J. A. St. Cyr

D-ribose aids advanced ischemic heart failure patients

Patients with advanced heart failure are exercise intolerant. Low cellular energy levels in the failing heart have been proposed. Energy enhancing substrates have revealed mixed results. Ribose, a pentose monosaccharide, has shown to replenish low myocardial energy levels, improving cardiac dysfunction following ischemia, and improving ventilation efficiency in patients with heart failure. As current pharmaceuticals do not address cellular energy levels, this study was designed to investigate the role of ribose on ventilation at anaerobic threshold in congestive heart failure patients. d-ribose (5 gms/dose, tid) was assessed in 16 NYHA class III-IV, heart failure patients with VO(2), tidal volume/VCO(2), heart rate/tidal volume evaluated at 8 weeks. All patients had a significant improvement in ventilatory parameters at anaerobic threshold, along with a 44% Weber class improvement. Ribose improved the ventilatory exercise status in advanced heart failure patients.

Myocardial Ischemia: Alterations in Myocardial Cellular Energy and Diastolic Function, a Potential Role for D-Ribose

Cardiovascular disease still remains the leading cause of deaths worldwide in both males and females. A variety of factors have been associated to play a role in the development of this disease, such as an individual’s genetic background and continual life style factors. Life style factors (including diet) have greatly influenced the occurrence and progression of this disease. The medical profession has made great efforts to adequately address and to continually stress to their patients an altered life style to confront the non-genetic factors, in order to potentially minimize their risk for cardiovascular disease. This campaign has centered on a continual direction for refinements in diet, regular exercise, smoking cessation, and to control blood pressure to lower their risk for cardiovascular disease.

Supplements for exercise.

Athletes, and to a lesser degree “weekend warriors,” are always looking for an edge to physically maintain or excel in their exercise performance, lessen muscular soreness, minimize fatigue, and speed recovery. To try to achieve this state, many have turned to nutritional supplements. However, in order to effectively promote and maintain acceptance by the public, well-structured studies with finite endpoints must be performed with high standards and accurately reported in reputable journals to satisfy interested parties. Researchers have addressed a more effective means in replenishing muscular energy levels postexercise, as well as reducing soreness and fatigue, resulting in a more rigorous training schedule. Furthermore, the production of oxygen-free radicals during and following exercise has attracted attention over the past decade. These free radical compounds have the potential to harm the cell’s wall and hinder intracellular processes. Therefore, today’s sports medicine market has entertained products that have the potential to lessen this cellular energy drain, minimize the damaging effects from formed oxygen-free radicals during and following exercise, and offer the means to maintain or potentially exceed performance goals. However, finding effective supplements in meeting these goals is often more difficult than not. Many individuals find that the advertised benefits of a supplement from information found in the media, including the Internet, do not always live up to their claims, which casts not only doubt about the product but also questions credibility in the nutraceutical industry. The goal of an energy supplement should center on replenishing energy most effectively and quickly following a workout session.

Pressure load-sensing assessments of the right ventricular outflow tract and main pulmonary artery.

ABSTRACT Surgical repairs for congenital right ventricular outflow tract disease have commonly required multiple procedures because of hemodynamic failures from previous operations. Over the past decade, the percutaneous placement of stented valve prostheses in a failed right ventricular outflow tract conduit to restore acceptable pulmonary valve function has produced acceptable results; however, the incidence of stent fractures post-implantation in these stented valve prostheses has aroused concerns. In order to investigate this problem, sequential, pressure load-sensing assessments throughout the right ventricular outflow tract and into the main pulmonary artery would be required to effectively evaluate the degree of physiological loading along these sites. Customarily, to perform these assessments, multiple cardiopulmonary bypass procedures, as well as multiple pulmonary arteriotomies would be required, both of which carry their own risks. Owing to these risks, we developed a successful surgical technique for sequential load-sensing evaluations throughout the right ventricular outflow tract and main pulmonary artery using a single cardiopulmonary bypass session and one pulmonary arteriotomy. This technique successfully provided a means to prevent multiple arteriotomies and bypass sessions without complications while obtaining reproducible data in evaluating pressure load-sensing states throughout the right ventricular outflow tract and main pulmonary artery in adult sheep.

Nutritional Supplementation of Donors May Improve Outcomes Following the Transfusion of Stored Red Blood Cells

The need for blood donations continues to be important. There continues a campaign to attract volunteer donors to try to meet the necessary available pool of stored blood that is needed to meet the needs in various clinical situations. These clinical situations include during and following surgical operations, acute and chronic disease states causing anemia, traumatic hemorrhagic situations, and in patients receiving chemotherapy for malignancies. Approximately 15 million units of blood are donated yearly in the United States, with approximately 32,000 units of red blood cells (RBCs) transfused every day. Donated blood may be transfused immediately; however, commonly, donated units of RBCs are stored for up to 42 days. During this storage period, alterations in pH, states of hypoxia, and the formation of toxic substances can produce “storage lesions” (Zubair, 2010). Such lesions may decrease an RBC’s integrity, functionality, and potentially its viability. (Zimrin & Hess, 2009) The production of storage lesions can have a deleterious effect on the normal functioning of RBCs following transfusion, at a time in which optimal function is critical. These storage lesions center on both biochemical and morphological changes, which can impair the efficacy of an RBC. Clinically, following transfusion, these affected RBCs can potentially alter clinical outcomes, including increase in morbidity and mortality, as reported in 21 separate clinical studies (Wang et al., 2012). Red blood cells depend upon an intact membrane and an internal cytoskeleton as well as an adequate supply of adenosine triphosphate (ATP) levels to maintain cellular integrity and functioning. RBCs have very high levels of 2,3 diphosphoglycerate (DPG) to aid in oxygen delivery. Equally important is an adequate level of ATP to provide necessary energy for the cell. During storage, there is a decline in DPG and ATP levels (Dawson et al., 1981a). Maintenance of the RBC’s membrane structure is paramount for functional stability (Card, 1988). Damage of an RBC membrane can also have negative effects on the recipient’s endothelium, which lines the interior surface of blood and lymphatic vessels, following transfusion. Furthermore, during this storage period, there can be an increase in reactive oxygen species (ROS) and advanced glycation end products (AGEs), which can affect cellular functionality. The production of AGEs has been implicated as a variable in many clinical diseases This production of ROS and AGEs during storage of RBCs is the result of the interaction of polyunsaturated fatty acids with oxygen and ferrous iron, as these are in close proximity to each other. The creation of lipid oxidation products (Addis et al., 1989; Emanuel et al., 1991), including aldehydic derivatives of polyunsaturated fatty acids and cholesterol oxides,

Re-Assessing Red Blood Cell Storage

Standard clinical practice guidelines dictate that stored RBCs are discarded at 42 days. During this storage interval, alterations in pH and a level of hypoxia occurs, as well as the accumulation of toxic substances which can interact with the RBCs, including its membrane. A state of reactive oxygen radicals and the formation of advanced glycation end products can ensue, both of which can produce detrimental effects to these stored cells. Furthermore, once transfused, the damage to the RBC’s membrane may also have a negative effect on the recipient’s endothelium.

Assessing diastolic dysfunction

The recent article referring to the use of cardiopulmonary exercise testing in assessing heart failure patients with diastolic dysfunction by Guazzi et al. in the Journal of Cardiopulmonary Rehabilitation and Prevention (May/June, 2010) was most enlightening.[1] Cardiopulmonary exercise testing has continued to reveal its usefulness in both diagnostic and therapeutic applications for cardiovascular and pulmonary diseases. Furthermore, cardiopulmonary exercise testing in heart failure patients, as reported by Guazzi et al., provides an assessment of a patients current physiologic and functional status and provides a more meaningful comparison in evaluating benefits of a chosen therapeutic regimen. Heart failure patients with diastolic dysfunction and preserved systolic function have decreased breathing efficiency with an increase in left atrial pressure, impacting pulmonary blood flow. Stroke output or oxygen pulse is compromised due to reduced left ventricular filling, thus resulting in a compensatory elevation in heart rate and ventilatory work. Even with todays accepted technologies, a more precise assessment during this physiological stressful state is missing. Cardiopulmonary exercise testing can provide this needed evaluation by offering multiple benefits, both as a diagnostic and also as a tool for future therapeutic guidance. Other researchers besides Guazzi et al. have reported similar benefits of cardiopulmonary exercise testing in congestive heart failure patients. MacCarter et al. assessed ventilation parameters using cardiopulmonary exercise testing in advanced heart failure patients, who consumed the nutraceutical supplement, Dribose.[2] They reported that D-ribose benefited measured ventilation parameters at anaerobic threshold using cardiopulmonary exercise

Right ventricular outflow tract reconstructive model in adult sheep.

Patients born with congenital right ventricular outflow tract lesions are faced with invasive procedures to establish hemodynamic and physiological stability. Commonly, multiple subsequent surgical procedures are required due to deterioration of a previous repair. These procedures carry additive risks of mortality and morbidity. Less aggressive procedures with accompanying lower risk is ideal. Success in percutaneously placing a transcatheter valve has previously been reported; however, continued safety and efficacy of any technique needs continual assessment. We developed a model for preclinical evaluation of a percutaneous placement of a pulmonic transcatheter valve in adult sheep, including preoperative, surgical, and postoperative techniques for long-term evaluation. Adult sheep were assessed and determined to be acceptable for study enrollment. Perioperative antibiotics and analgesics were given prior to a left thoracotomy. A Medtronic, Hancock 1 valve conduit was inserted for reconstruction of the right ventricular outflow tract. The Hancock 1 valve conduit alone represented the control group and the test animals comprised the addition of a Melody™ transcatheter pulmonary valve (TPV), within the Hancock 1 valve conduit. Fifteen adult sheep survived the surgical implant procedure with no perioperative mortality. There were four early postoperative deaths, three due to infection and one due to heart failure, secondary to intraoperative heart block. The remaining 11 animals remained healthy, gained weight, and survived to termination at 5 months. An initial definite-sized valve conduit was implanted, followed by inserting a single size TPV, which allowed a more accurate physiological assessment of any chosen valve. Our developed adult sheep model for percutaneous TPV implantation for right ventricular outflow tract lesions was successful for long-term assessment by utilizing our preoperative, surgical, and postoperative techniques.