Use Of Ventricular Assist Devices Research Articles

Outcomes in Patients With Symptomatic Cerebrovascular Disease Undergoing Heart Transplantation

We sought to determine outcomes in patients with and without symptomatic cerebrovascular disease (sCVD) undergoing heart transplantation. Second, we sought to determine factors associated with stroke in the perioperative period after heart transplantation. sCVD is considered a relative contraindication to heart transplantation. Despite this concern, outcomes in patients with sCVD undergoing heart transplantation have not been well defined. Data on all single-organ heart transplants performed in the United States between April 1994 and December 2006 in patients age 40 years or older were analyzed. Survival analysis was performed to examine the effect of sCVD on the combined outcome of stroke or death, stroke, death, and functional decline, adjusting for potential confounding variables over long-term follow-up. In a separate analysis, predictors of perioperative stroke during the transplant-related hospitalization were examined using multiple logistic regression. There were 1,078 patients with and 16,765 patients without sCVD. The annualized rates of stroke or death (11.5% vs. 7.8%; p < 0.001), stroke (4% vs. 1.4%; p < 0.001), death (8.9% vs. 7.4%; p < 0.001), and functional decline (3.7% vs. 3.0%; p = 0.002) were higher in patients with sCVD than in patients without sCVD. In multivariable analysis, patients with sCVD were at increased risk of stroke or death (hazard ratio [HR]: 1.29; 95% confidence interval [CI]: 1.17 to 1.42), stroke (HR: 2.24; 95% CI: 2.02 to 2.87), and functional decline (HR: 1.21; 95% CI: 1.03 to 1.42) compared with those without sCVD. We did not identify a higher risk of death in patients with sCVD (HR: 1.08; 95% CI: 0.98 to 1.20), compared with those without sCVD. sCVD, ventilator use, and ventricular assist device use were the most important predictors of perioperative stroke. Patients with sCVD are at an increased risk of stroke and functional decline after transplantation independent of other variables, but not death, during long-term follow-up. These results should assist programs in making informed decisions in patients with sCVD who are undergoing evaluation for heart transplantation.

Ethical Considerations for Ventricular Assist Device Support: A 10-Point Model

The potential for long-term support on a ventricular assist device (VAD) in the bridge-to-transplant (BTT) and destination therapy (DT) settings has created unprecedented ethical challenges for patients and caregivers. Concerns include the patient's adaptation to life on a device and the ethical, clinical, and practical issues associated with living on mechanical support. On the basis of our experience treating 175 consecutive VAD patients, we have developed a model to address the ethical and psychosocial needs of patients undergoing VAD implantation. Patient preparation for VAD implantation encompasses three phases: 1) initial information regarding the physical events involved in implantation, risks and benefits of current device technology, and the use of VAD as a rescue device; 2) preimplant preparation including completion of advance directives specific to BTT/DT, competency determination, and identifying a patient spokesperson, multidisciplinary consultants, and cultural preferences regarding device withdrawal; and 3) VAD-specific end-of-life issues including plans for device replacement and palliative care with hospice or device withdrawal. This three-phase 10-point model addresses the ethical and psychosocial issues that should be discussed with patients undergoing VAD support.

Primary Immunosuppression and Outcome Differences After Heart Transplantation: Tacrolimus Versus Cyclosporine

BackgroundThe superiority of tacrolimus (Tac) as primary immunosuppression for heart transplantation (HT) compared with cyclosporine (CsA) is still under debate. Outcomes of comparison studies are not consistent; the duration of these studies has been limited. The aim of this study was to evaluate long-term outcomes of patients undergoing HT based on primary immunosuppression regime. Methods and ResultsWe analyzed a single-center registry of all HT patients between 1998 and 2009, comparing outcomes based on primary immunosuppressions (Tac or CsA). Patients who died before starting immunosuppression were excluded. A total of 197 patients entered the study; 103 received Tac and 94 CsA. There were no differences between groups in baseline characteristics, United Network for Organ Sharing status 1A or ventricular assist device use, except for ischemia time (195 ± 50 min in Tac group vs 182 ± 55 min in CsA; P = .08) and days on waiting list (164 ± 155 vs 100 ± 73; P < .001). After mean follow-ups of 4.5 ± 2.3 years in the Tac group and 6.3 ± 4.3 years in the CsA group, there were 19 and 36 deaths, respectively. Kaplan-Meier analysis showed increased survival for the Tac group (log rank P = .04). Tac also was significantly superior to CsA regarding mortality (relative risk 0.55; 95% confidence interval, 0.31–0.98; P = .04). ConclusionsIn our series the use of tacrolimus resulted in improved long-term survival compared with cyclosporine. At 1-year follow-up, there were no differences in acute rejection episodes or the appearance of vasculopathy.

Use of Ventricular Assist Devices in Patients with Mitral Valve Prostheses

Use of ventricular assist devices (VADs) in patients with prosthetic valves may carry an increased risk of thromboembolism; however, clinical information is lacking. The aim of this study was to report our experience of the use of VADs in patients with prosthetic mitral valves. A retrospective analysis of 747 VAD patients from January 1995 to May 2010 was performed. Thirteen patients with a prosthetic mitral valve (average age 56 ± 10 years of age, nine mechanical valve, four biological valve) were identified. Indications for VAD implantation were as a bridge to transplant in 11 patients and destination therapy in two patients. At the time of VAD implant, no intervention to the prosthetic mitral valve was performed. Eight patients received a HeartMate I (Thoratec Corporation, Pleasanton, CA, USA), three patients received a HeartMate II (Thoratec Corporation), and two patients received a Thoratec VAD (Thoratec Corporation). Among nine mechanical valve patients, six patients were anticoagulated with warfarin, and one patient with heparin, while two patients did not receive anticoagulation due to bleeding. Ten patients were successfully transplanted at an average of 123 days post-VAD implant, one died after 48 days from multiorgan failure, and two remained on VAD support. No clinical thromboembolic events were observed. No intracardiac thrombus was detected by echocardiogram or on the pathology of the explanted hearts. Five patients had experienced a bleeding event (postoperative mediastinal bleeds, gastrointestinal bleedings, retroperitoneal hematoma, and subconjuctival bleeding). In patients with mitral valve prostheses who require VAD support, leaving the prosthesis intact does not increase the incidence of adverse events.

635 Use of Long-Term Ventricular Assist Devices in Bridging to Heart Transplantation – A UK National Survey

Use of Long-Term Ventricular Assist Devices in Bridging to Heart Transplantation – A UK National Survey A. Emin, C.A. Rogers, H.L. Thomas, S. Tsui, G. MacGowan, J. Parameshwar, N.R. Banner. on behalf of the UK VAD Forum and UK Cardiothoracic Transplant Steering Group, Clinical Effectiveness Unit, The Royal College of Surgeons of England, London, United Kingdom; Cardiopulmonary Transplantation, Harefield Hospital, Middlesex, United Kingdom; Statistics and Clinical Audit, NHS Blood and Transplant, Bristol, United Kingdom; Cardiopulmonary Transplantation, Papworth Hospital, Papworth Everard, Cambridgeshire, United Kingdom; Cardiopulmonary Transplantation, Freeman Hospital, Newcastle, United Kingdom.

Mechanical bridging to orthotopic heart transplantation in children weighing less than 10kg: feasibility and limitations

Infants and young children are considered the most difficult group to bridge to orthotopic heart transplantation (OHT) and data regarding outcomes are scarce. We reviewed our patients ≤ 10 kg with those who were bridged to OHT using ventricular assist device (VAD) Berlin Heart (BH) Excor ± extracorporeal membrane oxygenation (ECMO) between 2004 and 2009. Eleven children ≤ 10 kg with end-stage heart failure (cardiomyopathy or myocarditis) were treated with VAD as bridge to OHT: the median weight was 8.0 (range 3.9-10.0 kg)kg and median age was 12.3 (range 1.2-33.9 months) months. Five (45%) required ECMO support pre-BH and six were on mechanical ventilation and inotropes. In 9/11 (82%), the support mode was left ventricular assist device (L-VAD) (all alive): one of two patients needing Bi-VAD support died. On BH, the median support time was 27 days and time to extubation was 8 days. Two out of 11 (18%) suffered strokes confirmed on brain imaging; both recovered and one underwent resection of infarcted small bowel. Ten out of 11 (91%) were transplanted, one remains in hospital and nine are at home in good health. When compared to patients >10 kg bridged with BH (n = 15), the mortality (p = 0.51) and rates of neurological complications (p = 0.54) were similar. Post-transplant recovery (ventilation times and time to home discharge) was similar between the bridged children ≤ 10 kg and non-bridged children ≤ 10 kg who underwent OHT. Mechanical bridging to transplantation is clinically feasible in children ≤ 10 kg, achieving excellent outcomes. Judicious use of VADs in smaller children will optimise the use of donor organs; however, the effect on overall OHT waiting times, if mechanical bridging was extended to a large number of small children, is unknown.

Extracorporeal membranous oxygenation support for acute fulminant myocarditis: analysis of a single center's experience☆

Acute fulminant myocarditis (AFM) is a disease category that is easily neglected. Circulatory mechanical support is sometimes required for this devastating condition. We analyzed our experience in managing AFM with mechanical circulatory support. We applied extracorporeal membrane oxygenation (ECMO) as a first-line rescue for AFM. The diagnosis was mainly derived from clinical results and biopsy. Seventy-five patients were enrolled in the age range of 29.6 ± 18.6 years and the pediatric group (< 18 years) comprised 32% (n = 24) of our patient group. Thirty-five patients (47%) underwent cardiopulmonary resuscitation (CPR) before ECMO. The indication for ECMO included high inotropic support 69% (n = 54) and continuous CPR at ECMO setup 31% (n = 23). The ECMO duration was 171 ± 121 h. Survival to discharge was 64% (n = 48), 61% in adult group, and 70.8% in pediatric group. Six patients were later bridged to ventricular assist device use (5 left ventricular assist device (LVAD) and 1 bi-ventricular assist device (BVAD)) but three died of multiple-organ failure. Three patients (4%) underwent heart transplantation and all of them survived to discharge. Resuscitation did not have a significant factor for survival. Only two patients (3%) developed late mortality due to a cardiac event. AFM still carries high mortality rates in spite of advanced mechanical support. Most of the survivors did not require transplantation and could return to good lifestyle. Due to its simplicity and effectiveness, ECMO can be a first-line tool to rescue this group of patients.

Percutaneous ventricular assist devices: new deus ex machina?

The development of ventricular assist devices has broadened the means with which one can treat acute heart failure. Percutaneous ventricular assist devices (pVAD) have risen from recent technological advances. They are smaller, easier, and faster to implant, all important qualities in the setting of acute heart failure. The present paper briefly describes the functioning and assets of the most common devices used today. It gives an overview of the current evidence and indications for left ventricular assist device use in cardiogenic shock and high-risk percutaneous coronary intervention. Finally, extracorporeal life support devices are dealt with in the setting of hemodynamic support.

Nonsurround, nonuniform, biventricular-capable direct cardiac compression provides Frank-Starling recruitment independent of left ventricular septal damage

Right ventricular (RV) function is compromised in 25% of left ventricular (LV) assist device recipients despite effective LV support. The risk of such dysfunction has been enhanced by an ischemic or undamaged interventricular septum; however, we found septal infarction to be paradoxically protective. We, therefore, evaluated the potential of nonsurround, nonuniform, biventricular-capable direct cardiac compression (DCC) (using the HeartPatch DCC) to overcome RV dysfunction in hearts with a normal or infarcted interventricular septum. Ethanol ablation was used to create an interventricular septal infarction in 6 sheep, and 6 others served as the control sheep. The load-independent and in-series RV response to DCC was assessed using sonomicrometer heart dimension sensors. Triphenyltetrazolium perfusion delineated the septal damage. LV DCC caused a greater increase of the RV preload recruitable stroke work in the control sheep than in the study sheep (190.6 ± 23.5 and 135.0 ± 40.8 erg*10^3, respectively, P < .001). In contrast, RV end-systolic elastance increased more in the septal-ablated sheep with RV DCC (17.29 ± 3.40 vs 9.88 ± 2.01 mm Hg/mL in the control sheep, P < .001). Abnormal RV diastolic function before device insertion in the septal-ablated sheep was normalized with both passive DCC placement and after activation (RV diastolic relaxation constant 23.5 ± 2.3 and 20.0 ± 2.1 ms, respectively, P < .001). Both biventricular and RV DCC actuation increased the RV systolic pressure more in the septal-ablated sheep than in the control sheep (37.9 ± 6.3 and 47.7 ± 4.6 mm Hg vs 29.7% ± 4.8% and 40.3% ± 8.3%, respectively, P < .001). In contrast, the RV end-systolic diameter decreased more during LV DCC (70.1% ± 15.9% vs 90.5% ± 5.0%, P < .001). The HeartPatch DCC support of LV and RV function results from improvement of the systolic septal-lateral fractional change that is not influenced by septal infarction. The latter attenuated LV to RV device energy delivery during LV patch actuation but enhanced RV energy delivery during RV patch actuation. This DCC technique can provide effective support in high-risk RV failure situations arising from left ventricular assist device use.

Ventricular Tachycardia in the Era of Ventricular Assist Devices

Sustained ventricular tachycardia (VT) in patients with advanced cardiomyopathy is a potentially life-threatening arrhythmia. Newer treatment strategies have evolved that combine the use of catheter ablation to target the substrate for VT and ventricular assist devices (VADs) to hemodynamically support the failing ventricle. This editorial is targeted to the practicing clinician caring for these difficult patients. The current article reviews the use of percutaneous VADs to support catheter ablation of VT, the use of durable VADs to support the failing heart in patients with recurrent VT, ventricular arrhythmias in patients with durable VADs, and the use of catheter ablation to treat VT in patients with durable VADs.

Adult candidates for heart transplantation with larger body surface area have better prognosis on waiting list after progression to critically ill status

Smaller body size is one of the characteristics of female patients. We analyzed whether lower body surface area (BSA) of adult patients affects their prognosis after listing for heart transplantation (HTx). Adult candidates (≥ 18 and <65 years) for de novo HTx in our center, who were newly listed as T (transplantable) by Eurotransplant without ventricular assist device (VAD) support between 2000 and 2009 (n = 545), were studied. The patients were divided into two groups: group S (n = 272): BSA<1.9563 m(2) (median value of total patients) and group L (n = 273): BSA ≥ 1.9563 m(2). Most female patients (82/84, 97.6%) belong to group S. Among all these patients, 286 progressed to critically ill status, that is, they were listed in urgent status or received a VAD. Actuarial survival rates were studied in each group. Overall survival rates after listing for HTx in group S were comparable to those in group L (43.0% vs 43.7% for 7-year survival, p=0.95). However, 1-year survival rate on waiting list after progression to critically ill status in group S (58.0%, n = 135) and that of female patients in group S (55.8%, n = 33) were significantly lower than those in group L (67.3%, n = 151, all were men; p = 0.042 and p = 0.044, respectively). After multivariate Cox analysis, BSA<1.9563 m(2) (hazard ratio 2.120, p = 0.0019), serum creatinine (hazard ratio 1.202, p = 0.033), obesity defined as body mass index ≥ 30 kg m(-2) (hazard ratio 2.043, p = 0.0096) and primary use of VAD (hazard ratio 3.243, p < 0.0001) were identified as independent risk factors for mortality on waiting list after progression to critically ill status. One-year survival rate on waiting list after VAD implantation in group S (44.4%, n = 65) and that of female patients in group S (38.1%, n = 14) were significantly lower than those in group L (63.0%, n = 78, all were men; p = 0.020 and p = 0.012, respectively). Adult HTx candidates with lower BSA, including most women, had worse prognosis on waiting list after progression to critically ill status, especially after VAD implantation. As almost all HTx are nowadays performed in critical status, this problem has emerged as important.

Outcomes of ventricular assist device support in young patients with small body surface area

Although the ventricular assist device (VAD) has been a well-established therapy for larger adolescents and adult patients with advanced heart failure, current experience with the use of VAD for mechanical circulatory support in infants and young children with small body surface area is still limited. Between January 1999 and December 2009, 56 small children with body surface area<1.2 m² were implanted with Berlin Heart EXCOR pediatric VAD in Germany Heart Institute Berlin. The etiology of end-stage myocardial failure included non-congenital (75%) and congenital heart disease (25%); the median age at implant was 1 year (12 days to 14 years), and the median support time was 55 days (1-432 days). Of the 56 pediatric patients, 24 were bridged to heart transplantation, 12 were explanted following myocardial recovery, two continued to receive support, and the other 18 died on support. The accurate rate of survival on VAD support was 81.1% ± 5.8% and 51.4% ± 9.3% at 30 days and 1 year after EXCOR implantation. Patients receiving biventricular support had a trend towards higher post-implantation mortality as compared with children implanted with left ventricular assist device (LVAD) (P = 0.09). Lower post-implantation survival was also observed in patients with congenital cardiac disease compared with children with a non-congenital etiology (P < 0.001). Berlin Heart EXCOR pediatric VAD could provide satisfactory and safe circulatory support for small children with end-stage heart disease.

Use of Ventricular Assist Devices in Children Across the United States: Analysis of 7.5 Million Pediatric Hospitalizations

Recently, there has been a surge of interest by clinicians, industry, and the government in the development and use of ventricular assist devices (VAD) in children. Despite this rapidly expanding interest, the incidence of VAD use in children across the United States is unknown. The Healthcare Cost and Utilization Project (H-CUP) Kids' Inpatients Database (KID) was analyzed to characterize the current utilization of VADs in children nationwide. The most recent HCUP-KID (2006) was analyzed (n = 7.5 million). This database is a nationwide sampling of hospital discharges of patients less than 20 years old weighted to provide national estimates. In 2006, 187 children had a VAD implanted in the United States. Mean age was 13 ± 7 years. Forty patients (21%) were bridged to VAD by extracorporeal membrane oxygenation. Forty-nine patients (26%) were bridged to heart transplant. Fifty-six patients (30%) died in hospital. Eighty-six patients (46%) were discharged or transferred. Length of stay was 29 days (range, 0 to 285). Total cost was $174,743 (range, $4,230 to $1,911,588). Sixty-seven hospitals placed VADs; 66% of VADs (124) were implanted at large teaching hospitals (more than 500 beds), and 46% (85) were at high-volume hospitals (more than 5 VADs per year). High-volume, large teaching hospitals (10) had better survival (89% versus 61%; p < 0.001) and lower hospital cost ($236,000 ± $184,000 versus $300,000 ± $355,000; p = 0.002) compared with all other hospitals. On multivariate analysis, acute renal failure and extracorporeal membrane oxygenation were risk factors for mortality, whereas transplant and being at a high-volume large teaching hospital were protective factors from death. Preliminary data suggest that the growing use of VADs in children may be better served in regard to resource utilization and outcomes if centralized to high-volume large teaching hospitals.

Current Use of the EXCOR Pediatric Ventricular Assist Device

Since its initial application in the pediatric patient population, the Berlin Heart EXCOR ventricular assist device has become a widely accepted form of mechanical circulatory support in Europe and the USA. The versatility of the device makes it ideal for pediatric patients because it can be tailored to the size and needs of the patient. In this review, we will explore the broad range of clinical applications of this device including bridge to cardiac transplantation, bridge to recovery, and bridge to bridge implantation where the need for cardiac transplantation may be unclear but long-term mechanical support may be required.

Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS)-Defined Morbidity and Mortality Associated With Pediatric Ventricular Assist Device Support at a Single US Center

The use of ventricular assist devices (VADs) to bridge pediatric patients to heart transplantation has increased dramatically over the last 15 years. In this report, we present the largest US single-center report of pediatric VAD use to date. We present detailed descriptions of morbidity and mortality associated with VAD support, using standard Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) criteria for pediatrics to facilitate the comparison of these results to other studies. We retrospectively identified 25 patients younger than 18 years with 27 episodes of mechanical circulatory support using VADs as bridge to heart transplantation from January 1998 to December 2007. Survival to transplant for the entire cohort was 74%. The most common major morbidities, as defined by INTERMACS criteria for a pediatric population, were respiratory failure, major localized infections, major bleeding events, hepatic dysfunction, and right heart failure. Major neurological events occurred in 48% of the study population. The median time to the first occurrence of an adverse event was less than 14 days for respiratory failure, right heart failure, major localized infection, and major bleeding. Patients who died before transplantation had significantly more adverse events per day of support than did those who were successfully transplanted. Episodes of major bleeding, tamponade, acute renal failure, respiratory failure, and right heart failure were all associated with increased risk of mortality. INTERMACS criteria can be successfully used to analyze pediatric VAD outcomes. These data serve as a baseline for future studies of VAD support in children and indicate good survival rates but considerable morbidity.

Use of the AB5000™ Ventricular Assist Device in Cardiogenic Shock After Acute Myocardial Infarction

The mortality rate of patients experiencing acute myocardial infarction (AMI) complicated by cardiogenic shock remains high. After conventional therapies have failed, ventricular assist devices (VADs) have been used to bridge patients to recovery or transplantation. A voluntary US registry was established to track all patients implanted with the AB5000 VAD. We report the results of the first 100 patients in the registry with the indication of AMI cardiogenic shock. Data were retrospectively reviewed for demographics, preimplant condition, surgical techniques, and outcomes. Survival was assessed at 30 days after VAD explant or at discharge. Myocardial recovery (subset of survival) was defined as satisfactory unassisted native cardiac function for 30 days after VAD explant or at discharge. Forty patients (40%) survived to 30 days after VAD explant or discharge of the first 100 patients. Of the survivors, 63% (n = 25) experienced myocardial recovery. Patients who recovered required an average of 25 +/- 22 days of VAD support. The estimated survival after explant for the recovery patients at 2 years after VAD explant was 78%. Results from this nationwide registry suggest that VADs can restore normal hemodynamics and support recovery of native cardiac function in the majority of survivors when conventional therapies fail. However, a longer duration of support than previously recognized may be required. In the absence of clinical guidelines, early aggressive use of VAD support in AMI complicated by cardiogenic shock may improve outcomes, and recovery of native cardiac function should always be the primary goal.

Predictors for the Use of Left Ventricular Assist Devices in Infants With Anomalous Left Coronary Artery From the Pulmonary Artery

Left ventricular (LV) mechanical circulatory support (MCS) may be necessary after repair of anomalous left coronary artery from the pulmonary artery. We evaluated LV function parameters for their ability to predict postoperative need for MCS. Fourteen infants (median age, 3.6; range, 2.3 to 12 months) underwent direct aortic reimplantation of the left coronary artery. We compared preoperative LV end-diastolic diameter, end-diastolic pressure, ejection fraction, and fraction of shortening of 8 patients with successful weaning from cardiopulmonary bypass (group 1) and 6 patients with unsuccessful weaning from cardiopulmonary bypass and temporary MCS support (group 2). No perioperative or late deaths occurred. All patients at follow-up were free of reoperation (median follow-up, 10.4 years [range, 1.4 to 17 years]). Median preoperative LV end-diastolic diameter (47 [range, 41 to 60 mm] vs 32 mm [range, 21 to 36 mm]) and LV end-diastolic pressure (20 [range, 18 to 25 mm Hg] vs 12 mm Hg [range, 7 to 20 mm Hg]) were significantly higher in group 2 than in group 1 (p = 0.002 and p = 0.048). LV ejection fraction (0.28 [range, 0.19 to 0.37] vs 0.43 [range, 0.23 to 0.76]) and LV fraction of shortening (9% [range, 7% to 15%] vs 22% [range 13% to 30%]) were significantly lower in group 2 than in group 1 (p = 0.035 and p = 0.002). MCS support duration ranged from 4 to 12 days. There were no significant differences in LV function parameters at discharge or during follow-up between the groups. A preoperative LV end-diastolic diameter above 40 mm is the strongest predictor for postoperative temporary MCS after anomalous left coronary artery from the pulmonary artery repair in infancy. However, even with temporary MCS, direct aortic reimplantation for anomalous left coronary artery from the pulmonary artery can be performed with no mortality and excellent LV recovery.

Biomechanics of the Aortic Valve in the Continuous Flow VAD-Assisted Heart

The biomechanics of the aortic valve are altered in patients with ventricular assist devices (VADs). During high VAD flow and low cardiac function, transvalvular pressure is high, and the aortic valve remains closed throughout the cardiac cycle. This condition has been linked to the development of aortic valve fusion and incompetence during VAD use. Thus, physicians try to maintain pulsatile flow to assure periodic valve opening. The aim of this study was to determine the extent of aortic valve opening and alterations in valve leaflet strain before and during VAD support using a specially designed mock loop. The results showed that diastole is prolonged during VAD use. In addition, there is a reduction in valve opening area, producing a VAD-related functional stenosis. The average leaflet strain increased during VAD support, primarily due to an increase in the minimum strain, during systole, rather than the maximum strain during diastole. The findings support our hypothesis that altered biomechanics in the VAD-assisted heart results in increased strain in the aortic valve leaflets, which can stimulate soft tissue remodeling. The implication for clinical use is that valve opening during parallel VAD flow is reduced compared with normal flow conditions. Consequently, current clinical practice for VAD patients may not be achieving sufficient valve opening to prevent changes such as fusion and incompetence.

Left Ventricular Assist Devices and Other Devices for End-Stage Heart Failure: Utility of Echocardiography

The burgeoning ranks of patients with heart failure, the limited number of organs available for heart transplant, and technological improvements have made ventricular assist devices (VADs) important therapeutic options for patients with acute and chronic cardiac decompensation. The increased use of VADs is paralleled by an increased use of transthoracic and transesophageal echocardiography to 1) assist in the selection of patients for VAD therapy and VADs to meet patient needs; 2) identify important anatomic considerations prior to implant; 3) guide placement of VADs; 4) diagnose the etiology of VAD dysfunction; and 5) guide the weaning from VAD support and the optimization of VAD device settings. This review discusses types of VADs and the uses of echocardiography in the care of VAD patients.

Contemporary Use of Ventricular Assist Devices

The introduction of the heart lung machine more than 50 years ago proved in principle that heart function can be replaced, albeit for short periods. This was followed by attempts to produce total or partial artificial hearts that could function for prolonged periods of time. Progress in this field has been intermittent but has accelerated considerably in the past 10 years, with ventricular assist devices (VADs) reaching an impressive degree of sophistication and complexity owing to the contributions from clinicians, engineers, scientists, industrialists, and others. This review describes the currently available types of VADs, their current clinical use, the patient selection process, the trend toward use of VADs in patients with less severe heart failure, and the use of VADs for myocardial recovery in combination with novel pharmacological strategies, gene therapy, and cell therapy.