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OptiVol (Medtronic PLC, Minneapolis, MN) is a diagnostic feature of some cardiac implantable electronic devices (CIEDs) based on changes in thoracic impedance (TI) over time. Changes in TI can predict heart failure (HF) hospitalizations and mortality in HF populations. However, the utility of this feature is unknown in patients with a left ventricular assist device (LVAD). To determine if OptiVol and TI correlate with clinical HF events in a population of LVAD patients, hospitalization outcomes were collected retrospectively from the electronic health records at a single academic medical center in 80 LVAD patients with an OptiVol-capable CIED. Demographics, medical history, and available clinical data were reviewed and reported. The primary outcomes of interest were TI and OptiVol trends before and after hospitalization, and association of trends before and after these events was evaluated. Most patients had a HeartMate II LVAD and most CIEDs were defibrillators, and 23 (29%) had at least one HF hospitalization during the study period. HF hospitalizations were preceded by signs of volume overload in Optivol (60%) and TI (78%) with recovery of these measures post hospitalization in 33% and 25% of patients, respectively. Monitoring of TI and OptiVol may be one effective component of HF management in LVAD patients as part of a comprehensive program.

We observed different temporal patterns of HeartMate II left ventricular assist device (LVAD) thrombosis regarding clinical manifestations and lactate dehydrogenase (LDH) trends. We propose nomenclature for classification of LVAD thrombosis and compare patient characteristics and outcomes in each pattern of LVAD thrombosis. We reviewed electronic medical records of 362 consecutive HeartMate II devices implanted at Cleveland Clinic from October 2008 to July 2014. We categorized clinical courses of confirmed device thrombosis based on clinical manifestations and LDH patterns. Patients' characteristics, clinical variables, and outcomes were collected for comparison. From a total of 19 confirmed device thromboses, we categorized the patterns of thrombosis into three distinctive types; abrupt thrombosis (Type 1), subacute thrombosis (Type 2), and asymptomatic hemolysis (Type 3). Abrupt thrombosis (Type 1) tended to be the most morbid clinical course with acute-onset thrombosis at 56.5 (interquartile range: 44-71) days, all New York Heart Association functional class III or IV at presentation. Death and need for surgical intervention were not different in each pattern. Asymptomatic hemolysis had unique comorbidities of preexisting cardiac thrombi and preoperative bacteremia. Confirmed LVAD thrombosis has different patterns of clinical presentation and each pattern of thrombosis has unique characteristics and clinical manifestations.

Mechanical unloading with left ventricular assist device (LVAD) support can lead to clinically meaningful reversal of stress-related compensatory mechanisms. However, true assessment of left ventricular ejection fraction (LVEF) is not possible, whereas the left ventricle is unloaded by LVAD therapy making identification of patients with myocardial recovery even more challenging. We introduce our new protocol, the "reverse ramp test" for HeartWare HVAD, HeartMate II, and HeartMate 3. The reverse ramp is transthoracic echo (TTE) and right heart catheterization (RHC)-based protocol with LVAD turn down steps to minimal support allowing for a more accurate assessment of myocardial function.

Strokes remain a leading cause of morbidity and mortality in patients with ventricular assist devices (VADs). Varying study populations, event definitions, and reporting methods make direct comparison of neurologic event risk across clinical trials and registries challenging. We aim to highlight important differences among major VAD studies and standardize rates of neurologic events to facilitate a comprehensive and objective comparison. We systematically identified and analyzed key clinical trials and registries evaluating the HeartMate II (HMII), HeartMate 3 (HM3), and HVAD devices. Reported neurologic events were nonexclusively categorized into ischemic stroke, hemorrhagic stroke, disabling stroke, fatal stroke, and other neurologic events per the studies' definitions. Event rates were standardized to events per patient-year (EPPY) and freedom from event formats. Seven key clinical trials and registries were included in our analysis. There is significant variation and overlap in neurologic event rates for the three VAD platforms across clinical trials (all neurologic events [EPPY]: HM3 0.17-0.21; HMII 0.19-0.26; HVAD 0.16-0.28). None performs consistently better for all types of neurologic events. Furthermore, stroke rates among VAD trials correlated with baseline stroke risk factors including ischemic etiology, history of atrial fibrillation, and history of prior stroke.

The effect of blood group on heart transplant list mortality in the era of continuous flow left ventricular assist devices (VADs) is unknown. We sought to examine mortality from the United Network for Organ Sharing (UNOS) database, with focus on mortality among VAD versus non-VAD recipients according to blood group. The UNOS database from 2007 to 2015 was evaluated to compare the rates of waitlist mortality or delisting for clinical worsening at 1-year postlisting among various blood types based on the presence or absence of durable continuous VAD. Patients with pulsatile VAD, temporary VAD, or with incomplete data were excluded. A total of 16,803 patients met the inclusion criteria. Of these, 2,663 had a HeartMate II or HeartWare VAD implanted before listing or by 365th day of listing. The rate of adverse events on the waitlist, irrespective of VAD, was highest among group O patients (odds ratio [OR] 1.54, p < 0.001). The use of VAD was associated with significant relative risk reduction (OR 0.43, p < 0.001) in waitlist adverse events among all patients, with relative risk reduction that overall did not vary by blood group. Among VAD recipients, waitlist adverse events were similar across all blood types. Among listed patients, there is a significantly higher adverse event rate in group O patients compared with others, irrespective of VAD use. With implantation of continuous flow HeartMate II or HeartWare VAD, all blood groups experience similar relative benefit and similar rates of adverse events. All patients, but particularly those with blood group O, eligible for VAD as a bridge to transplant should be considered for VAD placement.

Left ventricular assist devices (LVADs) increase survival of patients with heart failure. However, long-term LVAD usage can result in aortic insufficiency (AI), thereby compromising LVAD efficiency. Transcatheter aortic valve replacement (TAVR) is an alternative for patients with high risk for surgical valve replacement. We present three cases that developed moderate to severe AI while on HeartMate II (Abbott Laboratories, Chicago, IL) LVAD support; hence, TAVR procedure was performed. Patients A and B (74 year old and 38 year old) developed severe AI and patient C (67 year old) developed moderate AI with cardiogenic shock, after 368, 1,288, and 342 days on LVAD support, respectively. Their aortic valve annulus sizes were 24.2, 24.6, and 23.3 mm, respectively. Oversized Edwards SAPIEN 3 valves (Edwards, Lifesciences, Irvine, CA) were implanted via a transfemoral approach. The patients were hemodynamically stable after the procedure with mild AI in patient A and no AI in patients B and C. Patients were all discharged to home. Follow-up in patients A and C have resulted in long-term (> 2 years) survival and patient B died 616 days after the procedure due to unrelated complications. Transcatheter aortic valve replacement may be an alternative way to manage AI in LVAD patients. Larger studies are needed to evaluate the long-term efficacy of this approach.

Gastrointestinal bleeding occurs in 20-30% of patients receiving ventricular assist devices (VADs) due, in part, to acquired von Willebrand syndrome. We examined factors to optimize a benchtop method to quantify changes in von Willebrand Factor (VWF) multimer distribution and function in VADs, then applied them to evaluate commercially available devices. Human plasma was circulated through flow loops with VADs. Several experimental conditions were examined, including temperature, viscosity, and enzyme inhibition. Samples were analyzed for VWF collagen-binding activity (VWF:CB) and VWF antigen level. von Willebrand Factor multimer profiles were quantified using gel electrophoresis, near-infrared in-gel visualization, and densitometric analysis. The VWF:CB/antigen ratio in the HeartMate II, CentriMag, and HVAD exhibited average decreases of 46%, 44%, and 36% from baseline after 360 minutes of operation. High molecular weight (hVWF) multimer loss occurred within 30 minutes, although the Levacor and control loop profiles were unchanged. Varying temperature and viscosity altered hVWF degradation rate, but not the final results. Inhibition of a disintegrin and metalloprotease with thrombospondin type 1 repeats, member 13 (ADAMTS13) can potentially distinguish mechanoenzymatic cleavage of VWF from mechanical degradation. We developed a repeatable benchtop method to evaluate VWF compatibility of VADs similar to hemolysis testing that can be adopted for preclinical VAD evaluation.

Introduction: Prior studies have shown that females have worse 3-month survival post-LVAD. Currently used prognostic scores including the Heartmate II Risk Score (HMRS), were developed in >75% male cohorts, and may not account for the increased residual risk in females. Hypothesis: A sex-specific risk score will predict post-LVAD mortality in females, and perform better than HMRS. Methods: Adult CF-LVAD patients from the ISHLT Mechanically Assisted Circulatory Support (IMACS) registry (Implant years: Jan 2013 - Sep 2017, age: 56 ± 13 yrs, 21% female, 36% centrifugal pumps) were randomly divided into derivation (DC, n=9113, 21% female) and validation cohorts (VC, n=6074, 21% female). Primary outcome of interest was 3-month mortality. IMACS risk score (IMACS-RS) was developed in the DC, from pre-operative candidate predictors selected using Akaike Information Criterion, or significant sex*variable interaction. Results: There were 1,466 deaths (9.7%) within 3 months after implant. In the DC, age, cardiogenic shock at implant, Body Mass Index, Blood Urea Nitrogen, bilirubin, hemoglobin, albumin, platelet count, LV End Diastolic Diameter, Tricuspid Regurgitation, dialysis and major infection pre-implant were retained as significant predictors of 3-month mortality. There was a significant ischemic HF*sex and platelet count*sex interaction. For each quartile increase in IMACS-RS, females had 93% increased odds (p Conclusions: A sex-specific risk score provides excellent risk prediction in LVAD patients. Future prognostic studies in advanced HF should present sex-specific secondary outcomes.

International normalized ratio (INR) measurements manage risks of bleeding and clotting sequelae in the population with left ventricular assist device (LVAD). Studies suggest that point-of-care (POC) INR does not significantly differ from plasma INR (P-INR) values in other patient populations, although this has not been validated in a multicenter LVAD study. We sought to determine whether POC-INR and P-INR values differ significantly in the LVAD population and reviewed patients with permanent LVAD implantation at seven institutions internationally. Our cohort comprised of 279 paired POC-INR and P-INR checks in patients supported on average 630 ± 598 days postimplant with predominately HeartWare, HeartMate II, and HeartMate III devices. The population averaged 57.9 years of age, and there were 86.7% male. We found no statistically significant difference between POC-INR and P-INR values. International normalized ratio accuracy correlated weakly with the time between INR measurements (p < 0.001). When the time difference was less than 4 hours, the difference between INR pairs was significantly lower than measurements greater than 8 hours (p = 0.006). There was no statistically significant difference when comparing paired INR values and time after implant to INR check (p = 0.43), age (p = 0.12), known coagulopathy (p = 0.12), bleeding history (p = 0.22), or thrombosis history (p = 0.34). This is the first large multicenter international study comparing POC-INR and P-INR measurements in patients with LVAD and found no statistically significant difference between either methods, particularly when measured within less than 4 hours of each other.

Left ventricular assist device (LVAD) thrombosis is a devastating complication that occurs in about 10% of patients despite anticoagulation and antiplatelet treatment. How the thrombus initiates and propagates is unknown. We pathologically and immunohistochemically examined 28 thrombi removed from 17 HeartMate II (HMII) left ventricular assist devices (LVADs). Two groups of thrombi were found, those formed in the inlet/outlet and those on the rotor. The four thrombi found at the inlet (three inlet conduit and one inlet tube) and outlet (three at outlet elbow and one outlet graft) appeared similar and were composed of a loose meshwork of fibrin(ogen), von Willebrand factor, leukocytes, and aggregated platelets. The majority of the thrombi (20/28), however, were located on the rotor: nine at the inlet bearing, five on the rotor vanes, and six at the outlet bearing. Laminated thrombi formed around the inlet bearing in rings, an area of blood recirculation. The inner rings of the thrombus had fibrin and von Willebrand factor. Aggregated platelets were found in the outer thrombi rings, but limited evidence of platelets within the laminated thrombi was noted. The presence of distinct rings suggests development of the clot over time. The increased platelets in the outer rings of the inlet bearing thrombi would support further investigation into their role in thrombus growth. Initiating events require further investigation, but the fibrin-rich structure of HMII thrombi suggests that alternative anticoagulation strategies are needed to prevent thrombosis in our LVAD patients.

Background: The MOMENTUM 3 trial compares the centrifugal HeartMate 3 (HM3) with the axial HeartMate II (HMII) continuous-flow left ventricular assist system in patients with advanced heart failure, irrespective of the intended goal of therapy. The trial’s 2-year clinical outcome (n=366) demonstrated superiority of the HM3 for the primary end point (survival free of a disabling stroke or reoperation to replace or remove a malfunctioning pump). This analysis evaluates health resource use and cost implications of the observed differences between the 2 devices while patients were enrolled in the trial. Methods: We analyzed all hospitalizations and their associated costs occurring after discharge from the implant hospitalization until censoring (study withdrawal, heart transplantation, and pump exchange with a nonstudy device or death). Each adjudicated episode of hospital-based care was used to calculate costs (device-attributable and non–device-attributable event costs), estimated by using trial data and payer administrative claims databases. Cost savings stratified by subgroups (study outcome [transplant, death, or ongoing on device], intended goal of therapy, type of insurance, or sex) were also assessed. Results: In 366 randomly assigned patients, 361 comprised the as-treated group (189 in the HM3 group and 172 in the HMII group), of whom 337 (177 in the HM3 group and 160 in the HMII group) were successfully discharged following implantation. The HM3 arm experienced fewer total hospitalizations per patient-year (HM3: 2.1±0.2 versus HMII: 2.7±0.2; P =0.015) and 8.3 fewer hospital days per patient-year on average (HM3: 17.1 days versus HMII: 25.5 days; P =0.003). These differences were driven by patients hospitalized for suspected pump thrombosis (HM3: 0.6% versus HMII: 12.5%; P P =0.002). Controlled for time spent in the study (average cumulative cost per patient-year), postdischarge HM3 arm costs were 51% lower than with the HMII (HM3: $37 685±4251 versus HMII: $76 599±11 889, P Conclusions: In this 2-year outcome economic analysis of the MOMENTUM 3 trial, the HM3 demonstrated a reduction in rehospitalizations, hospital days spent during rehospitalizations, and a significant cost savings following discharge in comparison with the HMII left ventricular assist system, irrespective of the intended goal of therapy. Clinical Trial Registration: URL: https://www.clinicaltrials.gov . Unique identifier: NCT02224755.

Gastrointestinal bleeding (GIB) is common in patients with continuous-flow left ventricular assist devices (CF-LVADs) possibly because of changes in blood flow. We aimed to test the hypothesis that a low pulsatility index (PI) is associated with an increased hazard of overt GIB in patients with CF-LVADs. We conducted a retrospective cohort study of patients who had a HeartMate II (HMII) CF-LVAD implanted at our center. The study end-point was the first overt GIB causing or occurring during a hospitalization between 6 days and 6 months after HMII implantation. HMII PI was recorded at 48 hours and at 1, 3, and 6 month intervals after implantation. We analyzed the associations of PI and clinical variables with the hazard of overt GIB. Ninety-five patients met eligibility criteria. PI ranged from 2.5 to 5.9 (low PI < 4.15 and high PI ≥ 4.15 on the basis of receiver operating characteristic curve analysis). Seventeen (18%) patients experienced overt GIB. In a multivariable model, only lower baseline hemoglobin was a significant predictor of an increased hazard of overt GIB. After adjusting for the baseline hemoglobin, low PI was independently associated with an increased hazard of overt GIB in our cohort of HMII recipients.

The role of routine right heart catheterizations (RHCs) in left ventricular assist device (LVAD) patients is undefined. We analyzed 105 continuous-flow LVAD recipients who underwent an RHC approximately 3 months after implant. In 38 patients, LVAD speed was ramped with the goal of optimizing hemodynamics. Our cohort consisted of 71 (68%) HeartMate II (HMII) and 34 (32%) HeartWare (HVAD) patients. Thirty patients (29%) had either a reduced cardiac index (CI ≤ 2.2 L/min/m), elevated pulmonary capillary wedge pressure (PCWP > 18 mm Hg), or both. A subgroup of 38 patients (19 with abnormal hemodynamics) underwent LVAD ramping. With LVAD ramping, normalization of hemodynamics was achieved in 13 (68%) patients with abnormal hemodynamics. In ramped patients, the CI increased from 2.1 L/min/m (2.0-2.3) to 2.5 L/min/m (2.3-2.6; p = 0.004), and the PCWP dropped from 21 mm Hg (20-26) to 18 mm Hg (14-21, p < 0.001). The 6-minute walk distance improved from 338 m (253-394) to 353 m (320-442, p = 0.041). A 400 rpm change in HMII speed was like a 130 rpm change in HVAD speed and led to a change in cardiac output (CO) of 0.3 L/min. The correlation between device-reported flow and measured CO for both the HMII (Rs = 0.50, p < 0.001) and HVAD (Rs = 0.47, p < 0.001) was moderate. At 3 months after LVAD implant, most patients have normal hemodynamics. Of those patients with abnormal hemodynamics, LVAD ramping results in normalization of hemodynamics and improvement in 6-minute walk distance.

This study aimed to compare the hemodynamic performance and clinical results of the EVAHEART and HeartMate II left ventricular assist devices (LVADs). From 2007 to 2016, fourteen patients received EVAHEART and 28 received HeartMate II at our center. Early survival, driveline infection, and neurologic events were evaluated. Hemodynamic performance was evaluated with transthoracic echocardiography and right heart catheterization. Mean follow-up was 35.5 ± 14.8 months for EVAHEART and 29.8 ± 6.5 months for HeartMate II. Survival rates were comparable between the two groups. After 24 months, freedom from driveline infection was 28% with EVAHEART, and 85% with HeartMate II; freedom from neurologic events was 21% with EVAHEART, and 89% with HeartMate II. Serum lactate dehydrogenase was significantly lower with EVAHEART. There was a significantly greater decrease in left ventricular size with HeartMate II. In catheter examination performed 1 month postoperatively, HeartMate II recipients had significantly lower pulmonary capillary wedge pressure and mean pulmonary pressure, despite a comparable cardiac index. Both devices provided excellent clinical results and hemodynamic performance. HeartMate II could be a better choice to avoid driveline infection and neurologic events. Our results suggest that HeartMate II reduced right ventricular afterload. However, further analysis of more cases is required.

Renal function improves early after left ventricular assist device (LVAD) implantation but later decline has been observed. We sought to determine the occurrence and evaluate possible causes for this decline. In 62 consecutive patients with HeartMateII LVAD with available calculated glomerular filtration rate (GFR, ml/min/1.73 m) 1 year after implant, GFR was assessed repeatedly and possible predictors for decline from 3 to 12 months were investigated. Post-mortem renal specimens for patients supported with an LVAD were evaluated. GFR 54.5 ± 19.5 at admission increased to 66.4 ± 22.3 preoperatively and to 79.2 ± 30.1 ~1 month after implantation. Subsequently at ~3 months GFR declined to 74.7 ± 25.4, at ~6 months to 68.8 ± 23.1, and ~1 year after implant to 63.9 ± 17.7. Glomerular filtration rate at 1 year was significantly lower (p < 0.0001, p < 0.0001, p = 0.005) than GFR 1, 3, and 6 months after implant. Early rise in GFR after surgery was not associated with late decline. Shorter bypass time (β = -0.09, p = 0.048) and higher albumin 3 months after LVAD (β = 14.4, p = 0.025) were significantly associated with less later decline in GFR. Arteriosclerosis was identified in autopsy renal specimens. In conclusion, early gains in renal function after LVAD implant are not sustained in many patients. Patient, device, and operative factors may influence long-term renal function in these patients.

There is insufficient data on patients with small body size to determine if this should be considered a risk factor for continuous-flow left ventricular assist device (CF-LVAD) support. We sought to evaluate survival outcomes, adverse events, and functional status of CF-LVAD patients with body surface area (BSA)

The HeartMate 3 (HM3) left ventricular assist device (LVAD) is designed to support advanced heart failure patients. This centrifugal flow pump has a magnetically levitated rotor, artificial pulse, textured blood-contacting surfaces, optimized fluid dynamics, large blood-flow gaps, and low shear stress. Preclinical tests were conducted to assess hemocompatibility. A computational fluid dynamics (CFD) model guided design for low shear stress and sufficient washing. Hemolysis testing was conducted on six pumps. Plasma-free hemoglobin (PfHb) and modified index of hemolysis (MIH) were compared with HeartMate II (HMII). CFD showed secondary flow path residence times between 27 and 798 min, comparable with main flow residence times between 118 and 587 min; HM3 vs. HMII shear stress exposure above 150 Pa was 3.3 vs. 11 mm within the pump volume and 134 vs. 604 mm on surfaces. In in vitro hemolysis tests at 2, 5, and 10 L/min, average pfHb 6 hours after test initiation was 58, 74, and 157 mg/dl, compared with 112, 123, and 353 mg/dl for HMII. The HM3/HMII ratio of average MIH at 2, 5, and 10 L/min was 0.29, 0.36, and 0.22. Eight 60 day bovine implants were tested with average flow rates from 5.6 to 6.4 L/min with no device failures, thrombosis, or hemolysis. Results support advancing HM3 to clinical trials.

Pump thrombosis (PT) is a common and potentially life-threatening complication among HeartMate II (HMII; Thoratec, Pleasanton, CA) patients. There have been efforts to correlate HMII geometry with higher risk of PT. The aim of this study was to test the validity of using HMII inflow cannula angle (ICA) and pump pocket depth (PPD) to predict PT. We performed a retrospective analysis of patients implanted with HMII left ventricular assist devices (LVADs) from January 2011 to March 2014 at our institution. Three blinded reviewers measured ICA and PPD from chest x-rays at postimplantation and most recent follow-up time points. The diagnosis of PT was visually confirmed upon device explantation by benchtop evaluation. HeartMate II was implanted in 90 patients. Sixteen (20%) patients experienced PT. There was no statistical difference between PT and non-PT patients in their initial ICAs (56.0° ± 10.1 vs. 54.6° ± 10.8, p = 0.63) and PPD (86.7 ± 24.9 mm vs. 81.1 ± 32.2 mm, p = 0.46). Prediction of PT using ICA and PPD by receiving operating characteristic was negative (area under curve (AUC) = 0.54 and 0.55, respectively). Changes in HMII geometry were measured over 112.5 (interquartile range = 34.3-337.3) days. A decrease in PPD was observed (p = 0.0001). Initial ICA was a significant predictor of future angle change and suggested a convergence toward the mean (55.4°) (analysis of variance p = 0.002). Pump thrombosis recurred in four (25%) patients. Postoperative ICA and PPD do not appear to predict PT in HMII patients in our experience. HeartMate II geometry changes over time secondary to remodeling with a decrease in PPD and a convergence toward the median in ICAs. Further investigation into the role of geometric ventricular assist device conformation postimplant may be warranted.

The Texas Heart Institute (THI) has grown significantly since its inception in 1962. By taking a multifaceted approach to research and patient care, THI has stayed at the forefront of innovation in cardiovascular medicine (Table). Nothing has symbolized this more than the opening of The Denton A. Cooley Building in 2002. Thanks to a successful $75 million campaign, this 10-story, 327 000-square-foot building, located next to St. Luke’s Episcopal Hospital, was built to provide the full spectrum of cardiovascular services. It includes 12 operating rooms, a postinterventional floor, a transplantation floor, a progressive-care floor, cardiovascular recovery beds, an imaging facility, a telemedicine center, 2 floors dedicated to basic science research, a 325-seat conference center (the largest in the Texas Medical Center), a Heart Information Center, and a museum dedicated to the heart and the pioneering cardiovascular research conducted at THI. View this table: Table. Historical Milestones of the Texas Heart Institute (2000–2017) Figure. Signing of an enhanced affiliation agreement between the Texas Heart Institute (THI) and the University of Texas (UT) System in 2009. Top row from left to right: UT System Executive Vice Chancellor for Health Affairs Kenneth Shine, MD; UT Health President Larry Kaiser, MD; and THI Board of Trustees Chairman Meredith Long. Bottom row from left to right: THI President Emeritus and Surgeon-in-Chief Denton Cooley, MD; THI President and Medical Director James Willerson, MD; and UT System Chancellor Francisco Cigarroa, MD (Published with permission from the Texas Heart Institute). A major focus of THI’s laboratories has always been the development and testing of mechanical assist devices and cardiac substitutes. In fact, the Cullen Cardiovascular Research Laboratory, established in 1972, has been involved in the development of most of the cardiac pumps used throughout the world today, including the Heartmate II and HeartWare ventricular assist devices. Currently, research is underway to …

Heart failure patients supported with left ventricular assist devices (LVAD) enjoy improvements in functional capacity and quality of life. We reasoned that such improvements in exercise capacity should be reflected in an objective increase in peak oxygen consumption as measured by cardiopulmonary exercise testing (CPET). We performed a retrospective review of all recipients of a HeartMate II LVAD at our center from June 2009 to June 2012 who completed CPET. Thirty-seven patients completed CPET an average of 6 months after implantation. Of these, 10 patients had CPET performed before LVAD implantation. Overall, 91.4% of patients improved by at least two New York Heart Association classes, with 34.3% improving by three classes. Postimplant VO2 max was significantly less than predicted (14.7 ± 3.1 vs. 29.8 ± 6.6 ml/kg/min, p < 0.001; percent-predicted 51% ± 12%). For 10 patients with pre- and post-implant studies, VO2 max increased significantly from 11.6 ± 5.0 to 15.4 ± 3.9 ml/kg/min (p = 0.009). VO2 max improves significantly with LVAD support but fails to normalize to predicted values, in spite of improvements in functional class. The severity of preimplantation heart failure does not associate with the degree of VO2 max improvement.

Successful long-term use of the HeartMate II (HM II) left ventricular assist device has become commonplace but may be complicated by mechanical failure, infection, or thrombosis necessitating device exchange (DE). A subcostal approach to device exchange with motor exchange only is less traumatic, but long-term outcomes have not been reported. A retrospective chart review of all patients who required HM II to HM II device exchange at our institution was conducted. Of the 232 HM II patients implanted between January 2008 and July 2013, 28 required 36 device exchanges during a follow-up of 33.72 ± 17.25 months. The Kaplan-Meier 1 year survival was 63% for sternotomy exchanges and 100% for subcostal exchanges. Twenty-one exchanges were performed for initial or recurring device thrombosis. Although there was no difference in the risk of subsequent thrombosis after subcostal versus sternotomy exchange, the overall risk of recurring device thrombosis after device exchange for the same was high (31%). HM II device exchange via the subcostal approach has excellent short- and long-term outcomes. Device exchange performed for thrombosis is associated with a high recurrence risk irrespective of surgical approach.

The optimal timing of left ventricular assist device (LVAD) implantation in the management of advanced heart failure remains controversial. We hypothesize that in patients with cardiogenic shock, the severity of end-organ dysfunction as determined by the sequential organ failure assessment (SOFA) score is a determinant of outcomes after LVAD implantation. We determined the preoperative SOFA score and short- and long-term outcomes of 97 consecutive patients who received HeartMate II or HeartWare LVAD at our institution since January 2007. Kaplan-Meier analysis was used to compare long-term survival across SOFA score subgroups. The overall 30 day mortality was 10.1%, with no significant difference among SOFA score subgroups. Patients with scores ≥9 had significantly longer hospital stay (26 ± 6 vs. 18 ± 10 days, p = 0.03). One-year survival for SOFA scores 0-2, 3-5, 6-8, and ≥9 was 94%, 75%, 64%, and 29%, respectively. SOFA score was significantly lower in survivors at 6, 9, 12, 24, and 36 months. SOFA score did not predict adverse outcomes of bleeding, cerebrovascular events, infection, or pump exchange. These results show that preoperative SOFA score is a powerful predictor of outcomes after LVAD implantation. Long-term outcomes can be significantly improved by early intervention before emergence of end-organ dysfunction.

B-type natriuretic peptide (BNP)-guided therapy during the early postoperative period following left ventricular assist device (LVAD) implantation has not been well described in the literature. We conducted a retrospective cohort study consisting of consecutive patients who underwent LVAD implantation at our institution during May 2009 to March 2013. The study was limited to patients receiving HeartMate II (Thoratec) or HVAD (HeartWare) LVADs. Patients with acute myocardial infarction were excluded. We compared between patients with multiple postoperative BNP tests (BNP-guided therapy) and earlier period patients who typically had only a baseline BNP measurement (non-BNP-guided therapy). A total of 85 patients underwent LVAD implantation during the study period. Eight patients were excluded (five acute myocardial infarction, three without BNP measurements). The only differences in the baseline characteristics of BNP versus non-BNP-guided therapy included age and female gender. The postoperative length of hospital stay (LOS) in the BNP-guided therapy group was 5 days shorter when compared with the non-BNP-guided therapy group. In multivariate analysis, BNP-guided therapy remained a significant predictor of reduced LOS. The use of repeated BNP measurements during the early postoperative period was associated with a significantly lower LOS post LVAD implantation.

Left ventricular assist devices (LVADs) are fast becoming standard of care for patients with advanced heart failure. However, despite continuous improvement in VAD technology, there remains a significant early postoperative morbidity and mortality in this extreme patient group. The aim of the current study was to explore the short-term outcomes and predictors for 90 day mortality in the patients after implantation of continuous-flow LVAD. Perioperative clinical, echocardiographic, hemodynamic, and laboratory data of 90 day survivors and nonsurvivors were collected and compared retrospectively. Multivariate logistic regression analysis was performed on univariate predictors for 90 day mortality with an entry criterion of p < 0.1. Between July 2006 and May 2012, 117 patients underwent implantation of a continuous-flow LVAD as a bridge to transplantation: 71 (60.7%) HeartMate II (Thoratec Corp, Pleasanton, CA) and 46 (39.3%) HVAD (HeartWare International, Framingham, MA). All-cause 90 day mortality was 17.1%. Multivariate analysis revealed higher preoperative central venous pressure (odds ratio [OR], 1.18; 95% confidence interval [CI], 1.014–1.378; p = 0.033) and higher age (OR, 1.14; 95% CI, 1.01–1.38; p = 0.045) as the only independent predictors for 90 day mortality. Optimization of preoperative volume status, preload, and right heart function as well as age-based selection of candidates for LVAD support are the critical factors influencing early outcome after continuous-flow LVAD implantation.

Postimplant device thrombosis remains a life-threatening complication and limitation of continuous-flow ventricular assist devices (VADs). Using advanced computational fluid dynamic (CFD) simulations, we successfully depicted various flow patterns, recirculation zones, and stagnant platelet trajectories which promote thrombus formation and observed that they matched actual thrombus formation patterns observed in Thoratec HeartMate II VADs explanted from patients with pump thrombosis. Previously, these small eddies could not be captured by either digital particle image velocimetry or CFD due to insufficient resolution. Our study successfully demonstrated the potential capability of advanced CFD to be adopted for device optimization, leading to enhanced safety and efficacy of VADs for long-term destination therapy.

I appreciate the editorial comments by Spartalis and associates on our article, “Left Ventricular Assist Device Malfunctions: It Is More Than Just the Pump.”1 I feel it is important to realize that the goal of this manuscript was not to compare pump thrombosis rates between the HeartMate II and the HeartWare left ventricular assist devices but rather to demonstrate that various categories of device malfunction encompass a much broader spectrum of device components that includes both the pump and its controller and peripheral attachments. It was a secondary finding that these categories of device malfunction in some cases do indeed occur at …

We read with great interest the article titled “Left Ventricular Assist Device Malfunctions: It Is More Than Just the Pump” by Kormos et al1 comparing the centrifugal continuous-flow pump HeartWare with the axial-flow pump HeartMate II. The study concluded that the rate of pump malfunction caused by pump thrombosis was higher among patients who received the axial-flow pump than among patients who received the centrifugal continuous-flow pump.1 The authors report an increase in pump thrombosis to a rate as high as 12% within 6 months after HeartMate II implantation.1 It would be of interest if the authors could provide an …

Assessment of patients with left ventricular assist devices (LVADs) can be challenging, and multiple modalities are sometimes necessary to arrive at the accurate diagnosis. We describe two patients with persistent heart failure symptoms after HeartMate II LVAD placement. After initial evaluation was unrevealing, retrospectively gated computed tomographic angiography (CTA) was used to diagnose partial inflow obstruction, leading to important changes in management. We describe the techniques and role of retrospective gating and discuss functional assessment by CT as well as future applications.

The development of current mechanical circulatory support (MCS) systems began in the 1960s as an effort to provide a therapeutic option for patients with refractory advanced heart failure.1 Today, MCS represents a viable alternative to cardiac transplantation for the overwhelming majority of patients in whom age, comorbidities, or the profound shortage of donors makes transplantation infeasible. Response by Owens and Jessup on p 3087 Painstaking work on the technique of orthotopic cardiac transplantation, coupled with advances in the knowledge of immunology, resulted in the improvements in survival and quality of life that make cardiac transplantation the treatment of choice for individuals with advanced heart failure. MCS has only recently become accepted for widespread clinical use.2 Early MCS designs were based on the assumption that maintaining pulsatility of flow was a physiological necessity. These bulky devices were of limited durability and resulted in a great deal of morbidity in the form of hematologic, neurological, and infectious complications.3 Current (second- and third-generation) devices deliver continuous flow (either axial [HeartMate II] or centrifugal [Heartware HVAD]) and have far fewer moving parts (only a rotor); as a result, they are smaller, quieter, and far more durable (estimated to last ≥10 years compared with 18 months) than the early pulsatile systems.4 Although no longer in common use, early pulsatile-flow left ventricular assist devices (LVADs) provided the first proof of principle that MCS can extend life of well-selected patients with advanced heart failure refractory to traditional optimal medical therapy. The development of continuous-flow devices has made MCS a practical clinical tool, and outcomes with the newer devices provide a convincing rationale for LVADs as standard of care in well-selected patients with refractory heart failure in whom transplantation is not an option. ### Proof of Principle Recognition that LVADs intended as a bridge to cardiac transplantation delivered …

In the article by Uriel et al,1 the authors evaluated a composite end point defined as hemocompatibility-related clinical adverse events (HRAEs) between the HeartMate 3 and the HeartMate II left ventricular assist device. The authors proposed a new hemocompatibility score (HCS) to describe the HRAE burden experienced by patients within the trial period. Mehra et al2 proposed the suggested HCS, which identified the need for a clinical score to quantify a burden of hemocompatibility. The grading system developed by Uriel et al1 relates more to a traditional rating because it consists of individual cutoff points derived from intuitive clinical reasoning. The …

We postulated that postoperative B-type natriuretic peptide (BNP) levels would be reflective of the degree of hemodynamic support rendered by various pump speeds settings (RPM) of continuous-flow left ventricular assist devices (LVADs). Twenty LVAD patients were evaluated prospectively (Jarvik 2000: n = 9, HeartMate II: n = 11). The mean age was 57.7 ± 14.9 years, and 14 were male. B-type natriuretic peptide levels were drawn while the patients were supported on LVADs at variable RPM settings. The RPM settings were correlated with the changes in BNP levels. Eleven patients underwent LVAD implantation for a lifelong support while the rest were as a bridge therapy to transplantation. Four patients required LVAD change out for various causes of pump failure. Postoperative BNP levels decreased dramatically with the initiation of LVAD support. The levels correlated inversely with the degree of hemodynamic support rendered at various RPM settings of the HeartMate II (p < 0.001). Overall, BNP levels decreased significantly in 2 days after RPM increase. We observed a significant inverse correlation between the postoperative BNP levels and the degree of LVAD support. The effective LVAD support seems to result in a marked reduction in BNP levels, and monitoring serial BNP levels may be helpful in managing patients supported on continuous LVAD.

Implantable left ventricular assist devices (LVADs) are being used to support patients for longer periods because of longer transplant waiting times and the application of LVADs for destination therapy. With longer implant times comes LVAD exchange for component failure or serious device-related infection that cannot be treated medically. LVAD exchange should be performed promptly and planned in accordance with the patient's condition, the type of device previously implanted, and the type used for exchange, as well as whether total system or individual component replacement is required. Most patients who experience pump failure after extended support are in good condition. Preoperatively, patients must be stabilized using standard inotropic and vasoactive medications and undergo a complete workup, including echocardiography. Coagulation abnormalities should be corrected preoperatively. Intraoperatively, continuous transesophageal echocardiography and standard hemodynamic monitoring should be utilized. After opening the chest, LVAD support should be minimized to prevent air entry. Detailed descriptions of the following exchange procedures are presented: Jarvik 2000 to Jarvik 2000, HeartMate (VE or XVE) to HeartMate (VE or XVE), HeartMate (VE or XVE) to HeartMate II, and HeartMate II to HeartMate II. Although more reliable systems may offer longer support times, the need for exchange procedures will likely continue to increase.

Introduction: Recent analyses have demonstrated an increasing risk of HeartMate II (HMII) left ventricular assist device (LVAD) thrombosis than previously reported. Elevation of serum lactate dehydrogenase (LDH), a biomarker of hemolysis secondary to thrombosis, parallels the overall pattern of HMII thrombosis. Hypotheses: We hypothesized that longitudinal trends of LDH could predict HMII thrombosis. Methods: From 10/2004 through 9/2014, 350 HMII devices were implanted in 323 patients at a single center. Of these, patients on 339 devices had at least 1 postop LDH value through 9/2014 (7,996 total measurements). A 2-step joint model combining longitudinal biomarker data and pump thrombosis events was generated to assess the impact of changing LDH on the risk of thrombosis. Device-specific LDH values were first estimated using Multivariate Boosted Trees to reduce measurement error and produce unbiased regression estimates. Estimated LDH values were then used as a time-varying covariate function in a multiphase hazard model to analyze time to thrombosis. Results: Thirty-five HMII pumps (10%) had either confirmed (18 HMIIs) or suspected (17 HMIIs) thrombosis, with 15 (43%) occurring within 3 months of implant. LDH was associated with pump thrombosis occurring both early and late after implant (P Conclusions: Longitudinal trends in surveillance LDH for patients on HMII support is useful for dynamic prediction of pump thrombosis, both early after implant and late. Incorporating upward and downward trends in LDH provides a dynamically updated model of LVAD thrombosis risk that may eventually be a tool for LVAD clinical management.

Device-related hemolysis leading to anemia is a recognized chronic complication of a left ventricular assist device (LVAD). With the increased usage of the LVAD in the management of end-stage heart failure, an increased number of complications are being recognized. We present a case where a combination of elevated mean arterial pressure and development of aortic regurgitation resulted in increased hemolysis, power spikes, and anemia, mimicking device thrombus, resulting in a diagnostic dilemma.

This report details two cases of left ventricular assist device (LVAD)-related fungal infection. In both cases, the infection occurred within the device and formed an obstruction resulting in intermittent variation in the output of the LVAD. This was manifested by a change in the pattern of aortic insufficiency (AI) from continuous to intermittent on transesophageal echocardiography. Recognition of this finding may allow for noninvasive diagnosis of LVAD flow obstruction.

The HeartMate II left ventricular assist device (LVAD) is a small axial-flow next-generation pump. Acute stoppage of this device is a potentially lethal complication. As these devices proliferate, many patients will be in areas remote to their implant center. Therefore, percutaneous stabilization of these patients before definitive surgical replacement could be potentially life saving. We present two cases of acute LVAD stoppage managed successfully using percutaneous means.

We appreciate the letter by Dr Jennings regarding our recently published review.1 This letter clarifies the anticoagulation protocol used by the Henry Ford Hospital for patients treated with Heartmate II left ventricular assist device, which we reported incorrectly.1 Our source for the reported international normalized ratio (INR) range of 1.8 to 2.2 was the abstract presented by Henry Ford group at the American Society of Artificial Organs in 2011 …

The Heartmate II Left Ventricular Assist Device is a new axial impeller pump that is smaller than many existing devices and has no need for percutaneous venting. These features have the potential to reduce complications, lengthen durability, and enhance full implantability and good left ventricular unloading. The optimal operating conditions, however, remain to be elucidated. Changes in pump speed can produce temporal and spatial changes in the pattern of blood flow in the left ventricle (LV). These changes could influence the overall pump flow, cardiac …