Use of Ventricular Assist Devices and Heart Transplantation for Advanced Heart Failure.

There are only 2 treatments for the thousands of patients who progress to the most advanced form of heart failure despite the application of guideline-based medical therapy, use of ventricular assist devices and heart transplantation. There has been a great deal of progress in both of these therapies that have led to improved outcomes including significant improvement in survival and functional capacity. Heart transplantation offers the best short- and long-term survival for patients with end-stage heart failure, and the majority of these recipients achieve relatively limitless functional capacity for their age. However, the chronic shortage of available donors limits the number of recipients in the United States to an only 2500 patients/y or only a fraction of potential candidates. The significant improvement in outcomes now possible with durable ventricular assist devices has led to a significant increase in their use, which now exceeds the volume of heart transplants in the United States, with the greatest growth in use for those not considered to be candidates for heart transplantation, previously referred to as destination therapy. This article will review the substantial progress that has taken place for both of these life-saving treatment options, as well as the future directions.

Preparing end-stage heart failure patients and care providers in the era of climate change-driven hurricanes.

Patients with end-stage congestive heart failure are at elevated risk for harm when extreme storms threaten and strike their communities. Individuals with compromised heart function require customized hurricane protection and preparedness approaches. We provide mitigation strategies for providers and their teams, as well as the patients themselves to ensure their safety and uninterrupted access to healthcare resources and quality care during hurricane impact and in the aftermath.

Intrapericardial Left Ventricular Assist Device for Advanced Heart Failure.

BACKGROUND: Mechanical circulatory support with a left ventricular assist device (LVAD) is an established treatment for patients with advanced heart failure. We compared a newer LVAD design (a small intrapericardial centrifugal-flow device) against existing technology (a commercially available axial-flow device) in patients with advanced heart failure who were ineligible for heart transplantation. METHODS: We conducted a multicenter randomized trial involving 446 patients who were assigned, in a 2:1 ratio, to the study (centrifugal-flow) device or the control (axial-flow) device. Adults who met contemporary criteria for LVAD implantation for permanent use were eligible to participate in the trial. The primary end point was survival at 2 years free from disabling stroke or device removal for malfunction or failure. The trial was powered to show noninferiority with a margin of 15 percentage points. RESULTS: The intention-to treat-population included 297 participants assigned to the study device and 148 participants assigned to the control device. The primary end point was achieved in 164 patients in the study group and 85 patients in the control group. The analysis of the primary end point showed noninferiority of the study device relative to the control device (estimated success rates, 55.4% and 59.1%, respectively, calculated by the Weibull model; absolute difference, 3.7 percentage points; 95% upper confidence limit, 12.56 percentage points; P=0.01 for noninferiority). More patients in the control group than in the study group had device malfunction or device failure requiring replacement (16.2% vs. 8.8%), and more patients in the study group had strokes (29.7% vs. 12.1%). Quality of life and functional capacity improved to a similar degree in the two groups. CONCLUSIONS: In this trial involving patients with advanced heart failure who were ineligible for heart transplantation, a small, intrapericardial, centrifugal-flow LVAD was found to be noninferior to an axial-flow LVAD with respect to survival free from disabling stroke or device removal for malfunction or failure. (Funded by HeartWare; ENDURANCE ClinicalTrials.gov number, NCT01166347 .).

Investigation of the inherent left-right flow balancing of rotary total artificial hearts by means of a resistance box.

With the incidence of end-stage heart failure steadily increasing, the need for a practical total artificial heart (TAH) has never been greater. Continuous flow TAHs (CFTAH) are being developed using rotary blood pumps (RBPs), leveraging their small size, mechanical simplicity, and excellent durability. To completely replace the heart with currently available RBPs, two are required; one for providing pulmonary flow and one for providing systemic flow. To prevent hazardous states, it is essential to maintain balance between the pulmonary and systemic circulation at a wide variety of physiologic states. In this study, we investigated factors determining a CFTAH's inherent ability to balance systemic and pulmonary flow passively, without active management of pump rotational speed. Four different RBPs (ReliantHeart HA5, Thoratec HMII, HeartWare HVAD, and Ventracor VentrAssist) were used in various combinations to construct CFTAHs. Each CFTAH's ability to autonomously maintain pressures and flows within defined ranges was evaluated in a hybrid mock loop as systemic and pulmonary vascular resistance (PVR) were changed. The resistance box, a method to quantify the range of vascular resistances that can be safely supported by a CFTAH, was used to compare different CFTAH configurations in an efficient and predictive way. To reduce the need for future in vitro tests and to aid in their analysis, a novel analytical evaluation to predict the resistance box of various CFTAH configurations was also performed. None of the investigated CFTAH configurations fully satisfied the predefined benchmarks for inherent flow balancing, with the VentrAssist (left) and HeartAssist 5 (right) offering the best combination. The extent to which each CFTAH was able to autonomously maintain balance was determined by the pressure sensitivity of each RPB: the sensitivity of outflow to changes in the pressure head. The analytical model showed that by matching left and right pressure sensitivity the inherent balancing performance can be improved. These findings may ultimately lead to a reduced need for manual speed changes or active control systems.

Outcomes in patients who underwent a concomitant tricuspid valve procedure during left ventricular assist device implantation.

BACKGROUND: Study findings have been inconsistent regarding whether a concomitant tricuspid valve replacement or repair performed concurrently with continuous-flow left ventricular assist device (CF-LVAD) implantation has additive clinical benefit in patients with severe tricuspid valve regurgitation (TR). AIM OF STUDY: To determine the effect of performing a concomitant tricuspid valve procedure (TVP) at the time of CF-LVAD implantation on patient outcomes. METHODS: We retrospectively reviewed our single-institution experience in 526 patients who underwent primary implantation of a CF-LVAD between November 2003 and March 2016. We identified 59 (11.2%) patients who had severe TR at the time of implantation and analyzed the effect of performing a concomitant TVP at the time of CF-LVAD implantation on the rate of survival, incidence of postoperative right heart failure (RHF), recurrence of TR, and incidence of 30-day readmission. RESULTS: We did not observe a significant difference in the overall survival rate (P = .51), incidence of postoperative RHF (P = .26), or recurrence of TR (P = .73) between patients with severe TR who underwent a TVP and those who did not at the time of CF-LVAD implantation. However, the incidence of 30-day readmission was significantly lower in patients who underwent a TVP than in those who did not (P = .002). CONCLUSIONS: Performing a concomitant TVP at the time of CF-LVAD implantation did not improve patient outcomes but reduced the incidence of 30-day readmission.

Acquired von Willebrand syndrome associated with left ventricular assist device.

Left ventricular assist devices (LVAD) provide cardiac support for patients with end-stage heart disease as either bridge or destination therapy, and have significantly improved the survival of these patients. Whereas earlier models were designed to mimic the human heart by producing a pulsatile flow in parallel with the patient's heart, newer devices, which are smaller and more durable, provide continuous blood flow along an axial path using an internal rotor in the blood. However, device-related hemostatic complications remain common and have negatively affected patients' recovery and quality of life. In most patients, the von Willebrand factor (VWF) rapidly loses large multimers and binds poorly to platelets and subendothelial collagen upon LVAD implantation, leading to the term acquired von Willebrand syndrome (AVWS). These changes in VWF structure and adhesive activity recover quickly upon LVAD explantation and are not observed in patients with heart transplant. The VWF defects are believed to be caused by excessive cleavage of large VWF multimers by the metalloprotease ADAMTS-13 in an LVAD-driven circulation. However, evidence that this mechanism could be the primary cause for the loss of large VWF multimers and LVAD-associated bleeding remains circumstantial. This review discusses changes in VWF reactivity found in patients on LVAD support. It specifically focuses on impacts of LVAD-related mechanical stress on VWF structural stability and adhesive reactivity in exploring multiple causes of AVWS and LVAD-associated hemostatic complications.

Bridging to a Long-Term Ventricular Assist Device With Short-Term Mechanical Circulatory Support.

Implanting short-term mechanical circulatory support (MCS) devices as a bridge-to-decision is increasingly popular. However, outcomes have not been well studied in patients who receive short-term MCS before receiving long-term left ventricular assist device (LVAD) support. We analyzed outcomes in our single-center experience with long-term continuous-flow (CF)-LVAD recipients with pre-implantation short-term MCS. From November 2003 through March 2016, 526 patients (mean age, 54.7 ± 13.5 years) with chronic heart failure (mean ejection fraction, 21.7 ± 3.6%) underwent implantation of either the HeartMate II (n = 403) or the HeartWare device (n = 123). Before implantation, 269 patients received short-term MCS with the TandemHeart, the Impella 2.5/5.0, an intra-aortic balloon pump (IABP), venoarterial extracorporeal membrane oxygenation (VA-ECMO), or the CentriMag. The short-term MCS patients were compared with the CF-LVAD-only patients regarding preoperative demographics, incidence of postoperative complications, and long-term survival. The 269 patients received the following short-term MCS devices: 57 TandemHeart, 27 Impella, 172 IABP, 12 VA-ECMO, and 1 CentriMag. Survival at 30 days, 6 months, 1 year, and 2 years was 94.2, 87.2, 79.4, and 72.4%, respectively, for CF-LVAD-only patients versus 91.0, 78.1, 73.4, and 65.6%, respectively, for short-term MCS + CF-LVAD patients (P = 0.17). Within the short-term MCS group, survival at 24 months was poorest for patients supported with VA-ECMO or the TandemHeart (P = 0.03 for both), and survival across all four time points was poorest for patients supported with VA-ECMO (P = 0.02). Short-term MCS was not an independent predictor of mortality in multivariate Cox regression models (hazard ratio = 1.12, 95% confidence interval = 0.84-1.49, P = 0.43). In conclusion, we found that using short-term MCS therapy-except for VA-ECMO-as a bridge to long-term CF-LVAD support was not associated with poorer survival.

Acute kidney injury after implantation of a left ventricular assist device: a comparison of axial-flow (HeartMate II) and centrifugal-flow (HeartWare HVAD) devices.

Continuous-flow left ventricular assist devices (CF-LVADs) are increasingly being used to treat advanced, refractory chronic heart failure. Herein, we sought to determine the incidence of postoperative acute kidney injury (AKI) in axial-flow (HeartMate II; HM-II) and centrifugal-flow (HVAD) CF-LVAD recipients, as well as the effect of AKI on mortality. The study cohort comprised 520 patients who received a HM-II (n = 398) or HVAD (n = 122) at our center between November 2003 and March 2016. Their records were reviewed to determine the incidence of RIFLE-defined AKI after LVAD implantation. We compared the perioperative characteristics, postoperative complications, and survival rates of the patients with and without AKI and differentiated the outcomes based on device type (HM-II or HVAD). Seventy-five patients (14.4%) developed AKI postoperatively. Patients with AKI after LVAD implantation had significantly reduced survival compared to patients without AKI (p = 0.01). Cox proportional hazards models showed that AKI was a significant independent predictor of mortality (HR = 1.54, p = 0.03). Preoperative mechanical circulatory support and prolonged cardiopulmonary bypass time were independent predictors of AKI. The incidence of AKI was similar for HM-II and HVAD recipients (p = 0.25). There was no significant difference in AKI rates for the HM-II and HVAD recipients. Developing AKI adversely affected survival.

Left ventricular outflow tract closure during LVAD implantation: 2 cases of patients supported for over 6 years.

We previously reported a series of 5 patients with advanced heart failure and aortic insufficiency (AI) who underwent concomitant left ventricular outflow tract (LVOT) closure at the time of continuous-flow left ventricular assist device (CF-LVAD) implantation. Although this technique of treating AI has been shown to be effective in the short term, its long-term durability has not been well studied. Here, we report the long-term outcomes of two patients with severe AI who underwent LVOT closure at the time of CF-LVAD implantation. Each of the two patients survived for more than 6 years without any complications related to LVOT closure.

Total artificial heart implantation for biventricular failure due to eosinophilic myocarditis.

Idiopathic hypereosinophilic syndrome is a condition of unknown etiology characterized by proliferation of eosinophils and their infiltration into tissues. Although cardiac involvement is rare, eosinophilic myocarditis can lead to life-threating fulminant congestive heart failure. Treatment of patients with eosinophilic myocarditis is challenging as heart failure can be caused by biventricular dysfunction. To our knowledge, this is the first case reported in the literature describing a patient with acute severe biventricular heart failure caused by eosinophilic myocarditis with mural left ventricular apical thrombus who was successfully treated with implantation of a total artificial heart as a bridge to heart transplant.

Safety and Feasibility of Open Chest Epicardial Mapping and Ablation of Ventricular Tachycardia During the Period of Left Ventricular Assist Device Implantation.

INTRODUCTION: Patients undergoing catheter ablation for ventricular tachycardia (VT) may require epicardial mapping. In patients with end-stage heart failure, hybrid surgical epicardial mapping and ablation during the period of left ventricular assist device (LVAD) implantation may be considered in select patients to reduce post-LVAD ventricular tachycardia. METHODS AND RESULTS: From March 2009 to October 2012, 5 patients (4 men and 1 woman, age range 52-73 years) underwent open chest electrophysiology study and epicardial mapping for recurrent ventricular tachycardia while the heart was exposed during the period of LVAD implantation. Epicardial mapping was considered if patients had recurrent VT despite failed prior endocardial ablation and/or electrocardiogram (EKG) features of an epicardial exit. Activation and/or a substrate mapping approach were employed during all procedures. Three of 5 patients (60%) had acute procedural success. In all patients, VT was either eliminated or significantly reduced with epicardial ablation. One patient had mediastinal bleeding delaying sternal closure. During a follow-up period of 363 ± 368 days, 4 patients died due to nonarrhythmic causes. CONCLUSIONS: Open-chest hybrid epicardial mapping and ablation for recurrent VT is feasible and can be considered in select patients during the period of LVAD implantation.

Through the Looking Glass: Real-Time Video Using 'Smart' Technology Provides Enhanced Intraoperative Logistics.

INTRODUCTION: In the setting of increasingly complex medical therapies and limited physician resources, the recent emergence of 'smart' technology offers tremendous potential for improved logistics, efficiency, and communication between medical team members. In an effort to harness these capabilities, we sought to evaluate the utility of this technology in surgical practice through the employment of a wearable camera device during cardiothoracic organ recovery. METHODS: A single procurement surgeon was trained for use of an Explorer Edition Google Glass (Google Inc., Mountain View, CA) during the recovery process. Live video feed of each procedure was securely broadcast to allow for members of the home transplant team to remotely participate in organ assessment. Primary outcomes involved demonstration of technological feasibility and validation of quality assurance through group assessment. RESULTS: The device was employed for the recovery of four organs: a right single lung, a left single lung, and two bilateral lung harvests. Live video of the visualization process was remotely accessed by the home transplant team, and supplemented final verification of organ quality. In each case, the organs were accepted for transplant without disruption of standard procurement protocols. Media files generated during the procedures were stored in a secure drive for future documentation, evaluation, and education purposes without preservation of patient identifiers. CONCLUSIONS: Live video streaming can improve quality assurance measures by allowing off-site members of the transplant team to participate in the final assessment of donor organ quality. While further studies are needed, this project suggests that the application of mobile 'smart' technology offers not just immediate value, but the potential to transform our approach to the practice of medicine.

Fibrosis and heart failure.

The extracellular matrix (ECM) is a living network of proteins that maintains the structural integrity of the myocardium and allows the transmission of electrical and mechanical forces between the myocytes for systole and diastole. During ventricular remodeling, as a result of iterations in the hemodynamic workload, collagen, the main component of the ECM, increases and occupies the areas between the myocytes and the vessels. The resultant fibrosis (reparative fibrosis) is initially a compensatory mechanism and may progress adversely influencing tissue stiffness and ventricular function. Replacement fibrosis appears at sites of previous cardiomyocyte necrosis to preserve the structural integrity of the myocardium, but with the subsequent formation of scar tissue and widespread distribution, it has adverse functional consequences. Continued accumulation of collagen impairs diastolic function and compromises systolic mechanics. Nevertheless, the development of fibrosis is a dynamic process wherein myofibroblasts, the principal cellular elements of fibrosis, are not only metabolically active and capable of the production and upregulation of cytokines but also have contractile properties. During the process of reverse remodeling with left ventricular assist device unloading, cellular, structural, and functional improvements are observed in terminal heart failure patients. With the advent of anti-fibrotic pharmacologic therapies, cellular therapy, and ventricular support devices, fibrosis has become an important therapeutic target in heart failure patients. Herein, we review the current concepts of fibrosis as a main component of ventricular remodeling in heart failure patients. Our aim is to integrate the histopathologic process of fibrosis with the neurohormonal, cytochemical, and molecular changes that lead to ventricular remodeling and its physiologic consequences in patients. The concept of fibrosis as living scar allows us to envision targeting this scar as a means of improving ventricular function in heart failure patients.

HeartMate II left ventricular assist device implantation in patients with advanced hepatic dysfunction.

BACKGROUND: We sought to determine the outcomes for patients with advanced hepatic dysfunction undergoing HeartMate II left ventricular assist device (LVAD) implantation. METHODS: Between November 1, 2003 and December 1, 2012, we implanted the HeartMate II continuous-flow LVAD in 338 patients, either for bridging to heart transplantation or for destination therapy. Twenty-three of these patients (19 men and 4 women; mean age, 47 ± 16 years) had advanced hepatic dysfunction, as characterized by alanine aminotransferase (ALT) or aspartate transaminase (AST) levels five times normal; serum total bilirubin levels three times normal; and/or necessity for a liver biopsy before or during device implantation. Of this group, 17 patients received the LVAD as a bridge to transplantation, and six patients received it for destination therapy. RESULTS: Nine of the 23 patients required either a transjugular or a core liver biopsy during LVAD implantation. Three patients died within the first postoperative month; the 20 surviving patients had significant improvements in their hepatic parameters. The ALT decreased from 238 ± 296 to 27 ± 13 U/L (p = 0.022), AST decreased from 209 ± 199 to 29 ± 8 U/L (p = 0.009), and total bilirubin level decreased from 6.9 ± 6.0 to 0.6 ± 0.1 mg/dL (p = 0.044). The serum albumin level increased from 3.2 ± 0.6 to 4.3 ± 0.3 g/dL (p = 0.003), and creatinine clearance increased from 77.6 ± 35.2 to 110.2 ± 35.7 mL/min/1.73 m2 (p = 0.101). CONCLUSION: Continuous-flow LVAD support may significantly improve hepatic function, allowing patients with poor preimplant liver function to become better candidates for heart transplantation.

Personalized Numerical Cardiovascular Model with Weight Growth for Evaluating Pediatric Left Ventricular Assist Devices: Derivation from an Experimental Mock Circulatory Loop.

Pediatric patients with heart failure have limited treatment options because of a shortage of donor hearts and compatible left ventricular assist devices (LVADs). To address this issue, our group is developing an implantable pediatric LVAD for patients weighing 5-20 kg, capable of accommodating different physiological hemodynamic conditions as patients grow. To evaluate LVAD prototypes across a wide range of conditions, we developed a numerical cardiovascular model, using data from a mock circulatory loop (MCL) and patient-specific elastance functions. The numerical MCL was validated against experimental MCL results, showing good agreement, with differences ranging from 0 to 11%. The numerical model was also tested under left heart failure conditions and showed a worst-case difference of 16%. In an MCL study with a pediatric LVAD, a pediatric dataset was obtained from the experimental MCL and used to tune the numerical MCL. Then, the numerical model simulated LVAD flow by using an HQ curve obtained from the LVAD's impeller. When the numerical MCL was validated against the experimental MCL, hemodynamic differences ranged between 0 and 9%. These findings suggest that the numerical model can replicate various physiological conditions and impeller designs, indicating its potential as a tool for developing and optimizing pediatric LVADs.

Predictors and Impact of Prolonged Vasoplegia After Continuous-Flow Left Ventricular Assist Device Implantation.

Background: Vasoplegia after cardiac surgery is associated with adverse outcomes. However, the clinical effects of vasoplegia and the significance of its duration after continuous-flow left ventricular assist device (CF-LVAD) implantation are less known. Objectives: This study aimed to identify predictors of and outcomes from transient vs prolonged vasoplegia after CF-LVAD implantation. Methods: The study was a retrospective review of consecutive patients who underwent CF-LVAD implantation between January 1, 2005, and December 31, 2017. Vasoplegia was defined as the presence of all of the following: mean arterial pressure ≤65 mm Hg, vasopressor (epinephrine, norepinephrine, vasopressin, or dopamine) use for >6 hours within the first 24 hours postoperatively, cardiac index ≥2.2 L/min/m2 and systemic vascular resistance <800 dyne/s/cm5, and vasodilatory shock not attributable to other causes. Prolonged vasoplegia was defined as that lasting 12 to 24 hours; transient vasoplegia was that lasting 6 to <12 hours. Patient characteristics, outcomes, and risk factors were analyzed. Results: Of the 600 patients who underwent CF-LVAD implantation during the study period, 182 (30.3%) developed vasoplegia. Mean patient age was similar between the vasoplegia and no-vasoplegia groups. Prolonged vasoplegia (n = 78; 13.0%), compared with transient vasoplegia (n = 104; 17.3%), was associated with greater 30-day mortality (16.7% vs 5.8%; P = 0.02). Risk factors for prolonged vasoplegia included preoperative dialysis and elevated body mass index. Conclusions: Compared with vasoplegia overall, prolonged vasoplegia was associated with worse survival after CF-LVAD implantation. Treatment to avoid or minimize progression to prolonged vasoplegia may be warranted.

Use of an intrapericardial, continuous-flow, centrifugal pump in patients awaiting heart transplantation.

BACKGROUND: Contemporary ventricular assist device therapy results in a high rate of successful heart transplantation but is associated with bleeding, infections, and other complications. Further reductions in pump size, centrifugal design, and intrapericardial positioning may reduce complications and improve outcomes. METHODS AND RESULTS: We studied a small, intrapericardially positioned, continuous-flow centrifugal pump in patients requiring an implanted ventricular assist device as a bridge to heart transplantation. The course of investigational pump recipients was compared with that of patients implanted contemporaneously with commercially available devices. The primary outcome, success, was defined as survival on the originally implanted device, transplantation, or explantation for ventricular recovery at 180 days and was evaluated for both noninferiority and superiority. Secondary outcomes included a comparison of survival between groups and functional and quality-of-life outcomes and adverse events in the investigational device group. A total of 140 patients received the investigational pump, and 499 patients received a commercially available pump implanted contemporaneously. Success occurred in 90.7% of investigational pump patients and 90.1% of controls, establishing the noninferiority of the investigational pump (P<0.001; 15% noninferiority margin). At 6 months, median 6-minute walk distance improved by 128.5 m, and both disease-specific and global quality-of-life scores improved significantly. CONCLUSIONS: A small, intrapericardially positioned, continuous-flow, centrifugal pump was noninferior to contemporaneously implanted, commercially available ventricular assist devices. Functional capacity and quality of life improved markedly, and the adverse event profile was favorable. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT00751972.

Fatal cardiac and renal allograft rejection with lenalidomide therapy for light-chain amyloidosis.

We describe a patient who underwent a successful heart and kidney transplant for light-chain amyloidosis. She had an excellent hematologic response to bortezomib/dexamethasone therapy. Follow-up therapy with lenalidomide was started, and the patient quickly had a fatal allograft rejection of the heart and kidney. We present evidence to support the theory that lenalidomide, a known immunomodulator, may have stimulated the immune system and precipitated the fatal rejection episode.

The Evolution of Durable, Implantable Axial-Flow Rotary Blood Pumps.

Left ventricular assist devices (LVADs) are increasingly used to treat patients with end-stage heart failure. Implantable LVADs were initially developed in the 1960s and 1970s. Because of technological constraints, early LVADs had limited durability (eg, membrane or valve failure) and poor biocompatibility (eg, driveline infections and high rates of hemolysis caused by high shear rates). As the technology has improved over the past 50 years, contemporary rotary LVADs have become smaller, more durable, and less likely to result in infection. A better understanding of hemodynamics and end-organ perfusion also has driven research into the enhanced functionality of rotary LVADs. This paper reviews from a historical perspective some of the most influential axial-flow rotary blood pumps to date, from benchtop conception to clinical implementation. The history of mechanical circulatory support devices includes improvements related to the mechanical, anatomical, and physiologic aspects of these devices. In addition, areas for further improvement are discussed, as are important future directions-such as the development of miniature and partial-support LVADs, which are less invasive because of their compact size. The ongoing development and optimization of these pumps may increase long-term LVAD use and promote early intervention in the treatment of patients with heart failure.

Transthoracic echocardiography of the HeartWare left ventricular assist device.

BACKGROUND: The unique findings on transthoracic echocardiography of the HeartWare left ventricular assist device (LVAD) have not been previously described. METHODS AND RESULTS: HeartWare LVADs were implanted in 19 patients from May 2009 through December 2010; 152 comprehensive transthoracic echocardiograms (TTEs) performed postoperatively on these patients were retrospectively analyzed for device component visualization, inlet cannula/outflow conduit flow velocities, and imaging artifacts. The inlet cannula was adequately visualized in 66% of studies, incompletely visualized in 14%, and not visualized in 20%. Spectral Doppler interrogation of inlet cannula flow velocity was always uninterpretable due to artifact. Standard parasternal long-axis and apical views always included the inlet cannula in the imaging sector, resulting in a prominent "waterfall" color Doppler artifact obscuring the mitral valve. Inclusion of the inlet cannula in the imaging sector also precluded spectral Doppler interrogation of the mitral valve owing to artifact. The outflow conduit was partially visualized and interrogated by spectral Doppler in 68% of studies, and the average measured peak flow velocity was 1.4 m/s (range 1.0-1.9 m/s). CONCLUSIONS: The HeartWare LVAD inlet cannula and outflow conduit are both readily visualized by TTE in a majority of patients. However, significant color and spectral Doppler artifacts occur when the inlet cannula is visualized in the imaging sector, necessitating routine off-axis Doppler interrogation of the mitral valve.