Continuous-Flow Left Ventricular Assist Research Articles

(819) - Evaluation of Platelet Activation by Flow Cytometry in Contemporary Continuous Flow Left Ventricular Assist Device Support

(819) - Evaluation of Platelet Activation by Flow Cytometry in Contemporary Continuous Flow Left Ventricular Assist Device Support

Abstract 18880: Ventricular Arrhythmia Prevalence and Burden in Patients With Third Generation Continuous Flow Left Ventricular Assist Devices

Background: Ventricular arrhythmias (VAs) are common in patients with left ventricular assist devices (LVADs). Little is known about the impact of third-generation LVADs (Heartmate 3, HM3) on VAs prevalence and burden. Aims : To characterize the impact of HM3 LVAD implantation on VAs prevalence and burden in patients with advanced heart failure (HF) and implantable cardioverter-defibrillators (ICDs). Methods: We included consecutive patients with advanced HF and ICDs who received HM3 devices at our center between 2016 and 2022. The study outcomes were the prevalence of sustained VAs, defined as >30s VA episode detected by the ICD monitor zone or appropriately treated (ATP or shock), sustained VA burden (total number of episodes), and VA storm (≥3 appropriate ICD interventions in 24/h period). Data was collected over the 1 year before and after HM3 implantation. Results: A total of 321 patients were included (28% female, mean age 60±12 years, mean INTERMACS score 3±0.95). At 1 year follow-up after HM3 implantation, 27 patients died. A total of 128 patients (43%) had at least one sustained VA episode in the year before the HM3 implantation compared to 51 patients (17%) in the year following the HM3 (p<0.001 for comparison). The sustained VA burden decreased from a mean of 3.8 events per person-year (PPY) to a mean of 0.8 events PPY (p=0.005). Similarly, appropriate ICD therapy occurred in 123 patients (38%) before implantation and 46 patients (14%) after implantation (p<0.001). The burden of appropriate therapy was also reduced (from a mean of 2.57 events PPY to a mean 1.32 events PPY; p=0.03). The prevalence of VA storm was reduced from 19% to 8% (p<0.001). Conclusions: In patients with advanced HF and ICDs undergoing HM3 implantation, the prevalence of sustained VAs, VAs burden, appropriate ICD interventions, and VA storm were all significantly reduced in the year following HM3 implantation.

Sensor-Free Biosensing of Mitral and Aortic Valvular Function During Continuous Flow Left Ventricular Assist Device Support

Sensor-Free Biosensing of Mitral and Aortic Valvular Function During Continuous Flow Left Ventricular Assist Device Support

A Multi-objective Physiological Control for Continuous Flow Left Ventricular Assist Devices: Comparison of Estimator versus Sensor-based Feedback.

Left Ventricular Assist Devices have been successfully used for the treatment of Congestive Heart failure in patients who are not eligible for heart transplantation. This paper describes the implementation and comparison of the performance of a pressure sensor-based feedback controller. The strategies were tested on a mock loop of the systemic circulation. The results show that the use of pressure sensors generated a more accurate response of the controller compared to the use of estimators.Clinical Relevance- The study describes the integration of a LVAD physiological controller to a dynamic wireless monitoring system.

Association of Nutritional Risk Index With Continuous Flow Left Ventricular Assist Device Complications

Studies revealing the relationship between major surgery outcomes and nutritional parameters are increasing daily. Publications demonstrating the relationship between early postoperative success and surgical complications in patients with chronic heart failure and continuous flow left ventricular assist device (cf-LVAD) are limited. The vast majority of patients with advanced chronic heart failure are cachexic, and the reason for this is multifactorial. The aim of this study is to investigate the link between the modified nutritional risk index (NRI) and 6-month survival and complication rates in patients with a cf-LVAD. This study included statistical analysis of NRI and postoperative parameters of 456 patients with advanced heart failure who had cf-LVAD implantation between 2010 and 2020. The results of this study showed a statistically significant difference between mean NRI values and postoperative parameters such as 6-month survival (P=.001), right ventricular failure (P=.003), infection (P=.001), driveline infection (P=.000), and sepsis (P=.000). This study revealed that 6-month postoperative complications and mortality rates of patients with advanced heart failure in patients with cf-LVAD are closely related to malnutrition status. In these patients, nutrition specialist use would be beneficial both preoperatively and postoperatively to increase surveillance and reduce postoperative complications.

P14: Degradation of High Molecular Weight Multimers of von Willebrand Factor under Whole Blood Conditions in High Turbulent Flow: Implications for Continuous Flow Left Ventricular Assist Devices

Background: High turbulent flow often found in continuous flow left ventricular assist devices (cf-LVADs) is believed to cause acquired von Willebrand Syndrome (AvWS). Our group recently published a study on the kinetic and dynamic effects of various flows on the loss of high molecular weight multimers (HMWMs) of von Willebrand factor (vWF). In the study, we applied high shear to citrated human platelet-poor plasma (PPP) and characterized the flow by Reynolds number (Re). The present study aims to extend upon our previous findings by investigating the degradation of HMWM under whole blood conditions at higher flow conditions to be characterized by energy dissipation rate and clinically relevant exposure times previously employed. Methods: Diluted ovine blood with a hematocrit of 25%, dynamic viscosity of 3.0 cP and density of 1030 kg/m3 was flowed through a custom high shear rotary device. The device is designed to provide a fully controlled exposure time, texp and flow regime. The flow rate was set at 1.75 ml/sec, 0.76 ml/sec, or 0.38 ml/sec, resulting in an exposure time of 22 ms, 50 ms, or 100 ms, respectively. The dynamic flow condition was controlled by the speed of the rotor, ω, and characterized by the energy dissipation rate per unit mass, ε. The ω of 10k, 12k, 15k, 18k, 20k, and 22k RPM were applied, and the corresponding ε were estimated by running a series of large eddy simulations (LES). After each run, a 0.5 ml sample solution was collected, frozen in dry ice immediately, and shipped to the Blood Center of Wisconsin for multimer analysis. The amount of multimer degradation at each testing condition was assessed with respect to the mean of the initial concentration of HMWM of vWF in the controls. Results: The results show that the loss of HMWM at all given exposure times increases in a logarithmic manner within the extended flow conditions (Fig. 1A). The loss of HMWM versus energy dissipation rate at given texp is shown in Fig. 1B. It is noted that as the flow becomes more chaotic, the loss of HMWM appears to be primarily dominated by the energy dissipation rate while the exposure time to chaotic flow becomes less significant. It is not clear if the less significant effect of kinetics at relatively high flow conditions (>18k RPM) is because there are no more HMWM left to be cleaved by ADAMTS13, an enzyme that cleaves vWF. The results are consistent with our previous observations using human PPP, in that both flow conditions and exposure time play crucial roles in the destruction of HMWM. Conclusion: This study demonstrated the relative roles of flow and exposure time using whole blood to characterize the loss of HMWM in terms of energy dissipation rate and exposure time. The findings have the potential to assist in the design and optimization of blood pumps, ultimately leading to improved clinical outcomes for patients with AvWS.

Contemporary Outcomes of Continuous-Flow Left Ventricular Assist Devices: A Systematic Review

End-stage heart failure is a major cause of morbidity and mortality, and its prevalence is expected to rise with the ageing population. For suitable patients, orthotopic heart transplantation remains the gold standard therapy; however, a paucity of donor organs has led to the development of left ventricular assist devices (LVAD). These devices can be utilised as either a bridge to transplant or as an alternative to heart transplantation. While these devices can prolong life and improve quality of life, they are associated with a significant number of adverse events. This study aimed to systematically review the literature to quantify survival and the incidence of adverse events following implantation of continuous flow left ventricular assist devices (cf-LVAD).

Association of Age, Sex, and Heart Failure Etiology in Continuous Flow Left Ventricular Assist Device Patients

Advanced heart failure studies demonstrate that ischemic factors increase in prevalence with age and are more prominent in men. Ejection fraction (EF) cannot be preserved in these patients, and ischemic cardiomyopathy develops. Non-ischemic factors are more prominent in female heart failure patients, where the EF is preserved. Although an age-associated increase in the rate of heart failure is acknowledged in both sexes, etiologic classifications by sex-based age groups are still lacking. This study examined the etiology of heart failure according to age and sex in ventricular assist device patients. The patient population included 457 end-stage heart failure patients who received a continuous flow-left ventricular assist device at Ege University Hospital between 2010 and 2017. Age, sex, and cardiomyopathy etiology data were obtained from the hospital database. The Mann-Whitney U test was applied to test the statistical significance among subgroups (95% CI, P < .05 for statistical significance). The prevalence of ischemic cardiomyopathy was significantly lower in male patients aged 18 to 39 years compared to older patients. Conversely, no difference was seen among female patients. The prevalence of dilated cardiomyopathy was higher in male patients who were 18 to 39 years of age compared to older patients, but no difference was present among the female patients. Age and heart failure etiology were demonstrated to be interrelated in men but not in women. The fact that etiologic factors of advanced heart failure in women have a wider range than in men makes the current classification systems insufficient for use in female populations.

(735) Impact of Asynchronous Rotational Speed Modulation of Continuous Flow Left Ventricular Assist Device on Cardiac Condition

(735) Impact of Asynchronous Rotational Speed Modulation of Continuous Flow Left Ventricular Assist Device on Cardiac Condition

18F-FDG PET/CT In The Characterization And Management Of Continuous Flow Left Ventricular Assist Device Infection

18F-FDG PET/CT In The Characterization And Management Of Continuous Flow Left Ventricular Assist Device Infection

(772) Fully Magnetically Levitated Continuous Flow Left Ventricular Assist Device: Are We There Yet?

(772) Fully Magnetically Levitated Continuous Flow Left Ventricular Assist Device: Are We There Yet?

Meta-Analysis on the Impact of Ventricular Arrhythmias on Mortality in Patients With Continuous Flow Left Ventricular Assist Devices

Patients with continuous flow left ventricular assist devices (CFLVADs) have an increased risk of ventricular arrhythmias (VA), but the impact of VA on survival is unclear. A systematic search of electronic databases was conducted to identify studies that reported the impact of VA on all-cause mortality and right ventricular failure (RVF) in patients with CFLVAD. The Mantel-Haenszel method was used to calculate the 95% confidence interval (CI) and pooled risk ratio (RR) with a random-effects model. A total of 19 observational studies with 4,544 patients and a median follow-up of 18.5months (interquartile range 11.5 to 26.4) were included. There was statistically significantly higher mortality in patients with any VA than in those with no VA after CFLVAD implantation (RR 1.33, 95% CI 1.01 to 1.75, p=0.04, I2=78%). On sensitivity analysis, after removing the largest study by Rehorn etal,10 the association between overall mortality and VA was lost, suggesting that these results should be interpreted with caution. Early VA developing within 30days after implantation was associated with a higher risk of mortality (RR 1.37, 95% CI 1.15 to 1.63, p <0.01, I2=52%), whereas late VA developing after 30days after CFLVAD implantation was not associated with any significant difference in mortality (RR: 1.00; 95% CI: 0.80 to 1.24; p=0.98, I2=35%). In addition, there was a statistically significant higher risk of RVF in patients with VA than in those with no VA (RR 1.58, 95% CI 1.20 to 2.08, p <0.01, I2=0%). In conclusion, in patients with CFLVAD, the development of any VA was associated with a 33% higher risk of all-cause mortality. Early VA developing within 30days after implantation was significantly associated with a higher risk of mortality, whereas late VA was not associated with mortality. VA after left ventricular assist device was significantly associated with a higher risk of developing RVF.

Clinical Validation of a Neointima-Inducing Inflow Cannula in a Continuous Flow Left Ventricular Assist Device.

Wedge thrombus formation around the inflow cannula of a continuous left ventricular assist device (LVAD) is a source of systemic thromboemboli. We previously reported the potential advantages of a new inflow cannula wrapped with titanium mesh (GU30) over the standard smooth surface oblique cut cannula (GU10). The objective of the present study was to clinically validate this new cannula. A retrospective cohort analysis of patients with implanted LVAD (EVAHEART) comparing the GU10 to the GU30 was conducted. Clinical outcomes, including survival, the incidence of thromboembolism, and bleeding events, were compared. Gross and histopathological analyses of explanted GU30 cannula were conducted following transplant or patient death. No significant differences in the survival rate, severe emboli, or cerebral bleeding were observed during the LVAD implantation. However, severe emboli occurred earlier after LVAD implantation when using the GU30 cannula compared with the GU10. In cases of long LVAD support, the neointima fully covered the inflow of the GU30 cannulae without wedge thrombus formation. The titanium mesh-wrapped inflow cannulae did not reduce the overall incidence of neurological events significantly. However, the titanium mesh-wrapped inflow cannula induced autologous neointimal growth over the cannula and prevented wedge thrombus formation in late-phase LVAD implantation.

Impact of Continuous Flow Left Ventricular Assist Device on Heart Transplant Candidates: A Multi-State Survival Analysis.

(1) Objectives: The aim of this study was to investigate the impact of the prolonged use of continuous-flow left ventricular assist devices (LVADs) on heart transplant (HTx) candidates. (2) Methods: Between January 2012 and December 2019, we included all consecutive patients diagnosed with end-stage heart failure considered for HTx at our institution, who were also eligible for LVAD therapy as a bridge to transplant (BTT). Patients were divided into two groups: those who received an LVAD as BTT (LVAD group) and those who were listed without durable support (No-LVAD group). (3) Results: A total of 250 patients were analyzed. Of these, 70 patients (28%) were directly implanted with an LVAD as BTT, 11 (4.4%) received delayed LVAD implantation, and 169 (67%) were never assisted with an implantable device. The mean follow-up time was 36 ± 29 months. In the multivariate analysis of survival before HTx, LVAD implantation showed a protective effect: LVAD vs. No-LVAD HR 0.01 (p < 0.01) and LVAD vs. LVAD delayed HR 0.13 (p = 0.02). Mortality and adverse events after HTx were similar between LVAD and No-LVAD (p = 0.65 and p = 0.39, respectively). The multi-state survival analysis showed a significantly higher probability of death for No-LVAD vs. LVAD patients with (p = 0.03) or without (p = 0.04) HTx. (4) Conclusions: The use of LVAD as a bridge to transplant was associated with an overall survival benefit, compared to patients listed without LVAD support.

Prognostic Impact of Implantable Cardioverter Defibrillators in Patients with Continuous Flow Left Ventricular Assist Devices

Purpose Preventative implantation of implantable cardioverter defibrillators (ICD) improves survival of symptomatic heart failure (HF) patients with reduced left ventricular ejection fraction. Nevertheless, the prognostic impact of ICD therapy in continuous flow left ventricular assist device (LVAD) recipients remains controversial. Methods 162 consecutive HF patients underwent LVAD implantation at our institution between 2010 and 2019. All patients were evaluated according to the presence (n=94, ICD-group) or absence (n=68, Control-group) of ICDs prior to LVAD implantation. Apart from clinical baseline and follow-up parameters, adverse events related to ICD therapy and overall survival rates were retrospectively analyzed. Results Predominantly male patients (87.0%) with a median age of 57 (48.8-64.0) years were mainly treated with the Medtronic HVAD device (87.0%). Ischemic cardiomyopathy (60.3% vs. 38.3%, p=0.007) and severe HF symptoms (e.g., NYHA-class IV 85.5% vs. 59.6%, p=0.001) were more prevalent within the Control-group. Furthermore, the preoperative use of short-term circulatory support devices (e.g., IABP, ECMO, Impella) was higher within the Control-group (54.4% vs. 13.8%, p <0.001). Nevertheless, baseline severity of LV and RV dysfunction (LVEF 20%, TAPSE 15mm; p=0.87) was similar. Apart from an increased rate of temporary RVAD implantation within the Control-group (45.6% vs. 17.0%; p<0.001), procedural characteristics and 30-day mortality rates were comparable. Furthermore, overall-survival during a median follow-up of 14 (3.0-36.5) months was similar within both study-groups (35.1% ICD-group vs. 33.8% Control-group; p=0.46). During the first 2 years after LVAD implantation 49 ICD-related adverse events occurred within the ICD-group. Thereof, lead-dysfunction occurred in 18 patients and unplanned ICD-reintervention in 10 patients. Furthermore, in 16 patients adequate, but awake shocks occurred, whereas inadequate shocks occurred in 5 patients. Conclusion ICD therapy in LVAD recipients was not associated with a survival benefit or reduced morbidity after LVAD implantation. Furthermore, in the majority of LVAD recipients ICD-related adverse events occurred during follow-up. A randomized controlled trial is essential to elucidate the role of ICD therapy in LVAD recipients. Preventative implantation of implantable cardioverter defibrillators (ICD) improves survival of symptomatic heart failure (HF) patients with reduced left ventricular ejection fraction. Nevertheless, the prognostic impact of ICD therapy in continuous flow left ventricular assist device (LVAD) recipients remains controversial. 162 consecutive HF patients underwent LVAD implantation at our institution between 2010 and 2019. All patients were evaluated according to the presence (n=94, ICD-group) or absence (n=68, Control-group) of ICDs prior to LVAD implantation. Apart from clinical baseline and follow-up parameters, adverse events related to ICD therapy and overall survival rates were retrospectively analyzed. Predominantly male patients (87.0%) with a median age of 57 (48.8-64.0) years were mainly treated with the Medtronic HVAD device (87.0%). Ischemic cardiomyopathy (60.3% vs. 38.3%, p=0.007) and severe HF symptoms (e.g., NYHA-class IV 85.5% vs. 59.6%, p=0.001) were more prevalent within the Control-group. Furthermore, the preoperative use of short-term circulatory support devices (e.g., IABP, ECMO, Impella) was higher within the Control-group (54.4% vs. 13.8%, p <0.001). Nevertheless, baseline severity of LV and RV dysfunction (LVEF 20%, TAPSE 15mm; p=0.87) was similar. Apart from an increased rate of temporary RVAD implantation within the Control-group (45.6% vs. 17.0%; p<0.001), procedural characteristics and 30-day mortality rates were comparable. Furthermore, overall-survival during a median follow-up of 14 (3.0-36.5) months was similar within both study-groups (35.1% ICD-group vs. 33.8% Control-group; p=0.46). During the first 2 years after LVAD implantation 49 ICD-related adverse events occurred within the ICD-group. Thereof, lead-dysfunction occurred in 18 patients and unplanned ICD-reintervention in 10 patients. Furthermore, in 16 patients adequate, but awake shocks occurred, whereas inadequate shocks occurred in 5 patients. ICD therapy in LVAD recipients was not associated with a survival benefit or reduced morbidity after LVAD implantation. Furthermore, in the majority of LVAD recipients ICD-related adverse events occurred during follow-up. A randomized controlled trial is essential to elucidate the role of ICD therapy in LVAD recipients.

Impact of Statins on the Incidence of Gastrointestinal Bleeding Events Among Patients with Continuous Flow Left Ventricular Assist Devices

<h3>Purpose</h3> Patients with continuous flow left ventricular assist devices (CF-LVADs) are at an increased risk of gastrointestinal bleeding (GIB) events due to von Willebrand factor degradation, enhanced angiogenesis and endothelial dysfunction resulting from non-pulsatile flows of the device. LVAD patients also commonly receive statins for the primary or secondary prevention of cardiovascular disease. However, the impact of such therapy on the incidence of GIB is controversial. Importantly, literature regarding the impact of statins on GIB in LVAD patients is lacking. <h3>Methods</h3> This was a single-center, retrospective review of adult patients that underwent CF-LVAD implantation between May 2016 and January 2020. Patients were categorized based on statin use throughout the study period. The primary outcome was the composite of arteriovenous malformation (AVM) confirmed GIB and other major GIB events for up to 1-year post-LVAD implantation. Secondary outcomes included each of the components of the primary outcome, non-clinically relevant GIB, time to GIB, and frequency of GIB. Multivariable Cox regression was utilized to assess association between confounding variables and major GIB. <h3>Results</h3> Of the 123 patients who met inclusion criteria, 66 (54%) received statin therapy during the study period. No difference was observed in the primary outcome of major GIB between the statin and non-statin groups (21.2% vs. 12.3%, p=0.20). Similarly, AVM confirmed GIB (12.1% vs. 5.3%, p=0.20), other major GIB (9.1% vs. 7.0%, p=0.75), and non-clinically relevant GIB (3.0% vs. 1.8%, p=0.68) were similar between the two groups. Using a competing risk modeling, we observed no difference in the development of a major GIB (32.4% vs. 18.7%, p=0.14) or in the frequency of major GIB [1.5 (interquartile range, 1-2) vs. 1 (1-1), p=0.12] within 12 months of device implantation. Multivariable Cox regression revealed that older age and higher baseline creatinine were associated with an increased risk of GIB within 1-year of LVAD implantation (p<0.05 for both). <h3>Conclusion</h3> Among patients with CF-LVADs, there was a non-significant increase in the incidence of major GIB events with the use of statin therapy. Further long-term studies are needed to determine if statin use has a significant impact on the incidence of GIB events among this patient population.

Risk of Infection, Endoplasmic Reticular Stress and Systemic Activation of NLRP3 Inflammasome in Patients Supported by Continuous Flow Left Ventricular Assist Devices

<h3>Purpose</h3> We investigated changes in stress-associated endoplasmic reticulum (ER) protein 1 (SERP1), ER-stress response proteins and inflammasome activation in heart failure (HF) patients before and after CF-LVAD implantation, and relationship to subsequent infection within 3 months. <h3>Methods</h3> We analyzed blood samples from 24 CF-LVAD patients (pre- and 1week post-VAD) and 10 non-HF controls. Culture positive Infections was confirmed (median 42 days post-VAD) from bloodstream, GI, respiratory tracts, or driveline. SARP1, ER-stress proteins (ATF-6, GRP78) and NLRP3 inflammasome (NLRP3, ASC, Caspase1) in peripheral blood mononuclear cells (PBMC) were assessed. <h3>Results</h3> HF patients had significantly (p<0.05) elevated baseline (pre-VAD) PBMC protein levels of ATF6 (0.41±0.05 vs. 0.54±0.11), GRP78 (0.20±0.07 vs. 0.33±0.18), NLRP3 (0.28±0.17 vs. 0.78±0.28), and ASC (0.27±0.13 vs. 0.44±0.15) compared to controls. Among CF-LVAD recipients, SERP1 declined in those without subsequent infection (Group1) but significantly increased in those with infection (Group2) (<i>Fig.A,B</i>). Baseline ATF6 and GRP78 differed between Group1 and 2 (<i>Fig.C,D</i>). In Group2, the post-VAD ATF6, GRP78, NLRP3 and ASC were significantly elevated compared to pre-VAD; while in group1, only the post-VAD GRP78 was significantly elevated (<i>Fig.C-G</i>). Post-VAD caspase1 increased but not-significant (0.36±0.07 vs. 0.43±1.2) in group2 compared to pre-VAD (<i>Fig.H</i>). Baseline SERP1 and NLRP3 among patients who developed infection were positively correlated with ATF6 and GRP78 (<i>Fig.I-L</i>). <h3>Conclusion</h3> Post-VAD upregulation of SERP1 may be associated with ER-stress response, which in turn may activate NLRP3 inflammasome and predispose to early infection. Post-VAD decrease in SERP1 in group1 may protect against ER stress and NLRP3 activation. Further investigation of the role of SERP1 in ER-stress and inflammasome activation in CF-LVAD recipients is needed.

Comparing Velocity and Mean Arterial Pressure to Assess Pulsatility in Patients with Continuous Flow Left Ventricular Assist Devices

<h3>Purpose</h3> An increasing number of end-stage heart failure patients are supported by continuous-flow Left Ventricular Assist Devices (cfLVADs). In these patients, accurate assessment of arterial pulsatility remains a challenge because of diminished pulse pressure. Limited pulsatility in modern cfLVADs itself can be associated with adverse events such as stroke. Our study investigates the value of simultaneous arterial pressure and arterial blood velocity assessment in cfLVAD patients. <h3>Methods</h3> Both velocity (cm/s) and pressure (mmHg) data were collected during routine follow up. Pressure was measured using a brachial cuff oscillometry system (Sphygmocor XCel) providing a systolic and diastolic readings, while velocity was measured using a digital doppler (Huntleigh) from the brachial artery. Velocity measurements obtained included peak, minimum, average velocity and pulsatility index. Pressure measurements obtained were systolic and diastolic which allowed us to derive a mean arterial pressure (MAP) from the brachial artery. <h3>Results</h3> From a total of 24 patients (88% males), there were 44 velocity and pressure measurements. Mean device support duration was 240 days (SD 116). Mean derived brachial MAP was 85 mmHg (SD 9), whereas mean peak brachial artery velocity was 14 cm/s (SD 9). Mean pulsatility index was 2 (SD 2). Correlation analysis using Spearman's rho demonstrated a significant inverse relationship between Brachial derived MAP and Peak velocity (Rho=-0.41, p=0.007). <h3>Conclusion</h3> Arterial doppler measurements may provide incremental value over purely pressure-based measurements. The inverse relationship between derived MAP and peak velocity in this study may be partially explained by the degree of arterial compliance. In turn, this provides significant information on the relationship between higher MAP and lower blood velocity to subsequently explain increased thrombus formation and stroke rate due to longer transit time of blood.

Gastrointestinal angiodysplasia in heart failure and during CF LVAD support

Angiodysplasias (AGD) are common sites of bleeding in the gastrointestinal (GI) tract after Continuous Flow Left Ventricular Assist Device (CF-LVAD) implantation. We sought to investigate whether AGDs are formed as a result of LVAD physiology or preexist as a consequence of heart failure. Thirty-six subjects with HF reduced EF (HFrEF) underwent video capsule endoscopy (VCE) to assess for the presence of AGD. Fifty-three subjects without HF who underwent VCE for a nonbleeding indication formed a control group. The prevalence of AGD was significantly higher in the HFrEF compared to the non-HF controls (50% vs 13%, p=0.0002). This association persisted after controlling for age and comorbidities. Within the HFrEF cohort, higher Ang2, NT-proBNP and BUN were associated with the presence of AGD. AGD in the GI tract are associated with HFrEF. This is the first description of a new pathology associated with HFrEF and adds to our understanding of CF LVAD associated GI bleeding.

Predictors and Long-Term Impact of De Novo Aortic Regurgitation in Continuous Flow Left Ventricular Assist Devices Using Vena Contracta.

The aim of this study was to identify the optimal echocardiographic measurement of aortic regurgitation (AR) in continuous flow left ventricular assist devices (LVAD) and determine risk factors and clinical implications of de novo AR. Echocardiographic images from consecutive patients who underwent LVAD implantation from February 2007 to March 2017 were reviewed. Severity of de novo AR was determined by vena contracta (VC). Preimplant clinical characteristics, LVAD settings at discharge, and outcomes including heart failure hospitalizations, all-cause mortality, and ventricular arrhythmias of patients with greater than or equal to moderate de novo AR were compared with those with mild or no AR. Among 219 patients, greater than or equal to moderate de novo AR occurred in 65 (29.7%). Left ventricular assist devices support duration was longer with greater than or equal to moderate AR than no or mild AR. In multivariable analysis, preimplant trivial AR and persistent aortic valve (AV) closure were independently associated with de novo AR. By time-varying covariate analysis, survival and freedom from cardiovascular events in greater than or equal to moderate AR were significantly worse (hazard ratio [HR] = 3.947, p < 0.001 and HR = 4.666, p < 0.001). In conclusion, de novo greater than or equal to moderate AR measured by VC increases risk of adverse events. Longer LVAD support duration, preimplant trivial AR, and a closed AV are associated with occurrence of greater than or equal to moderate de novo AR.