173 research outputs found
Short and long-term results of transluminal coronary interventions: an angiographic perspective
Percutaneous Transluminal Coronary Angioplasty (PTCA) is the original term describing the technique
of alleviating coronary artery narrowings by inflating a short balloon (8 - 45 mm long) mounted on a long hollow
plastic catheter, which is introdllced to the coronary artery over a thin (0.010 - 0.018 inch diameter) Hoppy
tipped guidewire via a peripheral arterial puncture (the femoral artery in the groin being in modern times the
most popular, then the bmchial artery at the elbow and more recently, the radial artery at the wrist). Since its
introduction in 1977, this non-surgical alternative to coronary artery bypass graft operation (with its attendant
risks and uw,avoury patient appeal) has undergone a metamorphosis from experimental clinical application into
the medical specialty of "Jnterventional Cardiology". With its increasing clinical application, in addition to
broadening indications and therapeutic possibilities, however, its limitations in consistently producing successful
amI uncomplicated results, have been exposed. Accordingly, a medical device industry rapidly burgeoned, handin-
hand with the specialty of interventional cardiology itself, providing extensive refinements in guidewire and
halloon catheter manufacture and design. Despite such advances in haUoon technology and the increasing
experience of physicians engaged in daily practise, procedural failure, or abrupt closure of the coronary artery,
during or shortly after angioplasty, has remained an inherent complication in 5-10 % of cases attempted
Improved regional wall motion 6 months after direct myocardial revascularization (DMR) with the NOGA DMR system
A60-year-old man was referred to our intervention laboratory for direct myocardial revascularization (DMR). He had received maximal medical therapy and had undergone coronary bypass surgery 10 years earlier, and his peripheral coronary anatomy was now found to be unsuited for surgical revascularization
Prevention of restenosis after coronary balloon angioplasty: rationale and design of the Fluvavastatin Angioplasty Restenosis (FLARE) Trial
Prevention of restenosis after successful percutaneous transluminal coronary balloon angioplasty (PTCA) continues to present the greatest therapeutic challenge in interventional cardiology. Experimental and pathological studies describe restenosis as no more than the biologic healing response to arterial injury. Studies of serial quantitative coronary angiography have demonstrated that this biologic process may be measured as the loss in minimal luminal diameter (MLD) from post-PTCA to follow-up angiography and that it is essentially ubiquitous and normally distributed. Thus, quantitative coronary angiography has become the gold standard for evaluation of the angiographic outcome of clinical trials of new agents and devices aimed at prevention of restenosis. The 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors inhibit biosynthesis of mevalonate, a precursor of non-sterol compounds involved in cell proliferation, and thus may control the neointimal response, which forms the kernel of restenosis. Experimental evidence suggests that fluvastatin may exert a greater direct inhibitory effect on proliferating vascular myocytes than other HMG-CoA reductase inhibitors, independent of any lipid-lowering action. The Fluvastatin Angioplasty Restenosis (FLARE) Trial was conceived, in collaboration between the Thoraxcenter, Erasmus University, Rotterdam, The Netherlands, and Sandoz Pharma, to evaluate the ability of fluvastatin 40 mg twice daily to reduce restenosis after successful single-lesion PTCA. Treatment of suitable patients begins 2 weeks before PTCA and continues after successful PTCA (residual diameter stenosis < 50%, without major cardiac complications) to follow-up angiography at 26 +/- 2 weeks. Restenosis is measured by quantitative coronary angiography at a core laboratory as the loss in MLD from post-PTCA to follow-up angiography. It is calculated (90% power, alpha = 0.05) that 730 evaluable patients will be needed to tes
Immediate and late outcome of excimer laser and balloon coronary angioplasty: A quantitative angiographic comparison based on matched lesions
Objectives.This study sought to compare acute lumen changes and late lumen narrowing during and after excimer laser-assisted balloon angioplasty, measured by quantitative coronary angiography, with the immediate and long-term outcome of balloon angioplasty alone.Background.Although excimer laser coronary angioplasty is used as an adjunct or alternative to balloon angioplasty, limited comparative data exist regarding the immediate and long-term efficacy of excimer laser-assisted balloon angioplasty versus balloon angioplasty alone.Methods.A series of 53 lesions in 47 consecutive patients successfully treated with excimer laser-assisted balloon angioplasty were individually matched after completion of 6-month follow-up angiography with 53 successfully treated balloon angioplasty lesions according to vessel location, preprocedural minimal lumen diameter and reference diameter. Immediate and long-term angiographic results were assessed by an automated lumen contour detection algorithm.Results.Before intervention in the laser and balloon angioplasty groups, respectively, minimal lumen diameter (mean ± SD) was 0.73 ± 0.47 and 0.74 ± 0.46 mm, and reference diameter was 2.71 ± 0.42 and 2.72 ± 0.41 mm. Laser angioplasty was followed by adjunctive balloon dilation in 50 lesions. Mean balloon diameter at maximal inflation was similar in both treatment groups (2.61 ± 0.32 and 2.65 ± 0.38 mm, respectively), resulting in similar minimal lumen diameters after intervention of 1.77 ± 0.41 and 1.78 ± 0.34 mm, respectively. At follow-up angiography, minimal lumen diameter after excimer laser-assisted balloon angioplasty was 1.17 ± 0.63 mm, and that after balloon angioplasty alone was 1.46 ± 0.67 mm (p = 0.02). The angiographic restenosis rates at follow-up using the 50% diameter stenosis cutoff criterion were 57% and 34%, respectively (p = 0.02).Conclusions.Quantitative angiographic analysis of a matched group of 106 successfully treated coronary lesions showed a similar immediate outcome but reduced long-term efficacy of excimer laser-assisted balloon angioplasty compared with that after balloon angioplasty alone
Can the same edge-detection algorithm be applied to on-line and off-line analysis systems? Validation of a new cinefilm-based geometric coronary measurement software
In the Cardiovascular Measurement System (CMS) the edge-detection algorithm, which was primarily designed for the Philips digital cardiac imaging system (DCI), is applied to cinefilms. Comparative validation of CMS and DCI was performed in vitro and in vivo with intracoronary insertion of stenosis phantoms in anesthetized pigs. The "obstruction diameter" (OD) was measured at the artificial stenoses visualized by angiography with calibration at the isocenter (ISO) and catheter calibration (CATH) and compared with the true phantom diameters. A clinical comparison of OD, reference diameter (RD), and percentage diameter stenosis (DS) was performed on 70 corresponding images from post-PTCA angiograms. In vitro, OD (CMS) yielded an accuracy of 0.18 +/- 0.14 mm with 100% (correlation coefficient: r = 0.97, y = 0.06 + 0.75x, standard error of estimate [SEE] = 0.09) and 0.19 +/- 0.15 mm with 50% contrast (r = 0.94, y = 0.02 + 0.81 x). OD (DCI) yielded an accuracy of 0.11 +/- 0.06 mm with 100% (r = 0.99, y = -0.03 + 0.91 x, SEE = 0.05) and 0.24 +/- 0.13 mm with 50% contrast (r = 0.94, y = 0.29 + 6.69 x, SEE = 0.12). In vivo, OD (CMS) yielded an accuracy of 0.18 +/- 0.23 mm with ISO (r = 0.89, y = 0.02 + 0.83 x, SEE = 0.22) and 0.26 +/- 0.24 mm with CATH (r = 0.89, y = 0.06 + 0.72 x, SEE = 0.19). OD (DCI) yielded an accuracy of 0.08 +/- 0.15 mm with ISO (r = 0.96, y = 0.08 + 0.86 x, SEE = 0.14) and 0.18 +/- 0.21 mm with CATH (r = 0.92, y = 0.09 + 0.76 x, SEE = 0.17). The clinical comparison showed reasonable agreement for OD only (r = 0.81, y = 0.26 + 0.81 x, SEE = 0.29). Transformation of an edge-detection algorithm from a digital to a cinefilm-based system can lead to impairment of measurement reliability
Short- and long-term clinical and quantitative angiographic results with the new, less shortening wallstent for vessel reconstruction in chronic total occlusion: A quantitative angiographic study
Coronary arteriography for quantitative analysis: experimental and clinical comparison of cinefilm and video recordings.
Although use of videotape for the recording of coronary angiograms continues to grow, the validity of quantitative coronary angiographic analysis of video images remains unknown. To estimate the realibility of angiographic images recorded on videotapes, experimental and clinical angiograms were recorded simultaneously on both 35 mm cinefilm and super-VHS videotape with normal images and with spatial filtering of the images (edge enhancement) on a digital cardiac imaging system. The experimental angiographic studies were performed with plexi
Variations of remodeling in response to left main atherosclerosis assessed with intravascular ultrasound in vivo.
Histopathologic studies have demonstrated that vessels enlarge to compensate for an increase in plaque burden; this has been confirmed in vivo using intravascular ultrasound (IVUS). The initial studies suggested a biphasic course of lesion formation with (1) preservation of lumen dimensions up to a plaque burden of approximately 40%, and (2) luminal narrowing as plaque burden further increases. In this study, we used IVUS and angiography to assess the extent of left main (LM) atherosclerosis in 107 patients undergoing catheter-based procedures of the left anterior descending or left circumflex coronary arteries. Using IVUS, atherosclerotic plaques were found in all LM arteries, but only 26 (24%) had varying degrees of luminal narrowing on the angiogram. Nevertheless, there was an inverse relation (r = −0.62, p 40% (or >30%), but persisted at plaque burden values of 20% to 40%. In addition, LM arteries with a plaque burden <40% had a similar total vessel area as did LM arteries with a plaque burden ≥40% (22.9 ± 6.1 vs 21.8 ± 4.8 mm2, p = 0.30). These data suggest that lumen dimensions may not be preserved even if plaque occupies no more than 20% to 40% of the total vessel area. Thus, there is more variation in remodeling response during earlier stages of plaque accumulation within the LM artery than is commonly suggested
Low molecular weight heparin (reviparin) in percutaneous transluminal coronary angioplasty. Results of a randomized, double-blind, unfractionated heparin and placebo-controlled, multicenter trial (REDUCE trial)
Objectives. The specific objective of the REDUCE trial was to evaluate the effect of low molecular weight heparin on the incidence and occurrence of restenosis in patients undergoing percutaneous transluminal coronary angioplasty (PTCA). Background. Unfractionated heparin and its low molecular weight fragments possess antiproliferative effects and have been shown to reduce neointimal smooth muscle cell migration and proliferation in response to vascular injury in experimental studies. Methods. The REDUCE trial is an international prospective, randomized, double-blind, multicenter study. Twenty-six centers in Europe and Canada enrolled 625 patients with single-lesion coronary artery obstructions suitable for PTCA. Three hundred six patients received reviparin as a 7,000-U bolus before PTCA, followed by 10,500 U as an infusion over 24 h and then twice-daily 3,500-U subcutaneous application for 28 days. The 306 patients in the control group received a bolus of 10,000 U o
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