Olaf Grebe

Reduction of Major Adverse Cardiac Events With Intracoronary Compared With Intravenous Bolus Application of Abciximab in Patients With Acute Myocardial Infarction or Unstable Angina Undergoing Coronary Angioplasty

Background—In patients with acute myocardial infarction or unstable angina undergoing coronary angioplasty, abciximab reduces major adverse cardiac events (MACE). Clinical trials have studied intravenous administration only. Intracoronary bolus application of abciximab causes very high local drug concentrations and may be more effective. We studied whether intracoronary bolus administration of abciximab is associated with a reduced MACE rate compared with the standard intravenous bolus application. Methods and Results—We stratified 403 consecutive patients with acute myocardial infarction or unstable angina undergoing coronary angioplasty according to the type of application of abciximab. A 20-mg bolus of abciximab was given intravenously in 109 patients and intracoronarily in 294 patients. There were no differences between the groups with regard to diabetes mellitus, cardiogenic shock, successful intervention, or preprocedural and postprocedural TIMI flow. At 30 days, the incidence of MACE (death, myocardial infarction, urgent revascularization) was significantly lower in the patients with intracoronary compared with intravenous administration of abciximab (10.2% versus 20.2%;P <0.008), which was independent from stenting in multivariate analysis. The effect was most pronounced in patients with preprocedural TIMI 0/1 flow (MACE: intracoronary 11.8% versus intravenous 27.5%, P <0.002; n=273). Conclusions—In patients with acute myocardial infarction or unstable angina undergoing emergency coronary angioplasty, intracoronary bolus application of abciximab is associated with a reduction of MACE compared with the standard intravenous bolus application of abciximab. Prospective, randomized trials are warranted to further assess intracoronary application of abciximab.

A randomized trial of elective stenting after balloon recanalization of chronic total occlusions

OBJECTIVES The aim of this study was to assess the role of Wiktor stent implantation after recanalization of chronic total coronary occlusions with regard to the clinical and angiographic outcome after six months. BACKGROUND Beside the common use of stents in clinical practice, the number of stent indications proven by randomized trials is still limited. METHODS Eighty-five patients with a thrombolysis in myocardial infarction grade 0 chronic coronary occlusion were examined. After standard balloon angioplasty, the patients were randomly assigned to stent implantation, or percutaneous transluminal coronary angioplasty (PTCA) alone (no further intervention). Quantitative coronary angiography was performed at baseline and after six months. RESULTS The minimal lumen diameter did not differ immediately after recanalization (stent group 1.61 +/- 0.30 mm vs. PTCA group 1.65 +/- 0.36 mm), and increased after stent implantation to 2.51 +/- 0.41 mm. After six months, the stent group still had a significantly greater lumen (1.57 +/- 0.59 vs. 1.06 +/- 0.90 mm; p < 0.01) and a significantly lower restenosis and reocclusion rate (32% and 3%) compared with the PTCA group (64% and 24%); restenosis analysis according to treatment was 72% (PTCA) versus 29% (stent, p < 0.01). Late loss was equal in both groups. At follow-up, the stent patients had a better angina class (p < 0.01), and fewer cardiac events (p < 0.03). A meta-analysis including this trial and three other controlled trials with the Palmaz-Schatz stent showed concordant results. CONCLUSIONS Stent implantation after reopening of a chronic total occlusion provides a better angiographic result, corresponding to a better clinical outcome with fewer recurrence of symptoms and reinterventions after six months.

Improved Accuracy of Quantitative Assessment of Left Ventricular Volume and Ejection Fraction by Geometric Models with Steady-State Free Precession

The purpose of this study was to determine whether steady-state free precession (SSFP) could improve accuracy of geometric models for evaluation of left ventricular (LV) function in comparison to turbo gradient echo (TGrE) and thereby reduce the acquisition and post-processing times, which are commonly long by use of the Simpsons Rule. In 25 subjects, cine loops of the complete heart in short and horizontal long-axis planes were acquired using TGrE (TR/TE/flip = 5.0/1.9/25) compared with SSFP (TR/TE/flip = 3.2/1.2/60). LV volumes and EF were measured with various geometric models for TGrE and SSFP. With three-dimensional data, the LV volumes were higher and the resulting EF lower for SSFP in contrast to TGrE (51 +/- 15% vs. 57 +/- 15%, p < 0.001). With SSFP, various geometric models yielded good to excellent correlations for LV volumes and LVEF compared to volumetric data (r = 0.94-0.98, mean relative difference 7.0-11.4%). In contrast, correlations were low using biplane or single-plane ellipsoid models in TGrE (r = 0.71-0.75, mean relative difference 15.9-30.2%). A new combined geometric model, taking all three dimensions into account, yielded the highest accuracy for SSFP in comparison to volumetric data (r = 0.99, mean relative difference 4.7%). Geometric models for assessment of LV volumes and EF yield higher accuracy and reproducibility by use of the SSFP sequence than by standard TGrE. This may increase clinical utility of magnetic resonance by shorter acquisition and processing times.

Myocardial biopsy findings and gadolinium enhanced cardiovascular magnetic resonance in dilated cardiomyopathy

In some patients suffering from dilated cardiomyopathy (DCM) magnetic resonance imaging (MRI) shows late gadolinium enhancement with variable distribution. Myocardial biopsies in DCM reveal a chronic myocardial inflammatory process in almost 50% and myocardial persistence of adenoviral or enteroviral genome in about 15% of the patients.

Assessment of myocardial perfusion for detection of coronary artery stenoses by steady-state, free-precession magnetic resonance first-pass imaging.

Objective: To evaluate the diagnostic impact of magnetic resonance imaging (MRI) first-pass perfusion using steady-state, free-precession (SSFP) sequences with parallel imaging (SENSE) for detection of coronary stenoses. Design: Prospective observational study. Setting: University hospital, cardiac MRI and catheterisation laboratories. Patients and methods: 228 patients were examined with coronary angiography and MRI (1.5 T Intera CV). A three-slice, short-axis SSFP perfusion scan with a saturation prepulse was performed during infusion of adenosine and at rest followed by myocardial scar (late enhancement) imaging. Gadolinium-DTPA was given at 0.1 mmol/kg body weight. Perfusion images were visually assessed. Analysis for myocardial hypoperfusion was done according to patient group and according to vessel. Results: Sensitivity, specificity and accuracy of MRI first-pass perfusion for detection of a coronary artery stenosis (>50% luminal narrowing) in the total patient group were 93.0%, 85.7%, 91.2% and for a significant lesion (>70% luminal narrowing) 96.1%, 72.0%, 88.2%, respectively. Based on 536 coronary artery territories without myocardial scar, the sensitivity of MRI perfusion analysis for detection of a significant lesion was for the left anterior descending artery 91.4%, for the circumflex artery 81.6% and for the right coronary artery 65.1% (p<0.001). Conclusions: MRI first-pass perfusion analysis using an SSFP sequence with three myocardial slices was a highly accurate diagnostic method for detection of coronary artery stenoses. This MRI technique can be included in daily practice and has the potential to guide the indication for invasive coronary angiography.

Intracoronary β-irradiation with a rhenium-188-filled balloon catheter: a randomized trial in patients with de novo and restenotic lesions ☆

Background Restenosis requiring reintervention is the main limitation of coronary angioplasty. Intracoronary irradiation reduces neointimal proliferation. We studied the efficacy of a self‐centering liquid rhenium‐188‐filled balloon catheter for coronary &bgr;‐brachytherapy. Methods and Results After successful coronary angioplasty with or without stenting, 225 patients (71% de novo lesions) were randomly assigned to receive 22.5 Gy intravascular &bgr;‐irradiation in 0.5‐mm tissue depth (n=113) or to receive no additional intervention (n=112). Clinical and procedural data did not differ between the groups except a higher rate of stenting in the control group (63%) compared with the rhenium‐188 group (45%, P<0.02). After 6 months of follow‐up, late loss was significantly lower in the irradiated group compared with the control group, both of the target lesion (0.11±0.54 versus 0.69±0.81 mm, P<0.0001) and of the total segment (0.22±0.67 versus 0.70±0.82 mm, P<0.0001). This was also evident in the subgroup of patients with de novo lesions and independent from stenting. Binary restenosis rates were significantly lower at the target lesion (6.3% versus 27.5%, P<0.0001) and of the total segment (12.6% versus 28.6%, P<0.007) after rhenium‐188 brachytherapy compared with the control group. Target vessel revascularization rate was significantly lower in the rhenium‐188 (6.3%) compared with the control group (19.8%, P=0.006). Conclusions Intracoronary &bgr;‐brachytherapy with a rhenium‐188 liquid‐filled balloon is safe and efficiently reduces restenosis and revascularization rates after coronary angioplasty. (Circulation. 2003;107:3022‐3027.)

Myocardial Perfusion Reserve in Cardiovascular Magnetic Resonance: Correlation to Coronary Microvascular Dysfunction

The present study examined the association of myocardial perfusion reserve index (MPRI) in cardiovascular magnetic resonance (CMR) with coronary microvascular dysfunction (CMD) and serum levels of markers of inflammation or endothelial activation. Twelve patients with typical angina pectoris without coronary artery disease were enrolled in this study, and CMR perfusion was analyzed using a steady-state-free-precession sequence with 3 short axis slices per heartbeat during first pass of 0.025 mmol Gadolinium-DTPA/kg body weight. The upslope of myocardial signal intensity curves was used to calculate MPRI. CMD was assessed by intracoronary Doppler flow measurement and biplane angiography. Both MPRI and CMD were assessed during endothelium-independent stimulation with intravenous adenosine and during endothelium-dependent stimulation with intracoronary infusion of acetylcholine. Serum values of soluble CD40 ligand (sCD40L), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-alpha), soluble intercellular adhesion molecule-1 (sICAM-1), and C-reactive protein (CRP) were measured. Impaired MPRI correlated significantly with a decrease in coronary blood flow reserve after both endothelium-dependent (p = 0.033) and endothelium-independent (p = 0.022) stimulation. Serum levels above the median of all normal ranged biomarkers sCD40L, TNF-alpha, IL-6, sICAM-1 and CRP were associated with an impaired MPRI for stimulation with adenosine as well as acetylcholine. In multivariable analyses, sCD40L (p < 0.001) and TNF-alpha (p = 0.011) were significantly associated with a decrease in MPRI on adenosine, as were TNF-alpha (p = 0.016) and sICAM-1 (p = 0.022) for a decrease in MPRI on acetylcholine. MPRI on adenosine significantly correlated with MPRI on acetylcholine (p < 0.001). Therefore, the present study demonstrates safety and feasibility of an intracoronary infusion of acetylcholine during CMR perfusion analysis, thus allowing direct assessment of endothelial dependent vasomotor function at the myocardial level by CMR. Furthermore, we show that an impaired myocardial perfusion reserved in CMR is associated with established biomarkers of early atherosclerosis and significantly correlated with CMD. CMR combined with adenosine could be proposed as a non-invasive tool to evaluate CMD.

Optimal Acquisition Parameters for Contrast Enhanced Magnetic Resonance Imaging After Chronic Myocardial Infarction

The aim of this study was to simplify the imaging of myocardial infarction based on theoretical aspects and patient variables and to define the optimal time for image acquisition. Thirteen patients with chronic myocardial infarction underwent magnetic resonance imaging. After injection of 0.2 mmol/kg body weight Gd-DTPA an inversion recovery turbo gradient echo sequence with different prepulse delays was applied every 3 to 5 minutes within an interval of 3 to 30 minutes. As parameters of investigation, the area of signal enhancement and the contrast between enhanced and nonenhanced myocardium were used. There was no influence of prepulse delay or time after contrast injection on the enhanced area. The contrast between enhanced and normal myocardium showed a peak at 6 minutes post Gd-DTPA injection and remained high. The contrast between blood and enhanced myocardium was best at 6 and 25 minutes with best intra- and interobserver variability. In conclusion, if a suitable contrast was achieved, the area of enhancement is independent of prepulse delay or imaging time. In most patients the highest contrast between blood, enhanced and normal myocardium is achieved 6 minutes and 25 minutes after contrast injection.

Assessment of left ventricular function with steady-state-free-precession magnetic resonance imaging. Reference values and a comparison to left ventriculography.

Die mittels Laevokardiographie bestimmten Parameter Ejektionsfraktion (EF), der enddiastolische und endsystolische Volumenindex (EDVI/ESVI) haben eine große prognostische Bedeutung. Die kardiale Magnetresonanztomographie (MRT) bietet bei Verwendung einer Steady-State-Free-Precession-Sequenz eine hervorragende Abgrenzbarkeit der linksventrikulären Wand und liefert gut reproduzierbare und präzise Ergebnisse für die Bestimmung der linksventrikulären Funktion. In dieser Studie wurde die MRT-Volumetrie mit unter Routinebedingungen angefertigten Laevokardiographien verglichen. Hierzu wurden bei 200 Patienten EDVI, ESVI und EF mittels Laevokardiographie und MRT-Volumetrie bestimmt. Das gleiche MRT-Protokoll wurde zusätzlich an 102 Herzgesunden Personen zur Etablierung von Normalwerten angewendet. Bei den Herzgesunden betrug die mittlere EF 68,8 ± 5,4% (59–84%), der mittlere EDVI 69,4 ± 9,8 ml (43–90 ml) und das mittlere endsystolische Volumen 22,0 ± 5,8 (10–35 ml). In dem gesamten Patientenkollektiv lag die Korrelation (Spearman R) zwischen Laevokardiographie und MRT-Volumetrie bei 0,86 für EF, 0,77 für EDVI und 0,88 für ESVI. Bei Patienten in den nur postextrasystolische Schläge auswertbar waren (38% aller Messungen) lag R bei 0,73/ 0,65/0,73 für EF/EDVI/ESVI. Die MRT zeigte die beste Korrelation mit biplaner Laevokardiographie während durchgehendem Sinusrhythmus (R = 0,96/0,85/0,93); die schlechteste Korrelation (0,78/ 0,81/0,83) ergab sich bei Patienten mit Wandbewegungsstörungen, die mit monoplaner Laevokardiographie gemessen wurden. Die MRT-Volumetrie liefert Ergebnisse, die mit denen einer unter Optimalbedingungen durchgeführten Laevokardiographie gut vergleichbar sind. Die Resultate lassen ferner den Schluss zu, dass dies unabhängig von regionalen Wandbewegungsstörungen und Arrhythmien gilt. Ejection fraction (EF) and end-diastolic and endsystolic volume index (EDVI/ ESVI) derived from ventriculography are important prognostic parameters. Cine magnetic resonance imaging (MRI) using a steady-state, free-precession sequence (SSFP) offers excellent delineation of the endocardial borders and highly reproducible and accurate results for cardiac volumes. We evaluated MRI volumetry against routine x-ray ventriculography. In 200 patients EF, EDVI and ESVI were measured with MRI volumetry and x-ray ventriculography. The same MRI protocol was applied to 102 healthy persons in order to establish reference values. In healthy subjects mean EF was 68.8% ± 5.4% (range 59–84%), mean EDVI 69 ± 10 (43–90) and mean ESVI 22 ± 5.8 (10–35 ml). In the patients, overall correlation (Spearman’s R) of MRI with ventriculography was 0.86 for EF, 0.77 for EDVI and 0.88 for ESVI. For postextrasystolic beats (38% of the measurements), R was 0.73/0.65/0.73 for EF/EDVI/ESVI. MRI correlated best with biplane ventriculography during sinus rhythm (0.96/0.85/0.93); the worst correlation (0.78/0.81/0.83) resulted from patients with wall motion abnormalities in comparison to monoplane x-ray ventriculography. Contemporary MRI volumetry compares well to invasive data obtained under optimal conditions. In view of the known limitations of single plane ventriculography, MRI seems to allow exact volumetry independent from regional wall motion abnormalities.

Assessment of left ventricular function with steady-state-free-precession magnetic resonance imaging

Die mittels Laevokardiographie bestimmten Parameter Ejektionsfraktion (EF), der enddiastolische und endsystolische Volumenindex (EDVI/ESVI) haben eine große prognostische Bedeutung. Die kardiale Magnetresonanztomographie (MRT) bietet bei Verwendung einer Steady-State-Free-Precession-Sequenz eine hervorragende Abgrenzbarkeit der linksventrikulären Wand und liefert gut reproduzierbare und präzise Ergebnisse für die Bestimmung der linksventrikulären Funktion. In dieser Studie wurde die MRT-Volumetrie mit unter Routinebedingungen angefertigten Laevokardiographien verglichen. Hierzu wurden bei 200 Patienten EDVI, ESVI und EF mittels Laevokardiographie und MRT-Volumetrie bestimmt. Das gleiche MRT-Protokoll wurde zusätzlich an 102 Herzgesunden Personen zur Etablierung von Normalwerten angewendet. Bei den Herzgesunden betrug die mittlere EF 68,8 ± 5,4% (59–84%), der mittlere EDVI 69,4 ± 9,8 ml (43–90 ml) und das mittlere endsystolische Volumen 22,0 ± 5,8 (10–35 ml). In dem gesamten Patientenkollektiv lag die Korrelation (Spearman R) zwischen Laevokardiographie und MRT-Volumetrie bei 0,86 für EF, 0,77 für EDVI und 0,88 für ESVI. Bei Patienten in den nur postextrasystolische Schläge auswertbar waren (38% aller Messungen) lag R bei 0,73/ 0,65/0,73 für EF/EDVI/ESVI. Die MRT zeigte die beste Korrelation mit biplaner Laevokardiographie während durchgehendem Sinusrhythmus (R = 0,96/0,85/0,93); die schlechteste Korrelation (0,78/ 0,81/0,83) ergab sich bei Patienten mit Wandbewegungsstörungen, die mit monoplaner Laevokardiographie gemessen wurden. Die MRT-Volumetrie liefert Ergebnisse, die mit denen einer unter Optimalbedingungen durchgeführten Laevokardiographie gut vergleichbar sind. Die Resultate lassen ferner den Schluss zu, dass dies unabhängig von regionalen Wandbewegungsstörungen und Arrhythmien gilt. Ejection fraction (EF) and end-diastolic and endsystolic volume index (EDVI/ ESVI) derived from ventriculography are important prognostic parameters. Cine magnetic resonance imaging (MRI) using a steady-state, free-precession sequence (SSFP) offers excellent delineation of the endocardial borders and highly reproducible and accurate results for cardiac volumes. We evaluated MRI volumetry against routine x-ray ventriculography. In 200 patients EF, EDVI and ESVI were measured with MRI volumetry and x-ray ventriculography. The same MRI protocol was applied to 102 healthy persons in order to establish reference values. In healthy subjects mean EF was 68.8% ± 5.4% (range 59–84%), mean EDVI 69 ± 10 (43–90) and mean ESVI 22 ± 5.8 (10–35 ml). In the patients, overall correlation (Spearman’s R) of MRI with ventriculography was 0.86 for EF, 0.77 for EDVI and 0.88 for ESVI. For postextrasystolic beats (38% of the measurements), R was 0.73/0.65/0.73 for EF/EDVI/ESVI. MRI correlated best with biplane ventriculography during sinus rhythm (0.96/0.85/0.93); the worst correlation (0.78/0.81/0.83) resulted from patients with wall motion abnormalities in comparison to monoplane x-ray ventriculography. Contemporary MRI volumetry compares well to invasive data obtained under optimal conditions. In view of the known limitations of single plane ventriculography, MRI seems to allow exact volumetry independent from regional wall motion abnormalities.