Surgical management of valvular disease in patients requiring left ventricular assist device support

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.

LVAD therapy as a catalyst to heart failure remission and myocardial recovery

The management of chronic heart failure over the past decade has witnessed tremendous strides in medical optimization and device therapy including the use of left ventricular assist devices (LVAD). What we once thought of as irreversible damage to the myocardium is now demonstrating signs of reverse remodeling and recovery. Myocardial recovery on the structural, molecular, and hemodynamic level is necessary for sufficient recovery to withstand explant and achieve sustained recovery post-LVAD. Guideline-directed medical therapy and unloading have been shown to aid in recovery with the potential to successfully explant the LVAD. This review will summarize medical optimization, assessment for recovery, explant methodologies and outcomes post-recovery with explant of durable LVAD.

Regurgitation during the fully supported condition of the percutaneous left ventricular assist device

Objective.A percutaneous left ventricular assist device (PLVAD) can be used as a bridge to heart transplantation or as a temporary support for end-stage heart failure. Transvalvularly placed PLVADs may result in aortic regurgitation due to unstable pump position during fully supported operation, which may diminish the pumping effect of forward flow and predispose to complications. Therefore, accurate characterization of aortic regurgitation is essential for proper modeling of heart-pump interactions and validation of control strategies.Approach.In the present study, an improved aortic valve model was used to analyze the severity of regurgitation produced by different pump position offsets. The link between pump position offset degree and regurgitation is validated in the fixed speed mode, and the influence of pump speed on regurgitation is verified in the variable speed mode, using the mock circulatory loop (MCL) experimental platform.Main results.The greater the pump offset and the more severe the regurgitation, the more carefully the pump speed needs to be managed. To avoid over-pumping, the recommended pump speed in this study should not exceed 30 000 rpm.Significance.The modeling approach provide in this study not only makes it easier to comprehend the impact of regurgitation events on the entire interactive system during mechanical assistance, but it also aids in providing timely alerts and suitable management measures.

Aortic Thrombosis in Patients on Mechanical Circulatory Support: A Systematic Literature Review

BACKGROUND

Aortic valve (AV) thrombosis is an uncommon but ominous complication in patients managed with mechanical circulatory support (MCS) devices. In this systematic review, we summarised the data on clinical presentations and outcomes in such patients.

METHODS

We searched articles on PubMed and Google Scholar, reporting at least one adult patient with aortic thrombosis on MCS support and where the individual patient data could be extracted. We grouped the patients by the type of MCS (temporary or durable), and the type of the AV (prosthetic, surgically modified, or native) RESULTS: We identified reports on six patients with aortic thrombus on short-term MCS, and on 41 patients on durable left ventricular assist devices (LVADs). On temporary MCS, AV thrombus typically causes no symptoms and is found incidentally pre- or intra-operatively. For those with durable MCS, the occurrence of aortic thrombus forming on prosthetic or surgically modified valves appears to be more related to the intervention on the valve, rather than from the presence of LVAD. The mortality in this group was 18%. In patients with native AV on durable LVAD support, 60% of patients presented with acute myocardial infarction, acute stroke, or acute heart failure, and mortality in this cohort was 45%. In terms of management, heart transplantation was most successful.

CONCLUSIONS

While the outcomes of aortic thrombosis were good in patients where temporary MCS was used in the setting of aortic valve surgery, patients with native AV who develop this complication on durable LVAD have high morbidity and mortality. Cardiac transplantation should be strongly considered in eligible candidates because other therapies provide inconsistent results.

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.

Outcomes of concomitant aortic valve procedures and left ventricular assist device implantation: A systematic review and meta-analysis

BACKGROUND

Left ventricular assist device (LVAD) implantation is frequently employed in patients with end-stage heart failure. The outcomes of addressing the repair of all substantial aortic valvular disease at the time of LVAD implantation remain unclear. We sought to assess the clinical outcomes in patients undergoing LVAD implantation concomitant with aortic valve procedures (AVPs) compared with isolated LVAD implantation.

METHODS

A literature search was performed using PubMed, Embase, and Cochrane library from inception till June 2022. Primary outcomes included short-term mortality and long-term survival. Random effects models were used to compute mean differences and odds ratios with 95% confidence intervals (CIs).

RESULTS

A total of 14 observational studies (N = 52 693) met our inclusion criteria. Concomitant LVAD implantation and AVPs were associated with higher short-term mortality (OR = 1.61 [95% CI, 1.06-2.42]; p = 0.02) and mean CPBt (MD = 43.25 [95% CI, 22.95-63.56]; p < 0.0001), and reduced long-term survival (OR = 0.70 [95% CI, 0.55-0.88]; p = 0.003) compared with isolated LVAD implantation. No difference in the odds of cerebrovascular accident (OR = 1.05 [95% CI, 0.79-1.39]; p = 0.74) and mean length of hospital stay (MD = 2.89 [95% CI, -4.04 to 9.82]; p = 0.41) was observed between the two groups. On adjusted analysis, short-term mortality was significantly higher in the LVAD group with concurrent AVPs when compared with the isolated LVAD group (aHR = 1.50 [95% CI, 1.20-1.87]; p = 0.0004).

CONCLUSIONS

Concurrent AVPs were associated with higher short-term mortality and reduced long-term survival in patients undergoing LVAD implantation compared with isolated LVAD implantation.

Reciprocal interferences of the left ventricular assist device and the aortic valve competence

Patients suffering from end-stage heart failure tend to have high mortality rates. With growing numbers of patients progressing into severe heart failure, the shortage of available donors is a growing concern, with less than 10% of patients undergoing cardiac transplantation (CTx). Fortunately, the use of left ventricular assist devices (LVADs), a variant of mechanical circulatory support has been on the rise in recent years. The expansion of LVADs has led them to be incorporated into a variety of clinical settings, based on the goals of therapy for patients ailing from heart failure. However, with an increase in the use of LVADs, there are a host of complications that arise with it. One such complication is the development and progression of aortic regurgitation (AR) which is noted to adversely influence patient outcomes and compromise pump benefits leading to increased morbidity and mortality. The underlying mechanisms are likely multifactorial and involve the aortic root-aortic valve (AV) complex, as well as the LVAD device, patient, and other factors, all of them alter the physiological mechanics of the heart resulting in AV dysfunction. Thus, it is imperative to screen patients before LVAD implantation for AR, as moderate or greater AR requires a concurrent intervention at the time of LVADs implantation. No current strict guidelines were identified in the literature search on how to actively manage and limit the development and/or progression of AR, due to the limited information. However, some recommendations include medical management by targeting fluid overload and arterial blood pressure, along with adjusting the settings of the LVADs device itself. Surgical interventions are to be considered depending on patient factors, goals of care, and the underlying pathology. These interventions include the closure of the AV, replacement of the valve, and percutaneous approach via percutaneous occluding device or transcatheter aortic valve implantation. In the present review, we describe the interaction between AV and LVAD placement, in terms of patient management and prognosis. Also it is provided a comprehensive echocardiographic strategy for the precise assessment of AV regurgitation severity.

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.

Selection and management considerations to enhance outcomes in patients supported by left ventricular assist devices

PURPOSE OF REVIEW

Left ventricular assist devices (LVADs) are life-saving therapies for patients in end-stage heart failure (HF) with reduced ejection fraction regardless of candidacy for heart transplantation. Multiple clinical trials have demonstrated improved morbidity and mortality with LVADs when compared to medical therapy alone. However, the uptake of LVADs as a therapeutic option in a larger section of end-stage HF patients remains limited, partly due to associated adverse events and re-hospitalization.

RECENT FINDINGS

Accurate assessment and staging of HF patients is crucial to guide appropriate use of LVADs. Innovative methods to risk stratify patients and manage cardiac and noncardiac comorbidities can translate to improved outcomes in LVAD recipients. Inclusion of quality of life metrics and measurements of adverse events can better inform heart failure cardiologists to help identify ideal LVAD candidates. Addition of machine learning algorithms to this process may guide patient selection to improve outcomes.

SUMMARY

Patient selection and assessment of reversible medical comorbidities are critical to the postoperative success of LVAD implantation. Identifying patients most likely to benefit and least likely to experience adverse events should be a priority.

Predictors and Long-Term Impact of De Novo Aortic Regurgitation in Continuous Flow Left Ventricular Assist Devices Using Vena Contracta

The aim of this study was to identify the optimal echocardiographic measurement of aortic regurgitation (AR) in continuous flow left ventricular assist devices (LVAD) and determine risk factors and clinical implications of de novo AR. Echocardiographic images from consecutive patients who underwent LVAD implantation from February 2007 to March 2017 were reviewed. Severity of de novo AR was determined by vena contracta (VC). Preimplant clinical characteristics, LVAD settings at discharge, and outcomes including heart failure hospitalizations, all-cause mortality, and ventricular arrhythmias of patients with greater than or equal to moderate de novo AR were compared with those with mild or no AR. Among 219 patients, greater than or equal to moderate de novo AR occurred in 65 (29.7%). Left ventricular assist devices support duration was longer with greater than or equal to moderate AR than no or mild AR. In multivariable analysis, preimplant trivial AR and persistent aortic valve (AV) closure were independently associated with de novo AR. By time-varying covariate analysis, survival and freedom from cardiovascular events in greater than or equal to moderate AR were significantly worse (hazard ratio [HR] = 3.947, p < 0.001 and HR = 4.666, p < 0.001). In conclusion, de novo greater than or equal to moderate AR measured by VC increases risk of adverse events. Longer LVAD support duration, preimplant trivial AR, and a closed AV are associated with occurrence of greater than or equal to moderate de novo AR.

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.

New Advances in Monitoring Cardiac Output in Circulatory Mechanical Assistance Devices. A Validation Study in a Porcine Model

Cardiac output (CO) measurement by continuous pulmonary artery thermodilution (CO_CTD) has been studied in patients with pulsatile-flow LVADs (left ventricular assist devices), confirming the clinical utility. However, it has not been validated in patients with continuous-flow LVADs. Therefore, the aim of this study was to assess the validity of CO_CTD in continuous-flow LVADs. Continuous-flow LVADs were implanted in six miniature pigs for partial assistance of the left ventricle. Both methods of measuring CO—measurement by CO_CTD and intermittent pulmonary artery thermodilution, standard technique (CO_ITD)—were used in four consecutive moments of the study: before starting the LVAD (basal moment), and with the LVAD started in normovolemia, hypervolemia (fluid overloading), and hypovolemia (shock hemorrhage). At the basal moment, CO_CTD and CO_ITD were closely correlated (r² = 0.97), with a mean bias of −0.13 ± 0.16 L/min and percentage error of 11%. After 15 min of partial support LVAD, CO_CTD and CO_ITD were closely correlated (r² = 0.91), with a mean bias of 0.31 ± 0.35 L/min and percentage error of 20%. After inducing hypervolemia, CO_CTD and CO_ITD were closely correlated (r² = 0.99), with a mean bias of 0.04 ± 0.07 L/min and percentage error of 5%. After inducing hypovolemia, CO_CTD and CO_ITD were closely correlated (r² = 0.74), with a mean bias of 0.08 ± 0.22 L/min and percentage error of 19%. This study shows that continuous pulmonary thermodilution could be an alternative method of monitoring CO in a porcine model with a continuous-flow LVAD.

Management of a mechanical aortic valve during left ventricular assist device implantation in a previously replaced aortic root

The use of left ventricular assist device (LVAD) in patients with mechanical aortic valves may result in thromboembolic events due to blood stasis around the valve and intermittent valve opening. Mechanical aortic valves encountered during LVAD implantation are managed by replacement with a tissue valve, or closure of the valve with a patch. Closure of the valve carries the risk of sudden death in cases of LVAD stoppage. Replacing the whole mechanical valve conduit is time consuming and carries a significant risk of bleeding and right ventricular (RV) failure. We describe an alternative technique of replacing a mechanical aortic valve by breaking its inner leaflets and sewing a tissue valve on top of the mechanical valve ring.

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.

Clinical impact of concomitant tricuspid valve procedures during left ventricular assist device implantation

BACKGROUND

Tricuspid regurgitation (TR) is common in patients with end-stage heart failure receiving left ventricular assist devices (LVADs), but the benefit of concomitant tricuspid valve procedures (TVPs) remains uncertain. This study examined the impact of TVP at the time of LVAD implantation on clinical outcomes and quality of life (QOL) metrics.

METHODS

We included adult patients in the Interagency Registry for Mechanical Circulatory Support database with various degrees of TR who received continuous-flow LVADs from 2008 to 2017. Patients undergoing concomitant TVP were compared with those without the intervention in a stratified analysis. Descriptive analyses, survival analyses, and Andersen‒Gill hazard models were used as appropriate to examine associations with clinical and patient-centered QOL outcomes.

RESULTS

Our analysis included 8,263 (53.1%) mild, 4,252 (33.3%) moderate, and 2,100 (13.5%) severe TR cases. TVP rate increased with severity: 8.6% of mild, 18.0% of moderate, and 43.9% of severe cases. TVP was not associated with survival benefit in cases of mild (adjusted hazard ratio [aHR]: 0.97, 95% CI: 0.79-1.19, p = 0.75), moderate (aHR: 1.03, 95% CI: 0.88-1.20, p = 0.72), or severe (aHR: 1.20, 95% CI: 0.98-1.48, p = 0.08) TR. For patients with combined moderate or severe TR, TVP was associated with increased mortality (log-rank p < 0.01, aHR: 1.13, 95% CI: 1.00-1.27, p = 0.04). After adjusting for TR severity, TVP was associated with increased risk of bleeding, arrhythmia, and stroke (p < 0.01 each) and no improvements in QOL (p > 0.05).

CONCLUSIONS

TVP at the time of LVAD implantation was not associated with either improved survival or QOL, and there were associations with increased risk of adverse events among patients with moderate and severe TR.

Insight into Atrial Fibrillation in LVAD Patients: From Clinical Implications to Prognosis

The use of left ventricular assist devices (LVADs), whether for destination therapy or bridge to transplantation, has gained increasing validation in recent years in patients with advanced heart failure. Arrhythmias can be the most challenging variables in the management of such patients but the main attention has always been focused on ventricular arrhythmias given the detrimental impact on mortality. Nevertheless, atrial fibrillation (AF) is the most common rhythm disorder associated with advanced heart failure and may therefore characterize the LVADs' pre- and postimplantation periods. Indeed, the consequences of AF in the population suffering from standard heart failure may require a more comprehensive evaluation in the presence of or in sight of an LVAD, making the AF clinical management in these patients potentially complex. Several studies have been based on this subject with different and often conflicting results, leaving many questions unresolved. The purpose of this review is to summarize the main pieces of evidence about the clinical impact of AF in LVAD patients, underlining the main implications in terms of hemodynamics, thromboembolic risk, bleeding and prognosis. Therapeutic considerations about the clinical management of these patients are also made according to the latest evidence.

Continuous-flow left ventricular assist device implantation in patients with preexisting mechanical mitral valves: a systematic review

Introduction: A preexisting mechanical mitral valve (MMV) is thought to be a thrombogenic risk factor after continuous-flow left ventricular assist device (CF-LVAD) implantation. We sought to evaluate the management and outcomes of preexisting MMVs in patients following CF-LVAD implantation.Areas covered: An electronic search was performed to identify the presence of an MMV at the time of CF-LVAD implantation. Of the 1,168 studies identified, only five studies consisting of seven CF-LVAD patients met the inclusion criteria. Patient-level data were extracted and analyzed.Expert opinion: The median patient age was 54 (IQR: 42-61) years and 71.4% (5/7) were male. Non-ischemic cardiomyopathy was the predominant etiology (83.3%, 5/6) of heart failure, and bridge-to-transplant the predominant indication (85.7%, 6/7) for CF-LVAD. Aortic valve prosthesis was present in 42.9% (3/7) of patients. Median time from MMV to CF-LVAD placement was 6.0 years (IQR: 1.3-15.0). The median lower limit of the INR range was 2.8 (IQR: 2.1-3.0) and upper limit of the INR range was 3.5 (IQR: 3.1-3.5). During a median follow-up time of 120 (IQR: 70-201) days, there were no major GI bleeds or clinically significant thromboembolic complications. With adequate anticoagulation, preexisting MMVs in CF-LVAD patients did not result in clinically significant thromboembolic events.

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.

LVAD with concomitant rapid deployment valve implantation - a case report

BACKGROUND

Aortic valve insufficiency can have significant hemodynamic consequences for patients with left ventricular assist devices. A circulation loop can limit systemic blood flow and increase left ventricular filling pressure.

CASE PRESENTATION

A 64-year-old male with non-ischemic dilated cardiomyopathy underwent Heartware™ HVAD left ventricular assist device implantation with successful concomitant aortic valve replacement with an Edwards Intuity rapid deployment prosthetic valve.

CONCLUSIONS

The use of this rapid deployment valve may have benefits over other techniques including shorter cross clamp times during surgery, intermediate-long term durability, and preservation of aortic valve opening to allow for potential ventricular recovery. The Intuity rapid deployment valve should thus be considered a viable and suitable option for aortic insufficiency intervention during LVAD implantation.

Percutaneous Aortic Valve Closure in Patient With Left Ventricular Assist Device and Dilated Aortic Annulus

Percutaneous transcatheter intervention for aortic regurgitation secondary to implantation of a continuous-flow left ventricular assist device remains challenging, because of the minimal global experience with these procedures. Two treatment options are available: transcatheter aortic valve replacement, which is not always feasible when a dilated aortic annulus is present, and percutaneous aortic valve occlusion. We report a successful percutaneous closure of the aortic valve using an oversized Amplatzer patent foramen ovale multifenestrated device (St Jude Medical, Saint Paul, MN) to treat aortic regurgitation associated with dilated aortic annulus in a patient with a continuous-flow left ventricular assist device.

Atrial Fibrillation Should Guide Prophylactic Tricuspid Procedures During Left Ventricular Assist Device Implantation

Atrial fibrillation (AF) and tricuspid regurgitation (TR) are common in patients undergoing left ventricular assist device (LVAD) implantation. TR progression is associated with the presence of AF, and questions remain as to who benefits from tricuspid valve procedures (TVPs). We examined the impact of preoperative AF on TR progression after LVAD implantation. From February 2007 to May 2014, 250 patients underwent LVAD implantation at our institution. Patients with concomitant TVP were excluded from this analysis (113 patients). The indication for LVAD was destination therapy in 80 patients (58%) and the etiology of heart failure was ischemic in 73 (53%). Follow-up was available in all early survivors for a total of 393 patient-years of support. Of the 137 non-TVP patients, 52 (38%) had AF preoperatively. Observed overall survival at 1, 3, and 5 years was 82%, 67%, and 55%, respectively. Median grade of TR increased from 2 preoperatively to 3 (p = 0.04) in the AF group and 2.2 (p = 0.75) in the non-AF group at 5 years of follow-up. We also observed a significant difference in the degree of TR between groups at 3 months (p = 0.03) and 12 months (p = 0.01) postimplantation, and a trend toward significance at 18 (p = 0.06) and 24 (p = 0.07) months. The presence of AF is associated with early progression of TR after LVAD implantation. Addition of concomitant TVP in patients with preoperative AF may be considered in patients with less than severe TR. The impact of these findings on right ventricular failure/remodeling remains to be evaluated.

Concomitant valve procedures in patients undergoing continuous-flow left ventricular assist device implantation: A single-center experience

OBJECTIVE

Long-term support with continuous-flow left ventricular assist devices (CF-LVADs) has improved the outcomes of patients with end-stage heart failure. However, valve disease management in patients who undergo CF-LVAD implantation remains controversial. The aim of this study was to assess our single-center experience with patients who underwent a concomitant valve procedure during implantation of a CF-LVAD.

METHODS

From November 2003 through March 2016, 526 patients underwent primary CF-LVAD implantation with a HeartMate II (St Jude Inc, St Paul, Minn; n = 403) or HeartWare (Medtronic, Minneapolis, Minn; n = 123) device at our center. Of those, 91 underwent a concomitant valve procedure during implantation (CF-LVAD+valve procedure group), whereas 435 did not (CF-LVAD-only group). We compared preoperative characteristics and short-term and mid-term survival rates between these groups.

RESULTS

The concomitant valve procedures performed included 13 tricuspid valve repairs, 19 aortic valve repairs or replacements, 30 mitral valve repairs or replacements, and 29 double valve repairs or replacements. Survival rates at 1 month, 6 months, 12 months, and 24 months were 90.3%, 81.4%, 74.9%, and 67.4%, respectively, for the CF-LVAD-only group and 89.0%, 75.8%, 70.3%, and 65.9%, respectively, for the CF-LVAD+valve procedure group (P = .55). The results of Cox regression multivariable modeling showed that performing a concomitant valve procedure was not an independent predictor of mortality (hazard ratio, 1.29; 95% confidence interval, 0.96-1.74; P = .08).

CONCLUSIONS

In our experience, performing a concomitant valve procedure during CF-LVAD implantation was not associated with an increased mortality rate. The decision to perform a concomitant valve procedure should be made primarily on the basis of clinical indications for the procedure.

Long-Term Continuous-Flow Left Ventricular Assist Device Support After Left Ventricular Outflow Tract Closure

Aortic valve insufficiency can be addressed during continuous-flow left ventricular assist device (CF-LVAD) implantation by performing aortic valve repair or replacement, or patch closure of the left ventricular outflow tract (LVOT). However, few studies have examined the safety of long-term CF-LVAD support after LVOT closure. From November 2003 through March 2016, 16 patients with advanced chronic heart failure underwent CF-LVAD implantation and concomitant LVOT closure for severe aortic insufficiency. We compared their long-term outcomes with those of 510 CF-LVAD recipients without concomitant LVOT closure. Total support time was 26.1 patient-years in the LVOT-closure group and 938.6 patient-years in the CF-LVAD-only group. Survival at 30 days, 6 months, 1 year, and 2 years was similar for CF-LVAD-only patients (90.4%, 80.6%, 74.3%, 67.5%) and LVOT-closure patients (81.3%, 81.3%, 75.0%, 68.8%; p = 0.59). There were no deaths related to LVOT closure. The event rate per patient-year for neurologic dysfunction (ND) was 0.23 in the LVOT-closure group (6 ND events) and 0.20 in the CF-LVAD-only group (136 ND events; p = 0.97). We conclude that for select patients with aortic insufficiency who are undergoing CF-LVAD implantation, LVOT closure produces acceptable outcomes and, therefore, is a viable option.

Protracted aortic valve closure during peripheral veno-arterial extracorporeal life support: is intra-aortic balloon pump an effective solution?

Background:

Left ventricular (LV) afterload increase with protracted aortic valve (AV) closure may represent a complication of veno-arterial extracorporeal membrane oxygenation (V-A ECMO). The aim of the present study was to assess the effects of an intra-aortic balloon pump (IABP) to overcome such a hemodynamic shortcoming in patients submitted to peripheral V-A ECMO.

Methods:

Among 184 adult patients who were treated with peripheral V-A ECMO support at Medical University Center Maastricht Hospital between 2007 and 2018, patients submitted to IABP implant for protracted AV closure after V-A ECMO implant were retrospectively identified. All clinical and hemodynamic data, including echocardiographic monitoring, were collected and analyzed.

Results:

During the study period, 10 subjects (mean age 60 years old, 80% males) underwent IABP implant after peripheral V-A ECMO positioning due to the diagnosis of protracted AV closure and inefficient LV unloading as assessed by echocardiography and an absence of pulsation in the arterial pressure wave.

Recovery of blood pressure pulsatility and enhanced LV unloading were observed in 8 patients after IABP placement, with no significant differences in the main hemodynamic parameters, inotropic therapy or in the ECMO flow (p=0.48). The weaning rate in this patient subgroup (mean ECMO duration 8 days), however, was only 10%, with another patient finally transplanted, leading to a 20% survival-to-hospital discharge.

Conclusion:

IABP placement was an effective solution in order to reverse the protracted AV closure and impaired LV unloading observed during peripheral V-A ECMO support. However, the impact on the weaning rate and survival needs further investigations.

Mitral Intervention with LVAD: Preparing for Recovery

Left ventricular assist device (LVAD) insertion is an increasingly common treatment of advanced heart failure. Insertion guidelines suggest regurgitant lesions of the mitral valve should not be addressed. However, recent evidence suggests that mitral regurgitation may not necessarily improve with LVAD insertion, and such patients may have worse outcomes. Thus, practice variability is high given the discrepancy between traditional thinking and new evidence that unrepaired mitral regurgitation may increase perioperative mortality. Additionally, the challenges of LVADs can make transesophageal echocardiography evaluation and assessment of mitral valve pathology difficult.

Role of Echocardiography in the Evaluation of Left Ventricular Assist Devices: the Importance of Emerging Technologies

The role of left ventricular assist devices (LVAD) in patients with end-stage heart failure is well known, both as a temporary treatment before transplantation and as destination therapy, in a scenario of a relative shortage of donors to satisfy the increasing requests for transplantation. The increased population of LVAD patients needs careful imaging assessment before, during, and after LVAD implantation; echocardiography is the best tool for their evaluation and is considered the diagnostic technique of choice for the assessment before, during, and after device implantation. Although the conventional echocardiographic assessment is quite effective in evaluating the main critical issues, the role of new technologies like three-dimensional echocardiography and myocardial deformation measurements is still not properly clarified. In this review, we aim to provide an overview of the main elements that should be considered in the assessment of these patients, underlining the role that could be played by new techniques to improve the diagnostic and prognostic effectiveness of echocardiography in this setting.

Daily transient discontinuation of extracorporeal LVAD to prevent thromboembolism of mechanical aortic valve prosthesis

Patients with mechanical aortic valves are generally contraindicated for left ventricular assist device (LVAD) insertion because the prosthetic valve often becomes fixed in closed position. A 41-year-old woman with mechanical aortic valve prosthesis experienced sudden chest pain and developed cardiogenic shock. A paracorporeal pulsatile LVAD and a monopivot centrifugal pump as a right VAD (RVAD) were implanted. The mechanical aortic valve was intentionally left in place. Soon after the operation, LVAD support was discontinued daily for few seconds to allow the mechanical aortic valve to open and to avoid thrombus formation. The patient was successfully weaned off RVAD and received anticoagulation therapy with warfarin. On postoperative day 141, she was transferred to a university hospital where a HeartMate II LVAD was implanted, and the aortic valve was successfully replaced with a bioprosthetic valve. The patient is currently awaiting heart transplantation.

Echocardiographic assessment for ventricular assist device placement

While many factors depend on successful implantation and outcome of left ventricular assist devices (LVAD), echocardiography remains an integral part and is vital to the success of this process. Transesophageal echocardiography (TEE) allows interrogation of all the cardiac structures and great vessels. The pre-implantation TEE exam establishes a baseline and may identify potential problems that need palliation. Among these, most significant are aortic insufficiency (AI), intracardiac thrombi, poor right ventricular (RV) function, and intracardiac shunts. The post-implantation exam allows for adequate de-airing of the heart and successful LVAD initiation. The position and flow profiles of the inflow and outflow cannulas of the LVAD may be assessed. Finally, it assists in the astute management and vigilant identification and correction of a number of complications in the immediate post-implantation period. TEE will continue to remain vital to the successful outcomes LVAD patients.

Mathematical analysis of the effects of valvular regurgitation on the pumping efficacy of continuous and pulsatile left ventricular assist devices

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We numerically investigated the physiological relationship between the severity of regurgitation and the effect of a left ventricular assist device (LVAD) on cardiovascular system responses.

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Under conditions of mitral regurgitation, the effects of both pulsatile and continuous LVAD treatment on ventricular unloading were significant.

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Under conditions of aortic regurgitation (AR), the effects of the LVADs on ventricular unloading were not significant. The effects of LVAD treatment decreased according to the severity of AR.

Background

A left ventricular assist device (LVAD) is normally contraindicated in significant aortic regurgitation (AR) and requires intraoperative valve repair or exclusion. Nevertheless, AR can coexist with an LVAD, so a valid question when asked might still be of clinical significance. The purpose of this study is to analyze the effects of valve regurgitation on the pumping efficacy of continuous and pulsatile LVADs with a computational method.

Methods

A cardiovascular model was developed based on the Windkessel model, which reflects the hemodynamic flow resistance and the blood wall elasticity. Using the Windkessel model, important cardiovascular components, such as the right atrium, right ventricle, pulmonary artery, pulmonary vein, left atrium (LA), left ventricle (LV), aorta, and branching blood vessels, were expressed.

Results

In the case of AR, continuous and pulsatile LVADs improved cardiac output and reduced mechanical load slightly. In the case of mitral regurgitation, the LVADs improved cardiac output (cardiac outputs were about 5 L/min regardless of the severity of regurgitation) and reduced afterload significantly.

Conclusion

AR reduced both continuous and pulsatile LVAD function significantly while mitral regurgitation did not affect their pumping efficacy.

Replacement of the aortic valve with a bioprosthesis at the time of continuous flow ventricular assist device implantation for preexisting aortic valve dysfunction

Left ventricular assist device (LVAD) implantation has become a mainstay of therapy for advanced heart failure patients who are either ineligible for, or awaiting, cardiac transplantation. Controversy remains over the optimal therapeutic strategy for preexisting aortic valvular dysfunction in these patients at the time of LVAD implant. In patients with moderate to severe aortic regurgitation, surgical approaches are center specific and range from variable leaflet closure techniques to concomitant aortic valve replacement (AVR) with a bioprosthesis. In the present study, we retrospectively analyzed our outcomes in patients who underwent simultaneous AVR and LVAD implantation secondary to antecedent aortic valve pathology. Between January 2004 and June 2010, 144 patients underwent LVAD implantation at a single institution. Of these, 7 patients (4.8%) required concomitant AVR. Five of the 7 patients (71%) survived to hospital discharge and suffered no adverse events in the perioperative period. One-year survival for the discharged patients was 80%, and no prosthetic valve-related adverse events were observed in long-term follow-up. Given our experience, we conclude that bioprosthetic AVR is a plausible alternative for end-stage heart failure patients at the time of LVAD implantation.

Review of recent results using computational fluid dynamics simulations in patients receiving mechanical assist devices for end-stage heart failure

Many end-stage heart failure patients are not eligible to undergo heart transplantation due to organ shortage, and even those under consideration for transplantation might suffer long waiting periods. A better understanding of the hemodynamic impact of left ventricular assist devices (LVAD) on the cardiovascular system is therefore of great interest. Computational fluid dynamics (CFD) simulations give the opportunity to study the hemodynamics in this patient population using clinical imaging data such as computed tomographic angiography. This article reviews a recent study series involving patients with pulsatile and constant-flow LVAD devices in which CFD simulations were used to qualitatively and quantitatively assess blood flow dynamics in the thoracic aorta, demonstrating its potential to enhance the information available from medical imaging.

Risk factors for prolonged mechanical ventilation for children on ventricular assist device support

BACKGROUND

Patients with end-stage heart failure possess many attributes that place them at risk for prolonged mechanical ventilation (MV). However, there are only limited data on MV support among children after ventricular assist device (VAD) implantation. We report the duration of MV after VAD placement, indications for respiratory support in the postimplantation period, and associated patient factors.

METHODS

This single-center retrospective study included 43 consecutive children (aged <18 years) with end-stage heart failure who were supported with a VAD as a bridge to transplantation from January 2005 to December 2011. Multivariable analysis was performed using the multiple Poisson regression model for the duration of MV.

RESULTS

Overall, 33% (n = 14) remained on MV until heart transplant or death. Of those requiring pre-VAD extracorporeal membrane oxygenation (ECMO) support, 63% (n = 12 of 19) remained on MV until heart transplant or death compared with 8% (n = 2 of 24) among those not on ECMO before VAD (p < 0.001). Patients with moderate or severe mitral regurgitation while on VAD support had 1.7-times more MV days compared with those with none or trivial on-VAD mitral regurgitation. In addition, previous support on ECMO, those with moderate or severe tricuspid regurgitation, and those with only left VAD implants had an increased risk of prolonged MV.

CONCLUSIONS

Our results suggest that VAD recipients previously supported on ECMO, those with moderate or severe mitral regurgitation, moderate or severe tricuspid regurgitation, and those with only left VAD implants had an increased risk of prolonged MV. Future studies in larger cohorts are necessary to confirm the findings from this single-institutional experience.

Relationship of tricuspid repair at the time of left ventricular assist device implantation and survival

PURPOSE

Tricuspid regurgitation contributes to right ventricular failure (RVF) and is associated with worse clinical outcomes in patients undergoing left ventricular assist device (LVAD) treatment. However, whether tricuspid valve repair (TVR) at the time of LVAD implantation improves outcomes is not clear.

METHODS

We identified all patients undergoing initial implantation of a long-term continuous-flow LVAD at our institution from March 2006 to August 2011. We assessed the impact of TVR on survival and incidence of RVF using Kaplan-Meier curves and proportional hazards regression adjusted for age, gender, baseline tricuspid regurgitation, RV function, MELD score, albumin, and indication (bridge vs. destination).

RESULTS

A total of 101 patients were included in the analysis, of which 14 patients underwent TVR concomitant LVAD. All TVR patients had moderate or severe baseline regurgitation. Crude survival was not different between groups. In multivariable models adjusted for confounding factors, TVR showed a significant association with improved survival (HR = 0.1, p = 0.049). Adjusted models showed no difference in RVF.

CONCLUSIONS

In this cohort of patients, TVR at the time of LVAD implantation appears associated with better survival. Additional larger studies are needed to verify the effect of TVR at the time of LVAD implantation, and whether it should be utilized more frequently.