HeartWare Left Ventricular Assist Device Research Articles

Is hemolysis a predictor of complications in patients implanted with a left ventricular assist device?

Aim: Life-threatening complications such as intra-device thrombus, infection, bleeding, kidney and liver failure are frequently encountered due to the use of left ventricular assist devices (LVADs). We aimed to determine the incidence of hemolysis in patients implanted with LVAD, the mechanical complications detected in patients with hemolysis, and whether hemolysis can be used as a predictor of complications. Material and Methods: In this single-center, retrospective clinical research study, we evaluated 40 patients with HeartWare (HeartWare International, Inc., MA, USA) LVAD implants to assess the incidence of hemolysis and its association with mechanical complications. Hemolysis parameters, including lactate dehydrogenase (LDH), bilirubin, serum-free hemoglobin (sfHg), corrected reticulocyte count (CRC), and haptoglobin, were measured in venous blood samples obtained from patients attending cardiovascular outpatient clinics. Patients were divided into two groups( group 1:without hemolysis,n=32; group 2: with hemolysis,n=8) based on the presence or absence of hemolysis, and demographic data, comorbidities, and laboratory results were compared. The time elapsed after implantation of the patients was min: 90 days, max: 3147 days. Results: Hemolysis was detected in 20% (8 out of 40) of the patients included in the study. Patients with hemolysis demonstrated higher CRC, LDH, and total bilirubin levels(p<0,005), and lower haptoglobin levels compared to those without hemolysis(p<0,001). Intra-device thrombus was detected as a mechanical complication in 2 patients with hemolysis. One patient died and the other was discharged after medical treatment. Conclusion: Our findings suggest that routine monitoring of hemolysis parameters in LVAD recipients may aid in the early detection of mechanical complications, such as pump thrombosis, before symptomatic manifestation, thus potentially reducing mortality. Assessing multiple parameters, including LDH, bilirubin, sfHg, CRC, and haptoglobin, is crucial for accurate hemolysis diagnosis and its association with mechanical complications. It should be supported by large series of studies with longer and similar follow-up periods and a larger number of patients.

HeartWare Left Ventricular Assist Device Exercise Hemodynamics With Speed Adjustment Based on Left Ventricular Filling Pressures.

Functional capacity remains limited in heart failure patients with left ventricular assist devices (LVADs) due to fixed pump speed and inability to offload the left ventricle adequately. We hypothesized that manually adjusting LVAD speed during exercise based on pulmonary capillary wedge pressures would increase total cardiac output and maximal oxygen consumption. Two participants with a HeartWare LVAD underwent an invasive ramp study at rest followed by an invasive cardiopulmonary stress test exercising in two randomized phases: fixed speed and adjusted speed. In the latter phase, speed was adjusted every 1 minute during exercise at ±20 rpm/1 mm Hg change from baseline pulmonary capillary wedge pressure. There was no difference in maximal oxygen consumption between the two phases, with a modest increase in total cardiac output during speed adjustment. Filling pressures were initially controlled during speed adjustment until speed was capped at 4,000 rpm, at which point filling pressures increased. Blood pressure was variable. The pressure across the head of the pump (ΔP) was higher with speed adjustment. Contrary to our hypothesis, LVAD speed adjustment during exercise did not improve total cardiac output and functional capacity. This variable response may be attributed to the native cardiac reserve and baroreceptor response; however, additional studies are needed.

PO-05-143 IMPLANTING AN ACTIVE HELIX-FIXATION LEADLESS PACEMAKER IN A PATIENT WITH EXISTING HEARTWARE LEFT VENTRICULAR ASSIST DEVICE

Leadless pacemakers (LP) are being increasingly utilized to avoid complications associated with transvenous pacemakers, such as infection, venous occlusion, tricuspid regurgitation, and lead related complications (dislodgment, fracture, or insulation failure). The new AVEIR LP (Abbott Medical, Sylmar, CA) is the second leadless pacing system to become available in the US in 2022 after the MICRA device. There is limited data regarding the safety and efficacy of LPs in patients with left ventricular assist devices (LVADs), electromagnetic interference (EMI) from LVADs is a concern, and little is known about the interaction of LVAD with novel conductive communication unique to AVEIR LP. We describe a case of successful implantation of an AVEIR LP in a patient with HeartWare LVAD. N/A A 66-year-old woman with a HeartWare (Medtronic) LVAD was referred for a permanent pacemaker implantation due to episodes of bradycardia dependent torsades. Given low pacing requirement with no need of defibrillator therapy, implantation of a AVEIR LP was planned to decrease risks associated with transvenous pacemakers. Prior to the procedure, noise, threshold, and saturation scores were evaluated for potential communication issues with the LP. Traditional antero-lateral patch placement revealed unacceptable results, and the two left sided patches were modified to a postero-lateral location circumferentially around the patient, and further from the LVAD, which resulted in acceptable values and confidence in device to programmer communication during the implant. The LP was implanted using standard techniques. After crossing the tricuspid valve, contrast injections revealed optimal low septal placement, and electrical mapping was used to identify an optimal location before fixating the helix. During the immediate postoperative period and at two-week follow up, the device showed no EMI and no difficulties communicating with the programmer. This is the first description of implantation of an AVEIR LP in a patient with HeartWare LVAD. LP implantation with perioperative mapping capability and helix-driven fixation method is feasible and may be an effective alternative to transvenous pacemakers in patients with LVAD. In the presence of an LVAD, optimizing conductive communication with the LP may require adjustment of patch placement to a nontraditional location. Further studies are needed to evaluate the safety and efficacy of leadless pacemaker devices in this unique cohort of patients.

PO-05-063 MORTALITY IN LEFT VENTRICULAR ASSIST DEVICE RECIPIENTS WITH VT REQUIRING ABLATION

Left Ventricular Assist Devices (LVADs) improve survival in patients with heart failure. However, an increased burden of ventricular tachycardia (VT) can occur following LVAD implantation. The role of ablation in the treatment of VT for LVAD recipients and the timing of when ablation should occur is unclear. To determine mortality in LVAD recipients with VT who required an ablation We retrospectively reviewed all patients who received a ventricular ablation from January 2014 to February 2021 and included those who underwent VT ablation after LVAD placement. The composite endpoints included transplant, lost to follow up, or last date of data collection. Event failure was defined as patient death. Survival rates were calculated with Kaplan-Meier analysis. Rate of event failure was calculated as per patient-year incident death rate (IR) and was compared between treatment groups by incident rate ratio with 95% confidence intervals (IRR [95% CI]). Survival analysis was performed using STATA. 36 patients underwent VT ablation after LVAD placement. Of those, 21 (58%) had documented VT prior to LVAD placement and 14 (42%) had de novo VT after LVAD placement. Within 30 days, one patient died (IR 0.339 over 2.95 patient-years); within one year, four patients died (IR 0.128 over 31.1 patient-years); within two years, ten patients died (IR 0.183 over 54.5 patient-years); and within eight years, twenty patients died (IR 0.217 over 92.2 patient-years). At a study endpoint of 2 years (the time interval between the most recent LVAD placement and the last date of data collection), a significantly higher death rate per patient-year was found in patients with VT onset within 7 days of LVAD placement (IRR 5.19 [1.08-21.87]), with a trend towards significantly higher death rate seen in patients with ischemic cardiomyopathy (ICM) (IRR 4.12 [0.82-39.9]) (Table 1). All patients who died underwent a VT ablation within 90 days of VT onset (Figure 1). Mortality in LVAD recipients was highest in the immediate post-operative period, especially when VT occurred within 7 days of LVAD placement. A higher death rate was also seen when ablation was performed within 90 days of VT onset. Further comparison to matched LVAD recipients without VT requiring ablation is needed to better understand the impact of VT on mortality in LVAD recipients.Tabled 1Table 1. IRRs of Patient Mortality Stratified by Presence or Absence of Specific Risk FactorsAbsentPresentIRR95% CIp-valueIschemic Cardiomyopathy0.0720.2984.12[0.82-39.9]0.059LVAD as Destination Therapy0.1100.2572.32[0.53-13.93]0.223HeartWare LVAD Placed0.1450.2241.55[0.37-7.47]0.516VT Prior to LVAD Placement0.1150.2462.14[0.49-12.80]0.283VT Ablation Prior to LVAD Placement0.2020.1680.83[0.14-3.64]0.825VT Within 7 Days of LVAD Placement0.1240.6455.19[1.08-21.87]0.023Ablation of VT Within 90 Days of VT Onset00.260------0.031Multiple Ablations Performed for Recurrent VT0.2180.0760.35[0.08-2.50]0.322 Open table in a new tab

Subcutaneous implantable cardioverter-defibrillator noise following left ventricular assist device implantation.

The incidence and impact of noise in a subcutaneous implantable cardioverter defibrillator (S-ICD) after left ventricular assist device (LVAD) implantation is not well established. We performed a retrospective study of patients implanted with LVAD and with a pre-existing S-ICD between January 2005 and December 2020 at the three Mayo Clinic centers (Minnesota, Arizona, and Florida). Of the 908 LVAD patients, a pre-existing S-ICD was present in 9 patients (mean age 49.1± 13.7 years, 66.7% males), 100% with Boston Scientific third-generation EMBLEM MRI S-ICD, 11% with HeartMate II (HM II), 44% with HeartMate 3 (HM 3), and 44% with HeartWare (HW) LVAD. The incidence of noise from LVAD-related electromagnetic interference (EMI) was 33% and was only seen with HM 3 LVAD. Multiple measures attempted to resolve noise, including using alternative S-ICD sensing vector, adjusting S-ICD time zone, and increasing LVAD pump speed, were unsuccessful, necessitating S-ICD device therapies to be turned off permanently. The incidence of LVAD-related S-ICD noise is high in patients with concomitant LVAD and S-ICD with significant impact on device function. As conservative management failed to resolve the EMI, the S-ICDs had to be programmed off to avoid inappropriate shocks. This study highlights the importance of awareness of LVAD-SICD device interference and the need to improve S-ICD detection algorithms to eliminate noise.

Left Ventricular Assist Device as a Bridge to Recovery: Single Center Experience of Successful Device Explantation.

Continuous-flow left ventricular assist devices (CF-LVAD) have been shown to enhance reverse remodeling and myocardial recovery in certain patients allowing for device removal. We sought to analyze the characteristics and describe outcomes of patients who underwent CF-LVAD explantation at a large academic center. We retrospectively identified all patients who underwent CF-LVAD explants due to recovery from 2006 to 2019. Patient baseline characteristics and data on pre- and postexplant evaluation were collected and analyzed. Of 421 patients who underwent CF-LVAD implantation, 13 underwent explantation (3.1%). Twelve HeartMate II and one HeartWare LVAD were explanted. All patients had nonischemic cardiomyopathy. Median time from heart failure diagnosis to LVAD implant was 12 months (interquartile range [IQR], 2-44) and the median time supported on LVAD was 22 months (IQR, 11-28). Two patients died within 30 days of explant. Three additional patients died during the follow-up period and all were noted to be nonadherent to medical therapy. After a mean follow-up duration of 5 years, overall survival was 52%. Mean pre-explant ejection fraction was 49%, which decreased at most recent follow-up to 32%. Mean pre-explant left ventricular internal diameter in diastole (LVIDD) was 4.37 cm and increased to 5.52 cm at most recent follow-up. Continuous-flow left ventricular assist device explantation is feasible and safe in select patients.

Time Spent Engaging In Healthcare In Patients With Left Ventricular Assist Devices

<h3>Objective</h3> While implantation of a left ventricular assist device (LVAD) in patients with Stage D heart failure (HF) can prolong survival, this often occurs at the expense of increased time spent in LVAD-related healthcare activities outside of the home. We sought to describe patient time spent obtaining LVAD-related clinical care after index hospital discharge. <h3>Methods</h3> Our single-site sample included LVAD patients discharged after index hospitalization between 5/9/2008-12/31/2019. LVAD-related healthcare encounters (defined based on study team consensus) between discharge date and censor date (earliest of death, heart transplant, LVAD explant, transfer of care, or 12/31/2019) were obtained from electronic health records. Encounters included inpatient admissions, emergency department visits, and LVAD-related ambulatory encounters (clinic visits, blood draws, diagnostic tests and procedures). We quantified the proportion of total number of healthcare encounter days (any day with at least one visit) and total time spent on healthcare encounters for each patient. Comparisons using Kruskal-Wallis tests were conducted for subgroup analyses. <h3>Findings</h3> Sample (n=374) characteristics were: mean age at implant=54.9 years; 78% male; 53% white. Median days from LVAD discharge to censor was 390 (IQR 158-840). Patients had median 86 (IQR 44-161) unique healthcare encounter days, accounting for 23% of their days from LVAD discharge to censor. Patients spent median 587 (IQR 191-1248) hours engaged in healthcare, accounting for 5.3% of their total time from LVAD discharge to censor. HeartWare LVAD was associated with greater % healthcare days, with a trend towards greater % healthcare days in bridge-to-transplant LVAD versus destination therapy (<b>Table</b>). <h3>Conclusions</h3> LVAD patients spent considerable time engaging in healthcare activities outside the home, which may be burdensome or adversely affect quality of life. Our findings may inform strategies to improve efficiency of post-discharge care delivery among LVAD patients.

Predictive Role of Soluble ST2 in Patients on Left Ventricular Assist Device Support

<h3>Purpose</h3> Soluble suppression of tumorigenicity-2 (sST2) is a prognostic indicator for mortality in heart failure (HF) patients and therefore a valuable tool in risk stratification. After implantation of a continuous flow left ventricular assist device (cf-LVAD), sST2 levels drop significantly. Whether sST2 levels are predictive of adverse outcome in patients on LVAD support remains unknown. We hypothesized that elevated sST2 predict mortality in LVAD patients. <h3>Methods</h3> Between March 2006 and July 2021, 422 patients were primarily implanted with a HeartMate II, HeartMate 3 or HeartWare LVAD in a single centre. sST2 was measured during regular outpatient visits and from biobanked samples if available. All sST2 measurements of these patients until July 2021 were retrieved. Time varying covariate cox regression was used to estimate the effect of sST2 on the primary outcome, stratified for device type and adjusted for the pre-operative variables age, sex, temporary support at implantation, INTERMACS 1 status and ischemic etiology. Primary outcome was death or urgent heart transplant (HTx) and patients were censored if they were explanted, received non-urgent HTx, or for ongoing support at the end of the follow-up. <h3>Results</h3> Post-operative sST2 measurements of 252 LVAD patients were included for analysis, of which 29%, 23%, and 48% received a HeartWare, HeartMate II or HeartMate 3, respectively. The median age was 55 and 64% were male. Median follow-up time was 899 days, during which 35 patients died, 12 patients received urgent HTx and 31 patients received HTx after normal listing. In total, 1475 post-operative sST2 measurements were used for analysis, with a median of 28.2 ng/ml (inter quartile range: 20.8 ng/ml). The multivariate adjusted time dependent cox model resulted in a HR of 1.02, with p<0.001 for sST2. <h3>Conclusion</h3> sST2 is predictive for all-cause mortality in patients on LVAD support. Therefore, a closer follow-up may be recommended in patients with high sST2 measures. In addition, further research is warranted into the mechanisms of elevated sST2 in LVAD patients and possible targeted interventions to improve prognosis.

LVAD Outflow Graft Stenosis

Introduction Left Ventricular Assist Device (LVAD) outflow graft obstruction is a known long-term complication, etiologies for obstruction include thrombosis, kinking as well as external compression. Here we present a clinical case presenting with low LVAD flows due to external compression of the outflow graft with marked improvement after surgical intervention. Case Report A 60-year-old woman with chronic systolic heart failure secondary to non-ischemic cardiomyopathy with a HeartWare LVAD implanted 2018 presented with one month of low flows prior to admission. She was in atrial fibrillation (AF) with rapid ventricular response and volume overloaded. Despite AF rhythm control and volume optimization, flows never returned to prior baseline (Figure A). Gated cardiac CT demonstrated narrowing within the bend relief down to 3.7mm. During an echo guided ramp study aortic valve opening frequency decreased only minimally with speed up titration with slight improvement in flows. Ventriculography was significant for narrowing of the proximal outflow graft with most contrast exiting through LVOT, however, a kink in the outflow tract vs external compression could not be distinguished (Figure B). Percutaneous stenting was deemed to be too high-risk due to the proximity to the rotor blade. In the OR, fibrinous tissue between the outflow graft and the externally reinforced goretex graft covering the strain relief was identified. Via a limited left subcostal incision, the goretex graft was sharply opened from distal end to proximal end resulting in immediate LVAD flow normalization (Figures C and D). The patient discharged home on post-operative day 5. Summary Mechanical LVAD outflow graft obstructions can be catastrophic and addressing its causes requires a multidisciplinary approach. Here we present a case where a symptomatic, mechanical outflow graft obstruction was identified via multimodal imaging. The mechanical obstruction was ultimately amendable to a minimally invasive surgical approach and avoided pump exchange or even cardiac transplant. Left Ventricular Assist Device (LVAD) outflow graft obstruction is a known long-term complication, etiologies for obstruction include thrombosis, kinking as well as external compression. Here we present a clinical case presenting with low LVAD flows due to external compression of the outflow graft with marked improvement after surgical intervention. A 60-year-old woman with chronic systolic heart failure secondary to non-ischemic cardiomyopathy with a HeartWare LVAD implanted 2018 presented with one month of low flows prior to admission. She was in atrial fibrillation (AF) with rapid ventricular response and volume overloaded. Despite AF rhythm control and volume optimization, flows never returned to prior baseline (Figure A). Gated cardiac CT demonstrated narrowing within the bend relief down to 3.7mm. During an echo guided ramp study aortic valve opening frequency decreased only minimally with speed up titration with slight improvement in flows. Ventriculography was significant for narrowing of the proximal outflow graft with most contrast exiting through LVOT, however, a kink in the outflow tract vs external compression could not be distinguished (Figure B). Percutaneous stenting was deemed to be too high-risk due to the proximity to the rotor blade. In the OR, fibrinous tissue between the outflow graft and the externally reinforced goretex graft covering the strain relief was identified. Via a limited left subcostal incision, the goretex graft was sharply opened from distal end to proximal end resulting in immediate LVAD flow normalization (Figures C and D). The patient discharged home on post-operative day 5. Mechanical LVAD outflow graft obstructions can be catastrophic and addressing its causes requires a multidisciplinary approach. Here we present a case where a symptomatic, mechanical outflow graft obstruction was identified via multimodal imaging. The mechanical obstruction was ultimately amendable to a minimally invasive surgical approach and avoided pump exchange or even cardiac transplant.

Not All Ventricular Arrhytmias Require A Reduction In LVAD Speed.

Background Despite hemodynamic optimization, ventricular arrhythmias following left ventricular assist device (LVAD) may persist. We present a case in which transthoracic echocardiogram (TTE) paired with LVAD waveform analysis at time of ventricular arrhythmias assisted in differential diagnosis for the precipitating etiology and helped guide management decisions. Case A 78-year-old African American male with stage D heart failure due to ischemic cardiomyopathy underwent implantation of a HeartWare LVAD. Post-operatively, the patient was weaned off inotropes and pressors with gradual speed adjusted to 2600 rpm over the course of a week. Following optimization, he had several episodes of ventricular tachycardia and ventricular fibrillation requiring defibrillation. The likely etiology of trigger was from a fascicular based premature ventricular contraction or suck down event from speed optimization. Intracardiac hemodynamics with Swan-Ganz catheter revealed normal filling pressures, cardiac index and pulmonary vascular resistance with low suspicion for right ventricular failure. An echocardiogram was without evidence of cardiac tamponade. Furthermore, at the time of TTE, another ventricular arrhythmia was captured (Figure 1). The inflow cannula was visualized to be well-positioned and there was no suction event, despite the ongoing arrhythmia. The left ventricle was not excessively decompressed either with an LVIDD at 4.9 cm with speed increased to 2700 rpm. HeartWare waveforms were visualized real-time without evidence of speed drops or alarms. The patient remained hemodynamically stable with a mean arterial pressure of 78 mmHg. He was successfully managed with metoprolol and sotalol. Conclusion Real-time waveforms on LVAD paired with a TTE can aide in the management in patients with ventricular arrhythmias. As this case demonstrates, not all ventricular arrhythmias merit a reduction in speed, particularly in those patients with normal pulmonary vascular resistance. Despite hemodynamic optimization, ventricular arrhythmias following left ventricular assist device (LVAD) may persist. We present a case in which transthoracic echocardiogram (TTE) paired with LVAD waveform analysis at time of ventricular arrhythmias assisted in differential diagnosis for the precipitating etiology and helped guide management decisions. A 78-year-old African American male with stage D heart failure due to ischemic cardiomyopathy underwent implantation of a HeartWare LVAD. Post-operatively, the patient was weaned off inotropes and pressors with gradual speed adjusted to 2600 rpm over the course of a week. Following optimization, he had several episodes of ventricular tachycardia and ventricular fibrillation requiring defibrillation. The likely etiology of trigger was from a fascicular based premature ventricular contraction or suck down event from speed optimization. Intracardiac hemodynamics with Swan-Ganz catheter revealed normal filling pressures, cardiac index and pulmonary vascular resistance with low suspicion for right ventricular failure. An echocardiogram was without evidence of cardiac tamponade. Furthermore, at the time of TTE, another ventricular arrhythmia was captured (Figure 1). The inflow cannula was visualized to be well-positioned and there was no suction event, despite the ongoing arrhythmia. The left ventricle was not excessively decompressed either with an LVIDD at 4.9 cm with speed increased to 2700 rpm. HeartWare waveforms were visualized real-time without evidence of speed drops or alarms. The patient remained hemodynamically stable with a mean arterial pressure of 78 mmHg. He was successfully managed with metoprolol and sotalol. Real-time waveforms on LVAD paired with a TTE can aide in the management in patients with ventricular arrhythmias. As this case demonstrates, not all ventricular arrhythmias merit a reduction in speed, particularly in those patients with normal pulmonary vascular resistance.

The LVAD Risk Matrix: A Scoring Tool for Patient Selection

<h3>Purpose</h3> To evaluate a risk assessment tool for LVAD patient selection. <h3>Methods</h3> Retrospectively, 197 LVAD patients implanted from October 2012-May 2021 were assigned a risk matrix score. LVAD implant devices included Heartmate II, Heartmate III, and Heartware LVAD devices. The risk matrix score was based on clinical risk factors categorized into four components, psychosocial, frailty, medical, and surgical. Each of the four components were given an individual score up to three points. Patients were then scored in totality from 0-12, with higher scores indicating increased risk. We examined the relationship between risk matrix score and survival time post-LVAD implant. <h3>Results</h3> On the risk matrix, 70 patients scored 0-3, 72 scored 4-5, and 54 scored 6-9. Patients with higher risk matrix scores tended to be older, more frail, more likely to be male, more likely to be white, had lower BMI, more likely to be HeartMate III patients, more likely to have self-identified with a mental illness, and had lower INTERMACS scores compared with patients with lower risk matrix scores. Patients scoring 6-9 on the risk matrix had an increased estimated hazard rate of mortality 2.925 times as high as those scoring 0-3 (p value less than 0.001). <h3>Conclusion</h3> The risk matrix scoring tool is a strong indicator of mortality. This scoring tool may be useful to guide other centers in the LVAD patient selection process.

Cardiac Tamponade Totalis: Unique Phenomenon of Biventricular Tamponade After LVAD Implant

<h3>Introduction</h3> Cardiac tamponade results in obstructive shock due to cardiac chamber compression and impaired cardiac output. This commonly involves the RV due to its lower pressure. We report the first case of biventricular tamponade in a patient with a LVAD. <h3>Case Report</h3> A 30 yr old female (ht 4'7", wt 32 kg, BSA 1.13 m²) with inotrope dependent non-ischemic cardiomyopathy presented for heart transplant evaluation. Right heart catheterization on milrinone 0.375 mcg/kg/min was notable for RA 32 mmHg, PA 51/30 (37) mmHg, PCWP 34 mmHg, CI 1.2 L/min/m², PVR 1.8 Wood units. She was listed for cardiac transplant as her vessels were too small for percutaneous peripheral short term mechanical circulatory support. She decompensated needing VA-ECMO and then HeartWare LVAD implantation (speed 2300 RPM). 7 days post operatively, low flow alarms occurred with hypotension requiring escalating doses of ino-pressors. Echocardiography revealed a large circumferential pericardial effusion resulting in biventricular collapse (Figure A). Emergent surgical drainage was performed with 500 ml blood removal, resulting in re-expansion of both ventricles (Figure B). <h3>Summary</h3> To our knowledge this is the first report of biventricular cardiac tamponade, or as we have termed it, tamponade totalis. In the presence of a pericardial effusion, continuous LV unloading via a LVAD can cause the LV pressure to be lower than the pericardial pressure. Coupled with reduced RV preload from post-operative bleeding, this results in biventricular compression and tamponade. A combination of patient (size, anticoagulation, surgical approach) and pump (RPM) related factors likely lead to the development of tamponade totalis. Diagnosis of tamponade in a patient with a continuous flow LVAD is challenging due to similarities in presentation of right heart failure and atypical signs. Unique clues suggestive of tamponade in patients with a LVAD are respiratory variation of the pulsatilitiy index waveform and pulseless paradoxus. Imaging is key to diagnosis.

Improved Detection Of Thromboembolic Complications In Left Ventricular Assist Device By Novel Accelerometer-Based Analysis.

We have previously demonstrated that accelerometer-based vibration analysis detects thromboembolism and pump thrombosis in HeartWare Left Ventricular Assist Device (HVAD) using the third harmonic frequency (pump_speedx3). Thromboembolism also affected the amplitude of the nonharmonic frequencies. The aim of this study was to determine whether nonharmonic-amplitude (NHA) analysis can improve the diagnosis of thromboembolic complications. An accelerometer was attached to HVAD in three in vitro and seven in vivo experiments. Control interventions, including load and pump speed alternations (n = 107), were followed by thromboembolic events (n = 60). A sliding fast-Fourier-transform was analyzed, and changes in NHAs were quantified in the acute phase and in a steady state. Receiver operating characteristic curves were constructed with cutoff values of NHA to detect thromboembolic events. Positive predictive values were calculated on the basis of a specificity of 1. In the acute phase, NHA change was 6.5 times higher under thromboembolism than under control interventions (p < 0.001). Most thromboembolic events lead to concomitant changes in both NHA and third-harmonic amplitude. Combining the two methods improved the PPV by 8.3%. At steady state, signal changes predominantly demonstrated either NHA or third-harmonic changes. Combined signal analysis improved the PPV by 36%. This method enhanced the detection of thromboembolism and pump thrombosis in the HVAD.

Electromagnetic interference from left ventricular assist devices detected in patients with implantable cardioverter-defibrillators.

Electromagnetic interference (EMI) from left ventricular assist devices (LVADs) can cause implantable cardioverter-defibrillator (ICD) oversensing. We sought to assess the frequency of inappropriate shocks/oversensing due to LVAD-related EMI and prospectively compare integrated (IB) versus dedicated bipolar (DB) sensing in patients with LVADs. Single-center study in LVAD patients with Medtronic or Abbott ICDs between September 2017 and March 2020. We excluded patients that were pacemaker dependent. Measurements were obtained of IB and DB sensing and noise to calculate a signal-to-noise ratio (SNR). Device checks were reviewed to assess appropriate and inappropriate sensing events. Forty patients (age 52 ± 14 years, 75% men, 38% ischemic cardiomyopathy) were included with the median time between LVAD implantation and enrollment of 6.7 months (2.3, 11.4 months). LVAD subtypes included: HeartWare (n = 22, 55%), Heartmate II (n = 10, 25%), and Heartmate III (n = 8, 20%). Over a follow-up duration of 21.6 ± 12.9 months after LVAD implantation, 5% of patients (n = 2) had oversensing of EMI from the LVAD (both with HeartWare LVADs and Abbott ICDs) at 4 days and 10.8 months after LVAD implantation. Both patients underwent adjustment of ventricular sensing with resolution of oversensing and no further events over 5 and 15 months of further follow-up. The SNR was similar between IB and DB sensing (50 [29-67] and 57 [41-69], p = 0.89). ICD oversensing of EMI from LVADs is infrequent and can be managed with reprogramming the sensitivity. There was no significant difference in the R-wave SNR with IB versus DB ICD leads.

Long-Term Outcome After Venoarterial Extracorporeal Membrane Oxygenation as Bridge to Left Ventricular Assist Device Preceding Heart Transplantation

To determine if venoarterial extracorporeal membrane oxygenation (VA ECMO) as a bridge to left ventricular assist device (LVAD) in heart transplant (HT) candidates (ie, double bridge to HT) was associated with increased morbidity and mortality when compared to LVAD bridging to HT (ie, single bridge to HT). A retrospective analysis of patients undergoing LVAD support from 2011 to 2020. A Kaplan-Meier survival curve and Cox-Mantel hazard ratios (HR) were calculated during LVAD support and after HT. Postoperative complications were collected. University Hospital Erasme. HT candidates requiring LVAD. VA ECMO bridging to LVAD (ECMO-LVAD group [n=24]) versus LVAD (LVAD group [n=64]). Eighty-eight patients underwent HeartWare LVAD (HVAD, Medtronic) placement. Survival to hospital discharge and during the entire study period were lower in the ECMO-LVAD group (66.7% v 92.2%; p=0.0027, and 37.5% v 62.5%; p=0.035, respectively). Overall HR of death was 2.46 (95% confidence interval [CI]: 1.13-5.37; p=0.005) in the ECMO-LVAD group and remained elevated throughout their time on LVAD support (HR 3.24 [95% CI: 1.15-9.14]; p=0.0036). However, in patients who underwent HT (n=50), mortality was similar between groups (HR 1.33 [95% CI: 0.33-5.31]; p=0.66). Postoperative complications were more frequent in the ECMO-LVAD group (infection=83.3% v 51.6%, p=0.007; renal replacement therapy=45.8% v 9.4%, p=0.0001; post-LVAD ECMO=25.0% v 1.6%; p=0.0003). VA ECMO as a bridge to LVAD support before HT was associated with increased morbidity and mortality during LVAD support. However, in patients who underwent HT, outcomes were similar regardless of VA ECMO bridging.

Absolute Risk of Death is Lower in Left Ventricular Assist Device Patients with Good Anticoagulation Control

<h3>Purpose</h3> Patients with continuous-flow (CF) left ventricular assist devices (LVADs) as destination therapy (DT) require anticoagulation with vitamin K antagonists (VKAs). A time in therapeutic range (TTR) of international normalized ratio above 60% is associated with fewer clinical events in atrial fibrillation patients. However, data on this association in LVAD patients are lacking. We therefore aimed to study the association between TTR and clinical events in patients with CF-LVAD as DT. <h3>Methods</h3> We performed a single center cohort study of patients implanted with a HeartWare LVAD as DT who were discharged from the hospital between 2010 and 2020. Patients were followed from day of discharge until their first event, death or end of follow-up. During follow-up, the TTR (< 60% and ≥ 60%) with periods of 1 month was calculated by means of the Roosendaal method. The outcomes were death, and thromboembolic, neurologic and hemorrhagic events that were adjudicated by two physicians according to the "2020 Updated definitions of adverse events for trials and registries of mechanical circulatory support". We calculated incidence rates (IRs) per 10 patient years with 95% confidence intervals (CIs) and stratified these by TTR. Incidence rate ratios (IRRs) with 95% CIs were calculated with TTR < 60% as reference group. <h3>Results</h3> A total of 63 patients were included with a median age of 63 years (range 29-72), under whom 50 (79%) males and 36 (57%) had ischemic heart failure. During 156 years of follow-up, 13 thromboembolic, 19 hemorrhagic, 19 neurologic events and 34 deaths occurred. IRs were slightly higher among patients with a TTR < 60% compared with ≥ 60% (any event 8.7 vs 6.0; thromboembolic 1.3 vs 0.5; hemorrhagic 2.0 vs 1.3; death 2.9 vs 1.1 resp, see Table) except for neurologic events (1.2 vs 1.9 resp). A high TTR was associated with a 62% reduction of death (IRR 0.38 95%CI 0.15-0.84). <h3>Conclusion</h3> A high TTR in patients with a CF-LVAD as DT is associated with fewer thromboembolic and hemorrhagic events and death.

Thromboelastography of Limited Benefit in LVAD Patient Management

Purpose The role of utilizing thromboelastography (TEG) in managing antiplatelet therapy (APT) in LVAD patients is controversial. The purpose of this study was to determine if the removal of TEG from APT protocol reduced late onset bleeding without an increase in thromboembolic events. Methods We performed a single-center retrospective cohort study at the University of Florida including all recipients of a HeartMate II, HeartMate III, or Heartware LVAD between April 2005 and November 2019 (n=293). LVAD recipients before June 1st,2017 (n=221) whose APT was monitored and adjusted using TEG were compared to LVAD recipients after June 1st,2017 (n=72) where TEG was not utilized. The occurrence of late-onset bleeding events after post-operative day 7, as defined by INTERMACs major bleeding, as well as thromboembolic events were collected. Patients were followed up to one year post-implantation or to time of death, transplant, or pump exchange. APT doses, warfarin use and INR values were collected at discharge as well as 1, 3, 6 and 12 months post-implantation. Results Over a median follow-up period of 12 months, INTERMACS major bleeding events occurred in 35% of patients where TEG was utilized compared to 29% where TEG was not utilized (p-value 0.375), and procedural intervention was required in 29% compared to 18% respectively (p-value 0.058). After June 1st 2017, patients had a higher average BMI (31 compared to 29, p-value 0.020), were more likely to be on digoxin on discharge (24% compared to 12%, p-value 0.019), and were less likely to be of white race (p-value 0.043) or have ischemic cardiomyopathy (p-value 0.019). In a multivariable Cox proportional-hazards regression model including all these variables, older age was the only independent predictor of bleeding events (HR 1.03 for each additional year of age, 95% CI 1.01-1.05, p 0.008). Use of TEG was associated with use of higher doses of aspirin (>325mg 41% vs. 0%), and use of a second antiplatelet (43% vs. 1%). There was no significant difference in thromboembolic events (15% in each). Conclusion In this single center retrospective study, thromboelastography monitoring after LVAD implantation was associated with significantly higher rates of multidrug antiplatelet regimen use, at significantly higher doses, with no difference in thromboembolic events compared to LVAD patients managed without TEG. Bleeding events were more common in elderly recipients.

Incidence and Clinical Findings Associated to Incomplete Hemodynamic Unloading of the Left Ventricle under LVAD Support

Purpose Normalization of hemodynamics plays an important role in achieving an optimal clinical benefit after LVAD Implantation. However the hemodynamic optimization during follow-up continues to be a challenge. We assessed the likelihood of effective hemodynamic unloading of the Left ventricle (HLVU) during LVAD support, when the current standard recommendations for LVAD speed optimization were applied in the clinical practice, and its association with different clinical and echocardiographic (TTE) conditions. Methods Retrospective study that included consecutive patients who had primary received an LVAD as bridge to heart transplantation (BTT) and underwent a right-side catheterization (RHC) at least 3 months after the LVAD implantation as part of the screening process for BTT candidacy.Routinely ambulatory follow-up consisted in clinical, TTE and hematological examination.LVAD rotor speed was optimized during each follow-up visit according to the current clinical recommendations. Results 104 p (87% male, 55+/-6 years, 42% HeartWare LVAD, 58% HM3 LVAD) were studied. Incomplete HLVU was defined if the pulmonary capillary wedge pressure was above 15 mmHg (hPCWP), and it was present in 29 p (28%). Patients with hPCWP were older, had worse postoperative renal function, higher BNP levels, received fewer renin-angiotensin-Aldosteron blocking agents(RAB) and required higher dose of diuretics (p 300 pg/dl could predict hPCWP with 78% accuracy, 74% specificity and a 78% sensitivity (p Conclusion An incomplete HLVU under LVAD support is common in the clinical practice, when the current standard recommendations are applied. Our study highlights the negative effect of age and renal dysfunction in the likehood of effective HLVU and the potential contribution of the RAB to achieve this goal.The BNP levels and the magnitude of the echocardiographic reverse LV remodeling seem to be useful non-invasive tools to evaluate the degree of effective LV unloading during follow-up.

Heart* to Heart*: Thrombosed HeartWare LVAD Exchanged to a Heartmate 3 LVAD

<h3>Introduction</h3> Left ventricular assist devices (LVADs) have undergone technological advances over the past several years, however, device thrombosis remains a feared complication. We present a case of a HeartWare HVAD presenting with pump thrombosis which failed medical therapy and was exchanged for an Abbott HeartMate 3 pump. <h3>Case Report</h3> The patient is a 38-year-old male with end stage-systolic heart failure due to a HIV associated cardiomyopathy who underwent HVAD implantation six years prior to presentation. The patient was in his usual state of health when he presented to the hospital due to a "high watt" alarm. He was asymptomatic. The patient, who was maintained on aspirin and warfarin, had a presenting INR which was subtherapeutic (1.2). Interrogation of the device logs showed an abrupt increase in power up to 9W with flows >10 L/min (baseline ∼4.5W and ∼5.5 L/min) (Figure). Computed tomography (CT) angiogram did not reveal an outflow graft thrombosis but did note pulmonary edema. The patient was diagnosed with pump thrombosis and was initially treated with two doses of alteplase 20 mg (Figure arrows). The power and flow normalized. Multiple lactate dehydrogenase (LDH) specimens were hemolyzed, but the LDH 3 days after admission ultimately was 3,550 U/L (baseline 268 U/L). Two days later, power spikes recurred. The patient was given one dose of alteplase 50 mg without success. The patient underwent emergent exchange to a HeartMate 3 LVAD via a re-do sternotomy. Surgery was notable for the epicardial ring of the HVAD being firmly incorporated at the left ventricular apex. To minimize trauma, the epicardial ring of the HeartMate 3 was sutured directly onto the epicardial ring of the HVAD. The Heartmate 3 was then inserted through both epicardial rings while the outflow graft was anastomosed to the remnant outflow graft of the HVAD. The patient did well post-operatively and was discharged on post-operative day number 15. <h3>Summary</h3> A thrombosed HVAD can be successfully managed with exchange to a HeartMate 3 LVAD.

Characteristics of strokes associated with centrifugal flow left ventricular assist devices

Stroke is a devastating complication of left ventricular assist device (LVAD) therapy. Understanding the characteristics, risk factors and outcomes of strokes associated with the centrifugal flow LVADs is important to devise better strategies for management and prevention. This is a retrospective cohort study at a single US academic medical center. The cohort includes patients who received a first time Heartmate 3 (HM3) or Heartware (HVAD) LVAD between September 2009 through February 2018 and had a stroke while the LVAD was in place. Descriptive statistics were used when appropriate. A logistic regression analysis was used to determine predictors of poor outcome. Out of a total of 247 patients, 12.1% (N = 30, 24 HVAD and 6 HM3) had a stroke (63% ischemic) and 3 of these patients had pump thrombosis. Events per patient year (EPPY) were similar for HVAD and HM3 patients (0.3 ± 0.1). INR was subtherapeutic in 47.4% of ischemic stroke patients and supratherapeutic in 18.2% of hemorrhagic stroke patients. Concurrent infections were more common in the setting of hemorrhagic stroke than ischemic stroke (45.4% vs 5.3%, p = 0.008). Strokes were severe in most cases, with initial NIH stroke scale (NIHSS) higher in HM3 patients compared to HVAD patients (mean 24.6 vs 16) and associated with high in-patient mortality (21.1% of ischemic stroke vs. 88.8% of hemorrhagic stroke). Predictors of death within 30 days and disability at 90 days included creatinine at stroke onset, concurrent infection, hemorrhaghic stroke, and initial stroke severity (NIHSS). A score derived from these variables predicted with 100% certainty mortality at 30 days and mRS ≥ 4 at 90 days. For patients with centrifugal flow LVADs, ischemic strokes were more common but hemorrhagic strokes were associated with higher in-patient mortality and more frequently seen in the setting of concurrent infections. Infections, sub or supratherapeutic INR range, and comorbid cardiovascular risk factors may all be contributing to the stroke burden. These findings may inform future strategies for stroke prevention in this population.