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Background— Both whole-heart magnetic resonance coronary angiography (WH-MRCA) and multidetector computed tomography (MDCT) have been proposed for the noninvasive identification of the coronary stenosis. The authors sought to directly compare the diagnostic accuracy of these noninvasive imaging techniques using the invasive quantitative coronary angiography as a reference standard. Methods and Results— Seventy-seven consecutive patients (56 men, 61�14 years) prospectively underwent WH-MRCA and 40- or 64-slice MDCT before the quantitative coronary angiography. Diagnostic accuracy of WH-MRCA and MDCT for the visual identification of >50% diameter stenosis in segments of >1.5 mm size was compared using the quantitative coronary angiography as a reference. According to the quantitative coronary angiography, 49 of 992 coronary segments >1.5 mm diameter had >50% diameter stenosis. MDCT had a higher success rate (100% versus 88%, P P P =0.9) but significantly lower specificity (644/943 or 68% versus 863/943 or 92%, P P 50% diameter stenosis than did MDCT. On a per-patient basis, the sensitivity was similar (17/17 or 100% versus 16/17 or 94%, P =0.9), but specificity (43/60 or 72% versus 53/60 or 88%, P =0.024) and diagnostic accuracy (60/77 or 78%, versus 69/77 or 90%, P =0.044) of WH-MRCA for the detection of >50% diameter stenosis were significantly lower than of MDCT. Conclusions— Because of the higher success rate and higher number of interpretable segments, 40- or 64-slice MDCT performs better than WH-MRCA.

Eighty patients with ischemic heart disease and 17 normal subjects were evaluated for left ventricular regional wall motion by means of a new method. The wall motion analysis is based on video intensity. This technique uses a temporally sliding analysis to evaluate the cardiac cycle in 100 msec intervals. Presence of coronary artery disease was defined as more than 50% measured diameter stenosis. Wall motion abnormalities in regions perfused by stenotic vessels were most common in early diastole (76%). Sensitivity of this method at rest in patients with coronary artery disease was 79.7% (p less than 0.0001) and overall accuracy was 84.2% (p less than 0.0001). Abnormalities in both systole and diastole were more common in regions perfused by severe lesions (greater than 75%) than in those perfused by moderately stenotic (less than 75%) vessels (p less than 0.05). A comparison of the new method with phase and amplitude analysis was performed in 15 patients and with two-frame analysis in 40 patients. This new method yielded a higher sensitivity than either of the other two methods.

To determine the ability of thallium-201 single-photon emission computed tomography (SPECT) after dipyridamole infusion (0.71 mg/kg body weight) to detect coronary disease and predict individual coronary stenoses, 76 patients unable to exercise adequately underwent thallium-201 SPECT and quantitative analysis with bull's eye polar maps immediately after dipyridamole infusion and again 4 hours later. Bull's eye maps were compared with files compiled from gender-matched normal patients who had less than 5% probability of coronary artery disease while undergoing exercise thallium-201 SPECT. All patients underwent coronary arteriography. Test sensitivity in detecting coronary disease (> 50% diameter stenosis of any vessel) was 89%, with sensitivities of 73% to 82% in detecting stenoses of individual vessels. Specificity for coronary artery disease was 47% (83% to 88% for individual vessels). However, 5 of the 8 patients with false-positive thallium-201 SPECT had 30% to 40% stenoses. The results, from a comparison of patients who underwent dipyridamole infusion with patients who exercised, indicate that dipyridamole infusion is a satisfactory alternative to exercise for thallium-201 SPECT. Coronary stenosis of less than 50% is a frequent cause of scan abnormalities

This study evaluated the association between progressively higher levels of fasting glycemia (G) and insulin resistance parameters with coronary artery disease (CAD) in patients referred for coronary angiography. All 145 patients (age 58.4+/-0.9 years, 51.7% men) underwent clinical and laboratory evaluation before coronary angiography and subjects were divided into four groups: normal (N,88 mg/dl), high-normal (H-N, 89-99 mg/dl), impaired fasting glucose (IFG, 100-125 mg/dl) and diabetes (DM,126 mg/dl or known diabetics). Arteriographic evidence of CAD was determined by two criteria: (1) a 30% or greater diameter stenosis in at least one major coronary artery; (2) a 70% or greater diameter stenosis in at least one major coronary artery. HOMA-IR increased progressively according to each group: N=1.74+/-0.2, H-N=3.14+/-0.3, IFG=4.67+/-0.6 and DM=8.00+/-2.9; p=0.001. The proportion of patients with CAD according to both criteria increased with each G level: CAD criteria 1: N=39.4%, H-N=50%, IFG=60% and DM=69.6%, p=0.006; CAD criteria 2: N=27.3%, H-N=30%, IFG=36% and DM=50%, p=0.03. We demonstrated a significant association between subtle disturbances of the glucose metabolism, assessed by subnormal levels of fasting glucose and insulin resistance parameters, and angiographically documented coronary artery disease.

We report our initial experience of carotid and vertebral stenting. Three haemodynamically significant extra-cranial lesions (% diameter stenosis >70) in 3 clinically symptomatic patients were treated by stenting between March 1996 and September 1996. Two lesions of the internal carotid arteries were ostial and in one case a subtotal stenosis and ostial lesion of the vertebral artery were observed. All lesions looked more widely and smoothly dilated by stenting than by ordinary standard balloon angioplasty.

Primary intracoronary stent placement after successfully crossing chronic total coronary occlusions may decrease the high restenosis rate at long-term follow-up compared with conventional balloon angioplasty.In a prospective, randomized trial, balloon angioplasty was compared with stent implantation for the treatment of chronic total occlusions. Patients were followed for 12 months with angiographic follow-up at 6 months. Quantitative coronary analysis was performed by an independent core lab.A total of 200 patients were enrolled. Baseline characteristics were evenly distributed. After the procedure the mean minimal luminal diameter in the conventional group was 2.34 +/- 0.46 mm versus 2.90 +/- 0.41 mm in the stented group (P.0001). The 6-month angiographic follow-up showed a mean minimal luminal diameter of 1.57 +/- 0.74 mm in the conventional group versus 1.93 +/- 0.85 mm in the stented group (P =.009) and a mean diameter stenosis of 44.7% +/- 25.0% versus 35.5% +/- 26.5% (P =.036). Binary angiographic restenosis (50% diameter stenosis) was seen in 33% in the conventional group versus 22% in the stented group (P =.137). The reocclusion rates were 7.3% and 8.2%, respectively (P = 1.00). At 12 month follow-up, the rate of target lesion revascularization was significantly higher in the conventional group (29% versus 13%, P.0001).These data demonstrate that stenting of chronic total occlusions is superior to balloon angioplasty alone with a statistically significant reduction in the need for target lesion revascularization and a lower, but not significant, restenosis rate.

To assess the validity of locally performed off-line quantitative coronary angiography (QCA) measurement in clinical trials, we carried out a comparative study between on-site QCA analysis and analysis performed at an independent external core laboratory. One local operator analyzed the pre, post and follow-up angiograms of 116 patients participating in the Stenting in Small Coronary Arteries Study (SISCA) prior to final QCA analysis in the core laboratory. The mean values of the reference diameter (RD), minimal lumen diameter (MLD) and diameter stenosis (DS) showed acceptable agreement between study site and core laboratory. However, on the level of individuals the interobserver differences were large, affecting the outcome of restenosis rate significantly, and in a such way that the conclusions in the SISCA trial might have come out differently if a core laboratory had not been used. This emphasizes the importance of using independent core laboratories in coronary interventional trials.

Magnetic resonance imaging and computed tomography (CT) have recently emerged as two techniques that can noninvasively visualize the coronary arteries. The latest generation 16-row detector multislice CT scanner is now considered the most reliable technique to visualize the coronaries. The sensitivity and specificity to detect a significant (>50% diameter stenosis) coronary stenosis is +/-94% and +/-90%, respectively. Further technical improvements are necessary to make CT a clinically reliable diagnostic tool.

Background: Visual assessment (VA) of postprocedural % diameter stenosis (DS) is used routinely in clinical practice to determine the adequacy of coronary intervention. Although VA has been shown to underestimate final %DS after balloon angioplasty compared to quantitative coronary angiography (QCA), the impact of this effect on clinical outcomes following treatment with intracoronary radiation therapy (IRT) with Sr-90 for instent restenosis (ISR) is unknown. Methods: To determine the effect of VA on the rate of major adverse cardiac events (MACEs) after IRT for ISR, we compared the clinical outcomes of 102 consecutive patients based on postprocedural %DS by QCA vs. %DS by VA. MACE was defined as death, MI or need for target vessel revascularization (TVR). Results: MACE rates for the 102 consecutive patients grouped according to postprocedural %DS by QCA and VA were compared. The mean %DS by QCA was 30.7%, while the mean %DS by VA was 12.5%. The mean %DS by VA across the QCA subgroups were 13.67%, 10.71% and 13.37%, respectively (P=.244). Fifty-two patients (51.0%) had %DS ≥30% by QCA with the highest MACE percentage occurring in this subgroup. Conclusion: VA underestimated the %DS compared to QCA, and it was associated with worse MACE following treatment with Sr-90 for ISR.

The authors sought to determine the incidence and causes of geographical miss (GM) and evaluate its impact on edge restenosis after 'primary', centered, intracoronary beta-radiation therapy.Edge restenosis is a limitation of intracoronary beta-radiation therapy. GM occurs when the radiation source does not fully cover the injured segment and may account for this phenomenon.One hundred and eighty-one patients enrolled in the Dose-Finding study were retrospectively analyzed. The patients were randomized to receive 9, 12, 15 or 18 Gy at 1 mm tissue depth. Using quantitative coronary angiography the effective irradiated segment (EIRS) and both edges were studied prior to and after intervention, and at six-month follow-up. GM was defined as a situation where the effective radiation source length (24 mm) did not fully cover the injured segment. The edges of the EIRS that were injured during the procedure constituted the GM edges. A greater than 50% diameter stenosis at follow-up was considered significant. GM was determined by the simultaneous, electrocardiographically matched, side-by-side projection of the source and balloons in place, in identical projections surrounded by contrast.In 16% of patients GM was noninterpretable owing to inadequate filming. GM constituted 21.1% of the interpretable edges and 40.1% of the interpretable vessels analyzed. The occurrence of restenosis in the EIRS and the analyzed vessel segment (VS) was similar between procedures with and without GM. In vessels with GM, restenosis was significantly increased from the EIRS to the VS (from 8.77% to 21%, p = 0.05) as opposed to non-GM vessels (from 11.9% to 19%, p = 0.6). GM tended to be associated with a greater incidence of significant stenosis at the edges of the EIRS (8.3% versus 4.0%, p = 0.15) compared with individuals with50 % stenosis but no GM. This effect was more prominent at the distal edge. The relation of GM and edge restenosis was independent of dosage.Since GM does not affect the incidence of restenosis in the EIRS, restenosis in this segment should be considered a treatment failure, probably due to inadequate dosage. GM is related to significant increase in restenosis from the EIRS to the VS. GM tends to be associated with restenosis at the edges of the EIRS. This is a local phenomenon, which is independent of dosage and which has a specific pathophysiology (combination of injury and low-dose radiation). If GM can be eliminated, the results of vascular brachytherapy will be improved.

In-stent restenosis (ISR) after carotid artery stenting (CAS) is a rare event. Endovascular treatment is considered for significant ISR (>80% diameter stenosis by Doppler US). Despite favorable acute results, recurrent ISR ranges between 0 and 50%. Evidence of DEB effectiveness for coronary and

The diameter stenosis (%DS) in 226 coronary lesions of 200 patients undergoing primary (p) PTCA was assessed on-site by both visual "eye balling" (EB) and independent digital quantitative coronary angiography (DQCA). EB overestimated the %DS up to 49% and had a bimodal distribution with a nadir at 55%DS between the two peaks at /spl sim/50% and /spl sim/75%DS and a mean of 69.8/spl plusmn/19.9% whereas DQCA of the identical lesions revealed a near gaussian distribution with a mean of 58.5/spl plusmn/11.3%. EB revealed a %DS/spl ges/60% in 166 stenoses (73.4%), an estimate that led to pPTCA. However, only 119 (52.6%) of these lesions had objectively a %DS/spl ges/60% by DQCA. With regard to the indication for PTCA 47 of 166 performed pPTCA (28.3%) would not meet the indication criteria based on objective DQCA information. EB and DQCA (/spl plusmn/5%DS) led to a concordant indication for pPTCA only in 103 of 226 (60.8%) coronary lesions. The conclusion was reached that independent on-site DQCA supports decision-making and is likely to avoid the bias of "self-referral" and thus improve patient selection for pPTCA.

To the Editor: We read with great interest the article on acceleration of atherosclerosis by nonspecific stimulation of the immune system. Lehr and colleagues1 showed data supporting the concept that atherosclerosis has an immunopathological component, making improbable that a single infectious agent should assume particular importance in its initiation or progression. We tested this hypothesis in 218 patients (119 men; 99 women; mean age 64.6; 29 to 83 years) referred for coronary angiography. We studied the possible association between seropositivity for a particular microbial agent and angiographically proven coronary artery disease (CAD), defined as more than 50% diameter stenosis of at least one coronary artery. Blood was tested for seromarkers of 6 pathogens (Hepatitis-A virus, Chlamydia pneumoniae , Helicobacter pylori …

In 27 patients, we compared the diagnostic value of magnetic resonance imaging (MRI) and electron beam computed tomography (EBCT) for noninvasive detection of coronary artery stenosis using conventional coronary angiography as the "gold standard." The overall sensitivity and specificity for EBCT to detect a 50% diameter stenosis were 70% and 95%, respectively. Therefore, we conclude that EBCT is slightly better than MRI in adequately visualizing and detecting a stenosis in the proximal and mid-coronary segments.

Purpose: To evaluate the clinical outcomes of patients undergoing renal artery stenting with intravascular ultrasound (IVUS) guidance and compare measurements between IVUS and angiography. Methods: One hundred thirty-one patients (71 women; mean age 71 ± 8 years) underwent IVUS-guided Palmaz stent implantation in 153 stenotic renal arteries at a single center. The indications for stenting were uncontrolled hypertension (102, 77.9%), renal insufficiency (10, 7.6%), and both conditions (19, 14.5%). The majority of lesions were ostial (114, 74.5%); the remainder occupied the proximal renal artery (39, 25.5%). The mean lesion length and diameter stenosis were 6.5 ± 3.0 mm and 74% ± 10%, respectively, as measured by angiography. Data were recorded in a pre-specified database; angiographic and IVUS images were analyzed at dedicated core laboratories and compared. Results: Angiographic success was achieved in all patients, but IVUS indicated the need for additional intervention in 36 (23.5%) cases. There was strong correlation between the angiographic and IVUS measurements of lesion length ( r = 0.60, p < 0.0001) and pre-/postprocedural minimal luminal diameter ( r = 0.72 and 0.63, respectively; p < 0.0001). The mean contrast volume was 74 ± 18 mL per case. In-hospital renal failure occurred in 8 (6.1%) patients; 2 (1.5%) required transient hemodialysis. At a mean 15-month follow-up, patients were treated with fewer antihypertensive medications (p = 0.05), and systolic and diastolic arterial blood pressures had decreased (p = 0.001); no significant change was noted in serum creatinine. Conclusions: IVUS-guided stenting facilitates safe renal artery revascularization. IVUS imaging may complement angiography in certain cases, which should be studied further in prospective studies with iodinated or noniodinated contrast agents.

BACKGROUND: Intravascular stents are increasingly being used to treat subclavian artery obstructive disease. This study aimed to assess the immediate and mid-term clinical outcome of subclavian artery stenting. METHODS AND RESULTS: Total occlusion of the subclavian artery was seen in 7 (28%) out of the 25 consecutive patients treated for subclavican artery stenosis. Mean lesion length was 14 +/- 4.3 mm. The mean preprocedure diameter stenosis was reduced from 83.2 +/- 14.9% to 9.6 +/- 5.4% postprocedure. Procedural success was achieved in all patients. Clinical follow-up was obtained in all patients. The initial success was maintained at follow-up (mean = 12 +/- 4 months) in 24 (96%) patients. Recurrence of symptoms occurred in 1 (4%) patient who had an angiographically documented restenosis four months after the procedure. It was successfully redilated. CONCLUSION: Stenting for subclavian artery obstructive disease is safe, technically feasible and has favorable clinical outcomes. It may be considered as the therapy of choice for subclavian artery obstructive disease.

We describe and analyze pressure measurements across vascular stenoses in an atherosclerotic human carotid bulb replica using catheters of different diameters. Replicas of an atherosclerotic human carotid bulb were created using the lost wax technique, and were placed in a circuit of pulsating non-newtonian fluid. Flows were adjusted to replicate human physiologic flow profiles. Common carotid artery total flow volume of 600 milli-liters/minute was studied. A pressure recording device was calibrated; data were received from catheters placed longitudinally in the common carotid artery and internal carotid artery. The internal carotid artery pressures were obtained both through the stenosis as is usually performed in the angiography suite and through the vessel side-wall beyond the stenosis as a control. Internal carotid artery flow volumes were also measured with and without the catheter through the stenosis. Multiple pressure recordings and volume measurements were obtained in the replica using 7 French, 5 French, and 2.5 French catheters. Measurements of the replica showed a 58% diameter stenosis and an 89% area stenosis of the carotid bulb. All longitudinal pressure measurements in the common carotid artery agreed with control values regardless of the diameter of the catheter used. Pressure measurements were also in agreement with control values in the internal carotid artery using the 2.5 French catheter. However, when larger diameter catheters were employed, pressures measured with the catheter through the stenosis fell when compared to control values. Additionally, internal carotid artery flow volumes were also decreased when the larger diameter catheters were placed across the stenosis. Large diameter catheters when placed across vascular stenoses may cause an occlusive or near-occlusive state and artifactually increase the measured transstenotic vascular pressure gradient as well as decrease forward vascular flow.

The flow dynamics and pressure relationships in an ulcerated atherosclerotic carotid bulb obtained at post-mortem were studied and correlated with angiographic findings in a similar live patient. Using the lost wax technique, we created replicas of an ulcerated atherosclerotic carotid bulb from a fresh cadaver, and placed those replicas in a circuit of pulsating non-Newtonian fluid. Flow profiles were adjusted to replicate human physiologic flows, and flow rates of 400,600, and 800 milliliters per minute were evaluated. In the replicas, the slipstreams were opacified with iso-baric dyes, and images were recorded both on 35 mm film and on SuperVHS high speed video. Data were collected from needles placed radially in the common carotid artery, in the region of the maximal atherosclerotic narrowing, and in the internal carotid artery. Though pressure relationships could not be obtained in the live human for ethical reasons, angiography in a similar stenosis was evaluated for slipstream dynamics. The post-mortem replica had a 55% diameter stenosis (88% area stenosis) of the carotid bulb with a shallow 3 mm ulcer. Flow in the common carotid artery showed undisturbed slipstreams, but as these slipstreams entered the narrow bulb, they crowded together, accelerating dramatically, with a jet continuing distally beyond the maximal narrowing for at least 2 vessel diameters, where flow again became normal. As fluid entered the narrowed bulb, radial pressures decreased and within the ulcer a vortex circulation was found. Similar findings were observed on the angiographic images of the live patient. This combination of events, the slowly swirling fluid in the ulcer, which would allow platelet aggregates to form, and the intermittent low pressure of the Bernoulli effect which could pull the aggregates into the adjacent rapidly flowing blood may help explain how ulcerated carotid plaques lead to embolic stroke.

Background: Dobutamine stress echo (DbE) is accurate for the detection of coronary artery disease (CAD), but interpretation is subjective and accuracy is dependent on observer experience. Strain rate imaging (SRI) offers a quantitative technique for identification of CAD, but it is unclear whether this could improve the results of less expert readers. Methods: We studied 121 pts (42 female, 64 ± 10 years) who underwent DbE, SRI, and coronary angiography. Segmental peak systolic SR (SR) was measured independently and previously derived cut-offs were applied to categorize segments as normal or abnormal. The accuracy of WMS by novice, experienced and expert readers, and SRI were compared with quantitative coronary angiography (significant CAD = QCA diameter stenosis >50%). Results: The accuracy of WMS by novice (57%, AUC 0.59) and experienced echocardiographers (67%, AUC 0.63) was less than experts in DbE (89%, AUC 0.67, p < 0.0001). By applying a cut-off of

An understanding of how angiographic progression correlates with events is useful at this time for two reasons. First, to more fully comprehend the contribution of these trials in the past and second, to interpret trials which are currently underway or in the planning stages. A grave disservice has been done to the angiographic trials by introduction of the concept of “small angiographic change” leading to a “large reduction in events”. The former is due solely to the denominator effect and the latter was not generally seen, at lest in terms of the traditional endpoint of death from coronary disease plus non-fatal myocardial infarction. The predictive power of angiographic progression of future clinical events (its ability to serve as a “surrogate”) has been demonstrated during long term follow-up of three major angiographic trials. The success of sequential angiography to serve as a surrogate is probably based on the fact that angiography can detect plaque rupture. Thus angiographic trials could best be referred to as “plaque repture trails”.

Purpose To evaluate distal embolization while using the Hydrolyser (hydrodynamic thrombectomy catheter) with special attention to the severity of the stenosis and temporary distal or proximal flow obstruction. Materials and Methods The Hydrolyser procedure was assessed in plastic tubes (5–8 mm) with a 70% or 90% diameter stenosis with or without temporary distal flow obstruction and a 72-hour-old clot proximal to the stenosis. The weight of the embolized particles was established after passage through filters of 1,000, 500, 100, and 10 μm. To evaluate the influence of the absolute inner diameter of the stenosis 1.0-, 2.1-, and 3.0-mm stenoses were compared in 10-mm tubes. Results Thrombus removal was greater than 99.9% in all but one of the cases in the 5–8-mm tubes. Embolization with a weight of more than 1 mg was only found in tubes with a relative stenosis of 70% and a stenosis inner diameter of greater than 1.5 mm. There was a positive relationship between inner diameter of the stenosis and the amount of distal embolization. In the presence of a proximal or distal temporary flow obstruction during thrombectomy, no distal embolization greater than 1 mg was found. Conclusion In this in vitro study, the Hydrolyser thrombectomy device demonstrated minimal distal embolization. The amount of distal embolization that did occur was related to the absolute stenosis diameter and could be prevented by a severe distal stenosis and/or a temporary proximal or distal flow obstruction.

Due to high rates of late vessel reocclusion, balloon angioplasty of recent or chronic coronary occlusions is not associated with a sustained improvement in left ventricular function. Recent studies have suggested that stent implantation at coronary occlusions significantly reduces late vessel occlusion. We thus designed a study to analyze the effect of stent implantation at coronary occlusions on late vessel potency and left ventricular function. Twenty-four consecutive patients with recent or chronic coronary occlusions had successful stent implantation and were enrolled in a 6-month angiographic follow-up program. Contrast left ventricular cineangiography, at baseline and 6-month follow-up, as well as preprocedural, postprocedural, and follow-up angiograms analyzed with quantitative angiography were available in 22 of the patients (92%). At follow-up, no vessel reocclusion was observed and 32% of the patients, as analyzed by the50% diameter stenosis criterion, had restenosis. There was a significant improvement in global left ventricular function with a decrease in both left ventricular end-diastolic volume index (LVEDVI, p0.01) and left ventricular end-systolic volume index (LVESVI, p0.0001) and an increase in left ventricular ejection fraction (LVEF, p0.0001). Similarly, regional wall motion in the territory of the recanalized artery was also significantly improved (p0.05). These effects were associated with a reduction in left ventricular filling pressure (p0.0001). Stent implantation following balloon angioplasty of recent or chronic coronary occlusion is associated with a low rate of late vessel reocclusion, a reduction in cardiac volume, and an increase in ejection fraction. Such effects on left ventricular volumes could have a significant impact on patient survival.

We evaluated the long-term angiographic outcome of balloon angioplasty by comparing original and follow-up target coronary narrowing. Rather than using restenosis to determine outcome, as in most angioplasty studies, we took an unusual approach and analyzed outcome in terms that are commonly used in progression and regression studies after medical interventions. Quantitative angiographic measurements were undertaken in 315 narrowings with an initial diameter stenosis90% before and after angioplasty and at follow-up. Angiographic deterioration (10% increase in follow-up diameter stenosis) was identified in 44 (14%) narrowings. Angiographic deterioration was not influenced by age, sex, risk factors, lipid profile, or the indication for angioplasty. Deterioration was also not predicted by the severity, length, or the location of the narrowing. The deteriorating narrowings had a higher recoil after dilatation compared with narrowings with angiographic improvement (21% +/- 31% vs 12% +/- 17%, p = 0.006); the residual stenosis after angioplasty was therefore higher. The late loss was also significantly increased compared with narrowings with angiographic improvement (65% +/- 26% vs 8% +/- 24%, p0.001). We conclude that the incidence of angiographic deterioration of coronary disease as a result of restenosis is uncommon but not negligible. Interventional cardiologists should resist the temptation to dilate mild, silent coronary narrowings because the procedure might have an unfavorable angiographic (and probably clinical) effect.

The new generation quantitative angiographic systems apply the interpolated technique to calculate the reference diameter at the site of the stenosis by integrating measurements of the segments proximal and distal to the stenosis. After stent implantation these measurements can be misleading as the treated segment, which is frequently larger than the adjacent not stented segments, is included in the measurements. The consequence is an overestimation of the reference diameter and the residual diameter stenosis. The present study was performed to compare this conventional technique of measurement with a new method which excludes the stented segment for the calculation of the reference diameter. Fifty-two lesions treated with poorly radiopaque stents (56% Palmaz-Schatz, 28% NIR, 10% Gianturco-Roubin, 6% Wallstent) expanded at high pressure (> = or 16 atm) were analyzed according to the conventional and stent excluded method. After stent implantation the reference diameter was 3.39 +/- 0.48 mm with conventional measurements and 3.02 +/- 0.45 mm with the stent excluded method (P < 0.05). The corresponding % diameter stenosis was 13 +/- 9 for the conventional technique and 1 +/- 13 for the stent excluded analysis (P < 0.05). The new approach to quantitative coronary analysis after stenting provides higher accuracy in reference diameter calculations and allows a more appropriate matching of stented segments with adjacent normal segments.

Optimized stent expansion by high-pressure inflations of oversized balloons has initially been derived from experience obtained with the Palmaz-Schatz stent, whereas there is little experience with this strategy in the Wallstent. By using this approach with quantitative coronary angiographic guidance, 20 Wallstents and 20 Palmaz-Schatz stents were implanted in 34 patients and consecutively examined by conventional two-dimensional (2D) intracoronary ultrasound (ICUS) and three-dimensional (3D) ICUS on the basis of the application of a pattern recognition algorithm. Ultrasound criteria of adequate stent expansion were defined as a complete apposition of the stent to the vessel wall, a stent symmetry index (SSI = minimum/maximum lumen diameter)or = O.7, and a stent-reference lumen area ratio (SRR = Minimum intrastent lumen area/Average of proximal and distal reference lumen area)or = O.8. In all cases a smooth angiographic lumen and a negative diameter stenosis, on the basis of a distal reference, was achieved. For the Wallstents ICUS showed a higher SSI (2D, 0.95 +/- 0.04 vs 0.85 +/- 0.09; p0.001; 3D, 0.90 +/- 0.09 vs 0.82 +/- 0.11, p0.05) and a lower SRR (2D, 0.66 +/- 0.12 vs 0.81 +/- 0.13, p0.005; 3D, 0.63 +/- 0.14 vs 0.74 +/- 0.15, p0.05) than for the Palmaz-Schatz stents. Ninety percent of failure in meeting these criteria resulted from a low SRR. The incidence of incomplete stent apposition (one in both stents) or SSI0.7 was low and generally associated with an SRR0.8. The Wallstents met the ICUS criteria less often (2D, 2(1O%) vs 10(50%), p0.01; 3D, 3(15%) vs 9(45%), p0.05), were significantly longer (35.1 +/- 7.7 mm and 14.3 +/- 3.3 mm, p0.0001), and generally demonstrated a larger vessel tapering, measured as proximal minus distal ICUS reference lumen area (1.33 +/- 2.91 mm2 vs 0.44 +/- 1.97 mm(2), not significant). Wallstents meeting the ICUS criteria, however, showed less vessel tapering (0.18 +/- 1.64 mm(2)). Thus optimized stent expansion was followed by excellent angiographic results for both Palmaz-Schatz and Wallstent. Although angiographic results and visual assessment of the ICUS examination suggested a good outcome, few Wallstents met the ICUS criteria in contrast to the Palmaz-Schatz stents. The low value of the SRR in the Wallstents is likely to be caused by vessel tapering, suggesting that this criterion may be unsuitable in assessing the adequacy of the expansion of relatively long stents such as the Wallstent.

This study evaluated the relative ability of two techniques to quantify carotid atheroma. Diameter stenosis and lesion width were used to predict clinical significance and morphologic characteristics of 54 carotid endarterectomy specimens. Diameter stenosis was a better predictor of symptoms than lesion width (P = 0.03 versus P = 0.085). Both parameters were predictive of complex atheroma (diameter stenosis P = 0.000; lesion width P = 0.03). However, use of lesion width allowed finer definition of categories permitting more precise subclassification of plaque. This resulted in a better correlation of symptoms to complexity when lesion width was used as the discriminating variable (lesion width P = 0.04; diameter stenosis P = 0.121). Lesion width is a valuable parameter for the classification of carotid atheroma, correlating with symptoms and plaque complexity. Lesion width should be evaluated in future studies of carotid atheroma. The discriminative ability of lesion width as detected by high-resolution ultrasonography needs to be evaluated.

This paper discusses prior criticism of human panel readings and presents the methodology of the Sanmarco/Blankenhorn ‘GCS’ along with its strengths and possible explanations of this strength.

PLAC 1 is a double-blind randomized placebo-controlled trial assessing the efficacy of monotherapy with an HMG-CoA reductase inhibitor (pravastatin) in altering the atherosclerotic process. This trial was an angiographic trial undertaken in the United States and was completed in early 1994. Despite the fact that angiographic endpoints were the prime focus during the planning and execution of the trial, significant impact was seen in the area of clinical events, particularly fatal and non-fatal myocardial infarctions. The latter were significantly reduced in the treated patients. These results were paralleled by a significant slowing of progression in the treated patients. Importantly, the angiographic effects were predominant in prevention of new lesion formation and in slowing the progression of mild/moderate lesions with less than 50% diameter stenosis at baseline. Current concepts suggest that the latter two categories of lesions are the most important in linking angiographic outcomes with clinical events. PLAC 1 is the first trial to show concomitantly statistically significant effects in clinical endpoints and angiographic endpoints in the category of new and/or mild stenoses. These results are compatible with the concept of plaque stabilization.

For a time there was uncertainty as to whether carotid endarterectomy (CEA) was beneficial. However, the North American Symptomatic Carotid Endarterectomy Trial (Nascet) published in mid-1991 revealed that “for patients with high-grade stenosis (70–99% narrowing in the luminal diameter) surgery was highly beneficial” (1). A European trial has yielded similar results for patients with 70–99% stenosis (2). The portions of those studies evaluating the benefits in patients with moderate stenosis (30–69%) are ongoing. There has also been confirmation by the NIH sponsored ACAS (Asymptomatic Carotid Artery Stenosis) trial that CEA is beneficial for the asymptomatic patient with diameter stenosis of greater than 60%. These results mean that we will perform more CEA’s than in the 1980’s.

To determine whether coronary angiography is predictive of the future site of coronary occlusion, we analyzed the coronary angiograms of 246 consecutive patients having two or more angiograms with therapeutic invasive intervention in the interval between angiograms. The average interval between studies was 46 months. Of 2183 normal segments at the first angiogram, 51 (2.3%) were occluded at the second angiogram, whereas in segments with minimal disease (1% to 25% diameter stenosis) 33 (8%) of 411 were occluded (p < 0.05). There was a further stepwise increase in the occlusion ratio, with increasing stenosis reaching a 31% occlusion ratio in lesions with critical (91% to 99%) stenosis at the first angiogram. For any given degree of stenosis, the occlusion ratio of “long” lesions (5 to 20 mm) was on the average more than twice that of “short” lesions (

Introduction Previous reports have indicated that a high level of Lp(a) is an independent risk factor for coronary artery disease. Data from angiographic regression trials suggest that the adverse effect of high Lp(a) can be ameliorated by lowering LDL-C. Methods Patients with mild coronary atherosclerosis and with total cholesterol of 6.43 ± 0.75 mmol/l, LDL-C 4.40 ± 0.69 mmol/l, and LP(a) 25.4 ± 27.6 mg/dl were treated with placebo (N = 167) or simvastatin 20 mg daily (N = 178). Quantitative Coronary Angiography was performed at oand 4 years. Both the changes in mean lumen diameter (diffuse coronary atherosclerosis), and minimum lumen diameter and diameter stenosis (focal coronary atherosclerosis) were assessed. Angiographic changes were stratified by Lp(a) level and by LDL-C level during the trial. Results Simvastatin lowered TC by 23%, LDL-C by 31%, Lp(a) was not influenced. The angiographic changes over 4 years were as follows: LDL-C l 3.5 ≥3.5 mmol/l P Mininum Diameter (mm): Lp(a)l 35 mg/dl -0.05 ± 0.24 -0.15 ± 0.27 0.005 ≥35 mg/dl -001 ± 0.24 -0.05 ± 0.25 ns Diameter stenosis (%): Lp(a) l 35 mg/dl 0.5 ± 7.8 4.1 ± 9.5 0.001 ≥ 35 mg/dl 0.5 ± 6.7 2.8 ± 7.9 ns Mean Lumen Diameter (mm): Lp(a)l35 mg/dl -0.05 ± 0.24 -0.09 ± 0.24 ns g 35 mg/dl 0.01 ± 0.25 -0.01 ± 0.24 ns Conclusions our findings contrast with previous reports and show that high Lp(a) is associated with more progression of focal atherosclerosis (but not diffuse) when LDL-C is low. Lowering LDL-C was more beneficial when Lp(a) was low.

The Shiga Pravastatin Study (SHIPS) is a 5 center randomized, double blind placebo controlled trial to test whether pravastatin, 10 mg twice daily begun at least 10 days prior to elective PTCA in patients with total cholesterol (T-Chol) hess than 280 mg/dl can decrease restenosis. The endpoint is a between group comparison of frequency of restenosis defined as a more than 50% loss of gain at PTCA site at 3 months follow-up by automated quantitative coronary arteriography. 179 lesions (85 pravastatin. 94 placebo) in 124 patients (62 pravastatin. 62 placebo) were randomized. The two groups were comparable for baseline clinical and angiographic characteristics. T-Chol decreased from 204 to 172 mg/dl in pravastatin group (P l 0.001), but not in placebo (201 vs 202 mg/dl). Although restenosis rate was not different in the two groups (29.4% in pravastatin vs 39.4% in placebo. P = 0.16) as a whole, it was reduced to about 1/5 (8.B%) in pravastatin group compared to 44.B% in placebo (P = 0.0011) when the analysis was restricted to high grade lesions (≥ 75% diameter stenosis by automated analysis. which is equivalent to ≥90% stenosis by visual analysis; 34 lesions in pravastatin, 29 lesions in placebo). The effect of pravastatin in prevention of restenosis in high grade lesions was equally seen both in the groups with baseline T-Chol of above (10.5 vs 45.5%, P = 0.029) and below 200 mg/dl (6.7 vs 44.4%. P = 0.015). Conclusion Pravastatin prevents restenosis after PTCA of high grade lesions irrespective of baseline T-Chol level.

To assess the angiographic outcome after “cutting” balloon (C-Ball) angioplasty, a technique which uses 3–4 longitudinal microtomes to incise atheroma reducing vascular barotrauma, we reviewed the cineangiograms of 86 patients (89 lesions) undergoing this procedure in Phase I and II clinical studies. On-line quantitative angiography (QCA) was used by investigators to approximate a 1:1 balloon artery ratios (BAR). In the Phase II Pilot study, adjunct balloon PTCA was not performed unless a g40% residual diameter stenosis remained after C-Ball. Off-line qualitative morphologic and quantitative angiographic (ImageComm) analyses were performed by independent Core Laboratory review. Phase I % (N = 22) Pilot Phase II % (N = 67) Vessel (%): RCA/LAD/LCx 41/36/23 37/36/27 Location (%): Ostial/Proximal/Mid-Distal 0/59/41 5/25/70 Eccentricity (%)/Bend ≤ 45 ≥ (%) 73/18 54/19 Length ≥ 10 mm (%)/Calcified (%) 9/36 24/25 Irregular (%)/Bifurcation (%) 14/0 8/6 ACC/AHA Class (%): A/B1/82/C 9/50/41/0 17/40/40/3 Reference Diameter, mm/C-Ball:Artery Ratio 2.83/0.96 2.97/1.00 MLD, mm: Pre/Post C-Ball/Final 0.87/1.59/2.01 1.11/1.63/2.12 % Stenosis: Pre/Post C-Ball/Final 69/45/29 63/48/29 %Adjunct PTCA/% Post-PTCA haziness 64/9.1 30/15 Final NHLBI Dissection (%): Grade B/C/D 0/14/0 16/0/0 Two patients in Phase II required intracoronary stents for dissections after C-Ball and adjunct PTCA. There were no deaths and no patient required emergency CABG. We conclude that “cutting” balloon PTCA: (1) can be performed safely without an untoward increase in dissections or other angiographic complications; and (2) results in a residual diameter stenosis (29%) comparable to standard balloon angioplasty. Its effect on reducing late lumen loss (angiographic restenosis) compared with balloon angioplasty is under-going evaluation in a randomized, Phase II clinical trial.

Objectives To evaluate the merits of intravascular ultrasound (IVUS) in the diagnosis and vascular Interventions for peripheral artery stenosis. Methods 94 in patients of department of cardiology of Southwest hospital from October 2006 to September 2010 were collected, who were diagnosed with Peripheral artery stenosis, there were 58 males and 36 females in them, ages were form 26 to 77 (58.4±18.3) years. The patients were divide to DSA (Digital Subtraction Angiography, DSA) group (43 patients) and DSA+IVUS group (51 patients), DSA was used in DSA group, DSA and IVUS were both used in DSA+IVUS group, and The outcome of two techniques were compared. Stenting was implemented under the guidance by DSA and IVUS respectively, and the effect of stenting was observed. Ultrasonic examination and CTA were used in follow up after stenting, DSA and IVUS were used when necessary. Results In DSA+IVUS group, 77 vascular stenosises were found by DSA, there were 42 eccentric stenosises and 22 concentric stenosises in them; 82 vascular stenosises were found by IVUS, there were 63 eccentric plaques and 19 concentric plaques in them. The diameter stenosis rate measured by IVUS (67.1±12.2)% was significant higher than that measured by DSA (54.5±11.4)%, (p Conclusions Compared with DSA, IVUS can accurately identify the lesion characteristics and the severity of stenosis, it9s more effectually to guide and evaluate stenting.

Objectives To clarify the relationship between quantitative coronary angiography (QCA) parameters and fractional flow reserve (FFR) for screening out ideal angiographic parameters to predict myocardial ischaemia. Methods The study included 121 lesions with QCA and FFR datas from 106 patients. The lesions were grouped into FFR>0.75 group and FFR≤0.75 group. Assessed parameters by QCA included percentage diameter stenosis, minimum luminal diameter (MLD), percentage area stenosis, minimum luminal area (MLA), reference vessel diameter (RVD) and lesion length (LL). Correlation analysis was used to identify the relationship between QCA parameters and FFR value, and receiver operating characteristic (ROC) curve was used to determine predictors of FFR≤0.75. Results When compared to FFR>0.75 group, FFR≤0.75 group had higher LL (14.8±7.9 mm vs 10.7±5.4 mm, p=0.024), lower MLD (1.47±0.31 mm vs 1.82±0.51 mm, p=0.028), lower RVD (2.30±0. 50 mm vs 2.81±0.64 mm, p=0.036), and lower MLA (2.30±1.50 mm 2 vs 3.60±2.30 mm 2 , p=0.038). By correlation analysis, significant negative correlation between QCA parameters and FFR included LL (r=−0.209, p=0.040), significant positive correlation included MLD (r=0.414, p=0.040), RVD (r=0.303, p=0.000) and MLA (r=0.315, p=0.002). By using a ROC, we identified MLD≥1.6 mm to be the best cut-off value to fit with a FFR>0.75 with sensitivity 63%, specificity 82%, and positive predictive value 96%. Conclusions Anatomic parameters of intermediate coronary lesions by QCA show a moderate correlation to FFR value. MLD by QCA may be used as an alternative to FFR when assessing the need for intervention in intermediate coronary lesions.

minimum lumen diameter (MLD) and area (MLA), and lesion length (LL) were recorded from the C7XR console. Diameter stenosis (DS%) and area stenosis (AS%) were calculated. RESULTS: The median of OCT parameters was not significantly different between Non-ACS (MLD 1.35; MLA 2.24; LL 11.5; DS% 53; AS% 68) and ACS groups (MLD 1.36; MLA 2.26; LL 9.5; DS% 43; AS% 64). OCT parameters showed modest correlation to FFR in the Non-ACS group (MLD 0.65; MLA 0.66; LL -0.57; DS% -0.56; AS% -0.53) but not in the ACS group. Stepwise logistic regression of OCT parameters found DS% an independent predictor of FFR 0.80 (p 0.03) in NonACS only, correctly classifying 76% of lesions (ROC optimal cut-off DS% 55%; sensitivity 61%, specificity 100%, AUC 0.87). CONCLUSION: OCT parameters correlate with FFR in NonACS presentations and OCT diameter stenosis independently predicts FFR 0.80. However, OCT in ACS does not correlate with or predict FFR.

The transluminal coronary extraction-endarterectomy catheter (TEC) consists of a torquing tube with a distal, conical rotating blade. We successfully treated 26 patients (27 lesions) using this catheter with adjunctive balloon angioplasty. Twenty-five patients (26 lesions) had serial angiography before, 1 day after, and 3 months after the procedure. All 17 patients without restenosis 3 months after the procedure had angiography at 6 months. Restenosis, defined as >50% diameter stenosis, was noted in nine lesions at 3 months (early restenosis) and in five lesions at 6 months (late restenosis). Between vessels with and without early restenosis, the percentage of diameter stenosis seen 1 day after the procedure and the luminal diameter were significantly different (38% ± 14% vs 22% ± 12%, respectively, p < 0.01; 2.3 vs 2.9 mm, p < 0.01, respectively). However, between vessels with and without late restensis, these variables were not significantly different. The overall restenosis rate was 54% (native vessels 50%; grafts 80%). This observational study suggests that very early diameter narrowing seen 1 day after the procedure has greater contribution to early restenosis than to late restenosis after successful TEC atherectomy with adjunctive balloon angioplasty.

The relationship between preoperative stenosis and the effect of carotid endarterectomy (CEA) upon internal carotid blood flow (ICF) is not well understood. With the intention of better characterizing this, we compared intraoperative measurements of internal carotid blood with the maximum single diameter stenosis found in preoperative angiograms.Fifty-two patients undergoing 64 carotid endarterectomies (12 bilateral) had transit-time ultrasound perivascular probes used to measure ICF before and after CEA, and the percent change in ICF (% delta ICF) achieved was calculated. Maximum single-diameter stenosis was determined by comparing the least diameter in the flow path from the common carotid to the normal-appearing internal carotid just distal to bifurcation disease.The entire group had a mean of 53 +/- 21% stenosis found on preoperative angiograms, and % delta ICF averaged 64 +/- 92%. When divided into subgroups based on degree of stenosis, patients with 0% to 40% stenosis (n = 17) had % delta ICF of 32 +/- 46%, patients with 41% to 70% stenosis (n = 30) had % delta ICF of 72 +/- 105%, and patients with more than 70% stenosis had % delta ICF of 168 +/- 160%. The differences in % delta IC were significant for the70% group compared with the other groups (analysis of variance, P0.005), and marginally significant (P = 0.056) between the 0% to 40% and the 41% to 70% groups. The scatter plot of % delta ICF versus stenosis showed a significant second order direct correlation (r = 0.428, P0.001) and disproportionate increases in ICF above 60% stenosis.A curvilinear relationship between stenosis and immediate increase in ICF after CEA was demonstrated in agreement with theory, and in those patients with more than approximately 60% single-diameter stenosis, large disproportionate increases in blood flow were more frequently observed.

Background. The limitations and inaccuracies in the measurement of stenosis geometry, especially after coronary interventions, have prompted investigators to use functional indexes of stenosis severity, assessing the reduction of flow induced by the stenosis under study. Coronary flow reserve is greatly affected by the hemodynamic conditions at the time of the measurement and can not be applied for the immediate assessment of the results of coronary interventions.

Visual interpretation of the degree of coronary artery stenoses may be grossly erroneous when compared with quantitative coronary angiography [1–7]: angiographers tend to overestimate the severity of tight stenoses and underestimate the degree of milder ones [4, 8, 9], a tendency which is particularly unfortunate when the results of interventional procedures such as coronary angioplasty must be “objectively” assessed [9–11]. Quantitative coronary angiography is now established as the “gold standard” for coronary stenosis assessment but its limitations have been recently emphasized [12] and it remains a time consuming technique, so that the use of digital calipers, an easier though less precise method, has been proposed for clinical purposes [5, 8].

Objective The objective of this study was to evaluate whether the drug eluting stents can affect the progression of coronary artery atherosclerotic plaque. Methods Four hundred and ten patients, who had angiography follow up at more than 9 months after drug eluting stents implantation, were included in the study. At the initial angiography immediately after stents there were 276 atherosclerotic plaques ≥10% diameter stenosis. According to the relationship of the plaque position and the stent, the plaques were classified into two groups: group 1, plaques located within 5–20 mm distance to the stents; group 2, plaques located more than 20 mm away from the stents. The QCA diameter stenosis was analysed at the initial and follow up angiography. Plaque progression was defined if the stenosis value aggravated 10. The plaque progression rate was compared between two groups with T test. Results One hundred and seven plaques located within 5–20 mm distance to the stents (group 1), among them 25 plaques progressed at the follow-up, and 14 lesions were stented at follow-up; 169 plaques located more than 20 mm away from the stents (group 2), among them 58 plaques progressed at follow-up, and 37 plaques were stented at follow-up. The plaque progression rate exists significant difference between different groups (23.36% vs 34.32%, p=0.035), the re-PCI rate exists difference too (13.08% vs 21.89%, p=0.045). Conclusions The plaques near the drug eluting stents (not in segments) seems less progressed at follow-up.

The aim of this study was to test the hypothesis that regional myocardial washout of technetium-99m teboroxime is slowed in the presence of coronary stenosis. Washout was assessed in 33 catheterized patients and in 13 with a low likelihood of coronary artery disease, using a triple detector camera and dynamic single-photon emission computed tomography, with serial 1-minute acquisitions after injection of 20 to 25 mCi of teboroxime at the third minute of adenosine-induced hyperemia. Washout was measured as the percent change in counts between the first, second and third minutes after injection, as measured in 6 short-axis myocardial regions of interest. Myocardial regions were classified as ischemic (or = 50% diameter stenosis and no prior myocardial infarct), infarcted, normal (no significant coronary stenosis) or "low likelihood" (from the 13 patients with a low likelihood of coronary artery disease). Teboroxime washout was significantly (p0.001) slowed in the ischemic myocardium (12.7 +/- 8.3%) compared with the normal (18.5 +/- 5.7%), low-likelihood (17.8 +/- 6.1%) and infarcted (17.8 +/- 4.4%) zones. There was regional variability in washout rates (% washout/min), with the anterior wall having the lowest (13.8 +/- 3.4%/min) and the inferior wall the highest (20.7 +/- 7.9%/min) values. In regard to individual coronary territories, 21 of 41 ischemic, noninfarcted territories (51%) had abnormal washout compared with 3 of 43 normal territories (7%) (p = 0.001). In conclusion, regional washout of teboroxime is detectably slowed in ischemic, noninfarcted myocardium. The clinical value of washout analysis in teboroxime single-photon emission computed tomography warrants further investigation.

To assess the mechanisms of luminal improvement, 40 patients undergoing directional coronary atherectomy and a matched control group of 25 patients undergoing angioplasty were evaluated with intracoronary ultrasound imaging before and after intervention. Despite similar sized vessels, a similar angiographic severity of diameter stenosis (75 ± 12% for the angioplasty group vs 69 ± 15% for the atherectomy group, p = NS), and a similar plaque burden (percent plaque area) before intervention (84 ± 5% in the angioplasty group vs 85 ± 13% in the atherectomy group, p = NS), the residual plaque area after intervention was significantly smaller in the atherectomy group (54 ± 14%) compared with the angioplasty group (65 ± 13%, p = 0.002). Despite excellent angiographic results, significant residual plaque was noted after either successful intervention. Based on the absolute changes in lumen area, plaque area, and vessel area, improvement in the lumen area in the atherectomy group occurred as a result of plaque "compression" (48%), plaque removal (37%), and vessel expansion (15%). In the angioplasty group, plaque "compression" accounted for 94% of the improvement in lumen area, whereas vessel expansion contributed 6%. Thus "compression" of plaque remains the major mechanism of luminal improvement during atherectomy.

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.

Angiographic follow-up studies on the evolution of coronary artery disease are of increasing relevance. It has still to be evaluated which coronary segments are predominantly involved in the process of atherosclerosis and, thus, should be preferably included in the analysis. Therefore, the correlation of progression and regression of coronary disease with the diameter and location (proximal, mid or distal) of coronary segments was investigated from the data of the INTACT-study, in which 25 different coronary segments were defined including anatomic variants of rather distal segments. In 348 patients with coronary artery disease, standardized coronary angiograms were repeated within 3 years and were quantitatively analyzed (CAAS). In 1063 coronary stenoses (% diameter stenosis20%) compared from both angiograms, progression and regression were not influenced by diameter nor location of arterial segments. In the follow-up angiograms, the number of new lesions (stenoses and occlusions) per coronary segment differed with regard to segment diameter (3 mm: 64/1125 (6%); 2-3 mm: 139/1967 (7%);2 mm: 44/1756 (2%); p0.001) and location of segments (proximal: 86/1285 (7%); mid: 84/1193 (7%); distal: 77/2370 (3%); p0.001). Out of 77 distal new lesions, only 25 (32%) were found in segments2 mm in diameter. Since the absolute number of new lesions was high in distal coronary segments, but low in segments with diameters2 mm, angiographic follow-up studies should analyze coronary segments at any location, but may neglect segments with diameters smaller than 2 mm.

The elastic behavior of the dilated coronary vessel has been reported to affect the immediate results of coronary angioplasty. To determine whether elastic recoil may also influence the long-term restenosis process, 98 consecutive patients with unstable angina and 1-vessel disease were studied. An automated coronary quantitative program was used for the assessment of balloon and coronary luminal diameters. Elastic recoil was defined as the percent reduction between minimal balloon diameter at the highest inflation pressure and minimal lesion diameter immediately after coronary angioplasty. Follow-up coronary arteriography was performed 8 to 12 months after the procedure in all patients. The mean elastic recoil averaged 17.7 +/- 16% and was correlated to the degree of residual stenosis immediately after coronary angioplasty (r = 0.64; p0.001). Restenosis, defined as50% diameter stenosis at follow-up, developed in 53 patients (54%). There was no correlation between the degree of elastic recoil and the changes in minimal lesion diameter observed during follow-up, whereas a positive correlation between the amount of elastic recoil and the incidence of restenosis was documented (r = 0.84; p0.05). Thus, the elastic properties of the dilated vessel do not influence the active process of restenosis. However, because elastic recoil negatively influences the initial results of angioplasty, it is more likely that further reductions in lumen diameter during follow-up can reach a threshold of obstruction considered critical for a binary definition of restenosis.