vs. 25%, P = 0.04). There was no difference in survival at 1 year between the groups (no‐to‐mild MR 85.5%, moderate‐to‐severe MR 87.9%, Wilcoxon P‐value = 0.63). There was no difference in re‐hospitalizations, length of stay, composite of death, transplant, or pump exchange during the length of follow‐up between the comparison groups.

Conclusions

Persistent moderate‐to‐severe MR after cfLVAD implantation is present in one fourth of patients and is associated with increased incidence of RHF, higher mean pulmonary pressure, and pulmonary capillary wedge pressure with no effect on 1 year survival. Increased left atrium size was associated with persistent moderate‐to‐severe MR at 6 months.

Understanding Longitudinal Changes in Pulmonary Vascular Resistance After Left Ventricular Assist Device Implantation

BACKGROUND

Elevated pulmonary vascular resistance (PVR) is common in patients with advanced heart failure. PVR generally improves after left ventricular assist device (LVAD) implantation, but the rate of decrease has not been quantified and the patient characteristics most strongly associated with this improvement are unknown.

METHODS AND RESULTS

We analyzed 1581 patients from the Interagency Registry for Mechanically Assisted Circulatory Support registry who received a primary continuous-flow LVAD, had a baseline PVR of ≥3 Wood units (WU), and had PVR measured at least once postoperatively. Multivariable linear mixed effects modeling was used to evaluate independent associations between postoperative PVR and patient characteristics. PVR decreased by 1.53 WU (95% confidence interval [CI] 1.27-1.79 WU) per month in the first 3 months postoperatively, and by 0.066 WU (95% CI 0.060-0.070 WU) per month thereafter. Severe mitral regurgitation at any time during follow-up was associated with a 1.29 WU (95% CI 1.05-1.52 WU) higher PVR relative to absence of mitral regurgitation at that time. In a cross-sectional analysis, 15%-25% of patients had persistently elevated PVR of ≥3 WU at any given time within 36 months after LVAD implantation.

CONCLUSION

The PVR tends to decrease rapidly early after implantation, and only more gradually thereafter. Residual mitral regurgitation may be an important contributor to elevated postoperative PVR. Future research is needed to understand the implications of elevated PVR after LVAD implantation and the optimal strategies for prevention and treatment.

MitraClip or Ventricular Assist Device?

The patient was a 59-year-old female with advanced heart failure and severe functional mitral regurgitation who was classified as INTERMACS profile 4 with repeated hospitalizations despite guideline-directed medical therapy. She was also listed for heart transplantation. After comparing the two major therapeutic strategies: (1) durable left ventricular assist device (LVAD) implantation and (2) percutaneous MitraClip procedure (Abbott Vascular, Abbott Park, IL, USA), we eventually decided to proceed with MitraClip, given her relatively lower B-type natriuretic peptide, lower MAGGIC Heart Failure risk score, and higher predicted survival without LVAD. The post-procedural course was favorable without any comorbidities or worsening of heart failure for 10 months. A diagnostic paradigm to guide which strategy to choose (LVAD or MitraClip) for patients with advanced heart failure and functional mitral regurgitation should be constructed.

Consequences of functional mitral regurgitation and atrial fibrillation in patients with left ventricular assist devices

BACKGROUND

Functional mitral regurgitation (MR) (FMR) and atrial fibrillation (AF) are common in patients undergoing left ventricular assist device (LVAD) implantation. However, the impact of FMR and AF on clinical outcomes is uncertain. This study aimed to investigate the characteristics and prognostic significance of FMR and AF in patients with LVADs.

METHODS

We retrospectively reviewed all patients who underwent LVAD implantation at our center between January 2010 and December 2017. We defined significant FMR as the ratio of MR color jet area to left atrial area of >20% and persistent or permanent AF (PeAF) as persistent or permanent AF at LVAD implantation.

RESULTS

A total of 380 patients were included in this analysis. Patients were divided into 6 groups: patients with no PeAF and no significant FMR (Group 1), patients with no PeAF but with significant FMR (Group 2), patients with PeAF but no significant FMR (Group 3), patients with PeAF and significant FMR (Group 4), patients with concomitant mitral valve surgery (MVS) at LVAD implantation and without PeAF (Group 5), and patients with concomitant MVS and with PeAF (Group 6). A total of 56 patients (15%) died within 2 years. Kaplan-Meier curve analysis demonstrated a 2-year survival of 81% in Group 1, 89% in Group 2, 87% in Group 3, 47% in Group 4, 87% in Group 5, and 79 % in Group 6 (log-rank test, p < 0.001). The multivariable Cox proportional-hazards model showed that classification in Group 4 was an independent predictor of mortality (hazard ratio, 4.31; 95% CI: 2.19-8.46; p < 0.001).

CONCLUSIONS

The coexistence of significant FMR and PeAF may represent a poor prognostic marker in patients undergoing LVAD implantation.

In-Hospital Outcomes of Left Ventricular Assist Device Implantation and Concomitant Valvular Surgery

Valvular heart disease is common among left ventricular assist device (LVAD) recipients. However, its management at the time of LVAD implantation remains controversial. Patients who underwent LVAD implantation and concomitant aortic (AVR), mitral (MVR), or tricuspid valve (TVR) repair or replacement from 2010 to 2017 were identified using the national inpatient sample. End points were in-hospital outcomes, length of stay, and cost. Procedure-related complications were identified via ICD-9 and ICD-10 coding and analysis was performed via mixed effect models. A total of 25,171 weighted adults underwent LVAD implantation without valvular surgery, 1,329 had isolated TVR, 1,021 AVR, 377 MVR, and 615 had combined valvular surgery (411 had TVR + AVR, 115 TVR + MVR, 62 AVR + MVR, 25 AVR + MVR + TVR). During the study period, rates of AVR decreased and combined valvular surgeries increased. Patients who underwent TVR or combined valvular surgery had overall higher burden of co-morbidities than LVAD recipients with or without other valvular procedures. Postoperative bleeding was higher with AVR whereas acute kidney injury requiring dialysis was higher with TVR or combined valvular surgery. In-hospital mortality was higher with AVR, MVR, or combined surgery without differences in the rates of stroke. Length of stay did not differ significantly among groups but cost of hospitalization and nonroutine discharge rates were higher for cases of TVR and combined surgery. Approximately 1 in 9 LVAD recipients underwent concomitant valvular surgery and TVR was the most frequently performed procedure. In-hospital mortality and cost were lower among those who did not undergo valvular surgery.

Evaluation of cardiac beat synchronization control for a rotary blood pump on valvular regurgitation with a mathematical model

We have studied the cardiac beat synchronization (CBS) control for a rotary blood pump (RBP) and revealed that it can promote pulsatility and reduce cardiac load. Besides, patients with LVAD support sometimes suffer from aortic and mitral regurgitation (AR and MR). A control method for the RBP should be validated in wider range of conditions to clarify its benefits and pitfalls prior to clinical application. In this study, we evaluated pulsatility and cardiac load reduction obtained with the CBS control on valvular failure conditions with a mathematical model. Diastolic assist could reduce cardiac load on the left ventricle by decreasing external work of the ventricle even in MR cases while it was not so effective in AR cases. Systolic assist can still promote pulsatility in AR and MR cases; however, aortic valve function should be carefully confirmed since pulse pressure can be wider not due to systolic assist but to AR.

Atrial arrhythmias in patients with left ventricular assist devices

PURPOSE OF REVIEW

Atrial arrhythmias commonly occur in patients with advanced heart failure with reduced ejection fraction (HFrEF) who require left ventricular assist devices (LVADs) implantation. This review summarizes the current literature regarding the incidence, prevalence, and predictors of atrial arrhythmias in LVAD patients and its impact on the clinical outcomes. Moreover, we review the mechanisms and management strategies of atrial arrhythmias in this population.

RECENT FINDINGS

Atrial arrhythmias including atrial fibrillation, atrial flutter, and atrial tachycardia are highly prevalent in patients with advanced HFrEF before or after the LVAD implantation. Atrial arrhythmias have a significant impact on overall clinical outcome including survival, heart failure hospitalization, quality of life, thromboembolic events and resource utilization. Atrial fibrillation and other atrial arrhythmias frequently coexist in this population. In patients with atrial arrhythmias and LVAD, anticoagulation and cardiovascular implantable electronic devices should be closely monitored and managed to prevent thromboembolic events or inappropriate shocks. Rhythm and rate control strategies are comparable regarding overall clinical outcomes in this population. LVADs induce favorable atrial remodeling in patients with HFrEF.

SUMMARY

Atrial arrhythmias are highly common in LVAD patients and have significant impact on overall clinical outcomes. Further studies are needed to determine optimal management and prevention of atrial arrhythmias in LVAD population.

Left Ventricular Assist Device as Destination Therapy: a State of the Science and Art of Long-Term Mechanical Circulatory Support

PURPOSE OF REVIEW

The purpose of this review is to synthesize and summarize recent developments in the care of patients with end-stage heart failure being managed with a left ventricular assist device (LVAD) as destination therapy.

RECENT FINDINGS

Although the survival of patients treated with LVAD continues to improve, the rates of LVAD-associated complication, such as right ventricular failure, bleeding complications, and major infection, remain high, and management of these patients remains challenging. The durability and hemocompatibility of LVAD support have greatly increased in recent years as a result of new technologies and novel management strategies. Challenges remain in the comprehensive care of patients with destination therapy LVADs, including management of comorbidities and optimizing patient function and quality of life.

Predictors of residual mitral regurgitation after left ventricular assist device implantation

Patients with advanced heart failure often have functional mitral regurgitation. Left ventricular assist device implantation improves functional mitral regurgitation through left ventricular unloading. However, residual mitral regurgitation after left ventricular assist device implantation leads to adverse outcomes, and whether patients need concomitant mitral valve surgery is not fully elucidated. Therefore, this study aimed to elucidate the predictors of residual mitral regurgitation and to describe the temporal changes in residual mitral regurgitation. We retrospectively enrolled 15 patients with implantable continuous-flow left ventricular assist device, who had significant mitral regurgitation on echocardiography before left ventricular assist device implantation. Three patients had residual mitral regurgitation (mitral regurgitation color jet area/left atrial area >0.2) 1 month after left ventricular assist device implantation. We investigated factors associated with residual mitral regurgitation and compared patients with or without residual mitral regurgitation. On univariate analysis, mitral valve tethering area and mitral regurgitation vena contracta before left ventricular assist device implantation were significantly associated with residual mitral regurgitation (odds ratio, 1.03; p = 0.036 and odds ratio, 10.45; p = 0.0087). One month after left ventricular assist device implantation, the mean pulmonary capillary wedge pressure and pulmonary artery pressure were higher in patients with residual mitral regurgitation (pulmonary capillary wedge pressure: 11.3 ± 3.5 vs 6.4 ± 3.4 mmHg, p = 0.029 and pulmonary artery pressure: 21.3 ± 4.0 vs 15.9 ± 3.3 mmHg, p = 0.023). However, the mitral regurgitation grading and hemodynamics were not significantly different 6 months after left ventricular assist device implantation. The hospitalization-free survival was not significantly different between the two groups. Mitral valve tethering area and mitral regurgitation vena contracta were predictors of residual mitral regurgitation. Residual mitral regurgitation improved until 6 months after left ventricular assist device implantation and might not affect the prognosis.

Guidelines for the Use of Transesophageal Echocardiography to Assist with Surgical Decision-Making in the Operating Room: A Surgery-Based Approach: From the American Society of Echocardiography in Collaboration with the Society of Cardiovascular Anesthesiologists and the Society of Thoracic Surgeons

Intraoperative transesophageal echocardiography is a standard diagnostic and monitoring tool employed in the management of patients undergoing an entire spectrum of cardiac surgical procedures, ranging from "routine" surgical coronary revascularization to complex valve repair, combined procedures, and organ transplantation. Utilizing a protocol as a starting point for imaging in all procedures and all patients enables standardization of image acquisition, reduction in variability in quality of imaging and reporting, and ultimately better patient care. Clear communication of the echocardiographic findings to the surgical team, as well as understanding the impact of new findings on the surgical plan, are paramount. Equally important is the need for complete understanding of the technical steps of the surgical procedures being performed and the complications that may occur, in order to direct the postprocedure evaluation toward aspects directly related to the surgical procedure and to provide pertinent echocardiographic information. The rationale for this document is to outline a systematic approach describing how to apply the existing guidelines to questions on cardiac structure and function specific to the intraoperative environment in open, minimally invasive, or hybrid cardiac surgery procedures.

Association of Inflow Cannula Position with Left Ventricular Unloading and Clinical Outcomes in Patients with HeartMate II Left Ventricular Assist Device

The relationship between the HeartMate II left ventricular assist device (LVAD) position and pump thrombosis has been reported. However, further clinical implications of device position are unknown. This study aimed to investigate optimal device position for better left ventricular (LV) unloading and patient prognosis. Patients undergoing a ramp test with right heart catheterization after HeartMate II LVAD implantation were enrolled to this study. Device position was quantified from the chest X-ray obtained at the time of the ramp test: (1) inflow cannula angle relative to horizontal line, (2) pump angle relative to spine, (3) pump depth, (4) angle between inflow cannula and pump, and (5) angle between pump and outflow graft. LV unloading was assessed by pulmonary capillary wedge pressure at set LVAD speed. Fifty-four patients (60 years old and 34 male [63%]) were enrolled. Nobody experienced device malfunction during the study period. Increased LV unloading (i.e., lower pulmonary capillary wedge pressure) was associated with a narrower inflow cannula angle relative to horizontal line. Inflow cannula angle <75° was associated with higher 1 year heart failure readmission-free survival rate (p < 0.05, hazards ratio 7.56 [95% confidence interval 2.32-24.7]). In conclusion, HeartMate II LVAD inflow cannula position was associated with LV unloading and patient prognosis. Prospective studies to ensure optimal device positioning and target better clinical outcomes are warranted.

Hemodynamic Effects of Concomitant Mitral Valve Surgery and Left Ventricular Assist Device Implantation

There are conflicting data regarding whether concomitant mitral valve surgery (MVS) at left ventricular assist device (LVAD) implantation is beneficial. This study aimed to assess the hemodynamic effects of concomitant MVS. Of all 73 enrolled patients, 44 patients had undergone concomitant MVS and 29 patients had not. Before LVAD implantation, MVS group had higher pulmonary capillary wedge pressure (p = 0.04). After LVAD implantation, MVS group had higher mean pulmonary artery pressure and cardiac output (CO). During the hemodynamic ramp study, MVS group had steeper CO slopes (0.18 [0.13 0.28] vs. 0.15 [0.08, 0.20] L/min/step; p = 0.04) at incremental LVAD speed and achieved a higher CO at the optimized set speed (5.5 [4.7, 6.9] vs. 4.9 [4.0, 5.7] L/min; p = 0.03). One-year freedom from death or heart failure readmission was statistically comparable between the two groups (61% vs. 80%, p = 0.20). Thus far, after LVAD implantation and concomitant MVS, patients had increased pulmonary hypertension, despite having higher CO and a better response of CO at incremental LVAD speed. The implication of hemodynamic features after concomitant MVS on clinical outcomes warrants further investigation.

Impact of left ventricular assist device implantation on mitral regurgitation: An analysis from the MOMENTUM 3 trial

BACKGROUND

Mitral regurgitation (MR) determines pathophysiology and outcome in advanced heart failure. The impact of left ventricular assist device (LVAD) placement on clinically significant MR and its contribution to long-term outcomes has been sparsely evaluated.

METHODS

We evaluated the effect of clinically significant MR on patients implanted in the MOMENTUM 3 trial with either the HeartMate II (HMII) or the HeartMate 3 (HM3) at 2 years. Clinical significance was defined as moderate or severe grade MR determined by site-based echocardiograms.

RESULTS

Of 927 patients with LVAD implants without a prior or concomitant mitral valve procedure, 403 (43.5%) had clinically significant MR at baseline. At 1-month of support, residual MR was present in 6.2% of patients with HM3 and 14.3% of patients with HMII (relative risk = 0.43; 95% CI, 0.22-0.84; p = 0.01) with a low rate of worsening at 2 years. Residual MR at 1-month post-implant did not impact 2-year mortality for either the HM3 (hazard ratio [HR],1.41; 95% CI, 0.52-3.89; p = 0.50) or HMII (HR, 0.91; 95% CI, 0.37-2.26; p = 0.84) LVAD. The presence or absence of baseline MR did not influence mortality (HM3 HR, 0.86; 95% CI, 0.56-1.33; p = 0.50; HMII HR, 0.81; 95% CI, 0.54-1.22; p = 0.32), major adverse events or functional capacity. In multivariate analysis, severe baseline MR (p = 0.001), larger left ventricular dimension (p = 0.002), and implantation with the HMII instead of the HM3 LVAD (p = 0.05) were independently associated with an increased likelihood of persistent MR post-implant.

CONCLUSIONS

Hemodynamic unloading after LVAD implantation improves clinically significant MR early, sustainably, and to a greater extent with the HM3 LVAD. Neither baseline nor residual MR influence outcomes after LVAD implantation.

Continuous-Flow Left Ventricular Assist Devices and Valvular Heart Disease: A Comprehensive Review

Mechanical circulatory support with implantable durable continuous-flow left ventricular assist devices (CF-LVADs) represents an established surgical treatment option for patients with advanced heart failure refractory to guideline-directed medical therapy. CF-LVAD therapy has been demonstrated to offer significant survival, functional, and quality-of-life benefits. However, nearly one-half of patients with advanced heart failure undergoing implantation of a CF-LVAD have important valvular heart disease (VHD) present at the time of device implantation or develop VHD during support that can lead to worsening right or left ventricular dysfunction and result in development of recurrent heart failure, more frequent adverse events, and higher mortality. In this review, we summarize the recent evidence related to the pathophysiology and treatment of VHD in the setting of CF-LAVD support and include a review of the specific valve pathologies of aortic insufficiency (AI), mitral regurgitation (MR), and tricuspid regurgitation (TR). Recent data demonstrate an increasing appreciation and understanding of how VHD may adversely affect the hemodynamic benefits of CF-LVAD support. This is particularly relevant for MR, where increasing evidence now demonstrates that persistent MR after CF-LVAD implantation can contribute to worsening right heart failure and recurrent heart failure symptoms. Standard surgical interventions and novel percutaneous approaches for treatment of VHD in the setting of CF-LVAD support, such as transcatheter aortic valve replacement or transcatheter mitral valve repair, are available, and indications to intervene for VHD in the setting of CF-LVAD support continue to evolve.

Right ventricular function and residual mitral regurgitation after left ventricular assist device implantation determines the incidence of right heart failure

BACKGROUND

The effect of significant mitral regurgitation (MR) on outcomes after continuous flow left ventricular assist device (cfLVAD) implantation remains unclear.

METHODS

We performed a retrospective review of prospectively collected data from 159 patients with preoperative severe MR who underwent cfLVAD implantation (2003-2017). Two-step cluster analysis using the log-likelihood distance for post-cfLVAD implantation parameters, which included right ventricular (RV) dysfunction, MR severity, and tricuspid regurgitation (TR) severity. Post-cfLVAD implantation echocardiographic parameters were obtained within the first month.

RESULTS

Cluster analysis resulted in 3 groups. Group 1 (n = 67) had mild or less MR with moderate-severe RV dysfunction (RVD). Group 2 (n = 43) had moderate-severe MR with moderate-severe RVD. Group 3 (n = 49) had moderate MR with mild RVD. Group 2 had the largest proportion with Interagency Registry for Mechanically Assisted Circulatory Support score of 1 (30.2%) and 2 (41.9%). They were more likely to undergo temporary mechanical circulatory support (18.6%) and tricuspid valve procedure (62.8%). Group 2 had the highest rate of stroke (30.2%; P = .02), hemolysis (39.5%; P = .01), device thrombosis (30%; P = .01), and worst survival (46.5%; P = .01). Survival at 5 years for groups 1, 2, and 3 were 56.0%, 17.6%, and 55.8%. Regression analysis of the entire population showed that greater MR severity after cfLVAD was associated with RV failure (P < .05; odds ratio, 1.6) and RV assist device use (P = .09; odds ratio, 1.6). After excluding tricuspid valve repairs, MR severity had a positive correlation with TR severity (R = 0.33; P < .01).

CONCLUSIONS

After cfLVAD implantation, moderate-severe MR and RVD predicted RV failure. Patients with preoperative moderate-severe MR and TR coupled with moderate-severe RVD might benefit the most from mitral and tricuspid valve intervention.