[Reperfusion therapy in acute myocardial infarct].
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Aged↗
Biomedical subjects
R Erbel
Publications and source records attributed to R Erbel.
The safety of intracoronary ultrasound. A multicenter survey of 2207 examinations.
BACKGROUND: Intracoronary ultrasound (ICUS) is increasingly used in clinical practice to study the natural history of coronary artery disease and to assess the effects of intracoronary, catheter-based interventions. However, the risk associated with the procedure is not well documented. METHODS AND RESULTS: ICUS studies performed in 28 centers were retrospectively included; these centers agreed to contribute to the study among a total of 60 centers initially invited. Among the 2207 ICUS studies, 505 (23%) were performed in heart transplant recipients and 1702 (77%) in nontransplant patients. Indication for ICUS was diagnostic imaging in 915 (41%), drug testing in 244 (11%), and guidance for intracoronary interventions in 1048 patients (47%). There were no complications in 2034 patients (92.2%). In 87 patients (3.9%), complications occurred but were judged to be "not related" to ICUS by the operator. In 63 patients (2.9%), spasm occurred during ICUS imaging. In 9 patients (0.4%), complications other than spasm were judged to have a "certain relation" to ICUS, including acute procedural events in 6 (3 acute occlusion, 1 embolism, 1 dissection, and 1 thrombus) and major events in 3 patients (2 occlusion and 1 dissection; all resulting in myocardial infarction). In 14 patients (0.6%), complications with "uncertain relation" to ICUS were recorded, including acute procedural events in 9 (5 acute occlusion, 3 dissection, and 1 arrhythmia) and major events in 5 patients (2 myocardial infarction and 3 emergency coronary artery bypass surgery). The incidence of acute procedural or major complications judged to be associated with ICUS (uncertain relation or certain relation to ICUS) was compared in different patient groups. The complication rate was higher in patients with unstable angina or acute myocardial infarction (2.1% events) as compared with patients with stable angina pectoris and asymptomatic patients (0.8% and 0.4%, respectively; chi 2 = 10.9, P < .01). These complications were also more frequent in patients undergoing interventions (1.9%) as compared with transplant and nontransplant patients undergoing diagnostic ICUS imaging (0% and 0.6%, respectively; chi 2 = 13.5, P < .001). Adverse events were few, and no association was detected between these events and the size or type of ICUS catheter used. CONCLUSIONS: ICUS is associated with (but not necessarily the direct cause of) a minor acute clinical risk. Vessel spasm is the most frequent event occurring during ICUS. Other complications predominantly occur in patients with acute coronary syndromes and during guidance for intervention.
Adult↗
Left atrial appendage systolic forward flow.
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Adult↗
Acute coronary artery closure following intracoronary ultrasound examination.
Two patients undergoing intracoronary ultrasound examination were complicated by acute coronary artery closure. One of the complications was thought to be caused by intimal dissection and thrombus formation and the other was thought to be caused by intimal dissection and subsequent embolization. The complications were successfully managed conservatively in both cases.
Acute Disease↗
Improvement of coronary morphology and blood flow after stenting. Assessment by intravascular ultrasound and intracoronary Doppler.
Intravascular ultrasound (IVUS) and intracoronary Doppler (ICD) were performed in eight patients (54.3 +/- 6.5 years, 6 male) immediately after PTCA and after stenting. ICD was also performed before PTCA. After PTCA, IVUS has demonstrated intimal rupture in all patients. After stenting, IVUS revealed wall wrapping of the intimal flap with a free lumen in all patients. The lumen diameter was 2.42 +/- 0.55 mm after PTCA and was 2.74 +/- 0.49 mm after stenting (p < 0.001). The cross-sectional area increased from 4.70 +/- 1.99 mm2 post-PTCA to 6.40 +/- 2.15 mm2 post-stent (p < 0.005). Coronary flow velocity reserve, calculated by the ratio of mean flow velocity at rest and after intracoronary papaverine administration, increased from 2.05 +/- 1.01 to 2.99 +/- 1.14 after PTCA (p = 0.015); and increased to 4.51 +/- 1.33 after stenting (p < 0.001). The morphological data derived from IVUS correlated with the functional information obtained with ICD. In addition to its established role in bail out situations, stent implantation may be considered when a suboptimal morphological and functional result has been demonstrated.
Angioplasty, Balloon, Coronary↗
Improving the applicability of myocardial densitometry and parametric imaging by extended automated densogram analysis.
In clinical applications the analysis of X-ray contrast densograms acquired in regions of interest (ROI's) over the myocardium is disturbed by many complex factors. For this reason we acquire redundant densogram information for quality control before extracting densitometric parameters. In our approach, initially some stable measures of quality for densograms are used to lower the influence of poor quality densograms by a quality weighted averaging. For example a shape quality measure, Q1, is calculated using regions of optimal and minimal acceptable quality defined with respect to a prototype densogram. Not a few myocardial ROI's yield densograms that differ from single-source densograms (SSD's) due to e.g. superposition of different perfusion beds or the position of the ROI relative to the coronary sinus or stenoses. This might result in a densogram shape with oscillating or plateau behavior. For densograms of a such general shape many parameters defined in the usual way do not depend smoothly on the densogram values. The conventional definitions of some parameters (appearance time, rise time) are therefore extended for application to multi-maxima densograms as well as to SSD's. These new methods are evaluated using digitized clinical angiocardiograms and are applied to parametric imaging (pixeldensograms) in a slightly modified way. Taking into account the densogram quality, its shape and its origin results in a considerable improvement both for densitometry and parametric imaging of myocardial perfusion.
Absorptiometry, Photon↗
Intravascular ultrasound approach to the diagnosis of coronary artery aneurysms.
Coronary artery aneurysms are usually diagnosed by contrast coronary angiography, which portrays the silhouette of the lumen but cannot distinguish true and false aneurysms. To differentiate true and false aneurysms and to study the morphologic changes of the vessel wall, intravascular ultrasound (IVUS) was performed in patients with angiographic signs of coronary artery aneurysms. We used a 4.8F or 3.5F, 20 MHz IVUS catheter for ultrasound examination. Fourteen patients (12 men and two women ranging in age from 43 to 73 years) with angiographic signs of coronary aneurysm were enrolled. IVUS imaging was optimally obtained in all patients. The vessel area, lumen area, and plaque area of the aneurysm segment and of the proximal and distal segments were determined. IVUS showed that both the proximal and distal reference segments were severely affected by atherosclerotic lesions in all the patients and by calcium deposits in six patients. The percent stenoses were 63.0% +/- 13.7% and 60.9% +/- 17.8% in the proximal and distal reference segments, respectively. In nine patients the walls of the aneurysms showed signs of atherosclerosis. Three angiographically indicated aneurysms were found to be plaque ruptures. Although the lumen and the vessel areas of the aneurysm segments were larger than those of the proximal and distal segments (p < 0.01 and (p < 0.001), no significant differences in plaque area and plaque composition were found between the aneurysm segment and adjacent vessel segments (p > 0.05). In conclusion, IVUS allows detailed characterization of coronary aneurysms. Atherosclerosis seems to play an important role in the formation of acquired coronary aneurysms.
Adult↗
Guidance of anticoagulation after intracoronary implantation of Palmaz-Schatz stents by monitoring prothrombin and prothrombin fragment 1 + 2.
The primary objective of this study was to apply a sophisticated coagulation monitoring system including estimation of the concentration of prothrombin fragment 1 + 2 (PTF 1 + 2) and the activity of prothrombin (coagulation factor II or FII) to cases of stent implantation and to compare the results with those of standard coagulation tests. The secondary objective was to detect the incidence after stenting of subacute thrombosis (SAT) and bleeding complications in these patients and to compare the results with those of a group of patients with stent implantation in whom coagulation was monitored exclusively by standard tests. SAT several days after coronary stenting occurs in up to 20% despite aggressive intravenous and overlapping oral anticoagulation. According to a prospective study protocol 120 consecutive patients with implantation of 155 Palmaz-Schatz stents underwent coagulation monitoring including single daily estimation of the concentration of PTF1 + 2 (target range < 0.5 nmol/L) and of FII activity (15% to 35%) in addition to the standard tests of thrombin time (TT), partial thromboplastin time (aPTT), international normalized ratio (INR), antithrombin III (ATIII), and fibrinogen. Adjustment of heparin and phenprocoumon dosages in this study group was based only on the results of PTF1 + 2 and FII measurements. A control group consisted of 53 patients with implantation of 64 stents who were matched for baseline, angiographic, and procedure-related characteristics. After stenting, anticoagulation was monitored by estimation of TT (target range > 70 seconds), aPTT (> 70 seconds), INR (3.0 to 4.5), AT III (> 80%), and fibrinogen (< 450 mg/dl) in this control group. There was a weak correlation between PTF1 + 2 and aPTT (r = 0.337; PTF1 + 2 = -0.00169aPTT + 0.491) and PTF1 + 2 and TT (r = 0.328; PTF1 + 2 = -0.00142TT + 0.494). A better correlation was found between FII and INR (r = 0.983; FII = -23.8 INR + 134). Stable oral anticoagulation was maintained 2.8 +/- 0.9 days later according to an FII concentration of < 35% compared with an INR > 3. The incidence of SAT was 3.3% with 3.0% for elective versus 3.8% for nonelective stenting. The sensitivity, specificity, and accuracy of the PTF1 + 2 test were 100%, 88%, and 88%, respectively. In the control group the incidence of SAT was 17%, with 16.1% for elective versus 18% for nonelective stenting. Major bleeding complications occurred in 10% (study group) and in 11.3% (control group) of patients (no statistical difference).(ABSTRACT TRUNCATED AT 400 WORDS)
Adult↗
Intravascular ultrasound after low and high inflation pressure coronary artery stent implantation.
OBJECTIVES: We sought to characterize the differences seen after low or high pressure coronary artery stent deployment as assessed by intravascular ultrasound. BACKGROUND: Until 1992, the success of stent deployment was assessed by angiographic criteria only, but in 1993 the procedure was expanded to include postprocedural single-use intravascular ultrasound imaging. Ultrasound criteria for successful stent deployment were 1) symmetry, 2) minimal lumen diameter > 3.0 mm, 3) no echo-free spaces between the stent and the vessel, and 4) no uncovered dissections. METHODS: We used mechanical 4.8F or 3.5F 20- or 30-MHz monorail single-use intravascular ultrasound catheters. RESULTS: Fifty-two patients were included, 28 treated in 1991 and 1992 (group A) and 24 treated in 1993 or 1994 (group B); 87% of patients underwent elective stent implantation. The number of echocardiographic studies per patient increased from 1 +/- 0.1 (mean +/- SD) in group A to 2.0 +/- 0.85 in group B. Mean maximal balloon size increased from 3.3 +/- 0.33 to 3.73 +/- 0.24 mm and maximal inflation pressure from 6.9 +/- 1.1 to 15.8 +/- 2.4 bar (p < 0.001). The eccentricity index was 0.915 +/- 0.04 in group B versus 0.87 +/- 0.05 in group A. Minimal lumen diameter measured by echocardiography increased from 2.55 +/- 0.41 mm in group A to 3.14 +/- 0.37 mm in group B. The final mean values per cross-sectional area as a percent of calculated balloon area were similar in group A (67.5 +/- 23%) and group B (66.5 +/- 22.9%). No major acute complications occurred in either group; subacute thrombosis developed in two patients, both in group A. CONCLUSIONS: Intravascular ultrasound data confirm that high pressure stent deployment leads to increased minimal lumen area. Despite high pressure stent deployment, homogeneous stent geometry and optimal stent expansion were not observed in all patients.
Aged↗
Regression of pre-existing coronary artery disease in a donor heart after cardiac transplantation.
This report is about the angiographic follow-up, over 5 years, in a patient with urgent heart transplantation grafted with an atherosclerotic donor heart because of severe congestive heart failure due to dilative cardiomyopathy. Sequential quantitative angiography documented a regression of the luminal narrowing of a focal lesion in the right coronary artery with a minimal luminal diameter of 1.38 mm (56% diameter stenosis) in 1988 to 2.78 mm (13%) in 1993. During this catheterization in 1993 intravascular ultrasound imaging illustrated almost no atherosclerotic vessel wall abnormalities at the site of the previous angiographic luminal narrowing as well as in the adjacent segments. These findings might promote the potential acceptance of heart transplant donors with a certain extent of coronary artery disease in the case of urgent organ request, if close follow-up and strict guidance of the patient by the transplanting team is feasible.
Adolescent↗
Use of transoesophageal echocardiography in the diagnosis of abscess in infective endocarditis.
Transoesophageal echocardiography is invaluable clinically since it accurately images abscess cavities or aneurysms. It provides the information about the site and extension of abscesses which is needed by surgeons to time and define surgical intervention. Early diagnosis is advantageous, and abscesses should be expected in 5%-30% of patients with echocardiographically discernible vegetations. Since there is no 'abscess typical' organism, transoesophageal echocardiographic examination is helpful at the first indication of infective endocarditis, to identify high-risk patients. Involvement of the aortic valve, growth in the size of vegetations, and the presence of spontaneous echo contrast are echocardiographic indicators of high-risk endocarditis.
Abscess↗
Intravascular ultrasound: a guide for management of complications during intervention?
Within a few years, intravascular ultrasound (IVUS) has emerged from a research tool into an intrinsic part of modern invasive cardiology, mainly because histology can be obtained 'in-vivo'. For the first time in invasive cardiology it is possible to base decisions not only on lumenograms but also on vessel wall assessment. IVUS can be used as both a diagnostic tool and for intervention purposes. Its diagnostic strength lies in its ability to monitor compensatory coronary artery enlargement as a response to arteriosclerosis, to reveal occult left main stem disease, and angiographically 'silent' arteriosclerosis. As regards intervention, IVUS aids in optimal device selection, i.e. whether to use rotablators in calcified lesions or atherectomy devices in large plaques. The effects of PTCA on vessel wall morphology can be studied in great detail and the effect on luminal gain assessed almost on-line. Several groups have shown that the residual plaque area, even after angiographically successful PTCA, is about 60%. A significant reduction in this percentage may influence long-term outcome after PTCA. Luminal areas that are minimal after PTCA seem to indicate restenosis, while morphological appearance on its own seems to be less predictive. One answer to the shortcomings of standard PTCA are coronary artery stents. Intravascular monitoring of stent expansion led to the deployment of high-pressure stents with a significant increase in post-procedural luminal diameters, and finally the ability to withhold anticoagulation in patients with optimal stent deployment. Furthermore, integrated devices, such as balloons on IVUS catheters, steerable catheters, integrated flow measurements, pressure transducers, and, hopefully, tissue characterization, will further enhance the usefulness of IVUS.
Angioplasty, Balloon, Coronary↗
Cardiac involvement in seat belt-related and direct sternal trauma: a prospective study in management implications.
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Aortic Dissection↗
Identification of high-risk subgroups in infective endocarditis and the role of echocardiography.
The outcome of infective endocarditis remains poor. It has an overall mortality of around 30%, rising in high-risk subgroups to 50% and 100%. The prognosis can be improved by identification of high-risk patients and special management. Patients with infective endocarditis are found to be at high risk for death or serious complications when one or more of the following factors exist: old age (especially > 60 years old), delayed diagnosis, staphylococcal infection, aortic valve endocarditis, large valvular vegetation, congestive heart failure, embolization in the central nervous system or coronary artery, prosthetic valve infection, recurrent events, and failed antibiotic therapy. These factors often coexist and interrelate with one another. Early diagnosis and active treatment are critical for a better clinical outcome. However, infective endocarditis is difficult to diagnose because of the atypical clinical manifestations and frequent negative results from blood culture. Echocardiography plays an indispensable role in the diagnosis and management of suspected or known infective endocarditis. By detecting and monitoring certain pathological changes associated with the disease, e.g. vegetation, abscess formation, or valvular destruction, echocardiography helps to diagnose the disease early, to identify patients at high risk, to monitor the patients, and to optimize the timing and mode of surgical intervention. Serious complications can thus be avoided or cured at an early stage and the prognosis significantly improved.
Age Factors↗
Coronary interventions in Europe 1992.
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Angioplasty, Balloon, Coronary↗
Silent healing of spontaneous plaque disruption demonstrated by intracoronary ultrasound.
Intracoronary ultrasound was performed at diagnostic coronary angiography and 10 days later in a 45-year-old patient with a 3-day history of acute inferior myocardial infarction. Coronary angiography showed considerable stenosis (80%) in the distal right coronary artery (RCA) (pre the crux) and what appeared to be a dissection in the middle RCA. Intracoronary ultrasound identified this as plaque disruption. Coronary balloon angioplasty was then performed in the distal stenotic segment. Follow-up angiography 10 days after coronary intervention revealed that the flap in the lumen had disappeared. Intracoronary ultrasound imaging showed that the ruptured plaque had resealed and had the appearance of layering in the atheroma similar to thrombus formation. In summary, plaque disruption and subsequent thrombus formation can be demonstrated in vivo by intracoronary ultrasound. Monitoring this process may have important clinical significance in patient management and in assessing clinical prognosis.
Coronary Thrombosis↗
Novel techniques of coronary artery imaging.
Intravascular ultrasound imaging and intracoronary Doppler flow mapping are two new techniques used to diagnose coronary artery disease. One provides detailed information about coronary morphology; the other assesses coronary function. By combining these two techniques, mechanisms of coronary syndromes that were previously unclear can be elucidated. The preliminary use of electron beam computed tomography in scanning of the coronary arteries has demonstrated the potential to identify severe coronary artery disease noninvasively. Coronary arteries can be imaged by intravenous injection of contrast material. Magnetic resonance imaging and positron-emission tomography are also used for the noninvasive visualization coronary arteries. Both techniques have been tested after interventions, which offers the potential to study myocardial function and perfusion.
Contrast Media↗
Angiographically 'silent' plaque in the left main coronary artery detected by intravascular ultrasound.
BACKGROUND: Left main coronary artery (LMCA) atherosclerosis is a high-risk disease but its occurrence is often underestimated by coronary angiography. Intravascular ultrasound (IVUS) has been shown to be more accurate and sensitive than coronary angiography in identifying coronary atherosclerotic lesions. METHODS: Ninety-two patients (55 men and 37 women, aged 55.4 +/- 10.4 years) found to have angiographically normal coronary arteries or ambiguous lesions of the LMCA were examined by IVUS after diagnostic cardiac catheterization. The cross-sectional areas of the vessel, lumen, and atherosclerotic plaque (if any) of the LMCA were determined and the percentage area and diameter of stenosis were calculated. RESULTS: Atherosclerotic plaques in the LMCA were detected in 31 of the 92 patients (34%); 83% of the plaques were eccentric, and 17% contained calcium deposits. In patients with plaques detected by IVUS, the vessel area was 23.3 +/- 6.1 mm2. The plaque area was 6.3 +/- 3.3 mm2 (1.8-16.7 mm2). The area of stenosis was 31.6 +/- 12.1% (12-57.2%). The diameter of stenosis was 19.3 +/- 7.2% (8.7-34.6%). The area of stenosis was over 50% in four patients. The vessel area (23.3 +/- 6.1 mm2) in patients with plaques was larger than that in those without plaques (19.0 +/- 6.5 mm2, P < 0.01). CONCLUSION: Coronary angiography considerably underestimates the occurrence of atherosclerotic stenoses in the LMCA because of coronary remodelling and methodological limitations. The greater sensitivity and accuracy of IVUS in detecting LMCA lesions, at both early and advanced stages, is of great clinical importance in patient management.
Adult↗