Effects of metabolic stimulation on cardiac allograft recovery.

Background: We previously demonstrated that continuous perfusion of cardiac allografts during hypothermic storage with donor blood harvested at the time of organ retrieval improves myocardial recovery after transplantation. However, myocardial metabolism and function remain depressed compared to base line values. This study evaluated the use of a continuous infusion of donor blood enhanced with insulin to augment aerobic myocardial metabolism during and after hypothermic storage.

Transplantation of cryopreserved cardiomyocytes.

Background: The present study examined the survival and rate of contraction of (1) cardiomyocytes cultured from cryopreserved fetal rat myocardium and (2) cryopreserved cultured cardiomyocytes. In addition, the effects of transplantation of cryopreserved fetal cardiomyocytes were evaluated.

Methods: Segments of fetal rat myocardial tissue (0.

Reoperative coronary bypass surgery: effect of patent grafts and retrograde cardioplegia.

Objective: To determine the effects of patent or diseased aorta-coronary bypass grafts and retrograde cardioplegia on mortality during reoperative coronary bypass surgery.

Methods: We conducted a retrospective review of prospectively gathered data, supplemented by systematic chart review, of all patients (n = 744) undergoing reoperative coronary bypass surgery at our institution between 1990 and 1997. Independent predictors of survival were determined by stepwise logistic regression analysis.

Heart cell transplantation improves heart function in dilated cardiomyopathic hamsters.

Background: Little is known about the effect of heart cell transplantation into the dilated cardiomyopathic myocardium. This study was designed to evaluate the effect of heart cell transplantation into dilated cardiomyopathic hamsters.

Methods And Results: Ventricular heart cells were isolated from 4-week-old BIO 53.

Autologous smooth muscle cell transplantation improved heart function in dilated cardiomyopathy.

Background: Transplantation of myocytes into scarred myocardium has been shown to inhibit ventricular remodeling and maintain myocardial contractility. However, the effect of cell transplantation on hearts with global rather than regional dysfunction is unknown. Therefore, we evaluated the effect of transplantation of autologous smooth muscle cells on the morphometry and function of dilated cardiomyopathic hearts.

The changing pattern of reoperative coronary surgery: trends in 1230 consecutive reoperations.

Objective: We noted an increasing risk profile of patients undergoing reoperative coronary surgery. We evaluated the risk compared with primary procedures, our results over a 16-year span, and the predictors of hospital outcomes after redo surgery.

Methods: We analyzed 20,614 patients undergoing isolated coronary surgery at our institution from 1982 to 1997.

Insulin cardioplegia for elective coronary bypass surgery.

Background: Improved methods of myocardial preservation are required to reduce the morbidity and mortality of coronary bypass surgery for high-risk subgroups. Metabolic stimulation with insulin, glucose solutions, or both has been proposed as a method to preserve the ischemic myocardium. We performed a prospective, double-blind, randomized trial to evaluate the effects of insulin and glucose as cardioplegic additives when used as part of a tepid continuous blood cardioplegic strategy.

Construction of a bioengineered cardiac graft.

Objectives: Currently available graft materials for repair of congenital heart defects cause significant morbidity and mortality because of their lack of growth potential. An autologous cell-seeded graft may improve patient outcomes. We report our initial experience with the construction of a biodegradable graft seeded with cultured rat or human cells and identify their 3-dimensional growth characteristics.

Autologous heart cell transplantation improves cardiac function after myocardial injury.

Background: Fetal ventricular cardiomyocyte transplantation into a cardiac scar improved ventricular function, but these cells were eventually eliminated by rejection. We therefore examined the feasibility of autologous adult heart cell transplantation.

Methods: A transmural scar was produced in the left ventricular free wall of adult rats by cryoinjury.

Autologous porcine heart cell transplantation improved heart function after a myocardial infarction.

Objective: Fetal cardiomyocyte transplantation improved heart function after cardiac injury. However, cellular allografts were rejected despite cyclosporine (INN: ciclosporin) therapy. We therefore evaluated autologous heart cell transplantation in an adult swine model of a myocardial infarction.

Predictors of operative risk for coronary bypass operations in patients with left ventricular dysfunction.

Objectives: The prevalence of ventricular dysfunction in patients undergoing coronary operations, as well as the prevalence of other risk factors in these patients, has been increasing. We identified the predictors of mortality and morbidity in patients with ventricular dysfunction to permit more accurate evaluation of risk and to direct future strategies to improve outcomes.

Methods: Demographic, intraoperative, and outcome data were collected prospectively on 20,614 patients undergoing isolated coronary operations at our institution from 1982-1997.

Intraoperative myocardial protection: current trends and future perspectives.

Background: The results of contemporary coronary artery bypass graft surgery (CABG) are excellent. However, recently changing trends in the population at risk have necessitated new measures to minimize perioperative morbidity and mortality.

Methods: We reviewed cardioplegic innovations developed, evaluated, and currently employed at the Toronto Hospital.

Autologous transplantation of bone marrow cells improves damaged heart function.

Background: Autologous bone marrow cells (BMCs) transplanted into ventricular scar tissue may differentiate into cardiomyocytes and restore myocardial function. This study evaluated cardiomyogenic differentiation of BMCs, their survival in myocardial scar tissue, and the effect of the implanted cells on heart function.

In Vitro Studies: BMCs from adult rats were cultured in cell culture medium (control) and medium with 5-azacytidine (5-aza, 10 micromol/L), TGFbeta1 (10 ng/mL), or insulin (1 nmol/L) (n=6, each group).

Survival and function of bioengineered cardiac grafts.

Introduction: Patients with congenital heart disease frequently require graft material for repair of cardiac defects. However, currently available grafts lack growth potential and are noncontractile and thrombogenic. We have developed a viable cardiac graft that contracts spontaneously in tissue culture by seeding cells derived from fetal rat ventricular muscle into a biodegradable material.

Myocardial perfusion during warm antegrade and retrograde cardioplegia: a contrast echo study.

Background: We evaluated distribution of warm antegrade and retrograde cardioplegia in patients undergoing coronary artery bypass grafting (CABG).

Methods: Myocardial perfusion was evaluated pre- and post-CABG using transesophageal echocardiography with injection of sonicated albumin microbubbles (Albunex) during warm antegrade and retrograde cardioplegia. The left ventricle (LV) was evaluated in five segments and the right ventricle (RV) was evaluated in two segments.

Decreased cerebral emboli during distal aortic arch cannulation: a randomized clinical trial.

Background: Cerebral emboli occur during cardiopulmonary bypass and are a principal cause of postoperative neurologic dysfunction. We hypothesized that arterial cannulation of the distal aortic arch, with placement of the cannula tip beyond the left subclavian artery, will result in fewer cerebral microemboli than conventional cannulation of the ascending aorta.

Methods: Patients undergoing coronary bypass surgery with a single crossclamp technique were randomized to receive cannulation of the distal aortic arch (n = 17) or standard cannulation of the ascending aorta (control group, n = 17).

Fetal cell transplantation: a comparison of three cell types.

Objective: We have previously reported that fetal cardiomyocyte transplantation into myocardial scar improves heart function. The mechanism by which this occurs, however, has not been elucidated. To investigate possible mechanisms by which cell transplantation may improve heart function, we compared cardiac function after transplantation of 3 different fetal cell types: cardiomyocytes, smooth muscle cells (nonstriated muscle cells), and fibroblasts (noncontractile cells).

Cerebral microemboli during cardiopulmonary bypass: increased emboli during perfusionist interventions.

Background: Microemboli to the cerebral circulation occur during cardiopulmonary bypass (CPB) and can contribute to postoperative neurologic dysfunction. Cerebral microemboli are known to occur during specific surgical interventions, but the source of a large proportion of emboli remains unexplained. We investigated whether interventions by the perfusionist could account for the appearance of cerebral microemboli.

Coronary bypass and carotid endarterectomy: does a combined approach increase risk? A metaanalysis.

Background: Patients with concomitant carotid and coronary artery disease present a surgical dilemma. We compared the stroke and mortality rates for combined coronary artery bypass grafting and carotid endarterectomy in which both procedures were performed under a single anesthetic, versus a staged approach, in which coronary artery bypass grafting and carotid endarterectomy were performed separately.

Methods: A computerized MEDLINE search supplemented with a manual bibliographic review was performed for all peer-reviewed English language publications that contained both combined and staged coronary artery bypass grafting/carotid endarterectomy patient cohorts.

Optimal myocardial preconditioning in humans.

We developed a model of ischemia and reperfusion (I and R) in human ventricular myocytes (CM). CM injury and metabolics were studied after various interventions: endogenous preconditioning (PC) with anoxia, hypoxia, and anoxic or hypoxic supernatants; endogenous PC with or without SPT or adenosine deaminase; and exogenous adenosine PC before, during, or after I or continuously, with or without SPT. To assess the clinical implications of PC and the possible mediating effects of adenosine, patients undergoing elective coronary bypass surgery (CABG) received either a high or low dose of adenosine.

Adenosine myocardial protection: preliminary results of a phase II clinical trial.

Objective: To evaluate the safety, tolerance, and efficacy of adenosine in patients undergoing coronary artery bypass surgery.

Summary Background Data: Inadequate myocardial protection in patients undergoing coronary artery bypass surgery contributes to overall hospital morbidity and mortality. For this reason, new pharmacologic agents are under investigation to protect the regionally and globally ischemic heart.

Calcium channel blockers in myocardial and cerebral ischemia: a clinician's review from bench to bedside.

Calcium channel blockers constitute a very important group of drugs that are commonly used in the treatment of cardiovascular and cerebrovascular disorders. Current indications for these medications include hypertension, angina, supraventricular arrhythmias, and prevention of coronary and cerebral vasospasm. Although calcium channel blockers originally held great promise in the treatment of myocardial and cerebral ischemia, clinical results have been discouraging.

Smooth muscle cell transplantation into myocardial scar tissue improves heart function.

This study was designed to evaluate the effect of smooth muscle cell transplantation into myocardial ventricular scar formed by cryo-necrosis. The left ventricular free wall (LVFW) of adult rats was cryo-necrosed. At 4 weeks after cryo-injury cultured fetal rat stomach smooth muscle cells (transplanted group, n = 10) or culture medium (control, n = 10) were transplanted.

Should the pericardium be closed routinely after heart operations?

Background: Repeat coronary artery bypass grafting is more difficult if the right ventricle is firmly attached to the inner table of the sternum. Closure of the pericardium at the time of the initial procedure may prevent attachment of the right ventricle to the sternum. This study attempts to identify the geometric effects of pericardial closure early after isolated coronary artery bypass grafting.