Autologous mesenchymal stem cells produce concordant improvements in regional function, tissue perfusion, and fibrotic burden when administered to patients undergoing coronary artery bypass grafting: The Prospective Randomized Study of Mesenchymal Stem Cell Therapy in Patients Undergoing Cardiac Surgery (PROMETHEUS) trial.

RATIONALE: Although accumulating data support the efficacy of intramyocardial cell-based therapy to improve left ventricular (LV) function in patients with chronic ischemic cardiomyopathy undergoing CABG, the underlying mechanism and impact of cell injection site remain controversial. Mesenchymal stem cells (MSCs) improve LV structure and function through several effects including reducing fibrosis, neoangiogenesis, and neomyogenesis. OBJECTIVE: To test the hypothesis that the impact on cardiac structure and function after intramyocardial injections of autologous MSCs results from a concordance of prorecovery phenotypic effects. METHODS AND RESULTS: Six patients were injected with autologous MSCs into akinetic/hypokinetic myocardial territories not receiving bypass graft for clinical reasons. MRI was used to measure scar, perfusion, wall thickness, and contractility at baseline, at 3, 6, and 18 months and to compare structural and functional recovery in regions that received MSC injections alone, revascularization alone, or neither. A composite score of MRI variables was used to assess concordance of antifibrotic effects, perfusion, and contraction at different regions. After 18 months, subjects receiving MSCs exhibited increased LV ejection fraction (+9.4 ± 1.7%, P=0.0002) and decreased scar mass (-47.5 ± 8.1%; P<0.0001) compared with baseline. MSC-injected segments had concordant reduction in scar size, perfusion, and contractile improvement (concordant score: 2.93 ± 0.07), whereas revascularized (0.5 ± 0.21) and nontreated segments (-0.07 ± 0.34) demonstrated nonconcordant changes (P<0.0001 versus injected segments). CONCLUSIONS: Intramyocardial injection of autologous MSCs into akinetic yet nonrevascularized segments produces comprehensive regional functional restitution, which in turn drives improvement in global LV function. These findings, although inconclusive because of lack of placebo group, have important therapeutic and mechanistic hypothesis-generating implications. CLINICAL TRIAL REGISTRATION URL: http://clinicaltrials.gov/show/NCT00587990. Unique identifier: NCT00587990.

Plasma vascular endothelial growth factor (VEGF) levels after intramuscular and intramyocardial gene transfer of VEGF-1 plasmid DNA.

The purpose of this study was to document the kinetics of vascular endothelial growth factor (VEGF) protein release into the systemic circulation after phVEGF gene transfer for therapeutic angiogenesis. VEGF plasma levels were measured by ELISA in 64 patients undergoing gene transfer of plasmid DNA: intramuscular in 34 patients with peripheral artery disease, and intramyocardial in 30 patients with coronary disease. Baseline plasma VEGF was highly variable and not normally distributed. After intramuscular gene transfer, median plasma VEGF rose slightly, although significantly, by 7 days (38 to 41 pg/ml, p < 0.05), but was not different from baseline at 14, 21, or 28 days. After intramyocardial gene transfer, median plasma VEGF levels were significantly elevated compared with baseline on days 2, 3, and 7 (39, 38, and 45 pg/ml, respectively, each p < 0.05 vs. baseline value of 21 pg/ml). Day 7 plasma levels did not differ significantly as a function of phVEGF dose, or between intramyocardial and intramuscular injections (1.8 and 1.3 times baseline levels, respectively, p = 0.6), despite an almost 10-fold difference in mean phVEGF dose. Intramuscular and intramyocardial phVEGF injections result in significant, although modest, elevations of circulating gene product for <14 days, with no relationship to injected dose. While a statistically significant increase in circulating VEGF level can provide evidence of successful gene transfer for groups of patients, interpretation of results for individual subjects is complicated by wide variation in baseline VEGF and low circulating levels compared with baseline after gene transfer.

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. A randomized phase III trial is underway that will help determine the efficacy of vascular endothelial growth factor-2 gene transfer in "no-option" patients.

Heparinase enhances collateral vessel development in the ischemic limb.

Several angiogenic factors are bound to heparin and stored in the extracellular matrix of diverse tissues; thus, the controlled release of these factors can provide a novel approach of angiogenic stimulation to ischemic tissues. The purpose of this study was to test the hypothesis that heparinase, when administered in vivo, might enhance collateral vessel development in the ischemic limb by the controlled release of angiogenic factors such as basic fibroblast growth factor (bFGF). Eleven male New Zealand White rabbits underwent ligation and excision of the common and superficial femoral arteries in the left hindlimb. In the heparinase group (n = 6), 9.7 IU of heparinase (in 3 ml saline) was injected intramuscularly to the left thigh daily for 10 days, beginning 11 days after surgery. In the control group (n = 5), inactivated heparinase (also in 3 ml saline) was administered following the same experimental protocol. Calf systolic pressure was measured in both hindlimbs and was expressed as a ratio of left to right (L/R ratio) before injections (on day 10) and after injections (on days 20, 30, and 40). Vascularization was quantified by comparing the number of vessels along a line drawn across the mid-thigh on angiograms taken 4 seconds after contrast injection at day 40 when the study was terminated. The intramuscular injection of heparinase improves perfusion to the ischemic limb through the process of enhanced collateral vessel development. The angiogenic effect of heparinase on the ischemic tissue may result from release of endogenous angiogenic factors, such as bFGF.

Surgical treatment of an amniotic fluid embolism with cardiopulmonary collapse.

Amniotic fluid embolism is a rare but devastating condition associated with a very high rate of morbidity and mortality. The treatment has traditionally been aggressive supportive care. We report a case of a term pregnant woman with complete cardiovascular collapse secondary to a paradoxical amniotic fluid embolism. The embolism was seen on transesophageal echocardiogram during an emergency Cesarean section as a free-floating interatrial clot through a patent foramen ovale. She was subsequently and successfully treated with immediate cardiopulmonary bypass, thromboembolectomy, and closure of the patent foramen ovale.

Impact of aprotinin on adverse clinical outcomes and mortality up to 12 years in a registry of 3,337 patients.

BACKGROUND: Recent studies have suggested increased renal complications and long-term mortality with aprotinin use in coronary artery bypass grafting (CABG) patients. However, these studies have been criticized for including multiple centers and different dosing strategies. We analyzed prospectively collected registry data from a single center hospital utilizing a full-dose aprotinin regimen to evaluate if aprotinin was associated with increased mortality and adverse outcomes compared with Amicar. METHODS: Data were prospectively collected from 1994 to 2006 at a teaching hospital. Long-term mortality was collected from a Social Security database. To account for differences between aprotinin and Amicar-treated patients, a propensity score was generated and propensity-stratified multivariate model for mortality were performed. RESULTS: Compared with Amicar-treated patients (n = 1,830), aprotinin-treated patients (n = 1,507) were older, more often female, had lower creatinine clearance, and more baseline risk factors. Blood loss was lower in aprotinin-treated patients (median 715 mL vs 918 mL, p < 0.001). Postoperative renal failure was significantly higher in aprotinin patients (6.2% vs 2.7%, p < 0.001). At median 5.4-year follow-up (up to 12.2 years), aprotinin-treated patients had higher mortality versus Amicar-treated patients (Kaplan-Meier failure rates 43.5% vs 23.7% at 8 years, p < 0.0001). In a propensity-stratified model with multivariate adjustment, aprotinin remained associated with increased mortality (hazard ratio 1.62, 95% CI 1.39 to 1.90, p < 0.001). There was a stepwise relationship between weight-based aprotinin dose and mortality (p-trend < 0.001). CONCLUSIONS: Among patients undergoing CABG in this registry, aprotinin use was associated with increased renal failure and higher mortality through 12 years in a propensity-stratified analysis. The increased mortality may be related to higher concentrations of aprotinin received.

Factores de crecimiento para la angiogénesis terapéutica en las enfermedades cardiovasculares / Growth Factors for Therapeutic Angiogenesis in Cardiovascular Diseases

La angiogénesis terapéutica basada en la administración de factores de crecimiento con actividad angiogénica sirve para promover el desarrollo de vasos sanguíneos colaterales capaces de suplir la deficiencia de perfusión secundaria a la obstrucción de las arterias nativas. En la actualidad, este tipo de terapia se dirige a aquellos pacientes en los que los tratamientos convencionales (revascularización quirúrgica o percutánea) han fallado o no son viables. Los factores de crecimiento angiogénicos que han sido objeto de un estudio más exhaustivo son el factor de crecimiento del endotelio vascular (VEGF) y el factor de crecimiento de fibroblastos (FGF). Estas citocinas se pueden administrar en forma de proteína recombinante o de genes que codifican para estas proteínas. Cada uno de estos enfoques presenta una serie de ventajas e inconvenientes que están siendo investigados en detalle, tanto en modelos animales como en ensayos clínicos con humanos. Aunque los ensayos clínicos se han basado en series reducidas de pacientes, a menudo no aleatorizadas, los resultados preliminares son muy prometedores. Así, por ejemplo, en la isquemia miocárdica se han obtenido evidencias objetivas de aumento de la perfusión tisular, y en la enfermedad arterial periférica se ha documentado una mejoría significativa del dolor en reposo y de las úlceras isquémicas después de la administración de VEGF y FGF. Contrariamente a lo esperado, los efectos colaterales de este tipo de intervenciones han sido pocos, aunque será necesario incluir un mayor número de pacientes en los ensayos clínicos para probar la seguridad y efectividad de este tipo de terapia. Parece claro, sin embargo, que es posible inducir una angiogénesis terapéutica en pacientes seleccionados capaz de modular las alteraciones vasculares sin que se produzca una toxicidad asociada significativa (AU)