Dietmar Kivelitz

Intracoronary Compared With Intravenous Bolus Abciximab Application in Patients With ST-Elevation Myocardial Infarction Undergoing Primary Percutaneous Coronary Intervention. The Randomized Leipzig Immediate Percutaneous Coronary Intervention Abciximab IV Versus IC in ST-Elevation Myocardial Infarction Trial

Background— Abciximab reduces major adverse cardiac events in patients with ST-elevation myocardial infarction undergoing primary percutaneous coronary intervention (PCI). Intracoronary abciximab bolus application results in high local drug concentrations and may be more effective than a standard intravenous bolus. Methods and Results— Patients undergoing primary PCI were randomized to either intracoronary (n=77) or intravenous (n=77) bolus abciximab administration with subsequent 12-hour intravenous infusion. The primary end point was infarct size and extent of microvascular obstruction as assessed by delayed enhancement magnetic resonance. Secondary end points were ST-segment resolution at 90 minutes, Thrombolysis in Myocardial Infarction flow and perfusion grades after PCI, and the occurrence of major adverse cardiac events within 30 days. The median infarct size was 15.1% (interquartile range, 6.1% to 25.2%) in the intracoronary versus 23.4% (interquartile range, 13.6% to 33.2%) in the intravenous group (P=0.01). Similarly, the extent of microvascular obstruction was significantly smaller in intracoronary compared with intravenous abciximab patients (P=0.01). Myocardial perfusion measured as early ST-segment resolution was significantly improved in intracoronary patients with an absolute ST-segment resolution of 77.8% (interquartile range, 66.7% to 100.0%) versus 70.0% (interquartile range, 45.2% to 83.5%; P=0.006). The Thrombolysis in Myocardial Infarction flow after PCI was not different between treatment groups (P=0.51), but there was a trend toward an improved perfusion grade (P=0.09). There also was a trend toward a lower major adverse cardiac event rate after intracoronary versus intravenous abciximab application (5.2% versus 15.6%; P=0.06; relative risk, 0.33; 95% CI, 0.09 to 1.05). Conclusions— Intracoronary bolus administration of abciximab in primary PCI is superior to standard intravenous treatment with respect to infarct size, extent of microvascular obstruction, and perfusion.

Differential diagnosis of suspected apical ballooning syndrome using contrast-enhanced magnetic resonance imaging

AIMS The apical ballooning syndrome (ABS) is a new diagnostic entity which is increasingly recognized. Precise magnetic resonance imaging (MRI) data are not yet available and there is little evidence for the differential diagnosis of ABS assessed by MRI. METHODS AND RESULTS Between January 2005 and January 2008, 6100 consecutive patients with diagnosis of acute coronary syndrome underwent left heart catheterization. In 59 patients (1.0%), coronary angiography revealed normal coronary arteries, but left ventriculography showed left ventricular dysfunction with apical ballooning. These 59 patients underwent cardiac MRI using a 1.5 T MRI scanner. In 13 patients (22.0%), MRI revealed diagnosis of myocardial infarction, in eight patients (13.6%) diagnosis of myocarditis. In all other 38 (64.4%) patients (36 female, age 73 +/- 10 years) with suspected ABS, no delayed enhancement or signs of inflammation were detected. Follow-up MRI after 3 months showed a completely normalized left ventricular ejection in all patients with suspected ABS. Similarly, the end-diastolic volume and end-systolic volume improved at follow-up. CONCLUSION Cardiac MRI allows differentiating ABS from other rare causes with unobstructed coronary vessels such as myocarditis and coronary emboli with spontaneous lysis. Therefore, cardiac MRI can add valuable information in all patients with suspected ABS for further differential diagnosis.

Ross operation with a tissue-engineered heart valve

BACKGROUND The Ross procedure has gained increasing acceptance due to excellent hemodynamic results by replacing the diseased aortic valve with the viable autologous pulmonary valve. Consequently, the right ventricular outflow tract (RVOT) has to be reconstructed. In this report a viable heart valve was created from decellularized cryopreserved pulmonary allograft that was seeded with viable autologous vascular endothelial cells (AVEC). METHODS A 43-year-old patient suffering from aortic valve stenosis underwent a Ross operation on May 20, 2000, using a tissue engineered (TE) pulmonary allograft to reconstruct the RVOT. Four weeks before the operation a piece of forearm vein was harvested to separate, culture, and characterize AVEC. Follow-up was completed at discharge, 3, 6, and 12 months postoperatively by clinical evaluation, transthoracic echocardiography (TTE), and magnetic resonance imaging (MRI). Additionally, at 1-year follow-up a multislice computed tomographic scan was performed. RESULTS After four weeks of culturing 8.34 x 10(6) AVEC were available to seed a 27-mm decellularized pulmonary allograft. Trypan blue staining confirmed 96.0% viability. Reendothelialization rate after seeding was 9.0 x 10(5) cells/cm2. TTE and MRI revealed excellent hemodynamic function of the TE heart valve and the neoaortic valve as well. Multislice computed tomography revealed no evidence of valvular calcification. CONCLUSIONS After 1 year of follow-up the patient is in excellent condition without limitation and exhibits normal aortic and pulmonary valve function.

Multifocal nodular fatty infiltration of the liver mimicking metastatic disease on CT: imaging findings and diagnosis using MR imaging.

Abstract. The aim of this study was to describe the MR appearance of multifocal nodular fatty infiltration of the liver (MNFIL) using T1-weighted in-phase (IP) and opposed-phase (OP) gradient-echo as well as T2-weighted turbo-spin-echo sequences with fat suppression (FSTSE) and without (HASTE). Magnetic resonance imaging examinations at 1.5 T using T1-weighted IP and OP-GRE with fast low angle shot (FLASH) technique, and T2-weighted FSTSE, T2-weighted HASTE of 137 patients undergoing evaluation for focal liver lesions were reviewed. Five patients were identified in whom CT indicated metastatic disease; however, no liver malignancy was finally proven. Diagnosis was confirmed by biopsy (n = 3), additional wedge resection (n = 1) or follow-up MRI 6–12 months later (n = 5). Regarding the identified five patients, the number of focal liver lesions was 2 (n = 2) and more than 20 (n = 3). The MR imaging characteristics were as follows: OP-image: markedly hypointense (n = 5); IP image: isointense (n = 2) or slightly hyperintense (n = 3); T2-weighted FSTSE-image: isointense (n = 5); T2-weighted HASTE image isointense (n = 1); slightly hyperintense (n = 4). On OP images all lesions were sharply demarcated and of almost spherical configuration (n = 5). Further evaluation by histology or follow-up MR imaging did not give evidence of malignancy in any case. Histology revealed fatty infiltration of the liver parenchyma in three patients. Magnetic resonance follow-up showed complete resolution in two patients and no change in three patients. Multifocal nodular fatty infiltration can simulate metastatic disease on both CT and MR imaging. The combination of in-phase (IP) and opposed-phase (OP) gradient-echo imaging can reliably differentiate MNFIL from metastatic disease.

Gadolinium-enhanced MR angiography of the breast: Is breast cancer associated with ipsilateral higher vascularity?

Abstract The aim of this study was to assess a possible association between breast malignancy and ipsilateral higher vascularity on gadolinium-enhanced MR angiography. One hundred six patients were examined by dynamic gadolinium-enhanced 3D MR imaging. Magnetic resonance angiographic views were generated by image subtraction and maximum intensity projection. The study included 85 patients with unilateral malignant breast neoplasms and 21 with unilateral benign lesions. Three blinded readers independently reviewed the MR angiograms after masking the lesions and the corresponding contralateral sites. The readers were asked to determine whether vascularity was higher on the right side, higher on the left side, or equal on both sides. The results were analyzed by the Kappa statistic and Pearsons chi-square test. The blood vessels of the breasts were clearly seen in all cases. There was good agreement among the observers (kappa > 0.54 ) in assessing vascularity on both sides. Breasts harboring malignant neoplasms were found to have a higher vascularity than the contralateral breasts (p < 0.005). This sign of malignancy had a sensitivity of 76.5 %, a specificity of 57 %, and an accuracy of 72.6 %. Blood vessels of the breast can be depicted by MR angiography. Unilateral malignant neoplasms are associated with a higher ipsilateral vascularity. In conjunction with other indications of malignancy on gadolinium-enhanced MR images, a higher ipsilateral vascularity may serve as an additional sign of malignancy.

Coronary MR angiography using citrate-coated very small superparamagnetic iron oxide particles as blood-pool contrast agent: Initial experience in humans

To evaluate very small superparamagnetic iron oxide particles (VSOP‐C184) as blood‐pool contrast agent for coronary MR angiography (CMRA) in humans.

Coronary magnetic resonance angiography: Experimental evaluation of the new rapid clearance blood pool contrast medium P792

The signal‐enhancing characteristics of a new monodisperse monogadolinated macromolecular MR contrast medium (P792) were evaluated for magnetic resonance angiography (MRA) of the coronary arteries. A total of 15 cardiac examinations were performed in pigs at 1.5 T using a 3D gradient‐echo sequence. Images were acquired during breath‐hold before and up to 35 min after IV injection of Gd‐DTPA (0.3 mmol Gd/kg), Gd‐BOPTA (0.2 mmol Gd/kg), and P792 (13 μmol Gd/kg). An increase in the signal‐to‐noise ratio (SNR) of 97% ± 17%, 108% ± 37%, and 109% ± 31% in coronary arteries and of 82% ± 19%, 82% ± 24%, and 28% ± 18% in myocardium, respectively, was measured during the first postcontrast acquisition. The blood‐to‐myocardium signal‐difference‐to‐noise ratio (SDNR) was significantly higher for P792 than for the other Gd compounds (P < .05) for up to 15 min after injection. Qualitative assessment showed that visualization of the coronary arteries and their branches was significantly better for P792 compared to the low‐molecular Gd compounds (P < .05). The blood pool contrast medium P792 is well suited for MRA of the coronary arteries. Magn Reson Med 46:932–938, 2001.

MRI of cardiac rhabdomyoma in the fetus.

Primary cardiac tumors are rarely diagnosed in utero and are usually seen on prenatal echocardiography. Cardiac rhabdomyomata can be associated with tuberous sclerosis. Prenatal MRI can be performed to assess associated malformations. This case report illustrates the ability of fetal MRI to image cardiac rhabdomyata and compares it with prenatal and postnatal echocardiography.

Quantification of aortic valve stenosis: head-to-head comparison of 64-slice spiral computed tomography with transesophageal and transthoracic echocardiography and cardiac catheterization

Objectives:We sought to evaluate the accuracy of multislice computed tomography (MSCT) with 64 detector rows for determination of the aortic valve area (AVA) compared with transesophageal and transthoracic echocardiography (TEE and TTE) and cardiac catheterization (CATH). Materials and Methods:MSCT, TEE, TTE, and CATH were performed in 36 patients with aortic valve stenosis. AVA was determined by planimetry on MSCT and TEE and calculated using the continuity equation on Doppler TTE and the Gorlin formula on CATH. Results:The mean AVA on MSCT (0.88 ± 0.39 cm2) was not significantly different from TEE (0.94 ± 0.41 cm2; P > 0.05) but significantly larger than TTE (0.74 ± 0.28 cm2; P < 0.001) and CATH (0.75 ± 0.31 cm2; P < 0.001). A good correlation with acceptable limits of agreement was found between MSCT and TTE (r = 0.91, limits ±0.35 cm2) and between MSCT and CATH (r = 0.91, limits ±0.32 cm2). An inferior correlation with wider limits of agreement was found between MSCT and TEE (r = 0.82, limits ±0.48 cm2), but this applied also between TEE and TTE (r = 0.79, limits ±0.51 cm2) and between TEE and CATH (r = 0.78, limits ±0.52 cm2). Conclusions:AVA determined by MSCT correlated well with TTE and CATH, but a systematic difference must be taken into account when using MSCT findings for therapeutic decision-making. Validation against both TTE and CATH revealed a superior correlation and narrower limits of agreement for MSCT than for TEE suggesting that AVA planimetry with MSCT is more reliable than with TEE.

Ferric ammonium citrate as a positive bowel contrast agent for MR imaging of the upper abdomen. Safety and diagnostic efficacy.

Purpose: To evaluate the safety and diagnostic efficacy of two different doses of ferric ammonium citrate as a paramagnetic oral contrast agent for MR imaging of the upper abdomen. Material and Methods: Ninety-nine adult patients referred for MR imaging for a known or suspected upper abdominal pathology were included in this randomized multicenter double-blind clinical trial. Imaging was performed with spin-echo (T1- and T2-weighted) and gradient-echo (T1-weighted) techniques before and after administration of either 1200 mg or 2400 mg of ferric ammonium citrate dissolved in 600 ml of water. Safety analysis included monitoring of vital signs, assessment of adverse events, and laboratory testing. Efficacy with regard to organ distension, contrast distribution, bowel enhancement and delineation of adjacent structures was graded qualitatively. Results: No serious adverse events were reported for either of the two concentrations. A total of 31 minor side effects were noted, of which significantly more occurred in the higher dose group (p<0.01). The diagnostic confidence in defining or excluding disease was graded as better after contrast administration for 48% of all images. Marked or moderate enhancement of the upper gastrointestinal tract was achieved at both doses in 69.5% of cases with no evident difference between the two doses. The higher dose tended to show better results in terms of the contrast assessment parameters. Conclusion: Ferric ammonium citrate is a safe and effective oral contrast agent for MR imaging of the upper abdomen at two different dose levels. The higher dose showed a tendency toward better imaging results while the lower dose caused significantly fewer side effects. Therefore the 1200 mg dose can be recommended in view of the risk-to-benefit ratio.