A Decision Support System for the Treatment of Patients with Ventricular Assist Device Support (original) (raw)

New Circulatory Support System: Heartware

Transplantation Proceedings, 2012

Introduction. Through the new developments in medicine, heart failure therapy has advanced to mechanical circulatory support systems. The HeartWare Ventricular Assist System HVAD; HeartWare, Inc.; Miramar, Fla, USA) is a new device that is a centrifugal, intracorporeal, miniaturized and continuous flow pump that serves simple patient use and enhanced life quality. This article reports the midterm results of patients who underwent the heartware support system. Materials and methods. We retrospectively compiled our data from December 2010, including 10 patients of mean age 51.8 years with 90% males, 70% of the overall patient cohort had dilated cardiomyopathy and remaining ones, ischemic disease. Mean left ventricular ejection fraction was 20.1% and mean systolic pulmonary artery pressure was 49.2 mm Hg. A single patient was grade 1; seven were grade 2; and remaining ones, grade 3 according to the INTERMACS (Interagency Registry for Mechanically Assisted Circulatory Support) scale. All patients were operated with cardiopulmonary bypass (CPB) with moderate hypothermia. Tricuspid ring annuloplasty was performed in 3 (30%) patients. In one patient we removed a left ventricular thrombus. In a case with severe aortic regurgitation, we placed a simple coaptation stitch at the central portion of the three aortic cusps under the aortic cross clamp. The mean CPB duration was 95.5 minutes.

Ventricular Assist System Applications in End-stage Heart Failure

Transplantation Proceedings, 2011

Background. Mechanical circulatory support has an important role in the surgical therapy for heart failure. Patients deteriorating on transplantation waiting lists or those unsuitable for transplantation have been treated with ventricular assist devices. In this report, we have presented application of ventricular assist systems for patients with end-stage heart failure. Methods. Between April 2007 and September 2010, we treated 37 patients with end-stage heart failure with mechanical circulatory support, including 5 children younger than 16 years of age. Three patients were females, and the overall mean age was 40 Ϯ 18 years (range, 1.5-67). In 29 patients we implanted paracorporeal pneumatic ventricular assist devices. Axial flow pumps were chosen to support the left ventricle in 8 patients. Biventricular support was applied in 9 patients because of their poor preoperative clinical conditions and advanced evidence of right ventricular failure. Results. Heart transplantation was performed in 16 patients (43%). One subject, who was managed with a left ventricular assist device implantation and coronary bypass grafting, was weaned from the system because of recovery of ventricular functions. Eleven patients (30%) are still on pump support. Nine patients (24%) died during mechanical circulatory support. The most prevalent cause of mortality was multiorgan failure (n ϭ 5; 13.5%). Cerebrovascular hemorrhage was the cause of death in 2 patients. One patient died due to acute lung injury, and an other due to malignant melanoma. Conclusion. Use of a ventricular assist device as a bridge-to-transplantation or as destination therapy can be performed with acceptable mortality. It may be the most promising option for patients with end-stage heart failure. Development of device technology, advanced monitoring of anticoagulation and anti-aggregation therapy, and greater clinical experience may yield better results.

Design Concepts and Principle of Operation of the HeartWare Ventricular Assist System

ASAIO Journal, 2010

Implantable left ventricular assist devices provide circulatory support for patients at risk of death from refractory, end-stage heart failure. Rotary blood pumps have been designed for increased reliability and smaller size for use in a broader population of patients than the first-generation pulsatile devices. The design concepts and principle of operation of the HeartWare System are discussed. The HeartWare Ventricular Assist System (HVAD) is a small centrifugal flow pump with a displacement volume of 50 ml and an output capacity of 10 L/min. A unique wide-blade impeller is suspended by hybrid passive magnets and hydrodynamic forces. An integrated inflow cannula is inserted into the left ventricle and is held in position by an adjustable sewing ring; the pump is positioned in the pericardial space. The 10-mm outflow graft is anastomosed to the ascending aorta. External system components include the microprocessor-based controller, a monitor, lithiumion battery packs, alternating current and direct current power adapters, and a battery charger. Physiologic control algorithms are incorporated for safe operation. Preclinical life cycle tests have shown the HVAD to be highly reliable. This system design offers reliability, portability, and ease of use for ambulatory patients.

Destination therapy: the new gold standard treatment for heart failure patients with left ventricular assist devices

General thoracic and cardiovascular surgery, 2013

Heart failure continues to be a growing health problem, eluding large-scale improvement and treatment. Cardiac transplantation has been the gold standard treatment with high post-transplant survival rates and relatively good quality of life. However, there has been an extreme shortage of organ donations, limiting transplants to only a very small portion of patients with the condition. This led to a growing interest in alternative options for the increasing population of patients who are waitlisted or ineligible for transplantation. In recent years, ventricular assist device (VAD) technologies have advanced from pulsatile blood pumps to continuous-flow pumps that have demonstrated unprecedented post-implantation survival rates. The HeartMate II, the only commercially available, continuous flow left ventricular assist device (LVAD) in the United States and Europe, has been implanted in over 10,000 patients worldwide, setting a benchmark for biomedical modalities of advanced heart fail...

In Vitro Test Bench with Intelligent Behavior to Ventricular Assist Devices

Proceedings of the 15th International Conference on Informatics in Control, Automation and Robotics, 2018

The abstract The Ventricular Assist Device (VAD) is a mechatronic device used to treat patients with heart failure who are able to use them in short-and long-term strategies. However, with increasing population longevity, long-term use has been intensified. Thus, the development of resources that improve the robustness and reliability of these devices is justified. This work proposes an in vitro test bench with intelligent behaviour that through a systematic of protocols for the collection, treatment and monitoring of reliability data, coming from standard curves of monitored variables, such as: flow, pressure, vibration, rotation, density, viscosity and temperature, provides a decision support system with user friendly interface for verification, validation and certification of VAD. The proposed method is descriptive of an in vitro test bed model for VAD that considers the use of Petri net for validation of the dynamic behaviour in front of the variables and a decision support system based on big data analytics technology with extraction of dada, which subsidizes intelligent behaviour. The proposed model is consistent with the bibliographic base and its validation. The Petri net allows confirming its application in the decision making, with intelligent behaviour, from the data mining.

Specification of Supervisory Control Systems for Ventricular Assist Devices

Artificial Organs, 2011

One of the most important recent improvements in cardiology is the use of ventricular assist devices (VADs) to help patients with severe heart diseases, especially when they are indicated to heart transplantation. The Institute Dante Pazzanese of Cardiology has been developing an implantable centrifugal blood pump that will be able to help a sick human heart to keep blood flow and pressure at physiological levels. This device will be used as a totally or partially implantable VAD. Therefore, an improvement on device performance is important for the betterment of the level of interaction with patient's behavior or conditions. But some failures may occur if the device's pumping control does not follow the changes in patient's behavior or conditions. The VAD control system must consider tolerance to faults and have a dynamic adaptation according to patient's cardiovascular system changes, and also must attend to changes in patient conditions, behavior, or comportments. This work proposes an application of the mechatronic approach to this class of devices based on advanced techniques for control, instrumentation, and automation to define a method for developing a hierarchical supervisory control system that is able to perform VAD control dynamically, automatically, and securely. For this methodology, we used concepts based on Bayesian network for patients' diagnoses, Petri nets to generate a VAD control algorithm, and Safety Instrumented Systems to ensure VAD system security. Applying these concepts, a VAD control system is being built for method effectiveness confirmation.

Ventricular assist devices for heart failure: a focus on patient selection and complications

Research Reports in Clinical Cardiology, 2014

Heart transplantation represents the "gold standard" for the treatment of patients with end-stage heart failure, but remains challenged by inadequate donor supply, finite graft survival, and long-term complications arising from immunosuppressive therapy. In addition, a lot of patients waiting for a heart transplant experience clinical deterioration, and other patients become ineligible to undergo this treatment due to their age or relevant comorbidities. Left ventricular assist devices have emerged as a valid therapeutic option for advanced heart failure. In recent years, we have seen significant advances not only in the technologies available, but also in patient selection, indications for use, and management after implantation. Consequently, there has been an increase in the number of implants and an improvement in the survival rate and quality of life for these patients. At the same time, there are new challenges on the horizon. Patient selection is a difficult process, based on clinical and imaging parameters and risk scores, and more data are needed to refine patient selection criteria and the timing of the implant. Left ventricular assist device-related complications are still a serious problem, causing adverse events and hospital readmissions. Continuous progress in the development of these implantable devices, such as a further reduction in size and hopefully the abolition of the external driveline, will probably make ventricular assist devices an option also for less advanced stages of heart failure. Here, we discuss the current indications for left ventricular assist device implantation, patient selection criteria, and the most frequent complications associated with these devices.