Active clinical trials for "Ischemia"

This study will collect heart tissue that is routinely removed and discarded during open-heart surgery. The Cardiology Branch of the NHLBI is conducting a variety of laboratory experiments that require a sample of heart tissue. A segment of tissue is routinely cut out of the right atrial appendage of the heart during open-heart surgery to allow the heart-lung bypass machine to be attached to the heart for protection during surgery. This small tissue sample is not re-attached after the bypass machine is removed, but usually destroyed as medical waste.' People between 18 and 80 years of age who are scheduled to undergo coronary artery bypass surgery or aortic valve replacement surgery may be eligible for this study. Participants donate the right atrial appendage of the heart, which would normally be destroyed after their open-heart surgery. The tissue will be used by NHLBI investigators in studies directed at learning how to make the heart less sensitive to damage from a heart attack. The samples may be used, for example, to evaluate the effectiveness of known therapies, refine treatment approaches, identify potential new therapies, or explore opportunities for disease prevention.

Brain injury occurs in one-quarter to one-half of congenital heart defect infants during the perioperative period. A blood test using a biomarker to diagnose brain injury would be important. Postoperative cerebral ischemia may be decreased by inotropic support, ventilation, medical management aimed at increasing oxygen delivery to the brain. Currently there are no FDA approved blood tests to assess brain ischemia in infants undergoing cardiac surgery. Specific Aim 1: We will prospectively study 10 neonates (< 30 days of age) undergoing cardiac surgery utilizing cardiopulmonary bypass for arterial switch operation or Norwood operation to determine the specificity and sensitivity of a blood test for brain injury. This aim will be accomplished by analyzing blood samples for S-100 and NSE drawn prior to surgery, once each day following cardiac surgery as long as the patient remains in the intensive care unit (maximum 5 days)and at the time of postoperative brain magnetic resonance imaging. The S-100B and NSE values will then be correlated with brain magnetic resonance imaging studies before cardiac surgery and at following cardiac surgery. Hypothesis: We expect the concentration of S-100B and NSE will be significantly higher in the blood of neonates with congenital heart disease who have documented brain injury on brain magnetic resonance imaging (MRI). Furthermore, we predict that the blood levels of S-100B and NSE may correlate to clinical outcome (time to extubation, hospital discharge, neurodevelopmental outcome at 6 months of age). Specific Aim 2: We will prospectively study these neonates at 6 months following cardiac surgery to determine a correlation between neurodevelopment and concentration of S-100B and NSE. To achieve this specific aim, a blood sample for S-100B and NSE and neurodevelopmental testing will be done at 6 months following cardiac surgery. Hypothesis: We expect neonates with elevated S-100B and NSE and abnormal brain magnetic resonance imaging documented in specific aim 1 to have a significant decline in neurodevelopment at 6 months after cardiac surgery. Long-term: The long-term goal of this research is to diagnose brain ischemia in infants using a biomarker blood test.

In this proof-of-concept study, forearm vulnerability to ischemic exercise is studied in patients with type 1 diabetes mellitus with and without prior ischemic preconditioning (short period of ischemia that protects against subsequent ischemic exercise). Annexin A5 scintigraphy is used to quantify subtle signs of mild and reversible forearm injury that results from ischemic exercise. The following hypotheses are tested: Patients with type 1 diabetes are not more vulnerable to ischemic injury as compared with previously studied healthy volunteers. Ischemic preconidtioning is still present in patients with type 1 diabetes. Depending on the validity of hypothesis 2, the effect of short pharmacological interventions are studied on vulnerability to forearm ischemia/reperfusion injury in the absence or presence of local forearm ischemic preconditioning.

The purpose of this study is to investigate the effects of total intravenous anesthesia versus volatile anesthesia on the perioperative inflammatory response during and after major surgery.

To explore whether reduced systemic pain perception in response to painful stimuli and personality pain related variables characterizes silent MI patients.

To determine if silent myocardial ischemia was associated with an increased risk of cardiac mortality and morbidity during a one to three year follow-up in patients with coronary heart disease.

To examine factors affecting heart rate variability (HRV) and the role of HRV in heart disease. Specifically, to examine the role of HRV: as a predictor of fatal and nonfatal ischemic heart disease over a six year follow-up of the Atherosclerosis Risk in Communities (ARIC) population based, bi-ethnic cohort; on the six year progression of carotid atherosclerosis measured by B-mode ultrasound; and on the incidence of hypertension. Also, to study the effect of elevated fasting insulin, glucose, diabetes mellitus, and other metabolic abnormalities on changes in HRV over nine years of follow-up.

To examine the effect on health and disease of the work environment, psychological workload, control over work pacing and content, opportunity for use of skills, social support at work; the moderating effect on these relationships of social supports; and, the interaction between these psychosocial factors and other established risk factors in the etiology of chronic disease.

This prospective, observational study evaluates the accuracy of stress testing with the MyoStrain SENC CMR Imaging System to detect myocardial ischemia and viability in patients with suspected coronary artery disease using low levels of stress.

The number of patients with end stage renal disease is increasing continuously and kidney transplantation is the preferred treatment modality. Modern immunosuppressive therapy has reduced the number of acute rejection episodes and increased one year allograft survival dramatically. Nonetheless, 4% of allografts are lost beyond the first year annually due to a multifactorial process and the latter number has not changed for decades. One of the most important factors to determine long-term success after kidney transplantation is the quality of the donor organ. For example, transplantation of organs from elderly or extended criteria donors results in reduced allograft and patient survival. In previous work, the investigators specifically focused on age-associated molecular signatures including telomere length and mRNA expression levels of the cell cycle inhibitors CDKN2A (p16INK4a) and CDKN1A (p21WAF1) and assessed these parameters in pre-implantation biopsies of 54 patients. In a linear regression analysis CDKN2A turned out to be the best single predictor for serum creatinine after 1 year followed by donor age and telomere length. A multiple linear regression analysis revealed that the combination of CDKN2A values and donor age yielded even higher predictive values. In another study the investigators were able to show an interaction between donor age and use of calcineurin inhibitors with regard to outcome after renal transplantation. During these past activities an extensive set of whole genome transcriptomics profile information from zero hour biopsies and clinical follow-up data has been collected. In the TOPVAS study, existing data derived from 72 of the above mentioned set of biopsies (exclusion of live donor grafts) will be analysed with state of the art bioinformatical/system biology tools to derive a general (not purely age associated) prognostic biomarker panel for functional transplant outcome two years after transplantation. This marker panel will also be used to define organs preferentially suitable for MMF/tacrolimus based immunosuppression. Both panels will then be validated for their prognostic and predictive information on the long-term outcome after transplantation in a new independent patient population treated with tacrolimus and MMF. In addition to biomarker assessment and in pursue of identifying alternative and/or complementary parameters with predictive value , an advanced morphological investigation of tissue biopsy life stains will be performed employing an innovative cell viability staining technology ("BIOPSYCHRONOLOGY").