Project description:Data on relative safety, efficacy, and role of different percutaneous left ventricular assist devices for hemodynamic support during the ventricular tachycardia (VT) ablation procedure are limited.We performed a multicenter, observational study from a prospective registry including all consecutive patients (N=66) undergoing VT ablation with a percutaneous left ventricular assist devices in 6 centers in the United States. Patients with intra-aortic balloon pump (IABP group; N=22) were compared with patients with either an Impella or a TandemHeart device (non-IABP group; N=44). There were no significant differences in the baseline characteristics between both the groups. In non-IABP group (1) more patients could undergo entrainment/activation mapping (82% versus 59%; P=0.046), (2) more number of unstable VTs could be mapped and ablated per patient (1.05±0.78 versus 0.32±0.48; P<0.001), (3) more number of VTs could be terminated by ablation (1.59±1.0 versus 0.91±0.81; P=0.007), and (4) fewer VTs were terminated with rescue shocks (1.9±2.2 versus 3.0±1.5; P=0.049) when compared with IABP group. Complications of the procedure trended to be more in the non-IABP group when compared with those in the IABP group (32% versus 14%; P=0.143). Intermediate term outcomes (mortality and VT recurrence) during 12±5-month follow-up were not different between both groups. Left ventricular ejection fraction ?15% was a strong and independent predictor of in-hospital mortality (53% versus 4%; P<0.001).Impella and TandemHeart use in VT ablation facilitates extensive activation mapping of several unstable VTs and requires fewer rescue shocks during the procedure when compared with using IABP.
Project description:The left ventricular assist device (LVAD) is often used in the treatment of heart failure. However, 4% to 9% implanted LVAD will have thrombosis problem in one year, which is fatal to the patient's life. In this work, an interventional sonothrombolysis (IST) method is developed to realize the thrombolysis on LVAD. A pair of ultrasound transducer rings is installed on the shell of LVAD, and drug-loaded microbubbles are injected into the LVAD through the interventional method. The microbubbles are adhere on the thrombus with the coated thrombus-targeted drugs, and the thrombolytic drugs carried by the bubbles are brought into the thrombus by the cavitation of bubbles under the ultrasound. In a proof-of-concept experiment in a live sheep model, the thrombus on LVAD is dissolved in 30 min, without damages on LVADs and organs. This IST exhibits to be more efficient and safer compared with other thrombolysis methods on LVAD.
Project description:Driveline infections (DLI) are common adverse events in left ventricular assist devices (LVADs), leading to severe complications and readmissions. The study aims to characterize risk factors for DLI readmission 2 years postimplant. This single-center study included 183 LVAD patients (43 HeartMate II [HMII], 29 HeartMate 3 [HM3], 111 HVAD) following hospital discharge between 2013 and 2017. Demographics, clinical parameters, and outcomes were retrospectively analyzed and 12.6% of patients were readmitted for DLI, 14.8% experienced DLI but were treated in the outpatient setting, and 72.7% had no DLI. Mean C-reactive protein (CRP), leukocytes and fibrinogen were higher in patients with DLI readmission (P < .02) than in outpatient DLI and patients without DLI, as early as 60 days before readmission. Freedom from DLI readmission was comparable for HMII and HVAD (98% vs. 87%; HR, 4.52; 95% CI, 0.58-35.02; P = .15) but significantly lower for HM3 (72%; HR, 10.82; 95% CI, 1.26-92.68; P = .03). DLI (HR, 1.001; 95% CI, 0.999-1.002; P = .16) or device type had no effect on mortality. DLI readmission remains a serious problem following LVAD implantation, where CRP, leukocytes, and fibrinogen might serve as risk factors already 60 days before. HM3 patients had a higher risk for DLI readmissions compared to HVAD or HMII, possibly because of device-specific driveline differences.
Project description:ABSTRACTAdvanced Heart Failure (AHF) is a complex syndrome that affects the physiology of the heart to maintain efficient blood circulation resulting in multiorgan failure and, eventually, death. Left Ventricular Assist Devices (LVADs) have become the cornerstone therapy for AHF patients, both as a bridge to transplantation and as a decisive therapy. Recently the results of the MOMENTUM 3 Trial were published. The trial compared HeartMate 3 LVAD with HeartMate II LVAD in a randomized trial in The Multicenter Study of MagLev Technology in Patients Undergoing Mechanical Circulatory Support Therapy with HeartMate 3 (MOMENTUM 3). Of 366 patients, 190 were assigned to the centrifugal-flow pump group (HeartMate 3) and 176 to the axial-flow (HeartMate II) pump group. In the intention-to-treat population, the primary end point occurred in 151 patients (79.5%) in the centrifugal-flow pump group, as compared with 106 (60.2%) in the axial-flow pump group (P < 0.001 for noninferiority). Reoperation for pump malfunction was less frequent in the centrifugal-flow pump group than in the axial-flow pump group (P < 0.001).The results of the MOMENTUM 3 Trial are a big achievement in the cardiovascular world. Any improvement in LVADs that reduces the risk of stroke, perhaps the most feared complication of these devices, would be meaningful. Besides, given the observed lower rate of pump thrombosis and reoperation for pump malfunction, it already seems likely that the HeartMate 3 will supplant the HeartMate II in clinical practice. In addition, the risks that are associated with reoperation undoubtedly counterbalanced any unintentional bias in performing that intervention.
Project description:Mechanical circulatory support has emerged as an important therapy for advanced heart failure, with more than 18,000 continuous flow devices implanted worldwide to date. These devices significantly improve survival and quality of life and should be considered in every patient with end-stage heart failure with reduced ejection fraction who has no other life-limiting diseases. All candidates for device implantation should undergo a thorough evaluation in order to identify those who could benefit from device implantation. Long-term management of ventricular assist device patients is challenging and requires knowledge of the characteristic complications with their unique clinical presentations.
Project description:Continuous flow ventricular assist devices (cfVADs) constitute a viable and increasingly used therapy for end-stage heart failure patients. However, they are still operating at a fixed-speed mode that precludes physiological cfVAD response and it is often related to adverse events of cfVAD therapy. To ameliorate this, various physiological controllers have been proposed, however, the majority of these controllers do not account for the lack of pulsatility in the cfVAD operation, which is supposed to be beneficial for the physiological function of the cardiovascular system. In this study, we present a physiological data-driven iterative learning controller (PDD-ILC) that accurately tracks predefined pump flow trajectories, aiming to achieve physiological, pulsatile, and treatment-driven response of cfVADs. The controller has been extensively tested in an in-silico environment under various physiological conditions, and compared with a physiologic pump flow proportional-integral-derivative controller (PF-PIDC) developed in this study as well as the constant speed (CS) control that is the current state of the art in clinical practice. Additionally, two treatment objectives were investigated to achieve pulsatility maximization and left ventricular stroke work (LVSW) minimization by implementing copulsation and counterpulsation pump modes, respectively. Under all experimental conditions, the PDD-ILC as well as the PF-PIDC demonstrated highly accurate tracking of the reference pump flow trajectories, outperforming existing model-based iterative learning control approaches. Additionally, the developed controllers achieved the predefined treatment objectives and resulted in improved hemodynamics and preload sensitivities compared to the CS support.
Project description:Implanting centers often require the identification of a dedicated caregiver before destination therapy left ventricular assist device (DT LVAD) implantation; however, the caregiver experience surrounding this difficult decision is relatively unexplored.From October 2012 through July 2013, we conducted semistructured, in-depth interviews with caregivers of patients considering DT LVAD. Data were analyzed using a mixed inductive and deductive approach. We interviewed 17 caregivers: 10 caregivers of patients living with DT LVAD, 6 caregivers of patients who had died with DT LVAD, and 1 caregiver of a patient who had declined DT LVAD. The themes identified, which could also be considered dialectical tensions, are broadly interpreted under 3 domains mapping to decision context, process, and outcome: (1) the stark decision context, with tension between hope and reality; (2) the challenging decision process, with tension between wanting loved ones to live and wanting to respect loved ones' wishes; and (3) the downstream decision outcome, with tension between gratitude and burden.Decision-making surrounding DT LVAD should incorporate decision support for patients and caregivers. This should include a focus on caregiver burden and the predictable tensions that caregivers experience.
Project description:BACKGROUND:The assessment of hemodynamics in patients supported with left ventricular assist devices (LVADs) is often challenging. Physical examination maneuvers correlate poorly with true hemodynamics. We assessed the value of novel transthoracic echocardiography (TTE)-derived variables to reliably predict hemodynamics in patients supported with LVAD. METHODS AND RESULTS:A total of 102 Doppler-TTE images of the LVAD outflow cannula were obtained during simultaneous invasive right heart catheterization (RHC) in 30 patients supported with continuous-flow LVADs (22 HMII, 8 HVAD) either during routine RHC or during invasive ramp testing. Properties of the Doppler signal though the outflow cannula were measured at each ramp stage (RS), including the systolic slope (SS), diastolic slope (DS), and velocity time integral (VTI). Hemodynamic variables were concurrently recorded, including Doppler opening pressure (MAP), heart rate (HR), right atrial pressure, pulmonary artery pressure, pulmonary capillary wedge pressure (PCWP), Fick cardiac output (CO) and systemic vascular resistance (SVR). Univariate and multivariate regression analyses were used to explore the dependence of PCWP, CO, and SVR on DS, SS, VTI, MAP, HR, and RS. Multivariate linear regression analysis revealed significant contributions of DS on PCWP (PCWPpred?=?0.164DS?+?4.959; R?=?0.68). Receiver operating characteristic (ROC) curve analysis revealed that PCWPpred could predict an elevated PCWP ?18 mm Hg with a sensitivity (Sn) of 94% and specificity (Sp) of 85% (area under the ROC curve 0.88). CO could be predicted by RS, VTI, and HR (COpred?=?0.017VTI?+?0.016HR?+?0.12RS?+?2.042; R?=?0.61). COpred could predict CO ?4.5 L/min with Sn 73% and Sp 79% (AUC 0.81). SVR could be predicted by MAP, VTI, and HR (SVRpred?=?15.44MAP?-?5.453VTI?-?6.349HR?+?856.15; R?=?0.84) with Sn 84% and Sp 79% (AUC 0.91) to predict SVR ?1200 dyn-s/cm5. CONCLUSIONS:Doppler-TTE variables derived from the LVAD outflow cannula can reliably predict PCWP, CO, and SVR in patients supported with LVADs and may mitigate the need for invasive testing.
Project description:Background Metabolic impairment is common in heart failure patients. Continuous-flow left ventricular assist devices (CF-LVADs) improve hemodynamics and outcomes in patients with advanced heart failure; however, the effect of CF-LVADs on metabolic status is unknown. This study aims to evaluate the changes in metabolic status following CF-LVAD implantation and measure the correlation of metabolic status with outcomes. Methods and Results Prospective data on CF-LVAD patients were obtained. Metabolic evaluation, including hemoglobin A1C, free and total testosterone, thyroid-stimulating hormone (TSH), and free T4, was obtained before and at multiple time points following implantation. Patients with nonelevated thyroid-stimulating hormone and normal hemoglobin A1C and testosterone levels were defined as having normal metabolic status. Baseline characteristics, hemodynamics, and outcomes were collected. One hundred six patients were studied, of which 56 had paired data at baseline and 1- to 3-month follow-up. Before implantation, 75% of patients had insulin resistance, 86% of men and 39% of women had low free testosterone, and 44% of patients had abnormal thyroid function. There was a significant improvement in hemoglobin A1C, free testosterone, and thyroid-stimulating hormone following implantation (P<0.001 for all). Patients with normal hemoglobin A1C (<5.7%) following implantation had higher 1-year survival free of heart failure readmissions (78% versus 23%; P<0.001). Patients with normal metabolic status following implantation also had higher 1-year survival free of heart failure readmissions (92% versus 54%; P=0.04). Conclusions Metabolic dysfunction is highly prevalent in advanced heart failure patients and improves after CF-LVAD implantation. Normal metabolic status is associated with a significantly higher rate of 1-year survival free of heart failure readmissions.
Project description:The incidence, predictors, and impact of atrial arrhythmias along with left atrial structural changes in patients with left ventricular assist devices (LVADs) remain undetermined.All patients who underwent LVAD implantation from 2008 to 2015 at the University of Chicago Medical Center were included. Electronic medical records, electrocardiograms, echocardiograms, and cardiac electrical device interrogations were reviewed. The association of arrhythmias and clinical covariates with survival was evaluated by Kaplan-Meier and Cox proportional hazards analyses. A total of 331 patients were followed for a median of 330 days (range 0-2306 days). Mean age was 57.8±12.8 years, 256 participants (77.3%) were male, mean left ventricular ejection fraction was 20±6.6%, and 124 (37.5%) had ischemic cardiomyopathy. Atrial arrhythmias (53.8%) were highly prevalent and frequently coexisted before LVAD implantation: atrial fibrillation (AF) in 45.9%, atrial flutter in 13.9%, atrial tachycardia in 6.9%, and atrioventricular nodal reentrant tachycardia in 1.2%. New-onset AF was documented in 14 patients (7.8% of patients without prior AF) after the first 30 days with an LVAD. Increasing age, renal insufficiency, and lung disease were predictors of new-onset AF after LVAD implantation. Of patients with paroxysmal AF, 43% had no further AF after LVAD. Left atrial size and volume index improved with LVAD (P<0.005). History of persistent AF, atrial tachycardia, ventricular arrhythmia, coronary artery bypass, and low albumin were associated with decreased survival.Atrial arrhythmias are significantly prevalent in patients who require LVAD and are associated with increased mortality; however, LVADs induce favorable atrial structural and electrical remodeling.