Continuous-flow Left Ventricular Assist Device Research Articles

Abstract 15424: Phase-to-Phase Short Phenomenon in a Left Ventricular Assist Device: Navigating Through Clinical and Ethical Challenges

Description of Case A 59-year-old male with an axial continuous-flow left ventricular assist device (CF-LVAD) presented asymptomatically after noticing low-flow alarms. He reported extensive external driveline damage that accumulated over one year. The CF-LVAD was connected to an ungrounded cable and the driveline was repaired by the manufacturer. However, low-flow alarms continued. Log files revealed pump stoppages on all modes of power which was compatible with phase-to-phase short phenomenon (PtPSP). The patient was cannulated in case of emergent need for ECMO and upgraded to UNOS status 1 for heart transplant. Because PtPSP was considered unrepairable, the patient underwent emergent cardiac transplantation. Discussion The CF-LVAD driveline consists of three phases, each of which is formed by two electrical wires, connected to six motor stators. PtPSP causes driveline dysfunction due to a loss of insulation between the three phases owing to multiple breaches of the insulator, causing the pump to lose power when the damaged phases come into contact. Pump stoppages are likely and unpredictable even on batteries or an ungrounded cable. Patients may notice alarms associated with low flow, pump speed drops, or pump arrest. PtPSP is unrepairable, and pump exchange or urgent heart transplantation are the only viable treatment options.This case highlights the ethical complexity of the care of patients with advanced heart failure, whereby subjective treatment decisions often translate to objectively different levels of priority on the heart transplantation waiting list without intrinsic measures of disease severity, which may incentivize more aggressive care. Conclusions: CF-LVAD driveline dysfunction due to PtPSP is a clinically asymptomatic ominous scenario often uncovered by pump-controller alarms. Given the high risk of abrupt pump stoppage, a diagnosis of PtPSP necessitates emergent device exchange or explant with an orthotopic heart transplantation.

Abstract 13838: Hemostatic Disorder During Left Ventricular Assist Device Implantation in Swine

Introduction: Implantation of left ventricular assist devices (LVAD) conventionally requires the use of cardiopulmonary bypass (CPB). Among others, mechanical circulatory support devices favor intraoperative hemostatic disorder. Hypothesis: Despite the high risk of severe bleeding and thromboembolic complications, little is known about the intraoperative extent of hemostatic disorder during LVAD implantation.This study aimed to determine the extent of hemostatic disorder during LVAD implantation in a porcine model under CPB and LVAD support, separately. Methods: We performed LVAD implantation in 10 female German Landrace pigs (body weight 104 ± 13 kg). Blood samples were collected three times: at (1) Baseline, (2) after CPB and (3) after LVAD. For CPB, cannulation of the left jugular vein and right femoral artery was performed. After sternotomy and pericardiotomy, apical coring was performed under CPB. A continuous-flow LVAD with transventricular outflow graft was implanted. For CPB and LVAD, a flow rate of 3-7 L/min and a rotational speed of 4000 to 7200 rpm were aimed, respectively. Hemostatic laboratory markers from all times were compared by Wilcoxon signed rank test. Results: Compared to Baseline, CPB led to a significant decrease of fibrinogen and antithrombin as well as an increase of von Willebrand factor (vWF) ratio and D dimer (DD). Compared to after CPB, there was a continued decrease of antithrombin and an increase of DD, as well as a significant increase of vWF and vWF activity under LVAD support. Conclusion: Among others, CPB and LVAD separately contribute to hemostatic disorder during LVAD implantation. Human laboratory markers allowed early detection of intraoperative hemostatic changes in pigs. Further studies are needed to investigate whether off-pump LVAD implantation reduces perioperative hemostatic disorder.

Abstract 12859: Clinical Correlates and Prognostic Value of B-type Natriuretic Peptide in Left Ventricular Assist Device Recipients With Cardiogenic Shock: Insights From INTERMACS

Introduction: B-type natriuretic peptide (BNP) is a robust predictor of outcomes across the heart failure (HF) spectrum. However, data characterizing BNP levels in end-stage HF with cardiogenic shock (CS) is lacking. Furthermore, the prognostic value of BNP in left ventricular assist device (LVAD) receiving Stage D HF patients with CS has not been assessed previously. Methods: Continuous flow LVAD recipients with CS enrolled in INTERMACS between 2005 to 2017 were included. CS was defined as INTERMACS profile 1-3. The primary outcome of the study was long-term mortality. Long-term mortality was assessed in patients alive at 1-month post-surgery. Secondary outcomes included peri-operative mortality (<30 days of surgery), cardiovascular mortality, arrhythmia, and right HF. The cohort was stratified by quartiles of BNP levels. Multivariable Cox proportional hazard models, adjusted for age, sex, body mass index, INTERMACS profile, center volume, implantation year, device strategy, estimated glomerular filtration rate, employment status, and education level, were used to assess the association between BNP levels and outcomes. Results: Among 7,290 LVAD recipients with CS, the median pre-implantation BNP value was 859 (427, 1,614) pg/mL. Males [851(429, 1,557) pg/mL, P =0.07], non-Hispanic Blacks [777 (362, 1,514) pg/mL, P =<0.001], and obese [642 (311, 1,170) pg/mL, P =<0.001] patients had lower BNP values. Over a median follow-up of 14.7 (6.9, 28.7) months, the risk of long-term mortality was similar in the second [HR adj :1.06 (0.94-1.20)], third [HR adj :0.97 (0.85-1.10)], and fourth [HR adj :1.04 (0.91-1.18)] quartiles of BNP compared with the first quartile of BNP. Similarly, the risk of peri-operative mortality, cardiovascular mortality, arrhythmia, and right HF did not vary by the quartiles of BNP. Conclusions: BNP has poor prognostic value in LVAD recipients with CS and the value of routine measurement of BNP in this population needs further investigation.

Current and future options for adult biventricular assistance: a review of literature.

In cardiogenic shock various short-term mechanical assistances may be employed, including an Extra Corporeal Membrane Oxygenator and other non-dischargeable devices. Once hemodynamic stabilization is achieved and the patient evolves towards a persisting biventricular dysfunction or an underlying long-standing end-stage disease is present, aside from Orthotopic Heart Transplantation, a limited number of long-term therapeutic options may be offered. So far, only the Syncardia Total Artificial Heart and the Berlin Heart EXCOR (which is not approved for adult use in the United States unlike in Europe) are available for extensive implantation. In addition to this, the strategy providing two continuous-flow Left Ventricular Assist Devices is still off-label despite its widespread use. Nevertheless, every solution ensures at best a 70% survival rate (reflecting both the severity of the condition and the limits of mechanical support) with patients suffering from heavy complications and a poor quality of life. The aim of the present paper is to summarize the features, implantation techniques, and results of current devices used for adult Biventricular Mechanical Circulatory Support, as well as a glance to future options.

Changing Strategy Between Bridge to Transplant and Destination LVAD Therapy After the First 3 Months: Analysis of the STS-INTERMACS Database

Background: Left ventricular assist devices (LVADs) have been implanted as bridge to transplantation (BTT), bridge to candidacy (BTC) or destination therapy (DT) based on relative and absolute contraindications to transplantation. Multiple factors may lead to change in the strategy of support after LVAD implantation. Methods: From INTERMACS (Interagency Registry for Mechanically Assisted Circulatory Support) 2012-2020, 11,262 patients survived to 3 months on continuous flow LVADs with intent of BTT or DT. Pre-implant characteristics and early events post-LVAD were analyzed in relation to changes in BTT or DT strategy during the next 12 months. Results: Among 3216 BTT patients at 3 months, later transplant de-listing or death without transplant occurred in 536 (16.7%) and, was more common with age, Profiles 1-2, renal dysfunction, and independently for prior cardiac surgery (HR 1.25, 95% CI 1.04-1.51, p = 0.02). Post-LVAD events of infections, gastrointestinal bleeding, stroke, and right heart failure defined by inotropic therapy predicted de-listing and death, as did in-hospital location at 3 months (HR 1.67, 95% CI 1.20-2.33, p =0.0024). Of 8046 patients surviving to 3 months with intent as destination therapy, 750 (9.3%) subsequently underwent listing or transplant, often with initial history of acute HF (HR 1.70, 95% CI 1.27-2.27, p = 0.0012) or malnutrition-cachexia (1.73, 95% CI 1.14-2.63, p = 0.0099). Multiple gastrointestinal bleeding events (≥4) with LVAD increased transition from BTT to DT (HR 4.22, 95% CI 1.46-12.275, p = 0.0078) but also from DT to BTT (HR 5.17, 95% CI 1.92-13.9, p = 0.0011). Conclusions: Implant strategies change over time in relation to pre-implant characteristics and adverse events post implant. Pre-implant recognition of factors predicting later change in implant strategy will refine initial triage, while further reduction of post-LVAD complications will expand options including eventual consideration of heart transplant.

Hemodynamic Evaluation of Asynchronous Speed Modulation of a Continuous-Flow Left Ventricular Assist Device in an Acute-Myocardial Injury Sheep Model.

Asynchronous rotational-speed modulation of a continuous-flow left ventricular assist device (LVAD) can increase pulsatility; however, the feasibility of hemodynamic modification by asynchronous modulation of an LVAD has not been sufficiently verified. We evaluated the acute effect of an asynchronous-modulation mode under LVAD support and the accumulated effect of 6 consecutive hours of driving by the asynchronous-modulation mode on hemodynamics, including both ventricles, in a coronary microembolization-induced acute-myocardial injury sheep model. We evaluated 5-min LVAD-support hemodynamics, including biventricular parameters, by switching modes from constant-speed to asynchronous-modulation in the same animals ("acute-effect evaluation under LVAD support"). To determine the accumulated effect of a certain driving period, we evaluated hemodynamics including biventricular parameters after weaning from 6-hour (6h) LVAD support by constant-speed or asynchronous-modulation mode ("6h-effect evaluation"). The acute-effect evaluation under LVAD support revealed that, compared to the constant-speed mode, the asynchronous-modulation mode increased vascular pulsatility but did not have significantly different effects on hemodynamics, including both ventricles. The 6h-effect evaluation revealed that the hemodynamics did not differ significantly between the two groups except for some biventricular parameters which did not indicate negative effects of the asynchronous-modulation mode on both ventricles. The asynchronous-modulation mode could be feasible to increase vascular pulsatility without causing negative effects on hemodynamics including both ventricles. Compared to the constant-speed mode, the asynchronous-modulation mode increased pulsatility during LVAD support without negative effects on hemodynamics including both ventricles in the acute phase. Six hours of LVAD support with the asynchronous-modulation mode exerted no negative effects on hemodynamics, including both ventricles, after weaning from the LVAD.

Association of pre–left ventricular assist device defibrillator shocks for ventricular arrhythmia with clinical outcomes after left ventricular assist device implantation

Implantable cardioverter-defibrillation (ICD) shocks after left ventricular assist device therapy (LVAD) are associated with adverse clinical outcomes. Little is known about the association of pre-LVAD ICD shocks on post-LVAD clinical outcomes and whether LVAD therapy affects the prevalence of ICD shocks. The purpose of this study was to determine whether pre-LVAD ICD shocks are associated with adverse clinical outcomes post-LVAD and to compare the prevalence of ICD shocks before and after LVAD therapy. Patients 18 years or older with continuous-flow LVADs and ICDs were retrospectively identified within the University of Pittsburgh Medical Center system from 2006-2020. We analyzed the association between appropriate ICD shocks within 1 year pre-LVAD with a primary composite outcome of death, stroke, and pump thrombosis and secondary outcomes of post-LVAD ICD shocks and ICD shock hospitalizations. Among 309 individuals, average age was 57 ± 12 years, 87% were male, 80% had ischemic cardiomyopathy, and 42% were bridge to transplantation. Seventy-one patients (23%) experienced pre-LVAD shocks, and 69 (22%) experienced post-LVAD shocks. The overall prevalence of shocks pre-LVAD and post-LVAD were not different. Pre-LVAD ICD shocks were not associated with the composite outcome. Pre-LVAD ICD shocks were found to predict post-LVAD shocks (hazard ratio [HR] 5.7; 95% confidence interval [CI] 3.42-9.48; P <.0001) and hospitalizations related to ICD shocks from ventricular arrhythmia (HR 10.34; 95% CI 4.1-25.7; P <.0001). Pre-LVAD ICD shocks predicted post-LVAD ICD shocks and hospitalizations but were not associated with the composite outcome of death, pump thrombosis, or stroke at 1 year. The prevalence of appropriate ICD shocks was similar before and after LVAD implantation in the entire cohort.

Computational evaluation of heart failure and continuous flow left ventricular assist device support in anaemia.

Anaemia is common in end-stage heart failure patients supported with continuous flow left ventricular assist device (CF-LVAD) and is associated with adverse outcomes such as heart failure readmission. This study evaluates the haemodynamic effects of anaemia on cardiac function and cerebral blood flow in heart failure patients supported with CF-LVAD using computational simulations. A dynamic model simulating cardiac function, systemic, pulmonary and cerebral circulations, cerebral flow autoregulatory mechanisms and gas contents in blood was used to evaluate the effects of anaemia and iron deficiency in heart failure and during CF-LVAD support. CF-LVAD therapy was simulated by a model describing HeartMate 3. Anaemia and iron deficiency were simulated by reducing the haemoglobin level from 15 to 9 g/dL and modifying scaling coefficients in the models simulating heart chamber volumes. Reduced haemoglobin levels decreased the arterial O2 content, which increased cerebral blood flow rate by more than 50% in heart failure and during CF-LVAD assistance. Reduced haemoglobin levels simulating anaemia had minimal effect on the arterial and atrial blood pressures and ventricular volumes. In contrast, iron deficiency increased end-diastolic left and right ventricular diameters in heart failure from 6.6 cm to 7 cm and 2.9 cm to 3.1 cm and during CF-LVAD support from 6.1 to 6.4 cm and 3.1 to 3.3 cm. The developed numerical model simulates the effects of anaemia in failing heart and during CF-LVAD therapy. It is in good agreement with clinical data and can be utilised to assess CF-LVAD therapy.

PB0029 Bridging Therapy and Risk of Major Bleeding and Thrombosis with Continuous-Flow Left Ventricular Assist Device: A Quasi-Experimental Study

PB0029 Bridging Therapy and Risk of Major Bleeding and Thrombosis with Continuous-Flow Left Ventricular Assist Device: A Quasi-Experimental Study

Five-Year Outcome After Continuous Flow LVAD With Full-Magnetic (HeartMate 3) Versus Hybrid Levitation System (HeartWare): A Propensity-Score Matched Study From an All-Comers Multicentre Registry.

Despite the withdrawal of the HeartWare Ventricular Assist Device (HVAD), hundreds of patients are still supported with this continuous-flow pump, and the long-term management of these patients is still under debate. This study aims to analyse 5years survival and freedom from major adverse events in patients supported by HVAD and HeartMate3 (HM3). From 2010 to 2022, the MIRAMACS Italian Registry enrolled all-comer patients receiving a LVAD support at seven Cardiac Surgery Centres. Out of 447 LVAD implantation, 214 (47.9%) received HM3 and 233 (52.1%) received HVAD. Cox-regression analysis adjusted for major confounders showed an increased risk for mortality (HR 1.5 [1.2-1.9]; p = 0.031), for both ischemic stroke (HR 2.08 [1.06-4.08]; p = 0.033) and haemorrhagic stroke (HR 2.6 [1.3-4.9]; p = 0.005), and for pump thrombosis (HR 25.7 [3.5-188.9]; p < 0.001) in HVAD patients. The propensity-score matching analysis (130 pairs of HVAD vs. HM3) confirmed a significantly lower 5years survival (81.25% vs. 64.1%; p 0.02), freedom from haemorrhagic stroke (90.5% vs. 70.1%; p < 0.001) and from pump thrombosis (98.5% vs. 74.7%; p < 0.001) in HVAD cohort. Although similar perioperative outcome, patients implanted with HVAD developed a higher risk for mortality, haemorrhagic stroke and thrombosis during 5years of follow-up compared to HM3 patients.

Cardiopulmonary Performance Among Heart Failure Patients Before and After Left Ventricular Assist Device Implantation

BackgroundPatients with heart failure with reduced ejection fraction (HFrEF) have persistent impairments in functional capacity after continuous-flow left ventricular assist device (CF-LVAD) implantation. ObjectivesThis study aims to characterize longitudinal changes in exercise hemodynamics and functional capacity among patients with HFrEF before and after CF-LVAD implantation. MethodsTen patients underwent 3 invasive cardiopulmonary exercise tests on upright cycle ergometry with pulmonary artery catheterization: 1) Visit 1 before CF-LVAD implantation; 2) Visit 2 after device implantation with CF-LVAD pump speed held constant at baseline speed; and 3) Visit 3 with increases in pump speed during exercise (median: 1,050 rpm [IQR: 750-1,150 rpm] and 220 rpm [IQR: 120-220 rpm] for HeartMate 3 and HeartWare VAD, respectively). Hemodynamics and direct Fick cardiac output were monitored using pulmonary artery catheterization. Gas exchange metrics were determined using indirect calorimetry. ResultsMaximal oxygen uptake (Visits 1, 2, and 3: 10.8 ± 2.5 mL/kg/min, 10.7 ± 2.2 mL/kg/min, and 11.5 ± 1.7 mL/kg/min; P = 0.92) did not improve after device implantation. Mean pulmonary arterial and pulmonary capillary wedge pressures increased significantly during submaximal and peak exercise on preimplantation testing (P < 0.01 for rest vs peak exercise) and remained elevated, with minimal change on Visits 2 and 3 regardless of whether pump speed was fixed or increased. ConclusionsAmong patients with HFrEF, cardiovascular hemodynamics and exercise capacity were similar after CF-LVAD implantation, regardless of whether patients exercised at fixed or adjusted pump speeds during exercise. Further research is needed to determine methods by which LVADs may alleviate the HFrEF syndrome after device implantation. (Effect of mechanIcal circulatoRy support ON exercise capacity aMong pAtieNts with heart failure [IRONMAN]; NCT03078972)

Clinical Predictors and Outcomes After Left Ventricular Assist Device Implantation and Tracheostomy.

Postoperative respiratory failure is a major complication that affects up to 10% of patients who undergo cardiac surgery and has a high in-hospital mortality rate. Few studies have investigated whether patients who require tracheostomy for postoperative respiratory failure after continuous-flow left ventricular assist device (CF-LVAD) implantation have worse survival outcomes than patients who do not. To identify risk factors for respiratory failure necessitating tracheostomy in CF-LVAD recipients and to compare survival outcomes between those who did and did not require tracheostomy. Consecutive patients who underwent primary CF-LVAD placement at a single institution between August 1, 2002, and December 31, 2019, were retrospectively reviewed. Propensity score matching accounted for baseline differences between the tracheostomy and nontracheostomy groups. Multivariate logistic regression was used to identify tracheostomy risk factors and 90-day survival; Kaplan-Meier analysis was used to assess midterm survival. During the study period, 664 patients received a CF-LVAD; 106 (16.0%) underwent tracheostomy for respiratory failure. Propensity score matching produced 103 matched tracheostomy-nontracheostomy pairs. Patients who underwent tracheostomy were older (mean [SD] age, 57.9 [12.3] vs 54.6 [13.9] years; P = .02) and more likely to need preoperative mechanical circulatory support (61.3% vs 47.8%; P = .01) and preoperative intubation (27.4% vs 8.8%; P < .001); serum creatinine was higher in the tracheostomy group (mean [SD], 1.7 [1.0] vs 1.4 [0.6] mg/dL; P < .001), correlating with tracheostomy need (odds ratio, 1.76; 95% CI, 1.21-2.56; P = .003). Both before and after propensity matching, 30-day, 60-day, 90-day, and 1-year survival were worse in patients who underwent tracheostomy. Median follow-up was 0.8 years (range, 0.0-11.2 years). Three-year Kaplan-Meier survival was significantly worse for the tracheostomy group before (22.0% vs 61.0%; P < .001) and after (22.4% vs 48.3%; P < .001) matching. Given the substantially increased probability of death in patients who develop respiratory failure and need tracheostomy, those at high risk for respiratory failure should be carefully considered for CF-LVAD implantation. Comprehensive management to decrease respiratory failure before and after surgery is critical.

Clinical Outcomes of Left Ventricular Assist Device Pump Infection.

Few studies have focused on the clinical outcomes and risk factors of left ventricular assist device (LVAD) pump infection, and no standard treatment for LVAD pump infection has been established. Therefore, we used a therapeutic flowchart to manage LVAD pump infections. We retrospectively evaluated 220 patients who underwent continuous-flow LVAD implantation between January 2005 and March 2021 at Osaka University, Japan. First, we performed wound debridement, negative-pressure wound therapy, antibiotic treatment, and omental flap transposition. Subsequently, we administered conservative treatment, scheduled implantable LVAD exchange, or emergent removal of the implantable LVAD and exchange for extracorporeal LVAD or percutaneous LVAD (IMPELLA). Pump infections occurred in 32 patients. The survival rates of patients with pump infections during LVAD support were 93%, 74%, and 61% at 180 days, 1 year, and 2 years after LVAD pump infection, respectively. Fifteen patients underwent successful heart transplantation. Bridge-to-bridge surgery, preoperative use of venoarterial extracorporeal membrane oxygenation or percutaneous LVAD, high lactate dehydrogenase levels, and driveline infection were significantly associated with pump infection. Our study reveals that poor preoperative condition and driveline infection were significant risk factors for LVAD pump infection.

Effect of Aortic Valve Opening Pattern on Endothelial Function After Continuous-Flow Left Ventricular Assist Device Implantation.

This study aimed to evaluate the effects of aortic valve opening patterns on endothelial functions in patients undergoing continuous-flow left ventricular assist device (CF-LVAD) implantation. This study included 43 patients who underwent CF-LVAD implantation and 35 patients with heart failure reduced ejection fraction (HFrEF; control group). The CF-LVAD group was divided into three subgroups based on aortic valve opening patterns: open with each beat, intermittently opening, and not opening groups. Flow-mediated dilatation (FMD) and pulsatility index (PI) were compared before and 3 months after CF-LVAD implantation. Cardiopulmonary exercise test (CPET) and 6 minute walk test (6-MWT) scores were measured at baseline and follow-up in the CF-LVAD group. The mean FMD and PI of patients in the CF-LVAD group reduced 3 months after implantation. Patients with intermittently opening and not opening aortic valves had worse endothelial function at follow-up. Before and 3 months after implantation FMD% did not significantly differ in patients whose aortic valves were open with each beat (4.72 ± 1.06% vs. 4.67 ± 1.16%, p = 0.135). Pulsatility index changes paralleled FMD changes. Cardiopulmonary exercise test and 6-MWT scores improved after implantation but without significant differences between subgroups. Maintaining normal aortic valve function after CF-LVAD implantation may reduce endothelial dysfunction; however, larger studies are needed for long-term clinical effects.

Gastrointestinal bleeding and pro-angiogenic shift in the angiopoietin axis with continuous flow left ventricular assist device implantation

BackgroundGastrointestinal bleeding (GIB) affects up to 40% of continuous-flow left ventricular assist device (CF-LVAD) recipients. A higher risk of GIB is seen in CF-LVAD recipients with lower device pulsatility without a known mechanism. One hypothesis is that the novel hemodynamics in CF-LVAD recipients affect angiogenesis signaling. We aimed to (1) measure serum levels of angiopoietin (Ang)-1, Ang-2, and VEGF-A in CF-LVAD recipients with and without GIB and in healthy controls and (2) evaluate correlations of those levels with hemodynamics. MethodsWe recruited 12 patients with CF-LVADs (six who developed GIB after device implantation) along with 12 age-matched controls without heart failure or GIB and measured Ang-1, Ang-2, and VEGF-A levels in serum samples from each patient. ResultsCF-LVAD recipients had significantly higher Ang-2 and lower Ang-1 levels compared to controls with no difference in VEGF-A levels. CF-LVAD recipients with GIB had lower Ang-1 levels than those without GIB. There were trends for pulse pressure to be positively correlated with Ang-1 levels and negatively correlated with Ang-2 levels in CF-LVAD recipients with no correlation observed in healthy controls. ConclusionCF-LVAD recipients demonstrated a shift toward a pro-angiogenic phenotype in the angiopoietin axis that is significantly associated with GIB and may be linked to low pulse pressure.

Preoperative passive venous pressure-driven cardiac function determines left ventricular assist device outcomes

BackgroundRight heart output in heart failure can be compensated through increasing systemic venous pressure. We determined whether the magnitude of this “passive cardiac output” can predict LVAD outcomes. MethodsThis was a retrospective review of 383 patients who received a continuous-flow LVAD at the University of Michigan between 2012 and 2021. Pre-LVAD cardiac output driven by venous pressure was determined by dividing right atrial pressure by mean pulmonary artery pressure, multiplied by total cardiac output. Normalization to body surface area led to the passive cardiac index (PasCI). The Youden J statistic was used to identify the PasCI threshold, which predicted LVAD death by 2 years. ResultsIncreased preoperative PasCI was associated with reduced survival (hazard ratio [HR], 2.27; P < .01), and increased risk of right ventricular failure (RVF) (HR, 3.46; P = .04). Youden analysis showed that a preoperative PasCI ≥0.5 (n = 226) predicted LVAD death (P = .10). Patients with PasCI ≥0.5 had poorer survival (P = .02), with a trend toward more heart failure readmission days (mean, 45.09 ± 67.64 vs 35.13 ± 45.02 days; P = .084) and increased gastrointestinal bleeding (29.2% vs 20.4%; P = .052). Additionally, of the 97 patients who experienced readmissions for heart failure, those with pre-LVAD implantation PasCI ≥0.5 were more likely to have more than 1 readmission (P = .05). ConclusionsAlthough right heart output can be augmented by raising venous pressure, this negatively impacts end-organ function and increases heart failure readmission days. Patients with a pre-LVAD PasCI ≥0.5 have worse post-LVAD survival and increased RVF. Using the PasCI metric in isolation or incorporated into a predictive model may improve the management of LVAD candidates with RV dysfunction.

Preoperative higher right ventricular stroke work index increases the risk of de novo aortic insufficiency after continuous-flow left ventricular assist device implantation

During continuous-flow left ventricular assist device (CF-LVAD) support, hemodynamic shear stress causes a burden on aortic valve (AV) leaflets, leading to de novo aortic insufficiency (AI). This study investigated the influence of preoperative hemodynamic parameters on de novo AI in CF-LVAD recipients. We reviewed 125 patients who underwent CF-LVAD implantation without concomitant AV surgery between 2005 and 2018. De novo AI was defined as moderate or severe AI in those with none or trivial preoperative AI. During mean 30 ± 16 months of CF-LVAD support, de novo AI-free rate was 86% and 67% at 1 and 2 years, respectively. Multivariable analysis showed that higher right ventricular stroke work index (RVSWI) (hazard ratio, 1.12 /g/m2/beat; 95% confidence interval, 1.00–1.20; p = 0.047) and trivial grade AI (hazard ratio, 2.8; 95% confidence interval, 1.2–6.4; p = 0.020) were independent preoperative risk factors for de novo AI. The longitudinal analysis using generalized mixed effects model showed that higher RVSWI was associated with continuous AV closure after LVAD implantation (Odd ratio, 1.20/g/m2/beat; 95% confidence interval, 1.00–1.43 /g/m2/beat; p = 0.047). Right heart catheterization revealed that preoperative RVSWI was positively correlated with postoperative pump flow index in patients with continuously closed AV (r = 0.44, p = 0.04, n = 22). Preoperative higher RVSWI was a significant risk factor for de novo AI following CF-LVAD implantation. In patients with preserved right ventricular function, postoperative higher pump flow may affect AI development via hemodynamic stress on the AV.

Risk of Infections With Long-Term Left Ventricular Assist Device Support.

We retrospectively reviewed all the patients who underwent new continuous-flow (C-F) LVAD implantation between January 1, 2013, and December 31, 2014, at the University of Nebraska Medical Center. Patients were followed until heart transplant, LVAD explantation, death, or December 31, 2017. We defined LVAD infections as per the International Society of Heart and Lung Transplantation (ISHLT) definition: VAD-specific, VAD-related, and non-VAD infections. The primary outcome was to calculate the incidence of LVAD infections per 1000 days of LVAD support. Secondary outcomes were to assess the cause of death and the effect of bloodstream infections on LVAD thrombosis, stroke, and death. During the study period, a total of 94 patients underwent a C-F LVAD implantation. Five patients were lost in follow-up; 89 patients were included in the study. The mean age at LVAD implantation was 54 (SD+15) years. Out of 89 patients, 67 (75%) were men, and 53/89 (71%) received LVAD as destination therapy (DT). At the time of LVAD implantation,34/89 (38%) patients had ITERMACS (interagency registry for mechanically assisted circulatory support)score 1 (cardiogenic shock). The median duration of LVAD support was 387+493 days, with an interquartile range of 140 to 1083 days. The incidence rate of infections post-LVAD implantation decreased from 3.2 /1000 LVAD days (95% confidence interval [CI] 2.54-4.03) during the first year of LVAD support to 0.78/1000 LVAD days (95% CI, 0.38-1.65) during the following third year of LVAD support. Similarly, the incidence of VAD-specific infections in the first year post-LVAD implantation versus the third-year post LVAD implantation decreased from 0.83/1000 LVAD days (95% CI, 0.53-1.30) to 0.33/1000 LVAD days (95% CI, 0.10-1.04). On univariate survival analysis, an increased risk of death was associated with a one-year increase in age at LVAD implantation (hazard ratio (HR) 1.05 (95% CI, 1.01-1.09), p=0.01), the presence of infection within 30 days before LVAD implantation (HR 2.44 (95% CI, 1.09-5.48), p=0.03), underlying ischemic cardiomyopathy (HR 2.96 (95% CI, 1.28-6.80), p=0.01), and lower ITERMACS profile HR 3.64 (95% CI, 1.09-12.13, p=0.04). Bloodstream infections (BSIs) were not associated with an increased risk of death (HR 1.63 (95% CI, 0.56-4.80, p=0.37). Univariate survival analysis for poor outcomes (LVAD thrombosis, stroke, or death) showed BSIs increased the risk of having a poor outcome (HR 2.39 (95% CI, 1.02-5.57), p=0.04). The incidence rate of post-LVAD infections decreased significantly over time. LVAD implantation may not be contributing to immune suppression as previously suggested. In our study, BSIs were found to have a significantly increased hazard ratio for a poor outcome post-LVAD implantation.

Retinal Microvascular Remodelling Predicts Adverse Events in Continuous-flow Left Ventricular Assist Device Supported Patients

Retinal Microvascular Remodelling Predicts Adverse Events in Continuous-flow Left Ventricular Assist Device Supported Patients

Timelines of adverse event journeys of LVAD patients.

The INTERMACS Events data set contains an expansive collection of temporal evidence of the course of adverse events (AEs) of >15 000 patients that have received a left ventricular assist device (LVAD). The chronology of AEs may contain insightful information of the "AE journeys" of LVAD patients. The purpose of this study is to investigate the timelines of AEs within the INTERMACS database. Descriptive statistics were applied to 86 912 recorded AEs of 15 820 patients with a continuous flow-LVAD between 2008 to 2016, extracted from INTERMACS registry. The characteristics of the timelines of AE journeys were investigated by posing six descriptive research questions. The analysis revealed several time-related characteristics and patterns of the AE journey after LVAD including the most common time of occurrences of AEs after surgery, duration of AEs journeys, the time of first and last AEs, and the time gaps between AEs. The INTERMACS Event dataset is a valuable resource for research about the timeline of AE journeys of patients who received an LVAD. It is necessary for future studies to first explore and consider the time-related characteristics of the data set such as diversity and sparsity to effectively choose an appropriate scope of time and time granularity and to acknowledge potential challenges.