Imaging assessment of cardioprotection mediated by a dodecafluoropentane oxygen-carrier administered during myocardial infarction.

INTRODUCTION: The objective of this study was to investigate the cardioprotective effects of a dodecafluoropentane (DDFP)-based perfluorocarbon emulsion (DDFPe) as an artificial carrier for oxygen delivery to ischemic myocardium, using 99mTc-duramycin SPECT imaging. METHODS: Rat hearts with Ischemia-reperfusion (I/R) was prepared by coronary ligation for 45-min followed by reperfusion. The feasibility of 99mTc-duramycin in detecting myocardial I/R injury and its kinetic profile were first verified in the ischemic hearts with 2-h reperfusion (n = 6). DDFPe (0.6 mL/kg) was intravenously administered at 10 min after coronary ligation in fifteen rats and saline was given in thirteen rats as controls. 99mTc-duramycin SPECT images were acquired in the DDFPe-treated hearts and saline controls at 2-h (DDFPe-2 h, n = 7 and Saline-2 h, n = 6) or 24-h (DDFPe-24 h, n = 8 and Saline-24 h, n = 7) of reperfusion. RESULTS: SPECT images, showing "hot-spot" 99mTc-duramycin uptake in the ischemic myocardium, exhibited significantly lower radioactive retention and smaller hot-spot size in the DDFPe-2 h and DDFPe-24 h hearts compared to controls. The infarcts in the Saline-24 h hearts extended significantly relative to measurements in the Saline-2 h. The extension of infarct size did not reach a statistical difference between the DDFPe-2 h and DDFPe-24 h hearts. Ex vivo measurement of 99mTc-duramycin activity (%ID/g) was lower in the ischemic area of DDFPe-2 h and DDFPe-24 h than that of the Saline-2 h and Saline-24 h hearts (P < 0.05). The area of injured myocardium, delineated by the uptake of 99mTc-duramycin, extended more substantially outside the infarct zone in the controls. CONCLUSIONS: Significant reduction in myocardial I/R injury, as assessed by 99mTc-duramycin cell death imaging and histopathological analysis, was induced by DDFPe treatment after acute myocardial ischemia. 99mTc-duramycin imaging can reveal myocardial cell death in ischemic hearts and may provide a tool for the non-invasive assessment of cardioprotective interventions.

Evaluation of autologous platelet rich plasma for cardiac surgery: outcome analysis of 2000 patients.

BACKGROUND: Deep and superficial sternal wound infections (DSWI & SWI) following cardiac surgery increase morbidity, mortality and cost. Autologous platelet rich plasma (PRP) derived from the patient's own blood has been used in other surgical settings to promote successful wound healing. The goal of this study was to analyze the addition of PRP using a rapid point of care bedside system to standard wound care in all patients undergoing sternotomy for cardiac surgical procedures. METHODS: Over a 7 year period, 2000 patients undergoing open cardiac operations requiring sternotomy were enrolled. One thousand patients received standard of care sternal closure. The other 1000 patients received standard of care sternal closure plus PRP applied to the sternum at the time of closure. The outcomes related to wound healing, infection, readmissions, and costs were analyzed. RESULTS: In the 2000 patients, there were more ventricular assist device implants/heart transplants and emergency operations in the PRP group; otherwise there were no significant differences. The use of PRP reduced the incidence of DSWI from 2.0 to 0.6 %, SWI from 8.0 to 2.0 %, and the readmission rate from 4.0 to 0.8 %. The use of PRP reduced the costs associated with the development of deep and superficial wound complications from $1,256,960 to $593,791. CONCLUSIONS: The use of PRP decreases the incidence and costs of sternal wound complications following cardiac surgery. The routine use of platelet rich plasma should be considered for all patients undergoing sternotomy for cardiac surgical procedures. TRIAL REGISTRATION: Clinicaltrials.gov ( NCT00130377 ) for the data registry.

Magnetic resonance imaging (MRI) assessment of ventricular remodeling after myocardial infarction in rabbits.

To understand the structure-function relationship in the postinfarcted myocardium in rabbits, we induced cardiac ischemia by ligating the left circumflex coronary artery. Sham controls underwent thoracotomy only. At 7 and 30 d after ligation, cardiac MRI was conducted by using pulse-oxymetry-gated cine acquisition to provide complete phases of the heartbeat. The rabbits were anesthetized under 1.5% isoflurane ventilation, and ultrafast techniques made breath-hold 3D coverage in different cardiac axes feasible. Viability imaging was performed after intravenous injection of 0.15 mmol/kg gadolinium to assess the extent of infarction. Data (n ≥ 6) are presented as mean ± SEM and analyzed by ANOVA and ANCOVA. In postligation rabbits, end-systolic (mean ± SEM, 2.3 ± 0.3 mL) and end-diastolic (4.2 ± 0.4 mL) volumes were increased compared with preligation values (end-systolic, 1.1 ± 0.1 mL; end-diastolic, 2.98 ± 0.2 mL). Ejection fraction was influenced adversely by the presence of scar tissue at both 7 and 30 d after ligation and apparently nonlinear with the heart rate. Cardiac force was increased in the basal region in both end-systole and end-diastole in postligation hearts but progressively decreased toward the apex. Late gadolinium enhancement delineated 15.2 ± 5.8% myocardial infarction at 7 d after ligation and 14.5 ± 5.8% at 30 d, with limited wall motion and wall thinness. Compensatory wall thickening was present in the basal region when compared with that in preligation hearts. MRI offers detailed spatial resolution and tissue characterization after myocardial infarction.

Effects of the 2006 U.S. thoracic organ allocation change: analysis of local impact on organ procurement and heart transplantation.

BACKGROUND: The United Network for Organ Sharing (UNOS) implemented a thoracic organ allocation policy change (APC) in July 2006 that aimed to reduce death on the waiting list by expanding regional organ sharing. As such, organs would be allocated to the sickest recipients with highest listing status across the region. Our aim was to determine the impact of the new policy on the procurement and transplant process within our program. METHODS: We analyzed data supplied by UNOS as the contractor for the Organ Procurement and Transplantation Network and from the local organ procurement organization for 2 years before and 2 years after implementation of the APC. RESULTS: The APC resulted in an increase in the proportion of Status 1A patients transplanted (24% to 43%, p = 0.015) and a decrease in the proportion of Status 2 patients transplanted (56% to 24%, p = 0.001). Significant increases were observed in mean graft ischemic time (196 minutes to 223 minutes, p = 0.022), number of patients transplanted with ventricular assist devices (17% to 31%, p = 0.036), and procurement costs. There was no significant difference in waiting-list mortality (6% to 5%, p = 0.75) and short-term post-transplant survival. CONCLUSIONS: The 2006 change in UNOS organ allocation policy resulted in an increase in Status 1A transplants, graft ischemic time and procurement costs, and a decrease in Status 2 transplants, but no effect on mortality on the waiting list within our center. To assess the full effect of the APC on outcomes, the long-term impact of the increased graft ischemic time on survival should be quantified.