Continuous-flow Left Ventricular Assist Device Implantation Research Articles

Machine Learning Assisted Stroke Prediction in Mechanical Circulatory Support: Predictive Role of Systemic Mitochondrial Dysfunction.

Stroke continues to be a major adverse event in advanced congestive heart failure (CHF) patients after continuous-flow left ventricular assist device (CF-LVAD) implantation. Abnormalities in mitochondrial oxidative phosphorylation (OxPhos) have been critically implicated in the pathogenesis of neurodegenerative diseases and cerebral ischemia. We hypothesize that prior stroke may be associated with systemic mitochondrial OxPhos abnormalities, and impaired more in post-CF-LVAD patients with risk of developing new stroke. We studied 50 CF-LVAD patients (25 with prior stroke, 25 without); OxPhos complex proteins (complex I [C.I]-complex V [C.V]) were measured in blood leukocytes. Both at baseline (pre-CF-LVAD) and postoperatively (post-CF-LVAD), the prior-stroke group had significantly lower C.I, complex II (C.II), complex IV (C.IV), and C.V proteins when compared to the no-prior-stroke group. Oxidative phosphorylation proteins were significantly decreased in prior-stroke group at post-CF-LVAD compared to pre-CF-LVAD. Machine learning Least Absolute Shrinkage and Selection Operator (LASSO) and Random Forest modeling identified six prognostic factors that predicted postoperative stroke with an area under the receiver operating characteristic (ROC) curve (AUC) of 0.93. Oxidative phosphorylation protein reduction appeared to be associated with the new stroke after implantation. Our study found for the first time the existence of mitochondrial dysfunction at the peripheral level in CHF patients with prior ischemic stroke even before CF-LVAD implantation. The changes in OxPhos protein expression could serve as biomarkers in predicting new post-CF-LVAD strokes.

Comparison of continuous flow centrifugal left ventricular assist devices as a bridge to transplant strategy in a low organ donation environment: single center experience

ObjectiveIn patients with advanced heart failure, heart transplantation is currently the most effective treatment. However, in a low-organ environment, it is usually necessary to proceed in long-term mechanical circulatory support through left ventricular assist device (LVAD) implantation as bridge-to-transplantation. MethodsThe study included all patients with advanced heart failure who underwent continuous flow LVAD implantation as a bridge to transplant strategy in our center (n = 68). Following LVAD implantation and for the period that patients were on LVAD support, pump thrombosis, strokes, gastrointestinal bleeding, and right heart failure occurrence rates were recorded. Outcomes were compared between patients implanted with HeartMate 3 (HM3) and HeartWare LVADs, as well as between patients who did reach heart transplantation (HTx group) and those who did not (noHTx group). ResultsA total of 35 out of 68 patients underwent heart transplantation at a mean time of 691 ± 457 days; 41 received a HeartWare and 27 a HM3 device. HM3 patients had significantly better survival (p = 0.010) and lower complication rates (p = 0.025). In addition, the noHTx group had significantly higher complication rates compared with the HTx group (p = 0.00041). The 5-year estimated Kaplan–Meier survival rate following heart transplantation was 77%. ConclusionPatients with advanced heart failure gain substantial benefit from LVADs awaiting heart transplantation. In a low organ donation environment, the need for reliable LVADs can further improve the outcomes through the reduction of complications provided by current devices.

Impact of statins on incidence of gastrointestinal bleeding events among patients with continuous-flow left ventricular assist devices.

Patients with continuous flow left ventricular assist devices (CF-LVADs) are at increased risk of gastrointestinal bleeding (GIB). Statins are commonly prescribed in LVAD patients for cardiovascular disease prevention. However, their impact on GIB events is controversial. Importantly, literature regarding statins impact on GIB in CF-LVAD patients is lacking. A single-center, retrospective review of adult patients who underwent CF-LVAD implantation between May 2016 and January 2020 was performed. Patients were categorized based on statin use throughout the study period. The primary outcome was the composite of arteriovenous malformation confirmed GIB and major GIB events for up to 1-year post-LVAD implantation. Of 123 patients included in the final analysis, 66 (54%) received statin therapy during the study period. No difference was observed in the primary outcome between the statin and control groups (RR: 1.73; 95% CI: 0.75-3.98; p=0.20). Multivariable Cox regression revealed that older age and higher baseline creatinine were associated with an increased risk of GIB within 1-year of CF-LVAD implantation. Among patients with CF-LVADs, there was no significant difference in the incidence of major GIB events associated with the use of statin therapy. Further studies are needed to assess whether a true association exists.

Clinical Outcomes of Left Ventricular Assist Device Bleeding Complication.

Bleeding complications have emerged as major causes of morbidity and mortality in patients with implantable left ventricular assist devices (LVAD). We hypothesized that the hemodynamics after LVAD implantation may influence the occurrence of bleeding complications after LVAD implantation. We retrospectively evaluated 78 patients who underwent continuous-flow LVAD implantation and hemodynamic ramp test after LVAD implantation between July 2017 and July 2023 at Osaka University. The bleeding complication occurred in 13 patients. The rates of freedom from bleeding complications at 1, 3, and 5 years were 94%, 85%, and 74%. Gastrointestinal bleeding, nose bleeding, and intraperitoneal hemorrhage occurred in six, three, and two patients, respectively. Preoperative average brachial-ankle pulse wave velocity (baPWV) was positively associated with bleeding complication (1,276 ± 280 vs. 1,098 ± 190 cm/s p = 0.04). In the hemodynamic ramp test, systemic vascular resistance (SVR) in patients with bleeding complications was higher than that in patients without bleeding complications (SVR: 1,359 ± 341 vs. 1,150 ± 217 dyne sec/cm5, p = 0.01). High preoperative baPWV and high SVR in the hemodynamic ramp test were significantly associated with bleeding complications after LVAD implantation. Arteriosclerosis is a risk factor for bleeding complications after LVAD implantation.

326.2: Lifetime management after continuous-flow LVAD implantation as bridge to transplantation.

326.2: Lifetime management after continuous-flow LVAD implantation as bridge to transplantation.

Development of a hub-and-spoke durable left ventricular assist device program in Brazil, a middle-income country

ObjectivesTo describe the experience of a left ventricular assist device (LVAD) program in a middle-income country in a hub-and-spoke model. MethodsPatients fulfilling strict inclusion and exclusion criteria were referred from different centers in Brazil for LVAD implantation through a philanthropy program financed via a Brazilian Federal Government tax exemption structure. LVAD implantation was performed in hub-and-spoke model with a single implanting center. Data was collected retrospectively using hospital records and telephone contact with other centers. Patients that received LVAD implants external to the philanthropic program, either at this or other Brazilian centers, were not included. ResultsBetween January 1st, 2013, and December 31st, 2020, 20 adult patients underwent long-term continuous flow LVAD implantation with decentralization of post-implant patient care in regional centers. Patients were referred from 11 centers from 7 states in Brazil and underwent LVAD implantation through a philanthropy program. The median age was 52.5 years and 85% were INTERMACS profile 3 patients. Two patients had Chagas cardiomyopathy. The overall survival censored for competing risks at 1 year and 2 years were 90% and 84% respectively. Three patients (15%) underwent heart transplantation in the first 2 years after LVAD implantation. Twelve patients returned to their original centers and were followed remotely. ConclusionsThis study presents a successful LVAD implantation program in a hub-and-spoke model in Brazil. Centralization of LVAD implantation with decentralization of post-implant patient care in regional centers is feasible and safe, enabling optimal allocation of resources in middle-income countries.

Predictors and Impact of Prolonged Vasoplegia After Continuous-Flow Left Ventricular Assist Device Implantation

BackgroundVasoplegia after cardiac surgery is associated with adverse outcomes. However, the clinical effects of vasoplegia and the significance of its duration after continuous-flow left ventricular assist device (CF-LVAD) implantation are less known. ObjectivesThis study aimed to identify predictors of and outcomes from transient vs prolonged vasoplegia after CF-LVAD implantation. MethodsThe study was a retrospective review of consecutive patients who underwent CF-LVAD implantation between January 1, 2005, and December 31, 2017. Vasoplegia was defined as the presence of all of the following: mean arterial pressure ≤65 mm Hg, vasopressor (epinephrine, norepinephrine, vasopressin, or dopamine) use for >6 hours within the first 24 hours postoperatively, cardiac index ≥2.2 L/min/m2 and systemic vascular resistance <800 dyne/s/cm5, and vasodilatory shock not attributable to other causes. Prolonged vasoplegia was defined as that lasting 12 to 24 hours; transient vasoplegia was that lasting 6 to <12 hours. Patient characteristics, outcomes, and risk factors were analyzed. ResultsOf the 600 patients who underwent CF-LVAD implantation during the study period, 182 (30.3%) developed vasoplegia. Mean patient age was similar between the vasoplegia and no-vasoplegia groups. Prolonged vasoplegia (n = 78; 13.0%), compared with transient vasoplegia (n = 104; 17.3%), was associated with greater 30-day mortality (16.7% vs 5.8%; P = 0.02). Risk factors for prolonged vasoplegia included preoperative dialysis and elevated body mass index. ConclusionsCompared with vasoplegia overall, prolonged vasoplegia was associated with worse survival after CF-LVAD implantation. Treatment to avoid or minimize progression to prolonged vasoplegia may be warranted.

Kidney Function Trajectories and Right Heart Failure Following LVAD Implantation.

Preoperative kidney dysfunction is a risk factor for right heart failure (RHF) after implantation of a left ventricular assist device (LVAD). However, characteristic kidney function trajectories before and after post-LVAD RHF are uncertain, so we investigated this. We identified individuals who received primary continuous-flow LVAD implantation from July 1, 2014 to December 31, 2017 in the Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) data set. Incident RHF was ascertained using the INTERMACS definition at 1 and 3 months and classified as transient or persistent. Kidney function trajectories before and after RHF onset, and relationships of baseline kidney function with RHF risk at the different time points, were assessed. We identified 8076 LVAD recipients who met inclusion criteria. Incident RHF was present at 1 month in 26.4%. There were 4850 individuals with follow-up at 3 months, with incident RHF in 4.2%. Kidney function trajectories differed from pre-LVAD implantation to 1-month follow-up by RHF category, with those developing persistent RHF having no improvement in baseline kidney function. For trajectories before the 3-month RHF ascertainment time, the shape was similar for those with and without RHF, with lower estimated glomerular filtration rate levels among those who developed RHF. Baseline estimated glomerular filtration rate levels below the normal range were associated with higher risk of RHF at 1 and 3 months. In LVAD recipients, preimplantation kidney function and subsequent kidney function trajectories differed substantially by RHF at 1 and 3 months postimplantation, even after adjustment for several confounders. This may demonstrate bidirectional associations between kidney function and right ventricular function in LVAD recipients.

Improving the Prediction of 1-Year Right Ventricular Failure After Left Ventricular Assist Device Implantation.

Previous predictive models for postimplant right heart failure (RHF) following left ventricular assist device (LVAD) implantation have demonstrated limited performance on validation datasets and are susceptible to overfitting. Thus, the objective of this study was to develop an improved predictive model with reduced overfitting and improved accuracy in predicting RHF in LVAD recipients. The study involved 11,967 patients who underwent continuous-flow LVAD implantation between 2008 and 2016, with an RHF incidence of 9% at 1 year. Using an eXtreme Gradient Boosting (XGBoost) algorithm, the training data were used to predict RHF at 1 year postimplantation, resulting in promising area under the curve (AUC)-receiver operating characteristic (ROC) of 0.8 and AUC-precision recall curve (PRC) of 0.24. The calibration plot showed that the predicted risk closely corresponded with the actual observed risk. However, the model based on data collected 48 hours before LVAD implantation exhibited high sensitivity but low precision, making it an excellent screening tool but not a diagnostic tool.

Managing ventricular arrhythmias and implantable cardiac defibrillator shocks after left ventricular assist device implantation.

Continuous flow left ventricular assist devices (CF-LVADs) have been shown to reduce mortality and morbidity in patients with advanced heart failure with reduced ejection fraction. However, ventricular arrhythmias (VA) are common, are mostly secondary to underlying myocardial scar, and have a higher incidence in patients with pre-LVAD VA. Sustained VA is well tolerated in the LVAD patient but can result in implantable defibrillator (ICD) shocks, right ventricular failure, hospitalizations, and reduced quality of life. There is limited data regarding best practices for the medical management of VA as well as the role for procedural interventions in patients with uncontrolled VA and/or ICD shocks. Vast majority of CF-LVAD patients have a preexisting cardiovascular implantable electronic device (CIED) and ICD and/or cardiac resynchronization therapies are continued in many. Several questions, however, remain regarding the efficacy of ICD and CRT following CF-LVAD. Moreover, optimal CIED programming after CF-LVAD implantation. Therefore, the primary objective of this review article is to provide the most up-to-date evidence and to provide guidance on the clinical significance, pathogenesis, predictors, and management strategies for VA and ICD therapies in the CF-LVAD population. We also discuss knowledge gaps as well as areas for future research.

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.

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.

CARC12: Surgical Correction of De Novo Aortic Valve Insufficiency after Left Ventricular Assist Device Implantation

Background: Development of significant aortic insufficiency (AI) is a common complication associated with prolonged support with continuous-flow left ventricular assist device (CF-LVAD). The aim of this study is to investigate the clinical outcomes after surgical correction of de novo AI after LVAD implantation. Methods: Between January 2013 and June 2022, 190 patients underwent CF-LVAD implantation. Of them, 24 had trivial or less AI before LVAD implantation and developed moderate or greater de novo AI after LVAD implantation. Those who had undergone aortic valve surgery before or concomitant with LVAD surgery were excluded. Among the 24 patients, surgeries were indicated for medically refractory de novo AI in 11 patients, who were included in the current study. Primary endpoint was post-operative improvement in hemodynamics as assessed with right heart catheter examination, and the secondary endpoint was 3-year survival and freedom from death and/or heart failure readmission rate. Results: Correction of de novo AI were accomplished with aortic valve closure with bovine pericardial patch in 10 patients and prosthetic valve replacement in one patient. After surgery, pulmonary artery wedge pressure (PAWP), and cardiac index (CI), mixed venous blood oxygen saturation (SvO2) significantly improved compared with preoperative baseline (Figure). The mean follow-up after LVAD implantation was 1413days, and the 3-year survival rate was 90.9%. The freedom from postoperative moderate or greater AI rate, and the freedom from heart failure readmission rate were both 90.9% at 3 years. Conclusion: In patients who were indicated for surgical correction of de novo AI after LVAD implantation, postoperative hemodynamic improvement and survival were considered favorable.Figure 1. Hemodynamic change in three states

Pulmonary Capillary Recruitment Is Attenuated Post Left Ventricular Assist Device Implantation

There is limited knowledge of pulmonary physiology and pulmonary function after continuous flow-left ventricular assist device (CF-LVAD) implantation. Therefore, this study investigated whether CF-LVAD influenced pulmonary circulation by assessing pulmonary capillary blood volume and alveolar-capillary conductance in addition to pulmonary function in patients with heart failure. Seventeen patients with severe heart failure who were scheduled for CF-LVAD implantation (HeartMate II, III, Abbott, Abbott Park, IL or Heart Ware, Medtronic, Minneapolis, MN) participated in the study. They underwent pulmonary function testing (measures of lung volumes and flow rates) and unique measures of pulmonary physiology using a rebreathe technique that quantified the diffusing capacity of the lungs for carbon monoxide (DLCO) and diffusing capacity of the lungs for nitric oxide before and 3months after CF-LVAD implantation. After CF-LVAD, pulmonary function was not significantly changed (p >0.05). For lung diffusing capacity, alveolar volume (VA) was not changed (p=0.47), but DLCO was significantly reduced (p=0.04). After correcting for VA, DLCO/VA showed a trend toward reduction (p=0.08). For the alveolar-capillary component, capillary blood volume (Vc) was significantly reduced (p=0.04), and alveolar-capillary membrane conductance trended toward a reduction (p=0.06). However, alveolar-capillary membrane conductance/Vc was not altered (p=0.92). In conclusion, soon after CF-LVAD implantation, Vc is reduced likely because of pulmonary capillary derecruitment, which contributes to the decrease in lung diffusing capacity.

Implication to Prevent Tachyarrhythmia by Amiodarone Therapy During Durable Left Ventricular Assist Device Supports.

To the Editor: Graboyes et al.1 demonstrated that prophylactic amiodarone therapy was associated with a reduction in the incidence of postoperative arrhythmias, particularly atrial arrhythmias, without incremental incidence of amiodarone-related adverse events among those receiving durable continuous-flow left ventricular assist devices (CF-LVAD). Several concerns have been raised. The implication to prevent all postoperative tachyarrhythmias following CF-LVAD implantation is uncertain.1 Ventricular arrhythmias was not associated with in-hospital mortality and morbidity in patients receiving CF-LVAD supports in the US nationwide database.2 In another study conducted in Japan, the existence of atrial fibrillation was not associated with the development of hemocompatibility-related adverse events during CF-LVAD supports.3 On the contrary, the frequent low-flow alerts were managed by catheter ablation to treat ventricular tachyarrhythmias in a case report.4 It might be of great interest to investigate tachyarrhythmia-induced hemodynamic deterioration as a primary outcome. The definition of prophylactic treatment is unclear. In the authors’ study, some patients had history of arrhythmias and others received antiarrhythmic agents during CF-LVAD supports.1 The concomitant use of renin-angiotensin-aldosterone system inhibitors, which might also suppress the development of tachyarrhythmias, is unclear. The authors followed liver and thyroid function during amiodarone therapy for the safety analyses but did not investigate the incidence of interstitial pneumonia, which is one of the most fatal drug-related adverse events.1 How was associated biomarkers such as KL-6 and SP-D during amiodarone therapy? Although it did not reach statistical significance, more patients receiving amiodarone trended to encounter death or CF-LVAD exchange. Could the authors clarify the causes of their death?

Transcatheter valvular therapies in patients with left ventricular assist devices.

Aortic, mitral and tricuspid valve regurgitation are commonly encountered in patients with continuous-flow left ventricular assist devices (CF-LVADs). These valvular heart conditions either develop prior to CF-LVAD implantation or are induced by the pump itself. They can all have significant detrimental effects on patients' survival and quality of life. With the improved durability of CF-LVADs and the overall rise in their volume of implants, an increasing number of patients will likely require a valvular heart intervention at some point during CF-LVAD therapy. However, these patients are often considered poor reoperative candidates. In this context, percutaneous approaches have emerged as an attractive "off-label" option for this patient population. Recent data show promising results, with high device success rates and rapid symptomatic improvements. However, the occurrence of distinct complications such as device migration, valve thrombosis or hemolysis remain of concern. In this review, we will present the pathophysiology of valvular heart disease in the setting of CF-LVAD support to help us understand the underlying rationale of these potential complications. We will then outline the current recommendations for the management of valvular heart disease in patients with CF-LVAD and discuss their limitations. Lastly, we will summarize the evidence related to transcatheter heart valve interventions in this patient population.