Cardiopulmonary Bypass in a Patient with Factor XII Deficiency.

The performance of cardiopulmonary bypass (CPB) in the factor XII-deficient patient is challenging in that the normal method for monitoring anticoagulation is ineffective as a result of an impaired contact activation system. We report the case of a factor XII-deficient patient who underwent surgical revascularization on CPB. His factor XII level was replenished with fresh-frozen plasma immediately before surgery.

Dysregulation of antioxidant mechanisms contributes to increased oxidative stress in calcific aortic valvular stenosis in humans.

Objectives: The aim of this study was to determine whether oxidative stress is increased in calcified, stenotic aortic valves and to examine mechanisms that might contribute to increased oxidative stress.

Background: Oxidative stress is increased in atherosclerotic lesions and might play an important role in plaque progression and calcification. The role of oxidative stress in valve disease is not clear.

Presence of plasticizer di-2(ethylhexyl)phthalate in primed extracorporeal circulation circuits.

Many centers advocate the use of a standby wet-primed extracorporeal membrane oxygenation (ECMO) circuit for rapid deployment during cardiopulmonary resuscitation. However, concerns with regard to the potential health hazards associated with the release of the plasticizer di-2(ethylhexyl)phthalate (DEHP) from the polyvinyl chloride (PVC) tubing exist. The purpose of this study was to determine the time course of DEHP release from a preprimed ECMO circuit and to evaluate the effect of PVC tubing coatings on DEHP release.

Electrostatic potential generated during extracorporeal pump prime circulation before cardiopulmonary bypass initiation.

The development of electrostatic potentials generated during cardiopulmonary bypass (CPB) procedures using polyvinylchloride (PVC) tubing in conjunction with roller pumps has been previously documented. The resulting damage from the electrostatic discharge (ESD) has been reported to affect gas transfer devices, but details of potential damage to electronic components commonly used during extracorporeal circulation have not been similarly described. The purpose of this study was to measure the ability of a triboelectric potential to be generated from a primed, circulating, adult CPB pump before the initiation of CPB.

Latest developments in the field of assisted circulation.

The 51st Annual Meeting of the American Society for Artificial Internal Organs was held in Washington, DC, June 9 to 11, 2005. The abstract submission deadline for this meeting occurred on January 14, 2005. To ensure that the attendees were completely up-to-date with developments in the field of mechanical circulatory support, I was asked to provide a brief summary of developments or milestones that occurred after the abstract submission deadline.

Long-term (2-year) clinical events following transthoracic intramyocardial gene transfer of VEGF-2 in no-option patients.

Background: The short-term clinical impact of intramyocardial gene transfer (GT) of the angiogenic protein vascular endothelial growth factor-2 (VEGF-2) has been previously reported to significantly reduce Canadian Cardiovascular Society (CCS) angina class and to prolong exercise treadmill test (ETT) time. We describe the safety and long-term events (>1 year) in consecutive, nonrandomized, patients who received intramyocardial VEGF-2.

Methods: Thirty patients with intractable CCS class III or IV angina and no options for revascularization underwent direct intramyocardial GT of VEGF-2 naked DNA via limited thoracotomy at total doses of 0.

Transmyocardial revascularization: 5-year follow-up of a prospective, randomized multicenter trial.

Background: In prospective randomized trials at 1 year, transmyocardial revascularization (TMR) provided superior relief of angina, decreased rehospitalizations, and improved exercise times. We evaluated 5-year mortality and angina class in "no-option" patients with diffuse coronary artery disease randomized to TMR or continued medical management.

Methods: Two hundred twelve patients with refractory class IV angina who were not candidates for conventional therapy were randomized to receive holmium:yttrium-aluminum-garnet TMR (n = 100) or continued medical management (n = 112) at nine centers.

Enhanced cytomegalovirus infection in atherosclerotic human blood vessels.

Human cytomegalovirus (CMV) is a possible co-factor in atherogenesis and vascular occlusion, but its ability to actively infect medium and large blood vessels is unclear. A vascular explant model was adapted to investigate CMV infection in human coronary artery, internal mammary artery (IMA), and saphenous vein (SV). Vascular explants were inoculated with CMV Towne or low-passage clinical isolate and examined in situ for CMV cytopathic effect and immediate-early and early antigens, as indicators of active infection.

Left ventricular assist devices as permanent heart failure therapy: the price of progress.

Background Data: The REMATCH trial evaluated the efficacy and safety of long-term left ventricular assist device (LVAD) support in stage D chronic end-stage heart failure patients. Compared with optimal medical management, LVAD implantation significantly improved the survival and quality of life of these terminally ill patients. To date, however, there have been no analyses of the cost related to the LVAD survival benefit.

One-year follow-up of direct myocardial gene transfer of vascular endothelial growth factor-2 using naked plasmid deoxyribonucleic acid by way of thoracotomy in no-option patients.

This phase I open label, dose-escalating study shows that gene transfer of vascular endothelial growth factor-2 naked deoxyribonucleic acid by direct myocardial injection by way of thoracotomy in patients with Canadian Cardiovascular Society class 3 or 4 angina is feasible and safe. The procedure is well tolerated, with few major adverse cardiac events at 1 year, and without complications directly related to gene expression. In this prospective, nonblinded study, the procedure is associated with clinical improvement; however, there was no angiographic evidence of angiogenesis and there is a great potential for a sham or placebo effect in the study patients.

Surgical management of patients in the REMATCH trial.

The donor shortage makes cardiac transplantation a less than ideal treatment for end-stage heart failure. The utility of the left ventricular assist device (LVAD) as a permanent form of circulatory support has recently been established in the REMATCH (Randomized Evaluation of Mechanical Assistance for the Treatment of Congestive Heart Failure) trial. In this report, we describe the surgical management of LVAD patients in REMATCH and their short-term outcomes.

Low-level endotoxin induces potent inflammatory activation of human blood vessels: inhibition by statins.

Background: Low-level endotoxemia (ie, >or=50 pg/mL) in apparently healthy subjects was recently identified as a powerful, independent risk factor for atherosclerosis.

Methods And Results: We treated human saphenous veins (HSVs) with low levels of endotoxin. Release of the proinflammatory chemokines interleukin-8 (IL-8) and monocyte chemoattractant protein-1 (MCP-1) was measured by ELISA.

Education of the ventricular assist device patient's community services.

Two implantable, electric left ventricular assist systems have received approval from the Food and Drug Administration (FDA) for use outside a hospital environment. As patients supported with these systems are discharged from the hospital, it is important that various community services and agencies be involved in the care of this unique patient population. Between January 1999 and May 2001, The University of Iowa Hospitals and Clinics (UIHC) implanted 14 HeartMate VE LVAS (Thoratec Corporation, Pleasanton, CA) in patients as a bridge to cardiac transplantation.

Hospital discharge for the ventricular assist device patient: historical perspective and description of a successful program.

Patients who are supported with an implantable ventricular assist device (VAD) as a bridge to cardiac transplantation are potential candidates for hospital discharge. Hospital discharge rates in reported clinical series vary from 27% to 60%. Many of the patients included in these series, however, were subjects of premarket approval clinical trials and as such, are bound by rigid eligibility criteria for discharge.

Clinical trial: a clinician's perspective.

As a result of my participation in several clinical trials at The University of Iowa, I have now redrawn what I perceive to be the algorithm for conduct of a clinical trial. Of note, I have excluded the development of the new device, in vitro device testing, in vivo animal experimentation, clinical protocol development, granting of an Investigational Device Exemption, and the process by which clinical sites are selected. Following my algorithm I have made no mention of the commercialization of an experimental device, including the Pre-Market Approval process and FDA panel meetings.

Clinical evaluation of a new in-line continuous blood gas monitor.

Two methodologies for obtaining accurate blood gas and electrolyte values during cardiopulmonary bypass (CPB) are traditional laboratory analyzers, which use an electrochemical technology, and continuous in-line monitoring systems, which use a fluorometric and/or spectrophotometric technology. The purpose of the present study was to evaluate the accuracy of a new continuous in-line monitor, the 3M CDI Blood Parameter Monitoring System 500, which provides continuous in-line measurements of pH, PCO2, PO2, potassium (K+), oxygen saturation, hematocrit, hemoglobin, and temperature, during partial or complete CPB. Study parameters included arterial pH, PCO2, PO2, and K+ values.

In vivo demonstration of cavitation potential of a mechanical heart valve.

Cavitation is implicated as the cause of pitting and erosion of explanted mechanical heart valves that failed. Previous in vitro studies demonstrated transient negative pressure spikes upstream of mechanical heart valves at the instant of leaflet closure. When the magnitude of the transient negative pressure spike is below the vapor pressure of the fluid flowing across the mechanical valve, cavitation bubbles have been documented near the valve housing or occluder disc.