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

Special Considerations for Advanced Heart Failure Surgeries: Durable Left Ventricular Devices and Heart Transplantation

Heart transplantation and durable left ventricular assist devices (LVADs) represent two definitive therapies for end-stage heart failure in the modern era. Despite technological advances, both treatment modalities continue to experience unique risks that impact surgical and perioperative decision-making. Here, we review special populations and factors that impact risk in LVAD and heart transplant surgery and examine critical decisions in the management of these patients. As both heart transplantation and the use of durable LVADs as destination therapy continue to increase, these considerations will be of increasing relevance in managing advanced heart failure and improving outcomes.

Two-Year Clinical Outcome of MitraClip Transcatheter Edge-to-Edge Repair From the J-MITRA Registry Data

BACKGROUND

The introduction of transcatheter edge-to-edge repair for moderate-to-severe or severe mitral regurgitation (MR) utilizing the MitraClip system became reimbursed and clinically accessible in Japan in April 2018. This study presents the 2-year clinical outcomes of all consecutively treated patients who underwent MitraClip implantation in Japan and were prospectively enrolled in the Japanese Circulation Society-oriented J-MITRA registry.

METHODS AND RESULTS

Analysis encompassed 2,739 consecutive patients enrolled in the J-MITRA registry with informed consent (mean age: 78.3±9.6 years, 1,550 males, STS risk score 11.7±8.9), comprising 1,999 cases of functional MR, 644 of degenerative MR and 96 in a mixed group (DMR and FMR). The acute procedure success rate was 88.9%. After MitraClip implantation, >80% exhibited an MR grade ≤2+ and the trend was sustained over the 2 years. Within this observation period, the mortality rate was 19.3% and the rate of heart failure readmissions was 20.6%. The primary composite endpoint, inclusive of cardiovascular death and heart failure readmission, was significantly higher in patients with functional MR than in with degenerative MR (32.0% vs. 17.5%, P<0.001).

CONCLUSIONS

The 2-year clinical outcomes after MitraClip implantation were deduced from comprehensive data within an all-Japan registry.

Predictive Factors of Cardiac Mortality Following TEER in Patients with Secondary Mitral Regurgitation

Background: Transcatheter edge-to-edge mitral valve repair (TEER) has emerged as a viable approach to addressing substantial secondary mitral regurgitation. In the contemporary landscape where ultimate heart failure-specific therapies, such as cardiac replacement modalities, are available, prognosticating a high-risk cohort susceptible to early cardiac mortality post-TEER is pivotal for formulating an effective therapeutic regimen. Methods: Our study encompassed individuals with secondary mitral regurgitation and chronic heart failure enlisted in the multi-center (Optimized CathEter vAlvular iNtervention (OCEAN)-Mitral registry. We conducted an assessment of baseline variables associated with cardiac death within one year following TEER. Results: Amongst the 1517 patients (median age: 78 years, 899 males), 101 experienced cardiac mortality during the 1-year observation period after undergoing TEER. Notably, a history of heart failure-related admissions within the preceding year, utilization of intravenous inotropes, and elevated plasma B-type natriuretic peptide levels emerged as independent prognosticators for the primary outcome (p < 0.05 for all). Subsequently, we devised a novel risk-scoring system encompassing these variables, which significantly stratified the cumulative incidence of the 1-year primary outcome (16%, 8%, and 4%, p < 0.001). Conclusions: Our study culminated in the development of a new risk-scoring system aimed at predicting 1-year cardiac mortality post-TEER.

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.

Cellular and Molecular Mechanisms Activated by a Left Ventricular Assist Device

Left ventricular assist devices (LVADs) represent the final treatment for patients with end-stage heart failure (HF) not eligible for transplantation. Although LVAD design has been further improved in the last decade, their use is associated with different complications. Specifically, inflammation, fibrosis, bleeding events, right ventricular failure, and aortic valve regurgitation may occur. In addition, reverse remodeling is associated with substantial cellular and molecular changes of the failing myocardium during LVAD support with positive effects on patients' health. All these processes also lead to the identification of biomarkers identifying LVAD patients as having an augmented risk of developing associated adverse events, thus highlighting the possibility of identifying new therapeutic targets. Additionally, it has been reported that LVAD complications could cause or exacerbate a state of malnutrition, suggesting that, with an adjustment in nutrition, the general health of these patients could be improved.

Concurrent valvular procedures during left ventricular assist device implantation and outcomes: A comprehensive analysis of the Multicenter Study of MagLev Technology in Patients Undergoing Mechanical Circulatory Support Therapy With HeartMate 3 trial portfolio

BACKGROUND

Correction of valvular disease is often undertaken during left ventricular assist device (LVAD) implantation with uncertain benefit. We analyzed clinical outcomes with HeartMate 3 (HM3; Abbott) LVAD implantation in those with various concurrent valve procedures (HM3+VP) with those with an isolated LVAD implant (HM3 alone).

METHODS

The study included 2200 patients with HM3 implanted within the Multicenter Study of MagLev Technology in Patients Undergoing Mechanical Circulatory Support Therapy with HeartMate 3 (MOMENTUM 3) trial portfolio who underwent 820 concurrent procedures among which 466 (21.8%) were HM3+VP. VPs included 101 aortic, 61 mitral, 163 tricuspid; 85 patients had multiple VPs. Perioperative complications, major adverse events, and survival were analyzed.

RESULTS

Patients who underwent HM3+VP had higher-acuity Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) profiles (1-2: 41% vs 31%) compared with no VPs (P < .05). The cardiopulmonary bypass time (124 vs 76 minutes; P < .0001) and hospital length of stay (20 vs 18 days; P < .0001) were longer in HM3+VP. A higher incidence of stroke (4.9% vs 2.4%), bleeding (33.9% vs 23.8%), and right heart failure (41.5% vs 29.6%) was noted in HM3+VP at 0 to 30 days (P < .01), with no difference in 30-day mortality (3.9% vs 3.3%) or 2-year survival (81.7% vs 80.8%). Analysis of individual VP showed no differences in survival compared to HM3 alone. No differences were noted among patients with either significant mitral (moderate or worse) or tricuspid (moderate or worse) regurgitation with or without corrective surgery.

CONCLUSIONS

Concurrent VPs, commonly performed during LVAD implantation, are associated with increased morbidity during the index hospitalization, with no effect on short- and long-term survival. There is sufficient equipoise to consider a randomized trial on the benefit of commonly performed VPs (such as mitral or tricuspid regurgitation correction), during LVAD implantation.

Heart Failure and Secondary Mitral Regurgitation: A Contemporary Review

Secondary mitral regurgitation (SMR) in patients with heart failure (HF) is associated with significant morbidity and mortality. In recent decades, SMR has received increasing scientific attention. Advances in echocardiography, computed tomography and cardiac magnetic resonance imaging have refined our ability to diagnose, quantify and characterize SMR. Concurrently, the treatment options for this high-risk patient population have continued to evolve. Guideline-directed medical therapies including beta-blockers, angiotensin receptor-neprilysin inhibitors, mineralocorticoid receptor antagonists and sodium-glucose cotransporter-2 inhibitors target the underlying cardiomyopathy, and along with diuretics to treat pulmonary congestion, remain the cornerstone of therapy. Cardiac resynchronization therapy also reduces MR, alleviates symptoms and prolongs life in selected HF patients with SMR. While data supporting surgical mitral valve repair or replacement for SMR are limited, transcatheter edge-to-edge repair (TEER) has been demonstrated to improve survival, reduce the rate of hospitalization for heart failure, and improve functional capacity and quality-of-life in select patients with SMR who remain symptomatic despite medical therapy. Emerging transcatheter mitral valve repair and replacement technologies are undergoing investigation in TEER-eligible and TEER-ineligible patients. The optimal management of HF patients with SMR requires a multidisciplinary team of cardiologists, cardiac surgeons, imaging experts, and other organ specialists to select the best treatment approaches to improve the prognosis of these high-risk patients.

Durable Mechanical Circulatory Support: JACC Scientific Statement

Despite advances in medical therapy for patients with stage C heart failure (HF), survival for patients with advanced HF is <20% at 5 years. Durable left ventricular assist device (dLVAD) support is an important treatment option for patients with advanced HF. Innovations in dLVAD technology have reduced the risk of several adverse events, including pump thrombosis, stroke, and bleeding. Average patient survival is now similar to that of heart transplantation at 2 years, with 5-year dLVAD survival now approaching 60%. Unfortunately, greater adoption of dLVAD therapy has not been realized due to delayed referral of patients to advanced HF centers, insufficient clinician knowledge of contemporary dLVAD outcomes (including gains in quality of life), and deprioritization of patients with dLVAD support waiting for heart transplantation. Despite these challenges, novel devices are on the horizon of clinical investigation, offering smaller size, permitting less invasive surgical implantation, and eliminating the percutaneous lead for power supply.

Health status analysis is comparable in HM3 patients with different preoperative grades of mitral regurgitation

BACKGROUND

The guidelines for mechanical circulatory support of the International Society for Heart and Lung Transplantation do not recommend the routine replacement or repair of the mitral valve at the time point of left ventricular assist device (LVAD) implantation. We investigated different parameters of health status including exercise capacity, anxiety and depression after LVAD implantation in patients with different preoperative grades of mitral regurgitation (MR).

METHODS

A single-center analysis of health status was performed including 45 patients with HeartMate 3 (HM 3) implantation using the 12-items Short Form Health Survey (SF-12) and the Hospital Anxiety and Depression Score (HADS) questionnaires. The study groups were classified according to echocardiographically defined preoperative grade of MR. The group without severe MR comprised 33 patients; the group with severe MR comprised 12 patients.

RESULTS

Demographic and preclinical characteristics as well as LVAD complications such as thrombosis and bleeding events were comparable between LVAD patients with severe and not severe MR (p > 0.05). Severe MR resolved in all patients after LVAD implantation and improved to moderate, mild or no MR in both groups in a period ranging from 6 months until 2 years. The analyses of SF-12 questionnaire revealed that the physical (p = 0.44) and mental health (p = 0.64) was comparable. The grade of anxiety (p = 0.34) and depression (p = 0.44) was comparable between the groups. Exercise capacity measured by the 6 min walk test correlated positively with the SF-12-determined physical health (p < 0.01, r = 0.518) and negatively with the HADS anxiety (p = 0.01, r = -0.399) and depression (p < 0.01, r = -0.570) scores.

CONCLUSIONS

Our data showed that the health status is comparable in HM 3 patients with different preoperative MR severities in the post-LVAD period. Preoperative severe MR resolves in the majority of patients early after LVAD implantation and is not associated with concomitant mitral valve repair or replacement at the time of LVAD implantation.

Mitral Interventions in Heart Failure

Patients with heart failure with reduced ejection fraction who have secondary mitral regurgitation (SMR) have poorer outcomes and quality of life than those without SMR. Guideline-directed medical therapy is the cornerstone of SMR treatment. Careful evaluation of landmark trials using mitral transcatheter edge-to-edge repair in SMR has led to an improved understanding of who will benefit from percutaneous interventions with emphasis on a multidisciplinary approach. The success with mitral transcatheter edge-to-edge repair in SMR has also spurred the evaluation of its role in populations that were not initially studied, such as end-stage heart failure and cardiogenic shock. A spectrum of transcatheter devices in development and clinical trials promise to further provide a growing array of management options for heart failure with reduced ejection fraction patients with symptomatic SMR.

Late Right Heart Failure After Left Ventricular Assist Device Implantation: Contemporary Insights and Future Perspectives

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.

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.

Acute heart failure and valvular heart disease: A scientific statement of the Heart Failure Association, the Association for Acute CardioVascular Care and the European Association of Percutaneous Cardiovascular Interventions of the European Society of Cardiology

Acute heart failure (AHF) represents a broad spectrum of disease states, resulting from the interaction between an acute precipitant and a patient's underlying cardiac substrate and comorbidities. Valvular heart disease (VHD) is frequently associated with AHF. AHF may result from several precipitants that add an acute haemodynamic stress superimposed on a chronic valvular lesion or may occur as a consequence of a new significant valvular lesion. Regardless of the mechanism, clinical presentation may vary from acute decompensated heart failure to cardiogenic shock. Assessing the severity of VHD as well as the correlation between VHD severity and symptoms may be difficult in patients with AHF because of the rapid variation in loading conditions, concomitant destabilization of the associated comorbidities and the presence of combined valvular lesions. Evidence-based interventions targeting VHD in settings of AHF have yet to be identified, as patients with severe VHD are often excluded from randomized trials in AHF, so results from these trials do not generalize to those with VHD. Furthermore, there are not rigorously conducted randomized controlled trials in the setting of VHD and AHF, most of the data coming from observational studies. Thus, distinct to chronic settings, current guidelines are very elusive when patients with severe VHD present with AHF, and a clear-cut strategy could not be yet defined. Given the paucity of evidence in this subset of AHF patients, the aim of this scientific statement is to describe the epidemiology, pathophysiology, and overall treatment approach for patients with VHD who present with AHF.

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.

Predictors and clinical implications of residual mitral regurgitation following left ventricular assist device therapy

BACKGROUND

Correction of mitral regurgitation (MR) at the time of left ventricular assist device (LVAD) implantation remains controversial. There is conflicting evidence regarding the clinical impact of residual MR, and studies have not examined whether MR aetiology or right heart function impacts the likelihood of residual MR.

METHODS

This is a retrospective single-centre study of 155 consecutive patients with LVAD implantation from January 2011 to March 2020. Exclusion criteria were no MR pre-LVAD (n=8), inaccessible echocardiography (n=9), duplicate records (n=10) and concomitant mitral valve repair (n=1). Statistical analysis was performed using STATA V.16 and SPSS V.24.

RESULTS

Carpentier IIIb MR aetiology was associated with more severe MR pre-LVAD (severe 18/27 (67%) vs non-severe 32/91 (35%), p=0.004) and a higher likelihood of residual MR (8/11 (72%) vs 30/74 (41%), p=0.045). Of 95 patients with significant MR pre-LVAD, 15 (16%) had persistent significant MR, which was associated with higher mortality (p=0.006), post-LVAD right ventricle (RV) dilatation (10/15 (67%) vs 28/80 (35%), p=0.022) and RV dysfunction (14/15 (93%) vs 35/80 (44%), p<0.001). Aside from ischaemic aetiology, other pre-LVAD parameters that were associated with significant residual MR included left ventricular end-systolic diameter (LVESD) (6.9 cm (5.7-7.2) vs 5.9 cm (5.5-6.5), p=0.043), left atrial volume index (LAVi) (78 mL/m² (56-88) vs 57 mL/m² (47-77), p=0.021), posterior leaflet displacement (2.5 cm (2.3-2.9) vs 2.3 cm (1.9-2.7), p=0.042) and basal right ventricular end-diastolic diameter (RVEDD) (5.1±0.8 cm vs 4.5±0.8 cm, p=0.010).

CONCLUSION

LVAD therapy improves MR and tricuspid regurgitation severity in the majority, but 14% have persistent significant residual MR, associated with right ventricular dysfunction and higher long-term mortality. This may be predicted pre-LVAD by greater LVESD, RVEDD and LAVi and by ischaemic aetiology.

Left ventricular assist device inflow obstruction

Inflow cannula obstruction is a rare complication of left ventricular assist device implantation. In this report, we present a case of inflow obstruction that was successfully treated with left ventricle myectomy and mitral valvectomy. Transesophageal echocardiogram was essential in diagnosing this condition.

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.

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.

Right heart failure after left ventricular assist device: From mechanisms to treatments

Left ventricular assist device (LVAD) therapy is a lifesaving option for patients with medical therapy-refractory advanced heart failure. Depending on the definition, 5-44% of people supported with an LVAD develop right heart failure (RHF), which is associated with worse outcomes. The mechanisms related to RHF include patient, surgical, and hemodynamic factors. Despite significant progress in understanding the roles of these factors and improvements in surgical techniques and LVAD technology, this complication is still a substantial cause of morbidity and mortality among LVAD patients. Additionally, specific medical therapies for this complication still are lacking, leaving cardiac transplantation or supportive management as the only options for LVAD patients who develop RHF. While significant effort has been made to create algorithms aimed at stratifying risk for RHF in patients undergoing LVAD implantation, the predictive value of these algorithms has been limited, especially when attempts at external validation have been undertaken. Perhaps one of the reasons for poor performance in external validation is related to differing definitions of RHF in external cohorts. Additionally, most research in this field has focused on RHF occurring in the early phase (i.e., ≤1 month) post LVAD implantation. However, there is emerging recognition of late-onset RHF (i.e., > 1 month post-surgery) as a significant cause of morbidity and mortality. Late-onset RHF, which likely has a unique physiology and pathogenic mechanisms, remains poorly characterized. In this review of the literature, we will describe the unique right ventricular physiology and changes elicited by LVADs that might cause both early- and late-onset RHF. Finally, we will analyze the currently available treatments for RHF, including mechanical circulatory support options and medical therapies.

Case series of transcatherter edge-to-edge repair using MitraClip™ system with Impella® mechanical circulatory support

BACKGROUND

Secondary mitral regurgitation (SMR) is a major comorbidity in patients with heart failure with reduced ejection fraction (HFrEF). Transcatheter edge-to-edge repair (TEER) using the MitraClip™ system is a promising tool for selected patients with SMR and HFrEF. Durable success using this system in patients who have advanced heart failure and unsuitable anatomy remains a clinical challenge.

CASE SUMMARY

Three patients aged 67-72 years with HFrEF on inotropic support successfully underwent Impella®-assisted TEER at our centre. Following the procedure, two patients were able to be weaned off inotropic support and were discharged, while one patient expired during the index hospitalization.

DISCUSSION

Impella®-assisted TEER may be a feasible strategy for patients with SMR and HFrEF with unstable haemodynamics particularly when cardiac replacement therapy is not applicable.

Effect of Impella 5.5 on Preexisting Functional Mitral Regurgitation in Patients with Heart Failure-Related Cardiogenic Shock

Background

Heart failure-related cardiogenic shock (HF-CS) is increasingly common. Moderate/severe functional mitral regurgitation (FMR) is commonly seen in patients presenting with decompensated heart failure and is associated with worse outcomes. Percutaneous mechanical circulatory support devices are increasingly used to provide hemodynamic support for ongoing CS. There is no description of the impact of Impella device on hemodynamic response when used in combination with preexisting FMR.

Methods

Retrospective review of patients aged ≥18 years, who underwent Impella 5.5 implant for HF-CS, and who had a transthoracic echocardiogram performed pre- and post-Impella.

Results

Of 24 patients, 33% had moderate-to-severe/severe FMR, 38% had mild-moderate/moderate FMR, and 29% had trace/mild FMR on pre-Impella transthoracic echocardiogram. Additional right ventricular assist device was simultaneously inserted in 3 patients, of whom 1 had severe, 1 had moderate, and another had mild FMR pre-Impella. Despite maximally tolerated Impella unloading, 6 patients (25%) had persistent moderate-severe/severe FMR, and 9 (37.5%) patients had persistent moderate FMR. Overall, however, there was a decrease in central venous pressure, pulmonary artery diastolic pressure, serum lactate, and vasoactive-inotrope score at 24 ​hours post-Impella, and survival was high at 83%.

Conclusions

In a retrospective cohort of patients admitted with HF-CS who underwent Impella 5.5 implant for hemodynamic support, Impella did not seem to acutely ameliorate FMR severity. Despite this, there was a significant improvement in hemodynamic response at 24 ​hours post-Impella. In carefully selected patients, especially those with isolated left ventricular failure, Impella 5.5 may provide adequate hemodynamic support even in the presence of higher severity FMR.

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.

Epidemiology, Pathophysiology, and Management of Native Atrioventricular Valve Regurgitation in Heart Failure Patients

Atrioventricular regurgitation is frequent in the setting of heart failure. It is due to atrial and ventricular remodelling, as well as rhythmic disturbances and loss of synchrony. Once atrioventricular regurgitation develops, it can aggravate the underlying heart failure, and further participate and aggravate its own severity. Its presence is therefore concomitantly a surrogate of advance disease and a predictor of mortality. Heart failure management, including medical therapy, cardiac resynchronization therapy, and restoration of sinus rhythm, are the initial steps to reduce atrioventricular regurgitation. In the current review, we analyse the current data assessing the epidemiology, pathophysiology, and impact of non-valvular intervention on atrioventricular regurgitation including medical treatment, cardiac resynchronization and atrial fibrillation ablation.

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.

Isolated congenital cleft mitral valve leaflet: a rare cause of refractory cardiogenic shock complicating acute myocardial infarction

We report a unique presentation of isolated congenital cleft mitral valve complicating cardiogenic shock from acute myocardial infarction. Isolated cleft mitral valve is an uncommon diagnosis that can have significant clinical implications, especially if not recognized in patients presenting to the catheterization lab with acute myocardial infarction and cardiogenic shock. A review of this rare diagnosis including the options and timing of therapeutic interventions, which can include MitraClip, is important for publication.

The case is of a patient who presented with an anterior acute ST elevation myocardial infarction. Despite early coronary revascularization and conventional support, refractory cardiogenic shock ensued requiring mechanical circulatory support escalation to Veno-arterial extracorporeal membrane oxygenation. Subsequently, left ventriculography revealed a massively dilated left atrium and severe mitral regurgitation raising concerns for a mechanical mitral valve complication. The patient was taken to the operating room for possible mitral valve surgery, but a preoperative transesophageal echocardiogram revealed an isolated posterior cleft mitral valve. Since the patient had stabilized on mechanical circulatory support, emergent surgery was deferred. The patient successfully recovered during index hospitalization with mechanical circulatory support and discharged on guideline directed medical therapy.

In conclusion, isolated cleft mitral valve is a rare diagnosis that can often be underrecognized without comprehensive 3-dimensional transesophageal echocardiography evaluation. If diagnosed early with significant regurgitation, surgical treatment results in good outcomes and preservation of LV systolic function. Percutaneous correction of a CMVL with MitraClip has been described and may offer an alternative approach for high risk surgical patients.

Fate of preoperative moderate mitral regurgitation following left ventricular assist device implantation

OBJECTIVE

We examined for improvements in preoperative moderate mitral regurgitation following continuous-flow left ventricular assist device (cfLVAD) implantation.

METHODS

From 2006 to 2020, 190 patients with moderate MR underwent cfVLAD implant without concomitant mitral valve (MV) surgery. Cardiac dimensions and contractility, as well as valve function, were assessed with an echocardiogram (echo) pre-cfLVAD, and at approximately 1 month post-cfLVAD. Outcomes were determined by retrospective chart review.

RESULTS

Median echo follow-up was 0.94 (0.53, 1.38) months. Residual significant moderate or greater MR was present in 30/190 (15.8%) on follow-up. Patients with significant residual MR had larger preoperative left ventricular internal diameters in diastole (74.4 ± 8.7 vs. 71.1.0 ± 9.1 mm, p = .034). Significant residual MR was associated with higher preoperative mean pulmonary artery pressures (OR = 1.055, p = .035) and pulmonary capillary wedge pressures (OR = 1.060, p = .034). Significant residual MR on echo was not associated with any survival difference (p = .325). The 1, 5, and 10 year survival were 89.9%, 55.2%, and 34.2%, respectively.

CONCLUSIONS

For patients with moderate MR undergoing LVAD implantation, the likelihood of significant residual MR is low and mitral intervention in this population is not recommended. However, select patients with larger preoperative left heart dimensions and pulmonary vascular pressures may be at risk for persistent residual 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.

Impact of Pre-Existing Mitral Regurgitation Following Left Ventricular Assist Device Implant

OBJECTIVES

Optimal management of significant mitral regurgitation (SMR) during left ventricular assist device (LVAD) placement remains uncertain. This study evaluates the effect of untreated preop SMR on outcomes following LVAD implant.

METHODS

Adults undergoing primary LVAD placement from April 2004 to May 2017 were included. Most recent preop transthoracic echocardiogram (TTE) was used to divide patients into an SMR group with moderate or greater regurgitation, and a group without SMR. Patients underwent LVAD implant without correction of SMR. Primary endpoint was 3-year postoperative survival, with secondary endpoints of length of stay (LOS), resolution of SMR following LVAD on postdischarge (30 day) TTE, and 1-year TTE.

RESULTS

LVAD placement was performed in 270 patients, 172 (63.7%) without SMR and 98 (36.3%) with SMR. There were no differences in comorbidities including diabetes, hypertension, and renal disease. Preop ejection fraction was similar, but a higher pulmonary vascular resistance was recorded in the SMR group (3.6 vs 3.0 Wood Units, P = 0.048). There was no difference in 3-year mortality between the 2 cohorts (log-rank P = 0.0.803). The SMR group had decreased LOS (median 19.5 vs 22 days, P = 0.009). Of the 98 SMR patients, 91 (92.9%) had resolution of SMR to less than moderate at 30 days. At 1 year, 15% of those with preoperative SMR had recurrent SMR.

CONCLUSIONS

Patients undergoing LVAD placement with preop SMR experience no differences in mortality, and a majority experience resolution of MR after implant. Longer-term SMR recurrence and need for mitral intervention with LVAD implant warrant further investigation.