BACKGROUND:After cardioplegia, ischemia/reperfusion injury can induce apoptosis. The aim of this study was to evaluate our ex vivo microperfusion model on human myocardium during simulated cardioplegia (cp) and reperfusion (rep). In addition, the aim was to verify the anti-apoptotic properties of the phosphodiesterase 3 inhibitor milrinone.METHODS:Cardiac biopsies were retrieved from the right auricle of patients undergoing elective CABG prior to induction of cardiopulmonary bypass. Biopsies were exposed to ex vivo conditions with varying periods of cp/rep (30/10, 60/20, 120/40 min). Group I consisted of untreated controls (n=15), Group II of treated controls who had cp/rep (n=15) while Group III had cp/rep+milrinone (n=15). For the detection of apoptosis, anti-activated caspase-3 and PARP-1 cleavage immunostaining were used.RESULTS:The percentage of apoptotic cardiomyocytes in Group I was significantly (P<0.05) lower compared to Group II, revealing a time-dependent increase. In Group III with milrinone treatment, apoptosis was significantly suppressed (P<0.05).CONCLUSIONS:Milrinone significantly suppressed apoptosis in our ex vivo setting. This finding warrants further study aiming to evaluate the potential beneficial effects of milrinone on the suppression of ischemia/reperfusion injury in a clinical setting.

Endovascular aneurysm repair (EVAR) is a well-established alternative to open surgery. The presented case underwent endovascular therapy of an abdominal aortic aneurysm (AAA) with the anatomical prerequisite of a horseshoe kidney. We describe the technique used, including the embolization of aortic side branches, to avoid endoleaks, and the management of thrombotic complications during follow-up.

Introduction: Cardiac ischemia-reperfusion injury (IRI) is known to induce apoptosis in on-pump cardiac surgery. Our objective is to determine the impact of drugs on IRI using a novell in-vitro model of human cardiomyocytes.

Aims: Cardiac ischemia followed by reperfusion may induce apoptosis in on-pump cardiac surgery. We established a new in vitro model of human cardiomyocytes preserving the natural cellular environment to investigate apoptosis and furthermore by adding aprotinine and carvedilol, a selective ß-blocker.

Objectives: The ideal duration of reperfusion period after cadioplecic arrest is unclear. Common sense seems to be: the longer the better. We investigate inflammatory response and cardiac function after a short and long reperfusion period in a working heart model (WHM).

The purpose was to assess the practicability of low-dose CT imaging of late enhancement in acute infarction. Following temporary occlusion of the second diagonal branch, seven pigs were studied by multislice computed tomography (MSCT) and magnetic resonance imaging (MRI). Thus, 64-slice CT was performed at 3, 5, 10 and 15 min following the injection of contrast medium according to a bolus/low-flow protocol. Standard parameters of 120 kV and 800 mAs were compared with 80 kV and 400 mAs in various combinations. Infarct volumes were assessed as percentage of the ventricle for both MSCT and MR images. CT density values for viable and infarcted myocardium were obtained and image quality assessed. Mean infarct volume as measured by MRI was 12.33 +/- 7.06%. MSCT achieved best correlation of volumes at 5 and 10 min. Whilst lowering of tube current resulted in poor correlation, tube voltage did not affect accuracy of infarct measurement (r(2)=0.92 or 0.93 at 5 min, 800 mAs and 80 or 120 kV). In terms of image quality, greater image noise with 80 kV was compensated by significantly better contrast enhancement between viable and non-viable myocardium at lower voltage. Myocardial viability can accurately be assessed by MSCT at 80 kV, which ensures higher contrast for late enhancement and yields good correlation with MRI.

Objectives: Adhesion molecules (AM) are known to influence the postoperative function in lung transplantation. By mediating a leukocyte-endothelium interaction they are involved in the inflammatory response following the ischemia-reperfusion injury of the allograft. Therefore, inhibition of AM expression may be a promising strategy to decrease primary graft failure. Liposomal transfection with short interfering RNA (siRNA) is a powerful technique to knockdown activated genes by specific degradation of the respective messenger RNA.

Objective: The aim of this study was to assess the accuracy of MSCT in characterizing myocardial infarction (MI) and, thereby, determine the extent of early perfusion defect (ED), microvascular obstruction (MO) and transmural depth of late enhancement (LE) in comparison to MRI and histology.Materials and methods: Seven pigs were studied with MSCT (Somatom Sensation 64) and MRI (Magnetom Sonata) a median 1 and 21 days following temporary occlusion of a diagonal branch and creation of small reperfused infarction.For depiction of ED, CT images were acquired in the early arterial phase and following 35 s; LE and MO were evaluated on images obtained at 3, 5, 10 and 15 min. Thereby, a bolus/low-flow contrast injection protocol was used. Triphenyltetrazolium-chloride (TTC) stain and histology were obtained. Volumes of enhancement patterns were assessed as percentage of the ventricle and compared by Bland-Altman analysis. Segmental co-localization and graded transmurality was evaluated with weighted-kappa-test.Results: Close spatial agreement was observed for MRI-MO and MSCT-MO (bias= 0.55; CI = -1.49 to 2.60 at 5 min MSCT), TTC and MSCT-LE (bias= -1.28; CI = -3.76 to 1.19) or MRI-LE and MSCT-LE (bias= -0.79; CI = -4.19 to 2.60). There was good segmental co-localization for MO (weighted kappa 0.93) and high agreement for transmural extent of TTC, MRI-LE and MSCT-LE (weighted kappa = 0.84 TTC versus MSCT; 0.86 MRI versus MSCT). Arterial and 35 s ED significantly underestimated infarct size and showed poor segmental or transmural agreement (weighted kappa = 0.33; 0.44).Conclusions: MSCT late-scans not only reliably depict size of MO and LE in acute or subacute infarct phases but, moreover, allow for accurate determination of LE transmurality. (c) 2006 Elsevier Ireland Ltd. All rights reserved.

PURPOSE:Mesenchymal stem cells (MSC) seem to be a promising cell source for cellular cardiomyoplasty. We recently developed a new aptamer-based specific selection of MSC to provide "ready to transplant" cells directly after isolation. We evaluated MRI tracking of newly isolated and freshly transplanted MSC in the heart using one short ex vivo selection step combining specific aptamer-based isolation and labeling of the cells. MATERIALS AND METHODS:Bone marrow (BM) was collected from healthy pigs. The animals were euthanized and the heart was placed in a perfusion model. During cold ischemia, immunomagnetic isolation of MSC from the BM by MSC-specific aptamers labeled with Dynabeads was performed within 2 h. For histological identification the cells were additionally stained with PKH26. Approx. 3 x 10(6) of the freshly aptamer-isolated cells were injected into the ramus interventricularis anterior (RIVA) and 5 x 10(5) cells were injected directly into myocardial tissue after damaging the respective area by freezing (cryo-scar). 3 x 10(6) of the aptamer-isolated cells were kept for further characterization (FACS and differentiation assays). 20 h after cell transplantation, MRI of the heart using a clinical 3.0 Tesla whole body scanner (Magnetom Trio, Siemens, Germany) was performed followed by histological examinations. RESULTS:The average yield of sorted cells from 120 ml BM was 7 x 10(6) cells. The cells were cultured and showed MSC-like properties. MRI showed reproducible artifacts within the RIVA-perfusion area and the cryo-scar with surprisingly excellent quality. The histological examination of the biopsies showed PKH26-positive cells within the areas which were positive in the MRI in contrast to the control biopsies. CONCLUSION:Immunomagnetic separation of MSC by specific aptamers linked to magnetic particles is feasible, effective and combines a specific separation and labeling technique to a "one stop shop" strategy.

Objectives: The benefit of routine Anti Vitamin K (AVK) medication in patients after aortic valve bioprotheses replacement (AVBR) is dicussed controversily. In our institution patients after AVBR do not receive AVK medication routinely. The study was conducted to follow up patients after AVBR with special focus on outcome and anticoagulation medication.

The purpose was to assess 64-slice CT in the analysis of global and regional ventricular function, using a model of acute and subacute myocardial infarction in comparison with cine-MRI. Seven pigs underwent standard MSCT and MRI examination a median 1 and 21 days following creation of reperfused myocardial infarction. Endocardial and epicardial contours were manually defined and ventricular volumes calculated according to Simpson's method. Results were compared by Pearson's correlation coefficient and Blant-Altman analysis. Wall motion was assessed on cine-images and evaluated by kappa statistics. MSCT revealed a strong correlation with cine-MRI regarding quantification of end-diastolic volume (EDV; r = 0.97), end-systolic volume (ESV; r = 0.97), stroke volume (SV; r = 0.94), ejection fraction (EF; r = 0.95) or myocardial mass (MM; r =0.94 ). Minor overestimation was observed for EDV and ESV (bias -1.7 ml; -1.5 ml; P=0.095; 0.025), whilst the mean difference for EF was found to be negligible (bias 0.9%; P = 0.18). Both modalities showed a 96.2% segmental agreement in regional wall motion (weighted-kappa 0.91 for 238 segments). This was true for both acute and subacute infarct phase and MSCT, and thereby enabled accurate intraindividual follow-up of segmental dysfunction. Sixty-four-slice CT allows for reliable analysis of global cardiac function and, moreover, provides accurate evaluation of wall motion in acute and subacute myocardial infarct.

Objectives: Milrinone has been shown to be effective in corrective surgery for congenital heart disease. Increase in cardiac output is thought to be caused by a combination of inotropy and reduction of systemic and pulmonary vascular resistance. The aim of this study was to evaluate the pure cardiac effects of milrinone in isolated hearts after cardioplegic cardiac arrest.

Ziele: Bestimmung der Bypass-Offenheit und der Flussvolumina in Ruhe und nach medikamentöser Stressbelastung bei Patienten mit erneuten pectanginösen Beschwerden nach operativer Myokardrevaskularisation. Methode: An einem 1.5T Magnetom Sonata (SIEMENS) wurden 45 symptomatische Patienten mit 86 grafts postoperativ untersucht. Zunächst erfolgte die Bypassdarstellung mittels einer Kontrastmittel verstärkten FLASH-3D MR Angiographie (0,02 mmol/kg/KG Gd-DTPA). Danach wurden Phasenkontrast Flussmessungen im Bypass in Ruhe und nach medikamentöser Stressbelastung mit 0,56mg/kg/KG Dipyridamol zur Bestimmung der Flussreserve durchgeführt. Die Ergebnisse wurden mit der selektiven Bypassangiographie (SBA) oder Multi-Detektor-CT-Angiographie (MDCTA) verglichen (Sensation 16, SIEMENS). Es erfolgte ein Segment-zu-Segment-Vergleich. Ergebnis: 49 Bypasses waren in der SBA/MDCTA offen und 37 stenosiert.

In this prospective study, the feasibility of a comprehensive cardiovascular imaging protocol with a dedicated whole-body 1.5-T magnetic resonance (MR) imager with 32 receiver channels in 34 patients with peripheral arterial occlusive disease was evaluated. Informed consent and institutional review board approval were obtained. Three-dimensional MR angiographic data sets were acquired with adapted injection protocol. Cardiac functional imaging and delayed-enhancement imaging were performed, as were fluid-attenuated inversion-recovery imaging of the brain and time-of-flight MR angiography of the intracranial blood vessels. Sensitivity and specificity for depiction of significant vascular stenosis (> 70%) were 96%, with conventional digital subtraction angiography as the standard. Substantial microangiopathic tissue alterations (n = 4) and/or cerebral infarction (n = 4) were diagnosed in seven patients. In seven patients, subendocardial or transmural delayed enhancement was detected in corresponding regions, indicating prior myocardial infarction. Previously unknown findings diagnosed with MR imaging required midterm follow-up or therapy in 24 patients, whereas change of therapy or immediate treatment was necessary in three. For patients suspected of having systemic atherosclerotic disease, comprehensive risk assessment is feasible within 30 minutes.

Stroke after cardiac surgery is a devastating complication. We report a case of incidental diagnosis of a left ventricular thrombus in a patient scheduled to undergo coronary artery bypass grafting. The preoperative diagnosis of an apical left ventricular thrombus was assessed by a novel, whole body MRI-angiography technique (TIMRA), which led to alteration of the operative approach as an additional thrombectomy was performed through an apical left ventriculotomy.

Ziele: Vergleich unterschiedlicher Kontrastprotokolle hinsichtlich Darstellbarkeit von Late Enhancement (LE) und Mikrovaskulärer Obstruktion (MO) im Rahmen der CT-gestützten Vitaltätsdiagnostik. Methode: Durch intraoperative 90-minütige Okklusion eines Diagonalastes des Ramus interventrikularis anterior wurden die Herzen sieben Deutscher Landschweine infarziert.

Aims: The use of Aprotinin in many surgical disciplines is increasing. Most reported anaphylactic reactions occurred within one moth after first exposure, often in patients reexposed to aprotinin after failed mitral valve repair, or patients being on ventricular assist device as bridge to transplant. The present study was designed to investigate the immunopathologic reactions during the first 100 days post exposure.

Ziele: Als Systemerkrankung lässt die Atherosklerose prinzipiell einen umfassenden diagnostischen Ansatz zur Erkennung atherosklerotischer Manifestationen des kardiovaskulären Systems wünschenswert erscheinen. Hierfür hat die MRT in jüngster Zeit durch die Option einer effizienten Ganzkörperbildgebung zunehmend an Bedeutung gewonnen. In dieser Studie wurde untersucht, inwiefern eine kardiovaskuläre Ganzkörper MRT zu aktuellen Therapieentscheidungen und dem weiteren Patientenmanagement beiträgt. Methode: Bei 1,5T (Magnetom Avanto, Siemens, Erlangen) wurden 76 Patienten (mittleres Alter 66±10 Jahre, m:w=57:19) mit symptomatischer peripherer arterieller Verschlusskrankheit (pAVK) untersucht. Es wurden Funktions- und „Delayed enhancement“ Aufnahmen des Herzens sowie FLAIR Aufnahmen des Gehirns angefertigt. Die Ganzkörper MRA umfasste eine multi-slab 3D TOF MRA der intrakraniellen Gefäße sowie die kontrastangehobene Ganzkörper MRA. Es wurden insgesamt 0,25 mmol Gd-DTPA/kg Körpergewicht appliziert. “Relevante Befunde“ wurden definiert als Pathologika welche eine sofortige und/oder mittelfristige Therapie bzw. weiterführende Diagnostik notwendig machten. Verfügbare weitere diagnostische Untersuchungen (DSA, Doppler Ultraschall, Patientenakte, klinische Parameter) wurden als Referenzstandard verwendet. Ergebnis: Die Ganzkörper MRA lieferte eine sehr hohe Sensitivität und Spezifität, von jeweils über 95% im Vergleich zum Referenzstandard. Relevante Befunde im Bereich des ZNS wurden bei 12%, im Bereich des Herzens bei 19% und im Bereich des Gefäßsystems bei 53% der Patienten erhoben. Vorher nicht bekannte Läsionen wurden bei 93% der Patienten diagnostiziert, wobei 62% als relevant eingestuft wurden. Bei 9% der Patienten ergab sich hierdurch eine unmittelbare Änderung der primär vorgesehenen Therapie. Schlussfolgerung: Die Ganzkörper MRT ist eine präzise Methode um symptomatische und vorher unbekannte pathologische Befunde bei Patienten mit pAVK festzustellen. Ein mittel- und unmittelbarer Einfluss auf die Therapie und das weitere Patientenmanagement konnte nachgewiesen werden.