Long-term discontinuation of warfarin in a patient with HeartMate 3 left ventricular assist device without thromboembolic events.

The gold standard therapy for end-stage heart failure is cardiac transplantation. However, in the face of a donor shortage, a mechanical assist device such as the left ventricular assist device HeartMate 3 (Abbott Laboratories, Abbott Park, IL, USA) serves as bridging therapy to transplantation and/or destination therapy. Current guidelines recommend anticoagulation with a vitamin K antagonist in combination with low-dose aspirin. We herein report a challenging anticoagulation regimen in a patient with a HeartMate 3 in whom systemic anticoagulation with warfarin was not feasible for 4 years because of low compatibility and a rare X-factor deficiency. This is a rare hematological disorder, estimated to affect approximately 1 in every 500,000 to 1,000,000 people in the general population. The patient finally received a modified anticoagulation regimen involving the combination of rivaroxaban and clopidogrel without warfarin. Under this regimen, the patient remained free of thromboembolic complications for 4 years with in situ placement of the left ventricular assist device. This case illustrates that under specific circumstances, long-term absence of warfarin therapy is feasible in patients with a HeartMate 3.

FLAVOUR Study: FLow profiles And postoperative VasOplegia after continUous-flow left ventriculaR assist device implantation.

This study aims to associate the incidence of postoperative vasoplegia and short-term survival to the implantation of various left ventricular assist devices differing in hemocompatibility and flow profiles. The overall incidence of vasoplegia was 25.3% (73/289 patients) and 30.3% (37/122), 25.0% (18/72), and 18.9% (18/95) in the axial flow (AXF), centrifugal flow (CF), and centrifugal flow with artificial pulse (CFAP) group, respectively. Vasoplegia was associated with longer intensive care (ICU) and hospital length of stay (LOS) and mortality. ICU and in-hospital LOS and 1-year mortality were the lowest in the CFAP group. Post hoc analysis resulted in a p-value of 0.43 between AXF and CF; 0.35 between CF and CFAP; and 0.06 between AXF and CFAP. Although there is a trend in diminished incidence of vasoplegia, pooled logistic regression using flow profile and variables that remained after feature selection showed that flow profile was not an independent predictor for postoperative vasoplegia.

Gastrointestinal bleeding on continuous-flow left ventricular assist device therapy.

While technological advances in the field of continuous-flow left ventricular assist device (CF-LVAD) are constantly being made, CF-LVAD recipients are still subjected to a relatively high rate of LVAD-related adverse events, with post-LVAD gastrointestinal bleeding (GIB) being the most common one. GIB is associated with a significant impairment in quality of life, multiple hospital admissions, blood transfusion requirements and possibly death. Furthermore, of those patients who bled once, many will experience recurrent GIB events, which further aggravates their discomfort. While some medical and endoscopic treatment options are available, evidence regarding their benefit remains largely equivocal, with all related studies based on data from registries rather than clinical trials. Although having a major impact on LVAD recipients, an effective and validated pre-implant screening options to predict GIB events post-implant are scarce. This review focuses on the aetiology, incidence, risk factors, treatment options and the effect of new generation devices on post-LVAD GIB.

Device-device interaction between cardiac implantable electronic devices and continuous-flow left ventricular assist devices.

The current design of an innovative left ventricular assist device (LVAD) makes use of magnetic levitation technology, which enables the rotors of the device to be completely suspended by magnetic force, reducing friction and blood or plasma damage. However, this electromagnetic field can result in electromagnetic interference (EMI), which can interfere with proper functioning of another cardiac implantable electronic device (CIED) in its direct proximity. Approximately 80% of patients with an LVAD have a CIED, most frequently an implantable cardioverter-defibrillator (ICD). Several device-device interactions have been reported, including EMI-induced inappropriate shocks, inability to establish telemetry connection, EMI-induced premature battery depletion, undersensing by the device, and other CIED malfunctions. Unfortunately, additional procedures, including generator exchange, lead adjustment, and system extraction, are frequently required because of these interactions. In some circumstances, the additional procedure might be preventable or avoidable with appropriate solutions. In this article, we describe how EMI from the LVAD impacts the functionality of the CIED and provide possible management options, including manufacturer-specific information, for the current CIEDs (eg, transvenous and leadless pacemakers, transvenous and subcutaneous ICDs, and transvenous cardiac resynchronization therapy pacemakers and ICDs).

Vascular Function in Continuous Flow LVADs: Implications for Clinical Practice.

Left ventricular assist devices (LVADs) have been increasingly used in patients with advanced heart failure, either as a destination therapy or as a bridge to heart transplant. Continuous flow (CF) LVADs have revolutionized advanced heart failure treatment. However, significant vascular pathology and complications have been linked to their use. While the newer CF-LVAD generations have led to a reduction in some vascular complications such as stroke, no major improvement was noticed in the rate of other vascular complications such as gastrointestinal bleeding. This review attempts to provide a comprehensive summary of the effects of CF-LVAD on vasculature, including pathophysiology, clinical implications, and future directions.

Outcomes of continuous flow left ventricular assist device after surgical left ventricular restoration.

OBJECTIVES: This study aimed to report the clinical outcomes of continuous flow left ventricular assist device implantation in end-stage chronic heart failure patients with a history of surgical left ventricular restoration. METHODS: We retrospectively identified 190 patients undergoing continuous flow left ventricular assist device implantation at our center from November 2007 to April 2020. In total, six patients underwent continuous flow left ventricular assist device implantation after various types of surgical left ventricular restoration procedures, including endoventricular circular patch plasty (n = 3), posterior restoration procedure (n = 2), and septal anterior ventricular exclusion (n = 1). RESULTS: Continuous flow left ventricular assist device (Jarvik 2000, n = 2; EVAHEART, n = 1; HeartMate II, n = 1; DuraHeart, n = 1; HVAD, n = 1) was successfully implanted in all patients. During a median follow-up of 48 months (interquartile range, 39-60 months; censoring heart transplantation), no death was documented, which means that overall survival after left ventricular assist device implantation was 100% at any time point. Finally, three patients received heart transplantation (waiting time: 39, 56, and 61 months, respectively) and the other three patients are still awaiting heart transplantation (waiting time: 12, 41, and 76 months, respectively). CONCLUSIONS: In our series, continuous flow left ventricular assist device implantation after surgical left ventricular restoration was safe and feasible, even if an endoventricular patch was used, and effective for bridge to transplant strategy.

Distinctive kidney function trajectories following left ventricular assist device implantation.

BACKGROUND: The aim of this study was to assess for distinct kidney function trajectories following left ventricular assist device (LVAD) placement. Cohort studies of LVAD recipients demonstrate that kidney function tends to increase early after LVAD placement, followed by decline and limited sustained improvement. Inter-individual differences in kidney function response may be obscured. METHODS: We identified continuous flow LVAD implantations in US adults (2016-2017) from INTERMACS (Interagency Registry for Mechanically Assisted Circulatory Support). Primary outcomes were estimated glomerular filtration rate (eGFR) trajectories pre-implantation to ∼12 months. Latent class mixed models were applied to primary and validation samples. Clinical differences among trajectory groups were investigated. RESULTS: Among 4,615 LVAD implantations, 5 eGFR trajectory groups were identified. The 2 largest groups (Groups 1 and 2) made up >80% of the cohort, and were similar to group average trajectories previously reported, with early eGFR rise followed by decline and stabilization. Three novel trajectory groups were found: worsening followed by sustained low kidney function (Group 3, 10.1%), sustained improvement (Group 4, 3.3%), and worsening followed by variation (Group 5, 1.7%). These groups differed in baseline characteristics and outcomes. Group 4 was younger and had more cardiogenic shock and pre-implantation dialysis; Group 3 had higher rates of pre-existing chronic kidney disease, along with older age. CONCLUSIONS: Novel eGFR trajectories were identified in a national cohort, possibly representing distinct cardiorenal processes. Type 1 cardiorenal syndrome may have been predominant in Group 4, and parenchymal kidney disease may have been predominant in Group 3.

Transcatheter Aortic Valve Replacement for Severe Aortic Regurgitation in Patients With a Left Ventricular Assist Device.

BACKGROUND: There are limited invasive treatment options for patients with end-stage heart failure and left ventricular assist device (LVAD) who develop severe aortic valve regurgitation (AR). One option for such patients is transcatheter aortic valve replacement (TAVR). There are limited data on outcomes of patients with LVAD who receive TAVR for severe AR. We present a series of 4 consecutive patients with LVAD who underwent TAVR for severe AR. METHODS AND RESULTS: This is a retrospective chart review of 4 consecutive patients with LVAD who underwent TAVR for severe AR. All 4 patients underwent TAVR with a 34-mm self-expanding valve (Medtronic). One patient received a 29-mm balloon-expandable valve (Edwards Lifesciences) within the self-expanding valve (SEV) to postdilate the SEV and minimize paravalvular leak (PVL). All 4 procedures were technically successful. The patient who received rescue valve-in-valve TAVR continued to have persistent mild to moderate PVL. CONCLUSION: Although technically challenging, TAVR is a feasible option for carefully selected LVAD patients with severe AR. Procedural issues to consider include oversizing the transcatheter heart valve (THV) while being cognizant of the risks of annular rupture and valve dislocation, anticipating and avoiding ventricular migration of the THV and being ready to postdilate the THV if necessary, to limit hemodynamically significant PVL.

An external validation study of the Utah Bleeding Risk Score.

OBJECTIVES: Gastrointestinal bleeding in patients with continuous-flow left ventricular assist devices (CF-LVAD) impairs quality of life and increases hospitalization rate. The Utah Bleeding Risk Score (UBRS) has been created to predict gastrointestinal bleeding (GIB) in patients on left ventricular assist device. We here aimed to externally validate UBRS on our cohort of CF-LVAD patients. METHODS: Utah Bleeding Risk Score was calculated, GIB events summarized on follow-up and patients stratified into 3 risk groups. Predictive ability of UBRS was examined at 3 years and during whole support time and person time incidence rates correlated to UBRS. In a sub-analysis, single effects of UBRS variables on freedom from GIB were assessed. RESULTS: A total of 111 CF-LVAD patients were included. The median UBRS was 2 (3-1). Receiver operating characteristic curve analysis showed an area under the curve of 0.519 (P = 0.758, 95% confidence interval = 0.422-0.615) at 3 years and an area under the curve of 0.515 (P = 0.797, 95% confidence interval = 0.418-0.611) during whole support time. No significant difference was observed in UBRS between bleeders and non-bleeders (P = 0.80). No significant difference in freedom from GIB was observed (P3 years = 0.7; Psupport-time = 0.816) and no independent significance regarding the freedom from bleeding at 3 years for any variable was observed. Coronary artery disease was associated with higher risk of GIB beyond the 3rd year (P = 0.048). CONCLUSIONS: UBRS was not able to predict GIB and therefore not applicable in our cohort of patients. Coronary artery disease could lead to a higher risk for GIB during support time. An additional validation in a larger cohort is advisable.

Minimally invasive versus conventional continuous-flow left ventricular assist device implantation for heart failure: a meta-analysis.

Many studies have reported various minimally invasive techniques for continuous-flow left ventricular assist device implantation. There is no consensus on whether minimally invasive techniques can bring more benefits for patients compared with the conventional technique, due to the limited number of patients and diverse results in current studies. Our meta-analysis mainly discussed the comparison of minimally invasive and conventional techniques. We searched controlled trials from PubMed, Cochrane Library, and Embase databases until Dec 11, 2020. Perioperative and postoperative outcomes were analyzed among 10 included studies. The protocol has been registered with PROSPERO (CRD42020221532). There were no statistical differences in the 30-day mortality (OR 0.57; 95% CI 0.29 to 1.14), 6-month mortality (OR 0.66; 95% CI 0.41 to 1.05), neurological dysfunction (OR 1.10; 95% CI 0.69 to 1.76), major infection (OR 0.68; 95% CI 0.36 to 1.28), and pump thrombus (OR 1.49; 95% CI 0.63 to 3.52) among the cohorts. Minimally invasive techniques were associated with lower incidences of major bleeding (OR 0.39; 95% CI 0.22 to 0.68), severe right heart failure (OR 0.43; 95% CI 0.23 to 0.81), and less blood-product utilization (SMD -0.44). Sensitivity analysis suggested that minimally invasive techniques were associated with a lower incidence of respiratory failure (OR 0.50; 95% CI 0.26 to 0.96) and shorter mechanical ventilation time (SMD -0.53). Subgroup analysis demonstrated that patients, implanted with a centrifugal pump by minimally invasive techniques, were associated with a shorter length of intensive care unit (ICU) stay (SMD -0.27) and hospital stay (SMD -0.42), and less blood-product utilization (SMD -0.26). In conclusion, minimally invasive techniques can reduce the risks of major bleeding, severe right heart failure, and blood-product utilization, as well as have positive impacts on reducing mechanical ventilation time and the risk of respiratory failure. Minimally invasive centrifugal pump implantation can reduce the length of ICU and hospital stay.

Impact of using higher-risk donor hearts for candidates with pre-transplant mechanical circulatory support.

BACKGROUND: We evaluated post-heart transplant (HTx) outcomes after use of higher-risk donor hearts for candidates supported with pre-HTx mechanical circulatory support (MCS). METHODS: In this retrospective analysis of the national United Network for Organ Sharing registry, a total of 9,915 adult candidates on MCS underwent HTx from January 1, 2010 to March 31, 2019. Multi-organ, re-transplant, and congenital heart disease patients were excluded. Higher-risk donor organs met at least one of the following criteria: left ventricular ejection fraction <50%, donor to recipient predicted heart mass ratio <0.86, donor age >55 years, or ischemic time >4 hours. Primary outcome was 1 year post-transplant survival. RESULTS: Among HTx recipients, 3688 (37.2%) received higher-risk donor hearts. Candidates supported with pre-HTx extracorporeal membrane oxygenation or biventricular assist device (n = 374, 3.8%) who received higher-risk donor hearts had comparable 1 year survival (HR: 1.14, 95% CI: [0.67-1.93], p = 0.64) to recipients of standard-risk donor hearts, when adjusted for recipient age and sex. In candidates supported with intra-aortic balloon pump (n = 1391, 14.6%), transplantation of higher-risk donor hearts did not adversely affect 1 year survival (HR: 0.80, 95% CI: [0.52-1.22], p = 0.30). Patients on durable left ventricular assist devices (LVAD) who received higher-risk donor hearts had comparable 1 year survival to continued LVAD support on the waitlist, but mortality was increased compared to those who received standard-risk donor hearts (HR: 1.37, 95% CI: [1.11-1.70], p = 0.004). CONCLUSIONS: Patients requiring pre-HTx temporary MCS who received higher-risk donor hearts had comparable 1 year post-transplant survival to those who received standard-risk donor hearts. Stable patients on durable LVADs may benefit from waiting for standard-risk donor hearts.

Long-Term Neurocognitive Outcome in Patients With Continuous Flow Left Ventricular Assist Device.

OBJECTIVES: The authors sought to examine the long-term cognitive outcome of patients with continuous flow left ventricular assist device (CF-LVAD). BACKGROUND: Data on long-term neurocognitive outcome in LVAD are limited. We examined the neurocognitive outcome of patients who received a CF-LVAD as destination therapy. METHODS: Patients with HeartWare (HVAD) and HeartMate II who were enrolled in the ENDURANCE and ENDURANCE Supplemental trials were eligible. Cognition was evaluated with neuropsychological testing preoperatively and at 6, 12, and 24 months after implantation. General linear models identified demographic, disease, and treatment factors that predicted decline on each neurocognitive measure. RESULTS: Of 668 patients who completed baseline testing and at least 1 follow-up evaluation, 552 were impaired at baseline on at least 1 cognitive measure. At each follow-up, approximately 23% of tested patients declined and 20% improved relative to baseline on at least 1 cognitive measure. Of those who were intact at baseline, only 10%-12% declined in delayed memory and 11%-16% declined in executive function at all 3 follow-ups. For patients impaired at baseline, delayed memory decline was associated with the HVAD device and male sex, whereas executive function decline was associated with the HVAD device and stroke during CF-LVAD support. For patients intact at baseline, male sex and history of hypertension were associated with decline in immediate memory and executive function, respectively. CONCLUSIONS: Neurocognitive function remained stable or improved for most patients (∼80%) with CF-LVAD at 6, 12, and 24 months after implantation. Male sex, hypertension, HVAD, and stroke were associated with cognitive decline.

Continuous flow left ventricular assist devices do not worsen endothelial function in subjects with chronic heart failure: a pilot study.

AIMS: To evaluate endothelial function in subjects with left ventricular assist devices (LVADs), comparing them with subjects with chronic heart failure with reduced ejection fraction on the list for heart transplant (HT) and with HT patients with a normal systolic cardiac function to identify any differences. METHODS: We enrolled 28 subjects with LVAD, 55 subjects with HT, and 42 subjects with heart failure on the transplant list. The subjects underwent a general physical examination, assessment of laboratory blood parameters, and assessment of endothelial function through flow-mediated dilation (FMD) of brachial artery. RESULTS: The three groups were homogeneous as regards age, gender, smoke abuse, C-reactive protein (CRP) and FMD parameters (P = ns). In LVAD group percentage of FMD change showed an inverse correlation with CRP (rho: -0.5, P: 0.003), a well-known marker of inflammation and tissue damage. CONCLUSIONS: Continuous flow related to LVAD seems to not worsen endothelial function. Endothelial function was not affected by cardiovascular risk factors (hypertension, hypercholesterolaemia, diabetes, obesity, and tobacco habit), by the functional status expressed by New York Heart Association class, by the left ventricular systolic function and by the presence or absence of ischaemic heart disease in all the populations analysed. CRP was the only factor able to influence percentage of FMD change in patient with LVAD, reinforcing the hypothesis that inflammation is the main determinant of endothelial function.

Gender differences in psychosocial and clinical characteristics in the European Registry for Patients with Mechanical Circulatory Support.

BACKGROUND: Not much is known about psychosocial characteristics of men and women receiving continuous flow left ventricular assist devices (CF LVAD). OBJECTIVE: To investigate gender differences in clinical and psychosocial (demographic, behavioral, psychological) characteristics in CF LVAD recipients. METHODS: We analyzed European Registry for Patients with Mechanical Circulatory Support (EUROMACS) data (N=2395, 16.8% women; 2011 to 2017) and compared pre-implant characteristics in men and women intended for bridge-to-transplant (BTT) or destination therapy (DT). RESULTS: Women were underrepresented [DT (n=61): 13.4%; BTT (n=341): 17.6%]. They were more likely to be divorced/separated, widowed, in unstable clinical condition, and non-working (DT only), but less likely to be smokers, to have ischemic cardiomyopathy or diabetes, and younger (BTT only) than men. Missing data were abundant, especially those that reflect psychological characteristics (>87%). CONCLUSION: Gender differences were noted, some specific to device strategy. Improved collection of psychosocial characteristics is warranted to elucidate their relationship to future prognosis.

Continuous-flow left ventricular assist device versus orthotopic heart transplantation in adults with heart failure: a systematic review and meta-analysis.

BACKGROUND: Due to the lack of donor hearts, many studies have assessed the prognosis of heart failure (HF) patients treated with a continuous-flow left ventricular assist device (CF-LVAD). However, previous results have not been consistent and minimal data is available regarding long-term outcomes. There is no consensus on whether CF-LVAD as a bridge or destination therapy (DT) can equal orthotopic heart transplantation (HTx). The purpose of our study is to compare clinical outcomes between CF-LVAD and HTx in adults. METHODS: We searched controlled trials from PubMed, Cochrane Library, and Embase databases until July 1, 2020. The mortality at different time points and adverse events were analyzed among 12 included studies. RESULTS: No significant differences were found in mortality at one-year [odds ratio (OR) =1.08; 95% CI: 0.97-1.21], two-year (OR =1.01; 95% CI: 0.91-1.12), three-year (OR =1.02; 95% CI: 0.69-1.51), and five-year (OR =1.02; 95% CI: 0.93-1.11), as well as the comparison of stroke, bleeding, and infection between CF-LVAD as a bridge versus HTx. The pooled analysis of one-year mortality (OR =2.76; 95% CI: 0.38-20.18) and two-year mortality (OR =1.64; 95% CI: 0.22-12.23) revealed no significant difference between CF-LVAD DT and HTx. Comparisons of adverse events showed no differences in bleeding or infection, but a higher risk of stroke (OR =5.09; 95% CI: 1.74-14.84) for patients treated with CF-LVAD DT than with HTx. CONCLUSIONS: CF-LVAD as a bridge results in similar outcomes as HTx within five years. CF-LVAD as a DT is associated with similar one-year and two-year mortality, but carries a higher risk of stroke, as compared with HTx.

Pulmonary vasodilator use in continuous-flow left ventricular assist device management.

Pulmonary hypertension (PH) due to left heart disease is the most common etiology for PH. PH in patients with heart failure with reduced fraction (HFrEF) is associated with reduced functional capacity and increased mortality. PH-HFrEF can be isolated post-capillary or combined pre- and post-capillary PH. Chronic elevation of left-sided filling pressures may lead to reverse remodeling of the pulmonary vasculature with development of precapillary component of PH. Untreated PH in patients with HFrEF results in predominant right heart failure (RHF) with irreversible end-organ dysfunction. Management of PH-HFrEF includes diuretics, vasodilators like angiotensin-converting enzyme inhibitors or angiotensin-receptor blockers or angiotensin-receptor blocker-neprilysin inhibitors, hydralazine and nitrates. There is no role for pulmonary vasodilator use in patients with PH-HFrEF due to increased mortality in clinical trials. In patients with end-stage HFrEF and fixed PH unresponsive to vasodilator challenge, implantation of continuous-flow left ventricular assist device (cfLVAD) results in marked improvement in pulmonary artery pressures within 6 months due to left ventricular (LV) mechanical unloading. The role of pulmonary vasodilators in management of precapillary component of PH after cfLVAD is not well-defined. The purpose of this review is to discuss the pharmacologic management of PH after cfLVAD implantation.

Can the intermittent low-speed function of left ventricular assist device prevent aortic insufficiency?

Aortic insufficiency (AI) is known to associate with a persistently closed aortic valve during continuous-flow ventricular assist device support. Some devices carry an intermittent low-speed (ILS) function, which facilitates aortic valve opening, but whether this function prevents AI is unknown. In this study, the Jarvik 2000 device, which is programmed to reduce the pump speed each minute for 8 s, was chosen to examine this potential effect. Prospectively collected data of 85 heart transplant-eligible Jarvik 2000 recipients who met the study criteria (no pre-existing AI and aortic valve surgery) were retrospectively analyzed for the incidence, correlating factors, and clinical outcomes of de novo AI. All data were provided by the Japanese Registry for Mechanically Assisted Circulatory Support. De novo AI occurred in 58 patients, 23 of whom developed at least moderate AI during a median support duration of 23.5 months. Freedom from moderate or greater AI was 84.4%, 66.1% and 60.2% at 1, 2 and 3 years, respectively. Multivariate analyses revealed that progressive AI was correlated with decreased pulse pressure after implantation (hazard ratio 1.060, 95% confidence interval 1.001-1.127, p = 0.045). No correlation was found for mortality or other adverse events, including stroke, bleeding, infection, pump failure, hemolysis, and readmission. The benefit of the Jarvik 2000's current ILS mode against AI appears to be minimal. However, in this limited cohort where all recipients underwent implantation as a bridge to transplantation, the impact of de novo progressive AI on other clinical adversities was also minimal.

Driveline damage and repair in continuous-flow left ventricular assist devices: A systematic review.

With mounting time on continuous-flow left ventricular assist device (CF-LVAD) support, patients occasionally sustain damage to the device driveline. Outcomes associated with external and internal driveline damage and repair are currently not well documented. We sought to evaluate the outcomes of driveline damage and its repair. Electronic search was performed to identify all relevant studies published over the past 20 years. Fifteen studies were selected for analysis comprising of 55 patients with CF-LVAD dysfunction due to driveline damage. Demographic and perioperative variables along with outcomes including survival rates were extracted and pooled for the systematic review. Most patients (53/55) were supported on HeartMate II LVAD (Abbott Laboratories, Abbott Park, IL). Internal damage was more commonly reported than external damage [69.1% (38/55) vs. 30.9% (17/55), P = .01]. Median time to driveline damage was 1.9 years [IQR 1.0, 2.5]. Most patients presented with a CF-LVAD alarm [94.5% (52/55)] and patients with internal driveline damage had a significantly higher rate of alarm activation compared to that observed for those with external damage [38/38 (100%) vs. 14/17 (82.4%), P = .04]. Patients with internal driveline dysfunction were more likely to experience component wear compared to those with external driveline dysfunction [10/38 (26.3%) vs. 0/17 (0%), P = .05]; 14.5% of patients (8/55) underwent external repair of the driveline, 5.5% (3/55) were treated with rescue tape, and 5.5% (3/55) were placed on an ungrounded cable, indicating a short-to-shield event had occurred. A total of 49.1% of patients (27/55) underwent CF-LVAD exchange, 5.5% (3/55) were weaned off the CF-LVAD to explant, and 5.5% (3/55) underwent emergent heart transplantation. The median length of hospital stay was 12 days [IQR 7, 12] and 30-day mortality rate was 14.5% (8/55). Driveline damage was more commonly reported at an internal location and despite being a well-recognized complication, mortality still appears high.

Varying speed modulation of continuous-flow left ventricular assist device based on cardiovascular coupling numerical model.

Continuous-flow left ventricular assist devices (CFLVADs) routinely operate at a constant speed for the support of a failing heart, which decreases the pulsatility in the arteries. Some late complications could be related to a long-term lack of pulsatility. Modulating the CFLVAD speed is a solution to enhance the pulsatility. The purpose of this study is to modulate multiple varying speed patterns and investigate their effects on the ventricle and vascular system. A cardiovascular coupling numerical model is developed to provide a simulation platform for testing the varying speed patterns. The varying speed patterns are modulated by combining the shape, amplitude, frequency, phase shift, and pulsatile duty cycle of the speed profile. The influence of varying speed support is examined by analyzing the indexes of pulsatility, indexes of ventricular unloading, and hemodynamic variables. The results show that the synchronous counterpulsation pattern can effectively reduce the ventricular unloading indexes, whereas the low-frequency asynchronous pattern can effectively increase the vascular pulsatility indexes. Also, the hemodynamics with synchronous varying speed support is more physiological than that with asynchronous varying speed support. This study provides valuable insight for further optimization of varying speed modulation by weighing vascular pulsatility, ventricular unloading, and hemodynamics.