[Transmyocardial laser revascularization--a treatment option for coronary heart disease?]. / Transmyokardiale Laserrevaskularisation--Behandlungsoption der koronaren Herzerkrankung?

Transmyocardial laser revascularization (TMR) is a new therapeutic principle for patients with coronary artery disease and no possibility of conventional revascularization with CABG or PTCA. The clinical value of the method is not known. Therefore we investigated all 46 patients treated with sole TMR in our center using clinical investigation, LV and coronary angiography, right heart catheterization, MIBI perfusion imaging and myocardial FDG-PET pre- and 6 months post TMR. 117 patients judged not suitable for conventional revascularization procedures were submitted for TMR. The indication for the procedure was reevaluated in every case. 52 patients (mean EF 41 +/- 16%) could be further treated by intensified anti-anginal medication, seven patients received bypass grafts, four patients had PTCA, three patients were listed for heart transplantation, and five patients had a combined CABG plus TMR. Only 46 (38% of the submitted patients, mean EF 55 +/- 15%) were accepted for sole TMR. CCS class of these patients was 3.3 +/- 0.4, mean age was 63.6 +/- 7.3 years, 70% were males. The postoperative mortality within 30 days was 5/46 (10.8%); 9/46 patients (19.5%) suffered from perioperative myocardial infarction. Other complications were ventricular fibrillation in two cases on the second postoperative day and a rupture of the spleen on the 14th postoperative day. 8/46 patients (17%) had wound infections. Survivors showed an improvement in their CCS class (1.9, 2.1, 1.9 after 3, 6 and 12 months, respectively, mean observation time 0.61 +/- 0.4 years). These patients were able to perform bicycle stress tests significantly longer (98 s +/- 9 pre versus 120 +/- 13 s post TMR, p = 0.01). Angiographic EF fell from 57.8% +/- 15% to 52.6% +/- 19% (p = 0.02) and the number of hypokinetic chords rose from 23.6 +/- 20.9% to 30.6 +/- 24.1% per patient (p = 0.008), predominantly in the inferior wall. Nuclear studies showed reduced myocardial perfusion and vitality after TMR. Four patients in the TMR group had reintervention (PTCA) because of progression of coronary sclerosis of native vessels. One patient had mitral valve replacement due to severe regurgitation. Kaplan-Meier analysis showed no significant difference in survival between the TMR and the medical group when stratified according to initial ejection fraction. Sudden death and congestive heart failure are the most important causes of mortality. Our data show that TMR improves symptoms and exercise performance of otherwise not treatable patients with diffuse coronary artery disease. Due to a lack of an improvement of cardiac perfusion, function or prognosis TMR should be used only in highly selected cases when conventional methods fail to improve patients symptoms.

[Visual assessment or quantitative measurement of coronary stenoses: significance for "prima vista"-PTCA]. / Visuelle Einschätzung oder quantitative Vermessung von Koronarstenosen: Bedeutung für die "prima vista"-PTCA.

In 300 patients with 339 coronary lesions the percent diameter stenosis (%-DS) was assessed both by visual estimation and by digital quantitative coronary angiography (DQCA) by use of an on-line computer work-station. The decision for coronary angioplasty in the same setting ("prima vista"-PTCA) was based on history, evidence of ischemia and visual estimation of %-DS. DQCA measurements of the 339 stenoses revealed a normal distribution of lesion severity with a mean of 58.4 +/- 11.3%. In contrast to DQCA visual estimation led to a bimodal distribution with a nadir at approximately 55% between two peaks at approximately 45% and approximately 75% and a mean of 70.5 +/- 19.6%. Visual estimation underestimated lesions in the range of 30-55% and overestimated the %-DS between 55-99%. Visual estimation revealed a %-DS > or = 60% in 251 stenoses (74.0%) of the 339 lesions, an estimate that led to subsequent "prima vista"-PTCA. Conversely, DQCA revealed only 184 stenoses (54.3%) with a %-DS > or = 60%; thus, 86 stenoses (25.3%) did not meet the morphologic indication criteria for PTCA. The bimodal distribution of stenosis severity according to visual analysis with an overestimation of borderline stenosis severity reflects at tendency for "self-referral" of patients for PTCA. DQCA serves as an objective tool in the decision-making process for PTCA and may reduce "cosmetic" interventions or justify to defer PTCA. Especially in the selection process for "prima vista"-PTCA DQCA-quantification of stenosis severity is recommended.

Comparative in-vitro validation of eight first- and second-generation quantitative coronary angiography systems.

BACKGROUND: It is known that first-generation quantitative coronary angiography (QCA) systems overestimate small vessel sizes owing to the point-spread function of the respective X-ray imaging chain. With second-generation systems new algorithms were introduced to correct for this source of error. OBJECTIVE: To evaluate the efficiency of the modified contour detection algorithms. METHODS: Six second-generation QCA systems (CMS, QANSAD, AWOS, CAAS II, Cardio 500, and Angioimage) were validated and compared with first-generation systems (CAAS and ARTREK). By using an arterial phantom consisting of stenotic and nonstenotic glass tubes (of diameters 0.5-5.0 mm) the accuracy and precision of each analysis system, as well as their additional accuracy and precision values for phantom diameters < or = 1.0 mm were determined. RESULTS: All systems had high accuracy and precision values, but first-generation systems overestimated small vessel diameters. With second-generation systems a significantly improved accuracy in the submillimeter range (an accuracy within +/-0.028 mm) was obtained. This improvement was accompanied by a moderate reduction in precision in the submillimeter range. CONCLUSION: The new algorithms of the second-generation QCA systems allow accurate and reliable measurements of small coronary dimensions and, therefore, precise analysis of coronary stenoses of moderate-to-high grade seems feasible with the improved accuracy of the new systems.

The concept of archiving unedited and edited digital coronary angiograms.

Digital image data acquired during cardiac catheterization will soon be archived on standardized digital storage media. However, with the enormous amount of generated data, considerable time will be wasted at later reviewing or at conferences, or when performing additional quantitative studies. As a result major advantages of a digital acquisition and archiving technique will be lost. The concept of two way archiving includes an unedited (primary) digital archive as well as a (secondary) archive edited by operator guided "intelligent" data reduction (IDR). IDR is based upon the elimination of useless and redundant frame sequences (FS), documentation of coronary interventions on one representative single frame (F) and on the reduction of relevant FS and physiological data to and ECG-controlled representative cardiac cycle (CC). With a heart rate of 72/min and an acquisition rate of 12.5 F/s a documentation of each FS may be obtained with only 10 F. A redundancy-free set of 130 F of a diagnostic study as well as only 41-85 F of an interventional study will be archived on an individual 3.5" MOD or on a CD-R. Two cardiologists and two cardiosurgeons studied independently 24 IDR-edited and the corresponding unedited digital angiograms and found no significant differences in the diagnostically relevant coronary morphology and left ventricular function. IDR provides an edited digital coronary angiogram, e.g. a set of images free of redundance and without loss of relevant information. Uneditable FS can be archived in their unedited (primary) form. IDR is managed on-line by an operator interacting with the angiographer.

On-site digital quantitative coronary angiography: comparison with visual readings in interventional procedures. Implications for decision and quality control.

In order to review the morphological criterion for an interventional procedure, diameter stenosis (%DS) of 226 coronary lesions in 200 patients undergoing elective coronary angiography with an option for 'prima vista' angioplasty (pPTCA), was assessed on-site by both visual 'eye balling' (EB) and independent digital quantitative coronary angiography (DQCA) by means of an angiographic workstation. Compared to DQCA, EB overestimated the %DS between 50 and 80% and accounted for the majority of discrepancies with overestimation up to 45%. Concordant estimates of %DS by both methods were observed in only 10 of the total of 226 stenotic segments; in 20 of 226 cases, EB underestimated %DS up to 20%. EB revealed a %DS > or = 60% in 166 stenoses (73.4%), an estimate that led to subsequent pPTCA. However, only 119 (52.6%) of these lesions had a %DS > or = 60% as assessed objectively by DQCA. With regard to the criterion for PTCA 47 of 166 performed pPTCA (28.3%) would not meet the indication criteria based on objective DQCA information. EB and DQCA (+/-5%DS) had concordant results and criteria for pPTCA only in 103 of 166 coronary lesions (62.1%). These results lead to the conclusion that, on-site and on-line DQCA by an independent cardiologist eliminates both under- and overestimation of stenoses as seen with EB. DQCA supports immediate decision-making and appears necessary for reliable evaluation of coronary morphology in an interventional catheterization laboratory setting and may eventually ensure intraprocedural quality control.

[Individual archiving of digital angiocardiograms]. / Individuelles Archivieren von digitalen Angiokardiogrammen.

CD-R will be introduced internationally as a standardized individual archive and exchange medium allowing individual solutions for long-term archiving in a catheterization laboratory. The concept of digital archiving on two CD-R includes a long-term primary basic archive and a secondary one edited by intelligent (medical) data reduction (IDR). The basic archive is automatically composed by a background process consisting of unprocessed images or image series and is fundamental for further transfers, storage, presentations and additional studies. The digital working archive comprises a set of images and image series edited by IDR, as well as the results of morphometric studies as well as identification and documentation data. IDR is based upon the elimination of useless and redundant images series, documentation of coronary interventions on one single representative image and on the reduction of relevant images series and physiological data into an ECG-controlled representative cardiac cycle. IDR edits a redundancy-free set of 130 images (diagnostic study) or only 85 images of an interventional study. Two cardiologists and two cardiosurgeons independently studied 24 IDR-edited angiograms and the corresponding unedited digital angiograms and found no significant differences in the diagnostically relevant coronary morphology and left ventricular function. This study shows that an edited angiogram may not only serve for digital archiving but also form the basis for further evaluation or copies.

Differences in lipoprotein (a) and apolipoprotein (a) levels in men and women with advanced coronary atherosclerosis.

BACKGROUND: This study was designed to evaluate whether differences between sexes exist in serum-lipoprotein (a) [Lp(a)] and arterial-wall-apolipoprotein (a) [Apo(a)] levels in patients with advanced coronary artery disease. METHODS: The concentrations of Lp(a) in serum and Apo(a) in aortic biopsies were studied in 76 men and 20 women undergoing coronary artery bypass graft surgery. The severity of coronary artery disease was determined by a coronary atherosclerosis score that used quantitative coronary angiography. RESULTS: Serum-Lp(a) and tissue-Apo(a) do not correlate with the severity of coronary artery disease as expressed by the coronary atherosclerosis score (r = 0.09 and r = 0.14, respectively). Women were older (65 +/- 8 versus 57 +/- 8 years, P < 0.001) and had higher mean Lp(a) and higher mean Apo(a) levels (47 +/- 41 versus 32 +/- 40 mg/dl and 33 +/- 34 versus 19 +/- 24 micrograms/g wet weight, P < 0.05) than men with identical coronary atherosclerosis score (35 +/- 8 versus 33 +/- 8, P > 0.05). The serum levels of cholesterol, triglycerides, and high-density lipoprotein were similar in both groups. CONCLUSIONS: Men and women undergoing coronary artery bypass graft surgery had very similar severity of coronary artery disease as expressed by the coronary atherosclerosis score. Women were 8 years older and had 1.5 times higher mean serum-Lp(a) levels and 1.75 times higher mean tissue Apo(a) levels higher than the men. Sixty per cent of the women but only 39% of the men had serum Lp(a) levels higher than 25 mg/dl. Lp(a) level seems to be an additional risk factor for coronary artery disease confined to postmenopausal women.

[Association of lipoprotein (a) with the extent of coronary atherosclerosis in surgically revascularized men and women]. / Assoziation von Lipoprotein (a) mit dem Ausmass der koronaren Atherosklerose bei chirurgisch revaskularisierten Männern und Frauen.

Lipoprotein (a) (Lp(a)) levels are genetically determined and levels higher than 25 mg/dl are associated with increased prevalence of coronary artery disease (CAD). We studied gender differences in 76 men and 20 women undergoing coronary artery bypass graft surgery (CABG) for a potential association between Lp(a) levels both in serum and the aortic wall (Apo(a)) and the severity of CAD determined by an atherosclerosis score (CS) using quantitative coronary angiography (QCA). Serum Lp(a) and tissue Apo(a) do not correlate with the severity of CAD as assessed from QCA (r = 0.09 and r = 0.14, resp.). 60% of women but only 39% of men had serum Lp(a) levels higher than 25 mg/dl. Women were 8 years older (65 +/- 8 vs. 57 +/- 8 years, p < 0.001) and had 1.5 times higher mean serum Lp(a) and 1.75 times higher mean tissue Apo(a) levels (47 +/- 41 vs. 32 +/- 40 mg/dl and 33 +/- 34 vs. 19 +/- 24 micrograms/g WW, p < 0.05) than men with identical CS (35 +/- 8 vs. 33 +/- 8, p = NS). The serum levels of cholesterol, triglycerides, and high-density lipoprotein were similar in the two groups. There is no association between Lp(a) and Apo(a) and the severity of coronary atherosclerosis in men and women undergoing coronary artery bypass surgery.

[The value of spiral computed tomography in the imaging of aortocoronary bypass vessels]. / Validität der Spiral-Computertomographie bei der Darstellung aortokoronarer Bypass-Gefässe.

Spiral computer tomography (Sp-CT) was performed on 25 patients with 81 aorto-coronary bypasses, with persistent symptoms, following selective coronary angiography. The purpose was to determine to what extent Sp-CT is able to demonstrate patency or occlusion of individual bypasses. From the raw data, transverse sections and standardised 3D reconstructions were obtained. Statistical evaluation showed a sensitivity of 93% and a specificity of 100% with regard to patency. Sp-CT provides optimal contrast and complete demonstration of the bypass without movement artifacts from respiration. 3D reconstructions aid in the evaluation of complex anatomical situations but occasionally lead to incorrect diagnosis of stenoses or occlusions. Compared with other non-invasive procedures (conventional CT and NMR) Sp-CT has proved significantly better for the evaluation of bypass occlusions. Sp-CT cannot completely replace angiography but in some cases may be an acceptable alternative.

[Synchronized coronary vein retroperfusion for identification of myocardium with chronic ischemic disorders of wall movement ("hibernating myocardium")]. / Synchronisierte koronarvenöse Retroperfusion zur Identifizierung von Myokard mit chronisch-ischämischer Wandbewegungsstörung ("hibernating myocardium").

UNLABELLED: ECG-synchronized retroperfusion (SRP) via the coronary sinus has been recently demonstrated to efficiently deliver arterial blood to ischemic myocardium in an experimental setting and during PTCA. To assess the potential of SRP for identifying hibernating myocardium by improved contractile function resulting from retrograde delivery of oxygen, 10 patients (M/F = 9/1; age 56 +/- 9 years) with ischemic wall motion abnormalities, but, according to ECG-criteria, no transmural infarction in the territory of a totally occluded LAD, underwent 30 min of SRP at a flow rate of 145-250 ml/min prior to mechanical recanalization. Serial digital ventriculograms were obtained before, after 30 min of SRP and, finally, after successful PTCA at follow-up of 28 +/- 4 days. RESULTS: Wall motion analysis revealed improved global and regional contractile function in seven of 10 patients, which was maintained after successful PTCA. Continuous SRP over 30 min resulted in an improvement of global and segmental systolic function. Left ventricular ejection fraction (LVEF) increased from 53 +/- 8% to 58 +/- 5% with 30 min of SRP (p < 0.03) and significant improvement in regional function was detected in the anterobasal, apical and inferior segment of the left ventricular circumference (p < 0.05). CONCLUSION: An improved contractile response to retrograde delivery of oxygen by SRP appears to document the reversibility of myocardial hibernation. Thus, ECG-synchronized SRP via the coronary sinus has the potential to unmask viable myocardium likely to completely recover from contractile dysfunction after successful antegrade recanalization. Moreover, continuous SRP procedure over 30 min was safe and had no hazardous side-effects.

Digital flashing tomosynthesis: a promising technique for angiocardiographic screening.

A system for digital flashing tomosynthesis (DFTS) consists of four ECG-gated simultaneously flashed X-ray tubes, a 14-in image intensifier, a unit for digital subtraction angiography (DSA), a PC-hosted transputer network for three-dimensional (3-D) reconstruction as well as for quantitative coronary angiography and ventriculography, a display unit, and an individual digital archive. A presentation of DFTS tomoangiograms as a single slice or multiple slices of arbitrary thickness is available. DFTS also offers rotating and stereographic presentation of 3-D images. DFTS represents a system for standardized digital angiocardiography with digital archiving, and assures optimal reproducibility and safety. This system is feasible for both an ambulatory basis to allow high-volume cardiovascular angiographic screening by only one X-ray snapshot, and for quantification of natural progression or potential regression of coronary artery disease resulting from interventional or pharmacological therapy.

[Peripheral embolism of hemostasis collagen (VasoSeal)]. / Periphere Embolie von Hämostasekollagen (VasoSeal).

VasoSeal is a purified bovine, absorbable collagen plug currently successfully used to close the femoral arterial puncture site after cardiac catheterization under full anticoagulation. Up to now there has been no experience with potential complications. We observed acute ischemia in the right lower leg of 2/100 patients 36 resp. 24 h after successful closure of the puncture site with VasoSeal. Angiography confirmed acute occlusion of the distal A. poplitea dextra. A 25-mm resp. 50-mm long cylindrical foreign body embolus was removed with a Fogarty-catheter by retrograde indirect embolectomy. Histopathology confirmed a fresh collagen clot with appositional thrombosis.

Potential of digital flashing tomosynthesis for angiocardiographic evaluation.

A system for digital flashing tomosynthesis (DFTS) consists of four electrocardiogram-gated and simultaneously flashed x-ray tubes, a 14" image intensifier, a unit for digital subtraction angiography (DSA), a personal computer-hosted transputer network for three-dimensional (3D) reconstruction as well as for quantitative coronary angiography and ventriculography, a display unit and an individual digital archive. DFTS-tomoangiograms may be presented in single slice mode or as multiple slices of arbitrary thickness, using rotating and stereographic presentation of 3D images. DFTS represents a configuration for standardized digital angiocardiography with digital archiving and assures optimal reproducibility and safety. This angiographic configuration is feasible for both ambulatory angiography to allow high volume cardiovascular angiographic screening and for the quantitative assessment of natural progression or potential regression of coronary artery disease resulting from interventional or pharmacological therapy.

[Detection of dissection of the thoracic aorta: improved specificity by magnetic resonance tomography in comparison with echocardiography techniques]. / Nachweis der thorakalen Aortendissektion: Verbesserte Spezifität durch Magnetresonanztomographie gegenüber echokardiographischen Techniken.

The purpose of this study was to assess the reliability of conventional transthoracic and transoesophageal two-dimensional echocardiography combined with color-coded Doppler flow imaging (TEE) and ECG-triggered magnetic resonance imaging (MRI) for the diagnosis of thoracic aortic dissection and associated epiphenomena. A total of 53 patients with clinically suspected aortic dissection were subjected to a transthoracic and transoesophageal ultrasound examination and magnetic resonance imaging; the results of each imaging modality were compared and validated against the morphological standards of contrast angiography (n = 53) and/or intraoperative findings (n = 27) or autopsy (n = 7). In this series no deleterious events were encountered with either non-invasive imaging method. In contrast to conventional echocardiography the sensitivities of both MRI and TEE were 100% for detecting a dissection of the thoracic aorta, irrespective of its location. However, the specificity of TEE was lower than the specificity of MRI for a dissection (TEE 68.2% versus MRI 100%; p less than 0.005), which resulted from false positive TEE findings mainly confined to the ascending segment of the aorta (specificity of TEE 78.8% versus 100% by MRI; p less than 0.01). In addition, MRI proved to be more sensitive than TEE in detecting the formation of thrombus in the false lumen of both the aortic arch (p less than 0.01) and the descending segment of the aorta (p less than 0.05). There were no discrepancies between the two imaging techniques in detecting the site of entry to a dissection, aortic regurgitation or pericardial effusion. Both MRI and TEE are atraumatic, safe, and highly sensitive methods to identify and classify acute and subacute dissections of the entire thoracic aorta. However, TEE is associated with lower specificity for lesions in the ascending aorta. These results may still favor TEE after a precursory screening transthoracic echogram in suspected aortic dissection, but will establish MRI as an excellent method to avoid false positive findings. Anatomical mapping by MRI may emerge as a promising comprehensive approach and, eventually, as a morphological standard to guide surgical interventions.

Impact of compensatory enlargement of atherosclerotic coronary arteries on angiographic assessment of coronary artery disease.

To determine whether compensatory enlargement of atherosclerotic coronary arteries occurs and to what degree it affects the angiographic assessment of coronary artery disease, we performed postmortem coronary angiography of 30 human hearts with suspected coronary artery disease and studied 70 histologic cross sections of the proximal left anterior descending artery and proximal right coronary artery. Angiographic and morphometric analyses of 50 stenoses in proximal and middle sections of the left anterior descending artery, right coronary artery, and left circumflex artery were performed. The control group of 10 human hearts without suspected coronary artery disease was evaluated in the same way. For this purpose, coronary arteries were filled with a methylmethacrylic radiopaque resin at a pressure of 100 mm Hg and closely embedded in a methylmethacrylic resin by use of which shrinkage and mechanical artifacts could be avoided. The area circumscribed by the internal elastic lamina was taken as a measure of the area of the arterial lumen if no plaque had been present. The angiographic and corresponding morphometric degree of stenosis was assessed. A significant correlation (r = 0.85, p less than or equal to 0.0001) was found between the internal elastic lamina area and the area of the plaque (lesion area), suggesting that coronary arteries may enlarge as lesion area increases. With the morphometric degree of stenosis, the expected anatomic diminution of the coronary artery was abolished (r = 0.79, p less than or equal to 0.0001), indicating compensatory enlargement in atherosclerotic segments. Accordingly, the degree of stenosis assessed from in vitro angiograms was underestimated. Compensatory coronary enlargement of the stenotic segment was the main reason for angiographic underestimation. The underestimation factor of up to 3.50 for very mild stenoses decreased to 1.37 at an angiographic degree of 50% area stenosis and 30% diameter stenosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Digital flashing tomosynthesis (DFTS)--a technique for three-dimensional coronary angiography.

Digital Flashing Tomosynthesis (DFTS) represents a technique for three-dimensional (3D) coronary angiography. Four ECG-gated simultaneously flashed X-ray tubes generate a multiperspective digital substraction image as DFTS multiangiogram for 3D reconstruction and visualization. Computerized morphologic and morphometric quantitative analysis can be performed including videodensitometry. Postmortem coronary angiography of 30 human hearts with suspected coronary artery disease was performed by 35-mm cine technique and by DFTS. The results of angiographic measurements in 50 stenotic arterial segments were compared with the histologic reference and show excellent regression results with correlation coefficients of more than 0.95 (p less than or equal to 0.0001). No significant differences in standard errors of estimates between the techniques were found. DFTS yields an accuracy in depiction of the coronary arteries and angiographic estimation of arterial lumen equivalent to 35-mm cineangiography. DFTS images can be directly used for visual interpretation and for computerized morphologic and morphometric quantitative analysis. DFTS technology reduces the amount of radiation exposure, the amount of contrast medium, and the time of the procedure. DFTS offers the possibility to obtain 3D images of the coronary artery tree.