Valvular Heart Disease in Patients Supported With Left Ventricular Assist Devices

Improving the Prediction of 1-Year Right Ventricular Failure After Left Ventricular Assist Device Implantation

Previous predictive models for postimplant right heart failure (RHF) following left ventricular assist device (LVAD) implantation have demonstrated limited performance on validation datasets and are susceptible to overfitting. Thus, the objective of this study was to develop an improved predictive model with reduced overfitting and improved accuracy in predicting RHF in LVAD recipients. The study involved 11,967 patients who underwent continuous-flow LVAD implantation between 2008 and 2016, with an RHF incidence of 9% at 1 year. Using an eXtreme Gradient Boosting (XGBoost) algorithm, the training data were used to predict RHF at 1 year postimplantation, resulting in promising area under the curve (AUC)-receiver operating characteristic (ROC) of 0.8 and AUC-precision recall curve (PRC) of 0.24. The calibration plot showed that the predicted risk closely corresponded with the actual observed risk. However, the model based on data collected 48 hours before LVAD implantation exhibited high sensitivity but low precision, making it an excellent screening tool but not a diagnostic tool.

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.

Integration of implantable device therapy in patients with heart failure. A clinical consensus statement from the Heart Failure Association (HFA) and European Heart Rhythm Association (EHRA) of the European Society of Cardiology (ESC)

Implantable devices form an integral part of the management of patients with heart failure (HF) and provide adjunctive therapies in addition to cornerstone drug treatment. Although the number of these devices is growing, only few are supported by robust evidence. Current devices aim to improve haemodynamics, improve reverse remodelling, or provide electrical therapy. A number of these devices have guideline recommendations and some have been shown to improve outcomes such as cardiac resynchronization therapy, implantable cardioverter-defibrillators and long-term mechanical support. For others, more evidence is still needed before large-scale implementation can be strongly advised. Of note, devices and drugs can work synergistically in HF as improved disease control with devices can allow for further optimization of drug therapy. Therefore, some devices might already be considered early in the disease trajectory of HF patients, while others might only be reserved for advanced HF. As such, device therapy should be integrated into HF care programmes. Unfortunately, implementation of devices, including those with the greatest evidence, in clinical care pathways is still suboptimal. This clinical consensus document of the Heart Failure Association (HFA) and European Heart Rhythm Association (EHRA) of the European Society of Cardiology (ESC) describes the physiological rationale behind device-provided therapy and also device-guided management, offers an overview of current implantable device options recommended by the guidelines and proposes a new integrated model of device therapy as a part of HF care.

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.

Left Ventricular Assist Device Emergencies: Diagnosis and Management

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

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.

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

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

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Transcatheter valvular therapies in patients with left ventricular assist devices

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

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.

Considerations of valvular heart disease in children with ventricular assist devices

Ventricular assist devices have become a valuable tool in the treatment of heart failure in children. The use of ventricular assist devices has decreased mortality in children with end-stage heart failure awaiting transplant. It is not uncommon for children with end-stage heart failure associated with cardiomyopathy or congenital heart disease to have significant systemic semilunar and atrioventricular valve regurgitation, which can impact the efficiency and efficacy of hemodynamic support provided by a ventricular assist device. Therefore, implanting clinicians should carefully assess for valve abnormalities that may need repair and impact device selection and cannulation strategy to effectively support this diverse population. The purpose of this review is to provide an overview of this important and relevant topic and to discuss strategies for managing these patients.

Aortic valve disorders and left ventricular assist devices

Aortic valve disorders are important considerations in advanced heart failure patients being evaluated for left ventricular assist devices (LVAD) and those on LVAD support. Aortic insufficiency (AI) can be present prior to LVAD implantation or develop de novo during LVAD support. It is usually a progressive disorder and can lead to impaired LVAD effectiveness and heart failure symptoms. Severe AI is associated with worsening hemodynamics, increased hospitalizations, and decreased survival in LVAD patients. Diagnosis is made with echocardiographic, device assessment, and/or catheterization studies. Standard echocardiographic criteria for AI are insufficient for accurate diagnosis of AI severity. Management of pre-existing AI includes aortic repair or replacement at the time of LVAD implant. Management of de novo AI on LVAD support is challenging with increased risks of repeat surgical intervention, and percutaneous techniques including transcatheter aortic valve replacement are assuming greater importance. In this manuscript, we provide a comprehensive approach to contemporary diagnosis and management of aortic valve disorders in the setting of LVAD therapy.

Key questions about aortic insufficiency in patients with durable left ventricular assist devices

The development of the latest generation of durable left ventricular assist devices (LVAD) drastically decreased adverse events such as pump thrombosis or disabling strokes. However, time-related complications such as aortic insufficiency (AI) continue to impair outcomes following durable LVAD implantation, especially in the context of long-term therapy. Up to one-quarter of patients with durable LVAD develop moderate or severe AI at 1 year and its incidence increases with the duration of support. The continuous regurgitant flow within the left ventricle can compromise left ventricular unloading, increase filling pressures, decrease forward flow and can thus lead to organ hypoperfusion and heart failure. This review aims to give an overview of the epidemiology, pathophysiology, and clinical consequences of AI in patients with durable LVAD.

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.

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.

Hybrid Mock Circulatory Loop Simulation of Extreme Cardiac Events

OBJECTIVE

This paper presents preliminary methods of incorporating the pathological conditions of cardiac arrhythmias and valvular stenosis in hybrid mock circulation loop (hMCL) operation for the enhanced verification and validation of mechanical circulatory support devices such as VADs.

METHODS

The MGH/MF Waveform datasets from PhysioNet database (including both nominal and clinically diagnosed arrhythmic ECG measurements) as well as cardiovascular system model updates are used to recreate arrhythmic events and valvular stenosis in vitro.

RESULTS

Preliminary results show the hMCL can recreate each tested cardiac event within 2% and 4% mean error for reference pressure tracking in the aortic and left ventricular pressure chambers, respectively. Further, frequency spectrum analysis comparisons using the magnitude-squared coherence analysis shows close alignment between measured arrhythmic and hMCL realized pressure frequency content.

CONCLUSION

The generation of cardiac arrhythmias and valvular stenosis around a VAD via both model and acute measurement based methods was achieved.

SIGNIFICANCE

Pathological conditions such as cardiac arrhythmias and valvular stenosis are limited in documentation despite the large percentage of patients who experience these events. This paper provides a means to begin incorporating these events into hardware-in-the-loop mock circulatory systems for next generation VAD validation and verification.

Clinical considerations for the evaluation of patients with left ventricular assist devices

ABSTRACT

A left ventricular assist device (LVAD) provides mechanical circulatory support for patients with end-stage heart failure. As these devices become more prevalent, clinicians must be familiar with the device's function, common complications, and management strategies when evaluating this patient population.

Impact of concomitant cardiac valvular surgery during implantation of continuous-flow left ventricular assist devices: A European registry for patients with mechanical circulatory support (EUROMACS) analysis

BACKGROUND

We investigated the clinical outcomes after cardiac valvular surgery procedures concomitant (CCPs) with left ventricular assist device (LVAD) implantation compared to propensity score (PS) matched controls using the European Registry for Patients with Mechanical Circulatory Support (EUROMACS) data.

METHODS

Between 2006 and 2018, 2760 continuous-flow LVAD patients were identified. Of these, 533 underwent a CCP during the LVAD implant.

RESULTS

Cardiopulmonary bypass time (p < 0.001) and time for implant (p < 0.001) were both significantly longer in the LVAD+CCP group. Hospital mortality was comparable between the two groups from the unmatched population (15.7% vs. 14.1%, p = 0.073). Similarly, short-to-mid-term survival was similar in both groups, with 1-year, 3-year, and 5-year survival rates of 67.9%, 48.2%, and 27.7% versus 66.4%, 46.1%, and 26%, respectively (log-rank, p = 0.25). The results were similar in the PS-matched population. Hospital mortality was comparable between the two groups (18.9% vs. 17.4%, p = 0.074). The short-to-mid-term Kaplan-Meier survival analysis was similar for both groups, with 1-year, 3-year, and 5-year survival rates of 63.4%, 49.2%, and 24.7% versus 66.5%, 46%, and 25.1%, respectively (log-rank, p = 0.81). In the unmatched population, LVAD+CCP patients had longer intensive care unit (ICU) stays (p < 0.0001), longer mechanical ventilation time (p = 0.001), a higher rate of temporary right ventricular assist device (RVAD) support (p = 0.033), and a higher rate of renal replacement therapy (n = 35, 6.6% vs. n = 89, 4.0%, p = 0.014). In the PS-matched population, the LVAD+CCP patients had longer ICU stays (p = 0.019) and longer mechanical ventilation time (p = 0.002).

CONCLUSIONS

The effect of additive valvular procedures (CCPs) does not seem to affect short-term survival, significantly, based on our registry data analysis. However, the decision to perform CCPs should be balanced with the projected type of surgery and preoperative characteristics. LVAD+CCP patients remain a delicate population and adverse device-related events should be strictly monitored and managed.

Successful papillary muscle approximation for severe mitral regurgitation via apical cuff hole in HeartMate 3 implantation via left anterior thoracotomy

We herein report a case of successful papillary muscle approximation for severe mitral regurgitation and HeartMate 3 left ventricular assist device implantation via left anterior thoracotomy in a 39-year-old man diagnosed with dilated cardiomyopathy. He underwent papillary muscle approximation in the mitral valve for severe functional regurgitation via the apical cuff hole. The postoperative course was uneventful. Echocardiography revealed that mitral regurgitation has disappeared. He was awaiting heart transplantation while working.

Effect of Concomitant Tricuspid Valve Surgery With Left Ventricular Assist Device Implantation

BACKGROUND

Tricuspid regurgitation (TR) is common in advanced heart failure (HF) patients. However, the effect of concomitant tricuspid valve repair or replacement (tricuspid valve intervention [TVI]) with left ventricular assist device (LVAD) implantation is controversial. The aim of this study was to investigate the longitudinal trend of TR after LVAD implantation and the effect of TVI on the TR trend and clinical outcomes.

METHODS

We retrospectively reviewed patients at our institution who underwent LVAD implantation between April 2014 and August 2018. We evaluated the grade of TR by echocardiography before and after LVAD implantation. Moderate or greater TR was defined as significant.

RESULTS

Among 199 consecutive patients, 194 had at least 2 echocardiographic TR assessments before and after LVAD implantation. Of these patients, 108 were included in the TVI-positive (TVI+) group and 86 in the TVI-negative (TVI-) group. In the TVI+ group, the prevalence of significant TR decreased from 52% to about 20% in the first 6 months after implantation (P < .01). Overall survival and HF readmission-free survival were comparable between the TVI+ and TVI- patients. In contrast, patients in both groups who had significant postoperative TR during early follow-up had worse 2-year HF readmission-free survival (36% in patients with significant postoperative TR vs 55% in those without significant postoperative TR; P = .028).

CONCLUSIONS

Concomitant TVI with LVAD implantation improved TR in most patients but did not have an impact on clinical outcomes. Significant postoperative TR after LVAD implantation, in patients with and without TVI, was associated with worse HF-free outcomes.

Hemodynamic effects of support modes of LVADs on the aortic valve

As the alternative treatment for heart failure, left ventricular assist devices (LVADs) have been widely applied to clinical practice. However, the effects of the support modes of LVADs on the biomechanical states of the aortic valve are still poorly understood. Hence, the present study investigates such effects and proposes a novel fluid-structure interaction (FSI) approach that combines the lattice Boltzmann method (LBM) and finite element (FE) method. Two support modes of LVADs, namely constant speed mode and constant flow mode, which have been widely applied to clinical practice, are also designed. Results demonstrate that the support modes of LVADs could significantly affect the biomechanical states of the aortic valve and the blood flow pattern of the ascending aorta. Compared with those in the constant flow mode, the leaflets in the constant speed mode could achieve better dynamic performance and lower stress during the systolic phase. The max radial displacement of the leaflets in the constant speed mode is at 8 mm, whereas that in the constant flow mode is at 0.8 mm. Furthermore, the outflow of LVADs directly impacts the aortic surfaces of the leaflets during the diastolic phase by increasing the level of wall shear stress of the leaflets. The leaflets in the constant speed mode receive less impact than those in the constant flow mode. The condition with such minimal impact is conducive to maintaining the normal structure of leaflets and benefits the reduction of the risk of valvular diseases. In sum, the support modes of LVADs exert a crucial effect on the biomechanical environment of the aortic valve. The constant speed mode is better than the constant flow mode in terms of providing a good hemodynamic environment for the aortic valve.

Medical Management of Left Ventricular Assist Device Patients: A Practical Guide for the Nonexpert Clinician

Left ventricular assist devices (LVADs) provide short- or long-term circulatory support to improve survival and reduce morbidity in selected patients with advanced heart failure. LVADs are being used increasingly and now have expanded indications. Health care providers across specialties will therefore not only encounter LVAD patients but play an integral role in their care. To accomplish that, they need to understand the elements of LVAD function, physiology and clinical use. This article provides a concise overview of the medical management of LVAD patients for nonexpert clinicians. Our presentation includes the basics of LVAD physiology, design, and operation, patient selection and assessment, medical management, adverse event identification and management, multidisciplinary care, and management of special circumstances, such as noncardiac surgery, cardiac arrest, and end-of-life care. The clinical examination of LVAD patients is unique in terms of blood pressure and heart rate assessment, LVAD "hum" auscultation, driveline and insertion site inspection, and device parameter recording. Important potential device-related adverse events include stroke, gastrointestinal bleeding, hematologic disorders, device infection, LVAD dysfunction, arrhythmias, and heart failure. Special considerations include the approach to the unconscious or pulseless patient, noncardiac surgery, and palliative care. An understanding of the principles presented in this paper will enable the nonexpert clinician to be effective in collaborating with an LVAD center in the assessment, medical management, and follow-up of LVAD patients. Future opportunities and challenges include the improvement of device designs, greater application of minimally invasive surgical implantation techniques, and management of health economics in cost-constrained systems like those of Canada and many other jurisdictions.

Transfemoral aortic valve replacement for severe aortic valve regurgitation in a patient with a pulsatile-flow biventricular assist device

Severe aortic regurgitation (AR) is a rare but significant complication of ventricular assist device therapy. Experience with transcatheter aortic valve replacement (TAVR) in this setting of patients is very limited, while the scarcely reported cases exclusively refer to TAVR under continuous‐flow left ventricular assist devices. Here, we present the first successful TAVR while running a pulsatile‐flow biventricular assist device (PF‐BiVAD). Clinical data were collected based on the patient's electronic medical records after the patient's consent was obtained. We describe the case of a 57‐year‐old man in whom a PF‐BiVAD (EXCOR, Berlin Heart, Berlin, Germany) had been initially inserted after fulminant myocarditis with subsequent severe dilated cardiomyopathy as bridge‐to‐transplantation therapy. Over the following 2 years, the patient developed severe de novo AR under PF‐BiVAD therapy. This, along with progressive cardiac decompensation, led to the decision for TAVR by our heart team as a minimal invasive approach for severe AR. TAVR using two Edwards SAPIEN 3 bioprostheses as a valve‐in‐valve procedure resulted in a significant reduction of AR from severe to mild, with trace paravalvular leakage and without significant pressure gradients. The patient underwent total orthotopic heart transplantation afterwards. This is the first report of successful TAVR in a patient with severe de novo AR while running a PF‐BiVAD.

Concomitant mitral repair and continuous-flow left ventricular assist devices: Is it warranted?

BACKGROUND

Pre-existing mitral pathology is common in patients undergoing continuous-flow left ventricular assist device implantation. We sought to investigate whether concurrent mitral repair confers any advantage.

METHODS

From March 2004 to October 2014, 374 patients received a continuous-flow left ventricular assist device. Of these, a total of 115 patients with pre-existing mitral regurgitation (MR) greater than moderate were identified and included in the analysis. Outcomes were compared between patients with concurrent mitral repair (n = 52 [45.2%]; Group A) and without repair (n = 63 [54.8%]; Group B).

RESULTS

The mean age was 56.8 years and 25 (21.5%) were women. Patients in Group A were more likely to have undergone destination therapy (48.1% vs 11.1%; P < .001) and had a greater cardiopulmonary bypass time (125 vs 89 minutes; P < .001) than did patients in Group B. Longitudinal analysis using a generalized mixed-effects model demonstrated the odds of developing moderate or severe MR during device support were 86% lower for Group A patients (P < .001). Among those who were discharged alive, 9 (8.6%)-consisting of 1 (2.2%) in Group A and 8 (13.6%) in Group B (P = .039)-developed late right heart failure requiring a total of 13 readmissions (0.03 vs 0.15 readmissions per patient-year; P = .011). Multivariable competing risks regression revealed mitral repair to be a protective factor (hazard ratio, 0.16; 95% confidence interval, 0.03-0.94; P = .042) for late right heart failure occurrence.

CONCLUSIONS

Concurrent mitral repair appears to be efficacious in controlling MR after device implant. The fact that repaired patients developed late right heart failure less frequently than did patients without repair challenges the notion that concurrent mitral repair is unwarranted.

Mitral Valve Regurgitation with a Rotary Left Ventricular Assist Device: The Haemodynamic Effect of Inlet Cannulation Site and Speed Modulation

Mitral valve regurgitation (MVR) is common in patients receiving left ventricular assist device (LVAD) support, however the haemodynamic effect of MVR is not entirely clear. This study evaluated the haemodynamic effect of MVR with LVAD support and the influence of inflow cannulation site and LVAD speed modulation. Left atrial (LAC) and ventricular (LVC) cannulation was evaluated in a mock circulation loop with no, mild, moderate and severe MVR with constant speed and speed modulation (±600 RPM) modes. The use of an LVAD relieved pulmonary congestion during severe MVR, by reducing left atrial pressure from 20.5 to 10.8 (LAC) and 11.5 (LVC) mmHg. However, LAC resulted in decreased left ventricular stroke work (-0.08 J), ejection fraction (-7.9%) and higher MVR volume (+12.7 mL) and pump speed (+100 RPM) compared to LVC. This suggests that LVC, in addition to reducing MVR severity, also improves ventricular washout over LAC. LVAD speed modulation in synchrony with ventricular systole reduced MVR volume and increased ejection fraction with LAC and LVC, thus demonstrating the potential benefits of this mode, despite a reduction in cardiac output.

Tricuspid Valve Annular Dilation as a Predictor of Right Ventricular Failure After Implantation of a Left Ventricular Assist Device

BACKGROUND

Tricuspid annular (TA) dilation has been suggested as a more reliable marker of concomitant advanced right ventricular failure (RVF) than severity of tricuspid regurgitation (TR). Our objective was to examine the impact of TA dilation on occurrence of RVF and in-hospital mortality following left ventricular assist device (LVAD) implant.

METHODS

Consecutive patients undergoing implantation of a continuous-flow LVAD implant were grouped according to the presence or absence of preoperative dilated TA. Clinical characteristics, hemodynamics, and short-term postoperative outcomes were compared between groups. RVF was defined as unplanned right ventricular assist device (RVAD) or postoperative use of inotropes for >14 days. Linear and logistic regressions were used to explore associations of TA with occurrence of RVF and duration of inotrope use.

RESULTS

We included 69 patients who had continuous-flow LVAD implanted between 2006 and 2013 (50 ± 13 years old; 69% males; 37% ischemic etiology; 69% bridge-to-transplant LVAD; 18% INTERMACS 1-2; 48% with significant TR). RVF occurred in nine cases, and overall in-hospital mortality rate was 14%. Tricuspid valve repair was performed in ten cases. Dilated TA (OR 4.86; 95% CI 1.05-22.33; p = 0.04) was associated with RVF. In an adjusted multivariable analysis, indexed TA was an independent predictor of increased days of inotrope use (0.8-day increase in inotrope use for every 1 mm/m2 increase; p = 0.04).

CONCLUSION

In this cohort, TA dilation was a predictor of RVF after LVAD implant. The potential benefit of concomitant TVR in selected patients with a dilated TA undergoing LVAD implantation remains to be determined.

Medical management of patients with continuous-flow left ventricular assist devices

OPINION STATEMENT

The prevalence of patients living with advanced heart failure continues to rise. For a subset of these patients, continuous-flow left ventricular assist devices (LVADs) are a life-saving therapy. Given the efficacy and durability of contemporary LVAD devices, their use has increased exponentially in recent years. The medical management of patients with an LVAD is an area of expertise for advanced heart failure clinicians, but a general understanding of the initial approach to, and stabilization of, LVAD patients is an important skillset for many health care providers. The rapidly changing field of the medical management of LVAD patients is largely based on clinical experience and limited published data. In this manuscript, we integrate the available published data on the medical management of LVAD patients with the growing clinical experience.