Mechanical circulatory support: state of the art and future perspectives.

Mechanical circulatory support (MCS) has been viewed, until recently, as a rescue therapy to be applied when all else fails. Not surprisingly, this has resulted in suboptimal outcomes. Fortunately, the perseverance of a few dedicated groups has produced improved outcomes and the concept of MCS as an elective therapy is now steadily gaining acceptance.

Novacor left ventricular assist system long-term performance: comparison of clinical experience with demonstrated in vitro reliability.

Since the first implant of the Novacor wearable left ventricular assist system (LVAS) in 1993, median implant duration worldwide has increased from 93 days (max 2.2 years) to 202 days (max 4.1 years) in May 2001.

Flight experience with the Novacor LVAS.

As Novacor LVAS recipients continue to be discharged from the hospital to await cardiac transplantation, an increasing number of patients either need or desire to use air transportation. To date, two test experiences have been reported with the Novacor LVAS operating in a mock circulatory loop during air travel. One involved the transport of a mock loop on a medical helicopter, and another preceded an international flight of an LVAS recipient from Japan to the United States.

Improved outcomes with an implantable left ventricular assist system: a multicenter study.

Background: Cumulative experience with the Novacor wearable electric left ventricular assist system (LVAS) now exceeds 850 recipients. The pump inflow conduit (IFC) has been implicated in embolic complications.

Methods: Clinical outcomes were compared for two IFC designs in a retrospective, nonrandomized, multicenter study.

Mechanical circulatory support for advanced heart failure: effect of patient selection on outcome.

Background: Use of wearable left ventricular assist systems (LVAS) in the treatment of advanced heart failure has steadily increased since 1993, when these devices became generally available in Europe. The aim of this study was to identify in an unselected cohort of LVAS recipients those aspects of patient selection that have an impact on postimplant survival.

Methods And Results: Data were obtained from the Novacor European Registry.

Long-term mechanical circulatory support with the wearable Novacor left ventricular assist system.

Objective: As of July 1st 1999, 36 European patients have lived for more than 1 year supported by the Novacor wearable electric left ventricular assist system (LVAS). All were unresponsive to maximum medical therapy, prior to implantation. These patients offer an unique opportunity to evaluate the feasibility of long-term ambulatory mechanical circulatory support as a therapeutic option for patients in profound cardiac failure.

Structural changes in porcine bioprosthetic valves of a left ventricular assist system in human patients.

Background And Aim Of The Study: Porcine, specially manufactured bioprosthetic valves regulate blood flow from the left ventricle to pump sac (inflow valve) and from the pump to the aorta (outflow valve) in a wearable, electrically powered left ventricular support system (LVAS, Novacor). The increased need for long-term circulatory assistance requires information on the evolution of these valves when exposed to specific hemodynamic conditions and inflammatory reactions in the device. The study aim was to examine structural changes in valves from explanted LVASs.

Intermittent atrial level right-to-left shunt with temporary hypoxemia in a patient during support with a left ventricular assist device.

We report a 56-year-old male patient developing hypoxemia after surgical replacement of infected valves of a left ventricular assist device (LVAD, Novacor) which had supported him during the previous 15 months. Contrast transesophageal echocardiography (TEE) revealed an atrial septal defect with intermittent right-to-left shunt across a patent foramen ovale. We postulate that the shunt detected in this patient occurred as a consequence of reduced pulmonary vascular compliance due to positive end-expiratory pressure (PEEP) and an increase of mean intrathoracic pressure.

The contribution of donor management and modified cold blood lung perfusate to post-transplant lung function.

Background: Donor organ availability remains the major limiting factor in the treatment of patients with end-stage lung disease by lung transplantation. Maximising the use of available organs is therefore crucial. Details available at the time of organ referral may give a misleading impression of their quality.

An approach to the retrieval of thoracic organs for transplantation.

A critical, worldwide shortage of thoracic organs exists. The donor management program at Papworth Hospital, National Health Service Trust, Cambridge, United Kingdom, allows satisfactory transplantation of thoracic organs that initially appear unsuitable. The perioperative organ retrieval team members assess the cardiovascular status of all potential donors and manage suboptimal hemodynamics with hormonal replacement therapy consisting of triiodothyronine, antidiuretic hormone, epinephrine, and insulin.

Transforming the "unacceptable" donor: outcomes from the adoption of a standardized donor management technique.

Background: Donor management remains one of the most neglected areas of transplantation. A comprehensive donor management regimen has been developed. The results of the application of this strategy form the basis of this report.

Functional assessment and management of heart donors: a rationale for characterization and a guide to therapy.

Background: Traditional methods for the functional evaluation of a donor heart have relied on superficial hemodynamic data and visual inspection of the action of the heart at sternotomy. The International Registry has continued to report significant mortality for heart transplant recipients from primary graft dysfunction that may be due to donor management, donor organ selection, organ preservation, or recipient factors. The literature reports the loss of at least 25% of potential donors because of the provision of inadequate physiologic support.

Measurements of human coronary vascular impedance.

The aim of this study was to develop a method of measuring human coronary circulation impedance in a clinical setting. The authors measured coronary flow reserve (CFR) in 27 patients with chest pain and normal coronary arteries. A Judkins-style, 8F Doppler-tipped angiographic catheter was positioned in the left coronary ostium.

Cardiovascular dysfunction. A rationale for characterization and a guide to therapy.

Traditional clinical assessment of cardiac function has relied on the indirect measurement of systemic blood pressure, heart rate and rhythm, and central venous pressure. However, because the circulation comprises complex interactions between flow and impedance in two hydraulic systems coupled in series, the usual assumptions drawn from the measurement of only a representative sample of this system can lead to serious errors in interpretation. This is particularly significant in conditions leading to physiologic distortions.

Using "unsuitable" hearts for transplantation.

Donor availability is the single most limiting factor in heart transplantation. From a consecutive series of 100 heart donors, there were 21 which fell well outside our minimum criteria on initial inspection: mean arterial pressure (MAP) more than 60 mm Hg, central venous pressure (CVP) less than 12 mm Hg, pulmonary capillary wedge pressure (PCWP) less than 12 mm Hg, left ventricular stroke work index (LVSWI) more than 15 g.m.

Donor heart preservation survey.

A questionnaire requesting information on donor heart preservation technique and outcomes during the first 6 months of 1990 was circulated to heart transplantation centers worldwide. Seventy-nine usable replies representing 1371 clinical transplant operations were received. Twenty-seven percent of the respondents reported using some form of donor pretreatment.

Thoracic organ preservation.

Clinical heart transplantation began in December 1967 when Cristiaan Barnard performed the first human to human heart transplant on a 57 year old man with ischaemic heart disease, in Cape Town. This ushered in a bout of enthusiastic heart transplantations world-wide over the subsequent few years which soon waned as the problems of acute rejection and infection became apparent to those who had embarked on this venture without fully understanding the complications. The importance of a well functioning donor heart cannot be overemphasized.