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Left ventricular assist device (LVAD) implantation is one of the mechanical circulatory support (MCS) treatments for advanced heart failure (HF) patients. MCS has emerged as a lifesaving therapy that improves patients' quality of life. However, MCS remains limited by a paradoxical coagulopathy accompanied by thrombosis and bleeding. The mechanisms of MCS thrombosis are increasingly being defined, but MCS-related bleeding, which is related to shear-mediated alteration of platelet function, remains poorly understood. Complications might develop due to the high non-physiological shear stress in the device and as a consequence of individual variability in response to the antithrombotic therapy. Thromboelastography (TEG) and genotyping of gene polymorphisms that are involved in the coagulation cascade and in the metabolism of the antithrombotic therapy might be valuable sources of information for the reduction of complication development. The aim of the study was to identify genetic factors related to the development of device complications according to the implanted LVAD type. We compared the clinical and genetic data of HF patients (n = 98) with/without complications with three types of implanted devices: HeartWare HVAD (HW), HeartMate II (HMII), and HeartMate 3 (HM3). rs9923231 in VKORC1 (95%CI −6.28–0.22, p = 0.04) and rs5918 in ITGB3 genes (95%CI 0.003–4.36, p = 0.05) showed significant association with the TEG coagulation index parameter, which identified hyper- and hypo-coagulation states. The wild genotype of rs5918 in the ITGB3 gene prevailed in patients implanted with HM3 devices, which developed fewer complications than with HMII (p = 0.04). Individual genetic information could be useful in the management of patients with HF and the implantation of MCS to reduce the development of complications. [ABSTRACT FROM AUTHOR]

This case study reports the operative management of a 63-year-old male patient following implantation of the HeartMate II (HMII) left ventricular assist device (LVAD), with a non-compliant left ventricle (LV) and a reduced right ventricular (RV) end-diastolic volume. Intraoperatively, the patient had a thin, fragile LV wall with laminated clot; a ventricular septal defect was encountered during removal of the clot. Along with an aortic valve repair, the LV and the septum were reconstructed with multiple bovine pericardium patches, thus, moderately reducing the RV and LV stroke volume. A difference in cardiac output via a Swan-Ganz catheter (approximately 1.5 l/min) was observed as opposed to the HMII’s estimated flow. The result was later replicated and verified in vitro via the Donovan Mock Circulation System (DMCS), where about 2 l/min lower flow on the HMII system was observed. In conclusion, the HMII flow rate displayed can be inaccurate and should only be used for trending. [ABSTRACT FROM AUTHOR]

Abstract: Patients assisted with left ventricular assist device (LVAD) may require prolonged mechanical ventilatory assistance secondary to postoperative respiratory failure. The goal of this work is the study of the interdependent effects LVAD like pulsatile catheter (PUCA) pump and mechanical ventilatory support or thoracic artificial lung (TAL), by the hemodynamic point of view, using a numerical simulator of the human cardiovascular system. In the simulator, different circulatory sections are described using lumped parameter models. Lumped parameter models have been designed to describe the hydrodynamic behavior of both PUCA pump and thoracic artificial lung. Ventricular behavior atrial and septum functions were reproduced using variable elastance model. Starting from simulated pathological conditions we studied the effects produced on some hemodynamic variables by simultaneous PUCA pump, thoracic artificial lung or mechanical ventilation assistance. Thoracic artificial lung was applied in parallel or in hybrid mode. The effects of mechanical ventilation have been simulated by changing mean intrathoracic pressure value from −4mmHg to +5mmHg. The hemodynamic variables observed during the simulations, in different assisted conditions, were: left and right ventricular end systolic (diastolic) volume, systolic/diastolic aortic pressure, mean pulmonary arterial pressure, left and right mean atrial pressure, mean systemic venous pressure and the total blood flow. Results show that the application of PUCA (without mechanical ventilatory assistance) increases the total blood flow, reduces the left ventricular end systolic volume and increases the diastolic aortic pressure. Parallel TAL assistance increases the right ventricular end diastolic (systolic) volume reduction both when PUCA is switched “ON” and both when PUCA is switched “OFF”. By switching “OFF” the PUCA pump, it seems that parallel thoracic artificial lung assistance produces a greater cardiac output (respect to hybrid TAL assistance). Results concerning PUCA and TAL interaction produced by simulations cannot be compared with “in vivo” results since they are not presented in literature. But results concerning the effects produced by LVAD and mechanical ventilation have a trend consistent with those presented in literature. [Copyright &y& Elsevier]

Aims Heart transplantation (HTx) is limited by the scarcity of suitable donor hearts. Consequently, more patients with advanced heart failure require a ventricular assist device (VAD). We report UK activity, trends, and outcome for long-term VAD support as a bridging therapy to HTx. Methods and results Patients were grouped into three eras: E1, February 2004–March 2006; E2, April 2006–March 2009; and E3, April 2009–March 2011. Exclusions were patients who received isolated short-term support or extracorporeal membrane oxygenation without prior or subsequent long-term VAD support. A total of 247 patients received VAD support; 202 left ventricular (LVAD) support alone and 45 both left and right ventricular support. Activity increased over time, from 36 patients implanted in E1 to 123 in E3. Overall, 46 patients received a first-generation device, 80 a second-generation device, and 121 a third-generation device. Use of third-generation devices increased from <6% in E1 to 78% in E3. Median duration of LVAD support increased from 141 days in E1 to 578 days in E3 (P < 0.001). Overall survival to 1 year after LVAD implant rose from 58.3% [95% confidence interval (CI) 40.7–72.4%] in E1 to 72.5% (95% CI 63.3–79.8%) in E3 (P = 0.21), and improved significantly with device generation; at 1 year, 50% of patients with first-generation devices were alive compared with 68.1% and 76.9% of patients with second- and third-generation devices, respectively (P = 0.002). These differences remained after risk adjustment. HTx following LVAD implant reduced over time (P < 0.001). Conclusion VAD activity and duration of support have increased. There has been a shift from first- and second- to third-generation devices, and an associated improvement in survival. [ABSTRACT FROM AUTHOR]

This paper presents a novel mock circulation for the evaluation of ventricular assist devices (VADs), which is based on a hardware-in-the-loop concept. A numerical model of the human blood circulation runs in real time and computes instantaneous pressure, volume, and flow rate values. The VAD to be tested is connected to a numerical-hydraulic interface, which allows the interaction between the VAD and the numerical model of the circulation. The numerical-hydraulic interface consists of two pressure-controlled reservoirs, which apply the computed pressure values from the model to the VAD, and a flow probe to feed the resulting VAD flow rate back to the model. Experimental results are provided to show the proper interaction between a numerical model of the circulation and a mixed-flow blood pump. [ABSTRACT FROM PUBLISHER]

Implantable left ventricular assist systems (LVAS) consist of implantable pumps with small control consoles and power sources that can be worn externally. These systems provide far greater patient mobility and independence than external pumps with bulky control consoles. Patients with implantable LVAS can be discharged from hospital and are able to return to work and resume active sports. Most patients have received these systems as a bridge to heart transplantation. Clinical status and quality of life improve dramatically after device implantation and survival on support (60–70% after approx. 100 days of support) is acceptable compared with transplant candidates on medical therapy. Patient selection and adverse events, primarily bleeding, thromboembolism and infection, are important issues with LVAS. In the future, long-term support and bridging to myocardial recovery may become important indications for LVAS. [ABSTRACT FROM PUBLISHER]