Karsch Kr

Influence of sampling site and flow area on cardiac output measurements by Doppler echocardiography

In 40 patients cardiac output was simultaneously determined by pulsed Doppler echocardiography and thermodilution (range 4.0 to 10.2 liters/min). The sample volume was located in the center of the mitral anulus, at the tips of the mitral leaflets and in the center of the aortic anulus. Circular cross-sectional areas of the mitral anulus, aortic anulus and aortic bulbus were calculated from M-mode and two-dimensional echocardiographic diameters. The varying short axis of the elliptical mitral opening area was obtained from the diastolic leaflet separation in the M-mode, and the long axis was derived from the maximal mitral orifice area or mitral anulus diameter. Cardiac output was calculated by multiplying time-velocity integrals with the different areas and heart rate. Doppler flow measurements correlated significantly with the thermodilution method (r = 0.79 to 0.93). Flow measurements at the aortic anulus were most accurate (r = 0.93, SEE = 0.589 liter/min) if the annular area was derived from the M-mode tracing. Measurement of the anulus in the apical five chamber view yielded a significant underestimation and the area of the aortic bulbus provided an overestimation of cardiac output. Left ventricular inflow was underestimated at the mitral leaflet tips and overestimated at the mitral anulus. The accuracy of pulsed Doppler cardiac output measurements strongly depends on the assumed flow area and sampling site. Both should be determined at the same level in the inflow or outflow tract of the left ventricle. Measurement of cardiac output in the center of the aortic anulus provided the highest accuracy.

Acute complications of excimer laser coronary angioplasty: A detailed analysis of multicenter results

OBJECTIVES The aim of this study was to document and analyze the incidence and consequences of complications of excimer laser coronary angioplasty. BACKGROUND Excimer laser coronary angioplasty has been reported to be a safe and feasible alternative or adjunct to conventional balloon angioplasty, but serious and unique complications have been observed. METHODS Data on 1,595 interventions of excimer laser coronary angioplasty in 1,521 patients were analyzed, using a merged data base from the U.S. and European Percutaneous Excimer Laser Coronary Angioplasty (PELCA) registries. RESULTS Procedural success was achieved in 89.3% of interventions. Stand-alone laser angioplasty was performed in 17.8% of interventions. Complications included dissection (22.0%), vasospasm (6.1%), filling defects (4.8%), abrupt reclosure (6.1%), embolization (2.3%), perforation (2.4%), arrhythmia (0.7%) and aneurysm formation (0.3%). Major complications were non-Q wave myocardial infarction (2.3%), Q wave myocardial infarction (1.0%), coronary artery bypass grafting (3.1%) and death (0.7%). Logistic regression analysis revealed correlation between dissections and the use of larger catheter size (p = 0.0005), high energy per pulse levels (p = 0.0001 for native vessels), lesion length > 10 mm (p = 0.001) and presence of a side branch (p = 0.01). The incidence of perforations was higher in women (p = 0.004), in treatment of total occlusions (p = 0.02) and in the presence of a side branch (p = 0.03). Fatal complications were correlated with patients with multivessel disease (p < 0.0001), patients with acute myocardial infarction (p = 0.0009) and older patients (> 70 years old, p = 0.004). The incidence of major complications decreased after performance of 50 laser angioplasty procedures at one institution (p = 0.02). CONCLUSIONS This analysis defines both the learning curve and the profile of complications for excimer laser angioplasty and provides insight into the selection of appropriate patients and proper performance of the procedure.

Accuracy of doppler echocardiography in quantification of left to right shunts in adult patients with atrial septal defect

In previous experimental and pediatric studies, the ratio of pulmonary to systemic flow (Qp/Qs) was accurately estimated by Doppler echocardiography in various cardiac shunt lesions. The purpose of this study was to assess the accuracy of pulsed Doppler echocardiography in determining the magnitude of shunt flow in adult patients with an ostium secundum type atrial septal defect. In 32 patients with high quality echocardiograms and excellent Doppler signals, blood flow was measured in the right and left ventricular outflow tract by Doppler echocardiography. In 16 patients without heart disease, the correlation (r) between systemic (Qs) and pulmonary (Qp) blood flow was 0.96 (SEE = 0.417 liter/min, y = 1.05x - 0.21) and the mean Qp/Qs ratio was 1.01 +/- 0.09. In 16 patients with an atrial septal defect, the Qp/Qs ration measured by oximetry ranged from 1.34 to 4.61 and by pulsed Doppler echocardiography from 1.31 to 4.46 (p = NS). In these 16 patients, the correlation between the Qp/Qs ratio determined by oximetry and pulsed Doppler echocardiography was significant (r = 0.82, SEE = 0.54). In the total group of 32 patients, the correlation was stronger (r = 0.93, SEE = 0.37). Systematic differences between the invasive and noninvasive shunt calculations did not occur. Thus, in adult patients with an atrial septal defect of the secundum type and high quality echocardiograms, the magnitude of left to right shunt can be accurately assessed by pulsed Doppler echocardiography. In the absence of pulmonary hypertension, pulsed Doppler echocardiography provides precise information for the decision to undertake conservative or operative treatment.

Effect of chronic nicotine delivery on the proliferation rate of endothelial and smooth muscle cells in experimentally induced vascular wall plaques

To study the effect of nicotine, cholesterol feeding, and their combination on endothelial and smooth muscle cells in vascular wall plaques an experimental method was established which allows the immunohistochemical detection and quantification of the fractions of endothelial and smooth muscle cells in DNA synthesis under the effect of these stimuli. For this purpose standardized fibromuscular plaques were produced by electrostimulation in the common carotid arteries of rabbits. The animals received either nicotine via implanted osmotic minipumps or a cholesterol diet or both. Plaque size was determined at the end of the experiments after 7 or 14 days as well as the fraction of endothelial and smooth muscle cells in DNA synthesis during exposure to bromodeoxyuridine (BrdU). The BrdU labeling index of endothelial cells clearly increased under chronic nicotine administration for either 7 days or 14 days compared to controls. The combination of nicotine and cholesterol diet led to a more significant increase. In contrast, the BrdU labeling index of smooth muscle cells was not increased under nicotine delivery. The combination of nicotine and cholesterol, however, led to a significant increase of the BrdU labeling index of smooth muscle cells in the plaques compared to cholesterol feeding. Measurement of the plaque size revealed no difference between controls and nicotine-treated animals after 14 days of nicotine delivery, whereas the combination of cholesterol and nicotine produced increased plaque formation compared to a group of animals which received a cholesterol diet alone.

Paclitaxel: Ein Chemotherapeutikum zur Restenoseprophylaxe? Experimentelle Untersuchungen in vitro und in vivo

Paclitaxel, a potent anti-tumor agent, shifts the cytoskeleton equilibrium towards assembly of altered and extraordinarily stable microtubules. These cellular modifications lead to reduced proliferation, migration, and signal transduction. It is highly lipophilic, which promotes a rapid cellular uptake, and has a long-lasting effect in the cell due to the structural alteration of the cytoskeleton. This makes paclitaxel a promising candidate for local drug delivery intended to address the proliferative and migratory processes involved in restenosis. In this article, results of our in vitro and in vivo studies with paclitaxel are presented. Cell culture experiments with monocultures of human arterial smooth muscle cells as well as cocultures with human endothelial cells showed that paclitaxel leads to an almost complete growth inhibition within a dose range of 1.0–10.0μmol/l, even after a short (20 min) single dose application. The comparison of an active, semi-active, and passive delivery system (porous balloon, microporous balloon, and double balloon) favored the double balloon for the following in vivo experiments. Tubulin staining and electron microscopy enabled visualization of paclitaxel-induced vessel wall alterations. In the rabbit model, locally delivered paclitaxel resulted in reduced neointima formation and enlargement in vessel size; in the pig model, however, after stenting, this inhibition was not significant. Both reduced proliferation and enlargement in vessel size contribute to a preservation of vessel shape and are likely to be caused by a structural alteration of the cytoskeleton, which is also supported by vascular contraction force experiments. Paclitaxel, eine sehr potente antiproliferative Substanz, fördert die Bildung ungewöhnlich stabiler und funktionsgestörter Mikrotubuli und verändert dadurch zelluläre Mechanismen, die letztlich zu verminderter Proliferation, Migration und Signaltransduktion führen. Paclitaxel ist lipophil, was eine rasche Aufnahme in die Zelle fördert, und hat einen langanhaltenden Effekt in der Zelle aufgrund der strukturellen Veränderung des Zytoskelettes. Diese Eigenschaften machen Paclitaxel zu einem vielversprechenden Kandidaten für die lokale Medikamentenapplikation zur Restenoseprophylaxe. In dieser Arbeit werden die in-vitro und in-vivo Ergebnisse aus unseren Forschungsarbeiten zu Paclitaxel vorgestellt. Zellkulturexperimente mit Monokulturen von humanen glatten Gefäßmuskelzellen sowie mit Co-Kulturen mit humanen Endothelzellen zeigten, daß Paclitaxel in einem Dosisbereich zwischen 1,0 und 10,0μmol/l zu einer beinahe vollständigen Wachstumshemmung, selbst nach kurzer (20 min.) Einmalapplikation führt. Nach Vergleich von 3 verschiedenen Kathetersystemen (poröser Ballon, mikroporöser Ballon und Doppelballon) wurde der Doppelballon für die in-vivo Anwendung favorisiert. Anhand von Anfärbungen des Zytoskelettes sowie elektronenoptisch gelang der Nachweis der Paclitaxelwirkung in den glatten Muskelzellen der Gefäßwand. Im Kaninchen führte lokal appliziertes Paclitaxel zu einer signifikanten Hemmung der neointimalen Proliferation und Erweiterung des Gefäßdurchmessers im Vergleich zu ballondilatierten Kontrolltieren. In Zusatzexperimenten konnte eine drastische Verringerung der vaskulären Kontraktionskraft nach Paclitaxelgabe gezeigt werden. Ähnlich eindeutige Ergebnisse fanden sich nach Stentimplantation im Schweinemodell nicht.

Risiko der invasiven Diagnostik mit retrograder Sondierung des linken Ventrikels bei Patienten mit erworbener Aortenklappenstenose

In patients with aortic valve stenosis, the determination of the transstenotic pressure gradient is usually performed by cardiac catheterization with retrograde passage of the aortic valve. The aim of this study was to determine retrospectively the risk of the invasive examination with retrograde catheterization of the left ventricle and predictors for an increased risk. From 1984 to 1995, 457 patients (63 ± 11 years) with aortic stenosis were investigated in the Medizinische Klinik Tübingen. In 435 patients (95.2 %), the retrograde catheterization of the left ventricle was successful; in 19 cases a transseptal left heart catheterization was performed, and in 3 patients an invasive determination of the pressure gradient was not assessed. Complications occurred in 39 patients (8.5%). 5 patients died due to the catherization procedure (mortality rate 1.1%), 2 of them as a consequence of perforation of the left ventricle, one patient of heart failure, one of myocardial infarction, and another of fulminant pulmonary embolism. Four procedures (0.9%) were complicated by cerebral embolism, in 3 patients a pericard tamponade occurred, and in one case caused by transseptal punction of the interatrial septum. The most complications were peripheral vascular problems in 19 patients (4.2%). Predictors for increased risk dur to retrograde catheterization were age > 70 years (p = 0.008) and aortic valve area ≤ 0.7 cm2 (p = 0.02). Patients with a doppler echocardiographic instantaneous pressure gradient ≥ 70 mm Hg were more likely to sustain a complication (p = 0.04). The retrograde catheterization of a stenotic aortic valve was successful in most cases. In approximately 2 % of patients, complications occurred which can be attributed directly to retrograde catheterization and with significant higher frequency in patients over 70 years and with severe stenosis. Especially in these cases, invasive determination of the gradient should not be performed if reliable doppler echocardiographic information is available. Bei Patienten mit Aortenklappenstenose wird der transstenotische Druckgradient üblicherweise im Rahmen einer Herzkatheteruntersuchung mit transseptaler oder retrograder Sondierung des linken Ventrikels bestimmt. Ziel der Untersuchung war es, das Risiko der invasiven Untersuchung mit retrograder Sondierung des linken Ventrikels und die Prädiktoren für ein erhöhtes Risiko retrospektiv zu bestimmen. Im Zeitraum von 1984 bis 1995 hatten sich insgesamt 457 Patienten (63 ± 11 Jahre) mit Aortenklappenstenose in der Medizinischen Universitätsklinik Tübingen einer diagnostischen Herzkatheteruntersuchung unterzogen. Bei 435 Patienten (95,2%) gelang die retrograde Sondierung des linken Ventrikels, in 19 Fällen wurde eine transseptale Punktion durchgeführt, bei 3 Patienten auf eine invasive Bestimmung des Druckgradienten verzichtet. Insgesamt traten bei 39 Patienten (8,5%) Komplikationen auf. 5 Patienten starben im Zusammenhang mit der Untersuchung (Mortalität 1,1%), davon 2 Patienten durch Ventrikelperforation, je ein Patient durch kardiale Dekompensation, Myokardininfarkt und fulminante Lungenembolie. 4 Patienten (0,9%) erlitten eine zerebrale Embolie, 3 Patienten einen Perikarderguß, der in einem Fall infolge transseptaler Punktion auftrat. Der größte Teil der Komplikationen waren periphere Gefäßprobleme in 19 Fällen (4,2%). Prädiktoren für ein erhöhtes Risiko infolge der retrograden Passage der Aortenklappe waren ein Alter über 70 Jahre (p = 0,008) und eine Aortenklappenöffnungsfläche ≤ 0,7 cm2 (p = 0,02). Auch bei Patienten mit einem dopplerechokardiographisch bestimmten instantanen Gradienten ≥ 70 mm Hg war das Risiko signifikant erhöht (p = 0,04). Die retrograde Sondierung einer stenosierten Aortenklappe ist bei der überwiegenden Mehrzahl der Patienten erfolgreich durchführbar. Bei ca. 2% unseres Patientenkollektives kam es jedoch zu Komplikationen, die direkt infolge retrograder Passage und signifikant häufiger bei Patienten über 70 Jahren und bei hochgradiger Stenose auftraten. Insbesondere bei diesen Patienten sollte, wenn aussagekräftige dopplerechokardiographische Befunde vorliegen, auf eine invasive Bestimmung des Schweregrades verzichtet werden.

[Value of 2-D echocardiography in the detection of stress-induced wall-motion abnormalities in coronary heart disease--a comparison with biplane cineventriculography].

SummaryTo determine the accuracy of echocardiography in assessment of exercise-induced wall motion abnormalities, the results of stress-echocardiography were compared with exercise-cineventriculography.In 56 consecutive patients biplane cineventriculography at rest and immediately after supine bicycle exercise was performed. Cross-sectional echocardiography was obtained using the apical 2- and 4-chamber view for LV imaging under identical exercise conditions.In 6 of the 56 patients 2-D echo, in 8 patients LV-angio, and in 2 patients both methods were of inadequate quality during exercise.Thus, in 40 patients (34 patients had coronary artery disease) local wall motion of 360 wall segments was analysed. 49 segments (14%) of 24 patients showed exercise-induced ischemic wall motion abnormalities during cineventriculography. Only 24 of these 49 asynergics (49%) were also detected by 2-D-echo. Using cross-sectional echocardiography, ischemia related wall motion abnormalities were best detected lateraly and septaly, whereas apical asynergies were identified in 3 of 12 segments only.Thus, the clinical value of exercise 2-D echo as a screening method in patients suspected to have coronary artery disease is limited and restricted to patients with excellent visualization of the left ventricular endocardium.To determine the accuracy of echocardiography in assessment of exercise-induced wall motion abnormalities, the results of stress-echocardiography were compared with exercise-cineventriculography. In 56 consecutive patients biplane cineventriculography at rest and immediately after supine bicycle exercise was performed. Cross-sectional echocardiography was obtained using the apical 2- and 4-chamber view for LV imaging under identical exercise conditions. In 6 of the 56 patients 2-D echo, in 8 patients LV-angio, and in 2 patients both methods were of inadequate quality during exercise. Thus, in 40 patients (34 patients had coronary artery disease) local wall motion of 360 wall segments was analysed. 49 segments (14%) of 24 patients showed exercise-induced ischemic wall motion abnormalities during cineventriculography. Only 24 of these 49 asynergics (49%) were also detected by 2-D-echo. Using cross-sectional echocardiography, ischemia related wall motion abnormalities were best detected laterally and septaly, whereas apical asynergies were identified in 3 of 12 segments only. Thus, the clinical value of exercise 2-D echo as a screening method in patients suspected to have coronary artery disease is limited and restricted to patients with excellent visualization of the left ventricular endocardium.

Wertigkeit der 2-D-Echokardiographie zur Erkennung belastungsinduzierter Wandbewegungsstörungen bei koronarer Herzerkrankung — Ein Vergleich mit der biplanen Cineventrikulographie

SummaryTo determine the accuracy of echocardiography in assessment of exercise-induced wall motion abnormalities, the results of stress-echocardiography were compared with exercise-cineventriculography.In 56 consecutive patients biplane cineventriculography at rest and immediately after supine bicycle exercise was performed. Cross-sectional echocardiography was obtained using the apical 2- and 4-chamber view for LV imaging under identical exercise conditions.In 6 of the 56 patients 2-D echo, in 8 patients LV-angio, and in 2 patients both methods were of inadequate quality during exercise.Thus, in 40 patients (34 patients had coronary artery disease) local wall motion of 360 wall segments was analysed. 49 segments (14%) of 24 patients showed exercise-induced ischemic wall motion abnormalities during cineventriculography. Only 24 of these 49 asynergics (49%) were also detected by 2-D-echo. Using cross-sectional echocardiography, ischemia related wall motion abnormalities were best detected lateraly and septaly, whereas apical asynergies were identified in 3 of 12 segments only.Thus, the clinical value of exercise 2-D echo as a screening method in patients suspected to have coronary artery disease is limited and restricted to patients with excellent visualization of the left ventricular endocardium.To determine the accuracy of echocardiography in assessment of exercise-induced wall motion abnormalities, the results of stress-echocardiography were compared with exercise-cineventriculography. In 56 consecutive patients biplane cineventriculography at rest and immediately after supine bicycle exercise was performed. Cross-sectional echocardiography was obtained using the apical 2- and 4-chamber view for LV imaging under identical exercise conditions. In 6 of the 56 patients 2-D echo, in 8 patients LV-angio, and in 2 patients both methods were of inadequate quality during exercise. Thus, in 40 patients (34 patients had coronary artery disease) local wall motion of 360 wall segments was analysed. 49 segments (14%) of 24 patients showed exercise-induced ischemic wall motion abnormalities during cineventriculography. Only 24 of these 49 asynergics (49%) were also detected by 2-D-echo. Using cross-sectional echocardiography, ischemia related wall motion abnormalities were best detected laterally and septaly, whereas apical asynergies were identified in 3 of 12 segments only. Thus, the clinical value of exercise 2-D echo as a screening method in patients suspected to have coronary artery disease is limited and restricted to patients with excellent visualization of the left ventricular endocardium.

Einfluß der Schwere der Gefäßdissektion auf das Langzeitergebnis nach transluminaler perkutaner koronarer Angioplastie

Der Einfluß der Gefäßdissektionen auf das Langzeitergebnis nach PTCA ist in den vergangenen Jahren kontrovers diskutiert worden. Während zahlreiche tierexperimentelle Untersuchungen einen Einfluß des Dissektionsausmaßes auf die Inzidenz einer Rezidivstenose zeigten, war der Einfluß von Dissektionen in klinischen Langzeitstudien nur gering. Dabei wurde meist keine Differenzierung der morphologisch unterschiedlichen Schweregrade der Gefäßdissektionen vorgenommen. Im Rahmen der vorliegenden Untersuchung sollte daher der Einfluß einer Dissektion sowie deren Schweregrad und Konfiguration auf die Restenosierung nach PTCA untersucht werden. Dabei sollte die prognostische Bedeutung der Dissektionsklassifikation nach den National-Heart-Lung-and-Blood-Institute-Kriterien und nach einer weiteren Einteilung angiographischer Komplikationen überprüft werden, um so Aufschlußüber mögliche Pathomechanismen als Ursache der Restenosierung zu erhalten. Die Studie erfolgte bei 141 Patienten mit 143 stabilen Dissektionen nach PTCA. Eine Nachuntersuchung wurde im Mittel 13 Monate nach erfolgter PTCA durchgeführt. Im Rahmen dieser Untersuchung wurden klinische, symptomatische und funktionelle Aspekte der Patienten erhoben. In diesem Patientenkollektiv zeigten Typ-C-Dissektionen nach der Klassifikation nach Dorros et al. ein erheblich erhöhtes Risiko für ein klinisches Ereignis (41,0%) innerhalb der ersten 7 bis 25 Monate nach PTCA. Typ A erwies ein nur geringes Risiko (10,0%), bei Typ B stellte sich ein mäßiggradiges Risiko (18,0%) für ein nachteiliges Langzeitergebnis heraus. Typ-D-Dissektionen zeigten im Vergleich zu Typ-C-Dissektionen eine geringere klinische Ereignisrate von 33,3%. Die Einteilung der postinterventionellen Gefäßmorphologie nach der AC-Klassifikation (61) konnte in der vorliegenden Studie ein ungünstiges Langzeitergebnis nach PTCA besser voraussagen (p = 0,0003) als die übliche Klassifikation nach Dorros et al. (p = 0,0056). Schlußfolgerung: Der Grad der Dissektion zeigte sowohl bei der Einteilung nach der Dorros-Klassifikation als auch bei der AC-Klassifikation eine signifikante Korrelation zu einem späten ischämischen Ereignis nach PTCA (p = 0,0056/p = 0,0003). Aus der speziellen Anlehnung der AC-Klassifikation an das angiographisch bestimmte Ausmaß der Gefäßverletzung ergibt sich die Schlußfolgerung, daß Ausprägung und Tiefe der Dissektion mit dem Langzeitergebnis nach Koronarangioplastie korrelieren. The influence of a coronary dissection on long-term outcome after PTCA has been controversely discussed in the past. Whereas diverse experimental studies have shown a positive relation between dissection and the incidence of restenosis, clinical trials could not document an influence of dissection on long-term outcome. However, most of the trials did not distinguish between the different morphologic configuration of the vascular dissection. Thus, the aim of the present study was to determine the influence of dissections on restenosis in regard to their amount and morphologic configuration. The prognostic importance of the National Heart, Lung, and Blood Institute classification on dissection as well as the importance of an additional classification of angiographic complications after PTCA were investigated to determine possible pathophysiologic mechanisms of the restenosis process. The study included 141 consecutive patients with 143 stable dissections after PTCA. A follow-up study was performed 13 months in mean after successful PTCA, which included clinical, symptomatic, and functional aspects of patients. In this patient population, type C dissections (Dorros et al.) showed a relevantly increased risk of a clinical adverse event (41.0%), whereas patients with a type A dissection had only a small risk of an adverse event (10.0%) over the investigation period. Type B dissections revealed an intermediate risk (18.0%), and type D dissections showed a risk of 33.3% of an adverse event, which was lower than that observed for type C dissections. The AC-classification of the postinterventional coronary morphology was a stronger predicter of an adverse outcome after PTCA (p = 0.0003) than was the Dorros-classification (p = 0.0056). Conclusions: The grade of a coronary dissection was highly, positively related to an ischemic event after PTCA using both the Dorros and the AC-classification (p = 0.0056/p = 0.0003). In regard to the special association of the AC-class with the amount of vascular injury, we conclude that the amount and configuration of coronary dissection correlates with the long-term outcome after PTCA.

Einsatz von Abciximab bei drohendem Gefäßverschluss nach PTCA

The administration of GP IIb/IIIa antagonists has been shown to be effective in reducing myocardial infarction and cardial death when given before PTCA. This prospective study was performed to determine the efficacy of abciximab in a bail-out situation to manage threatened or acute vessel closure.¶   Methods: Acute or threatened vessel closure was observed in 104 (5.5%) out of 1903 consecutive patients treated with PTCA in our institution. Of the 104 patients 46 (44%) were treated for unstable angina (CCS IV). Abciximab was administered in bail-out situations in a dosage of 0.25mg/kg given as a bolus, which was followed by an intravenous infusion of 10μg/min over 12 hours. Repeat PTCA was performed shortly after the administration of the abciximab bolus. After the procedure, the sheathe was left in place and control angiography was carried out 24 h later.¶   Results: In 100 of the 104 patients TIMI flow III could be restored by abciximab therapy and RePTCA. In 4 patients an additional stent implantation was necessary due to persistent flow limitation. One day post PTCA, early follow-up angiography demonstrated patency of all vessels except two. In-hospital events occurred in 4 patients. Three of these patients underwent emergency CABG due to subacute vessel closure a few hours after PTCA and died during or directly after surgery. Follow-up after one year included clinical status and control angiography of the target vessel. During long-term follow-up, MACE occured in 15 patients (2 MI, 8 CABG and 5 RePTCA).¶   Conclusion: The results of this prospective trial demonstrate the efficacy of abciximab therapy in bail-out situations occurring during or early after PTCA. The use of abciximab in bail-out situations appears clinically beneficial. Further studies have to compare the efficacy of this approach with prophylactic abciximab treatment. Die klinische Wirksamkeit von GP IIb/IIIa Antagonisten wurde bei präinterventioneller prophylaktischer Applikation in großen klinischen Studien nachgewiesen. Ziel dieser prospektiven Studie war es, die Wirksamkeit von Abciximab bei der Anwendung in „bail-out” Situationen zu untersuchen.¶   Methoden: Insgesamt wurden bei 104 (5,5%) der 1903 Patienten, welche im Beobachtungszeitraum in unserem Zentrum dilatiert wurden, akute oder drohende Gefäßverschlüsse beobachtet. In dieser Situation wurde Abciximab in einer Dosierung von 0,25mg/kg als Bolus, gefolgt von einer Infusion von 10μg/min über 12 Stunden appliziert. Kurz nach der Gabe des Bolus wurde eine erneute PTCA durchgeführt. Am Ende der Intervention wurde die Schleuse belassen und nach 24 Std. eine Kontrollangiographie durchgeführt.¶   Ergebnisse: Bei 100 der 104 Patienten konnte ein ausreichender (TIMI III) Fluss wiederhergestellt werden. Bei 4 Patienten war die zusätzliche Implantation eines Stents notwendig. Eine Kontrollangiographie am Folgetag zeigte in allen bis auf 2 Fälle offene Gefäße mit gutem antegraden Fluss (TIMI III). Bei 4 Patienten trat nach der Intervention ein subakuter Gefäßverschluss auf. Drei von ihnen verstarben trotz einer sofort durchgeführten Notfall-ACVB OP. Das 12 Monats Follow-up beinhaltet den klinischen Status sowie eine Kontrollangiographie des Zielgefäßes. Während des Nachbeobachtungszeitraums kam es bei 15 Patienten zu einem klinischen Ereignis (2 MI, 8 ACVB, 5 Re-PTCA).¶   Schlussfolgerung: Die Ergebnisse dieser prospektiven Studie zeigen die hohe Wirksamkeit von Abciximab in „bail-out” Situationen während oder direkt nach der PTCA. Weitere Studien sollten dieses Konzept mit dem der prophylaktischen Behandlung vergleichen.