Angioscopic predictors of early adverse outcome after coronary angioplasty in patients with unstable angina and non-Q-wave myocardial infarction

Characterization of coronary atherosclerosis by intravascular imaging modalities

Coronary artery disease (CAD) is highly prevalent in Western countries and is associated with morbidity, mortality, and a significant economic burden. Despite the development of anti-atherosclerotic medical therapies, many patients still continue to suffer from coronary events. This residual risk indicates the need for better risk stratification and additional therapies to achieve more reductions in cardiovascular risk. Recent advances in imaging modalities have contributed to visualizing atherosclerotic plaques and defining lesion characteristics in vivo. This innovation has been applied to refining revascularization procedure, assessment of anti-atherosclerotic drug efficacy and the detection of high-risk plaques. As such, intravascular imaging plays an important role in further improvement of cardiovascular outcomes in patients with CAD. The current article reviews available intravascular imaging modalities with regard to its method, advantage and disadvantage.

Identification of vulnerable atherosclerotic plaques

There has been great interest in the possibility of identifying plaques that might be the site of future acute coronary events. These plaques are termed vulnerable and the majority are lipid-rich with an abundance of inflammatory cells and a thin fibrous cap. Several techniques developed to identify these plaques are in various stages of development and in the near future, one might employ a strategy to potentially identify and therapeutically modify such lesions during percutaneous intervention to avoid future acute events. Although this approach of identifying the vulnerable plaque seems promising, there are significant potential limitations. The natural history of a vulnerable plaque is unknown and clinical trials utilizing this strategy of identification and therapeutic intervention are lacking. Moreover, in any given patient, multiple vulnerable plaques are likely to be present. This article reviews some of the techniques for identifying a vulnerable plaque and discusses the potential advantages and limitations of this strategy.

The importance of functional tests in personalized medicine

Cardiovascular disease is the most prevalent disease mainly in the Western society and becoming the leading cause of death worldwide. Standard methods by which healthcare providers screen for cardiovascular disease have only minimally reduced the burden of disease while exponentially increasing costs. As such, more specific and individualized methods for functionally assessing cardiovascular threats are needed to identify properly those at greatest risk, and appropriately treat these patients so as to avoid a fate such as heart attack, stroke, or death. Currently, endothelial function testing-in both the coronary and peripheral circulation-is well established as being associated with the disease process and future cardiovascular events. Improving such testing can lead to a reduction in the risk of future events. Combining this functional assessment of vascular fitness with other, more personalized, testing methods should serve to identify those at the greatest risk of cardiovascular disease earlier and subsequently reduce the affliction of such diseases worldwide.

Implication of plaque color classification for assessing plaque vulnerability: a coronary angioscopy and optical coherence tomography investigation

OBJECTIVES

The purpose of this study was to assess the relationship between plaque color evaluated by coronary angioscopy and fibrous cap thickness estimated by optical coherence tomography (OCT) in vivo.

BACKGROUND

Yellow color intensity of coronary plaque evaluated by coronary angioscopy might be associated with plaque vulnerability.

METHODS

Seventy-seven coronary artery plaques in patients with acute coronary syndrome were observed by angioscopy and OCT. Plaque color was graded as white, light yellow, yellow, or intensive yellow.

RESULTS

There were significant differences among the groups classified by plaque color with respect to the fibrous cap thickness estimated by OCT: 389 +/- 74 mum in white plaques, 228 +/- 51 microm in light yellow plaques, 115 +/- 28 microm in yellow plaques, and 59 +/- 14 microm in intensive yellow plaques (p < 0.0001). In Spearman rank-order correlation analysis, there was a significant negative correlation between yellow color intensity and fibrous cap thickness (p < 0.0001). Furthermore, 80% of intensive yellow plaques were thin cap fibroatheroma with a cap thickness of < or =65 microm.

CONCLUSIONS

The plaque color in coronary angioscopy was determined by the fibrous cap thickness, which was assessed by OCT. Although coronary angioscopy remains a specialized research tool, it might allow us to evaluate plaque vulnerability.

Update on drug-eluting stents for prevention of restenosis

Despite the success of coronary stent implantations in the last decade, in-stent restenosis due to neointimal hyperplasia remains a problem to overcome. Neointimal hyperplasia is a vascular response to stent injury and mainly consists of proliferation of smooth muscle cells and deposition of extracellular matrix. Recently, local drug delivery has been advocated as a potential strategy to prevent in-stent restenosis. Unprecedented results have been obtained in early clinical studies on sirolimus-eluting and paclitaxel-eluting stents. Trials using various pharmaceutical coatings on different coronary stents are ongoing. More types of drug-eluting stents are expected on the market in the near future. Meanwhile, the evaluation of drug-eluting stents is entering the second phase in which the safety and efficacy in more complex lesion subsets and different clinical presentations are being investigated. Results including cost-benefit analyses are expected to have a tremendous impact on the practice of interventional cardiology in the next decade.

Distal embolization during intracranial carotid artery stenting

Intracranial stenting, with or without balloon angioplasty, has emerged as an effective alternative to medical therapy for intracranial atherosclerosis. However, this strategy appears to involve the potential risk of distal embolization, which may lead to disability and death. Here, the authors have described a successful case of distal balloon-protected intracranial carotid artery stenting for clinically and angiographically unstable intracarotid artery stenosis revealing aspirated embolic materials containing yellow plaque, red thrombus, and white debris.

High yellow color intensity by angioscopy with quantitative colorimetry to identify high-risk features in culprit lesions of patients with acute coronary syndromes

High yellow color intensity (HYCI) regions of atherosclerotic plaque, determined by angioscopy with quantitative colorimetry, are associated with lipid cores underneath thin fibrous caps in ex vivo tissue samples. To determine whether HYCI regions of coronary plaque are associated with disruption or thrombus in living patients, quantitative colorimetry was applied to angioscopy, and the color of culprit lesions was measured in patients with acute coronary syndromes. In 46 patients with acute coronary syndromes (acute myocardial infarction, n = 14; unstable angina pectoris [UAP] with culprit thrombus, n = 16; and UAP without culprit thrombus, n = 16), the recorded angioscopic images of culprit lesions were analyzed using a quantitative colorimetric method based on the L*a*b* color space applied to angioscopy (positive b* = yellow color intensity). HYCI was defined as b* value >23. Plaque disruption was significantly more prevalent in 19 of 24 HYCI regions (79%) than in 9 of 22 non-HYCI regions (41%) (p = 0.007). Culprit HYCI regions were prevalent in patients with myocardial infarction (11 of 14 [79%]), followed by those with UAP with thrombus (9 of 16 [56%]) and UAP without thrombus (4 of 16 [25%]) (p = 0.01 for trend), and were significantly more prevalent in 66% of patients with myocardial infarction and UAP with thrombus compared with 25% of those with UAP without thrombus (p = 0.007). In conclusion, HYCI regions of coronary plaque may be indicative of high-risk lesions vulnerable to thrombosis. Coronary angioscopy with quantitative colorimetry could be used to study the association between high-risk coronary lesions and future cardiovascular events.

Plaque Color Analysis by the Conventional Yellow-Color Grading System and Quantitative Measurement Using LCH Color Space

BACKGROUND

Yellow plaques of higher color grades are regarded as more vulnerable. We tried to elucidate the characteristics of yellow color that are regarded as the sign of vulnerable plaques by an objective and quantitative plaque color analysis.

METHODS

The color of yellow plaques was quantitatively analyzed using LCH color space and was presented by the maximum values of lightness (Lmax), chroma (Cmax), and hue (Hmax). Effect of light intensity on these parameters was experimentally examined (five plaque models, six light intensities). Relation between conventional yellow-color grade and LCH parameters was examined (31 plaques). Color analysis with LCH color space was applied (1) to compare the culprit lesions of unstable angina (eight patients) and of stable effort angina (nine patients) and (2) to evaluate the regression of yellow plaque by 80-week statin treatment (four patients, 19 plaques).

RESULTS

Cmax and Hmax were not influenced by light intensity so far as it was within appropriate range. Cmax (13 +/- 3, 25 +/- 5, and 28 +/- 4) became higher and Hmax (178 +/- 26, 134 +/- 10, and 91 +/- 16) became lower as the grade became higher (P < 0.0001). Culprit lesions of unstable angina had higher Cmax (22.8 +/- 7.9 vs 14.8 +/- 7.5, P = 0.04) and lower Hmax (73.3 +/- 19.7 vs 168.0 +/- 71.5, P = 0.002) than stable effort angina. Statin treatment reduced Cmax (21.3 +/- 9.6 vs 14.6 +/- 3.1, P = 0.004) and increased Hmax (82.6 +/- 25.8 vs 142.3 +/- 54.1, P = 0.0005).

CONCLUSIONS

Plaque color was consistently and quantitatively measurable using LCH color space uninfluenced by light intensity of appropriate range. Vulnerable yellow color had high chroma and low hue, indicating vivid and reddish-yellow color.

Feasibility and safety of thrombectomy with TVAC aspiration catheter system for patients with acute myocardial infarction

Early reperfusion with angioplasty and stenting is established as a central, effective treatment for acute myocardial infarction (AMI). The role of thrombectomy prior to angioplasty remains to be elucidated. To evaluate its feasibility, safety, and efficacy, thrombectomy using a TVAC aspiration catheter system was attempted prior to angioplasty and stenting in 40 consecutive patients with AMI. Fifty consecutive patients with AMI in whom angioplasty and stenting were performed without prior thrombectomy served as controls. Neither distribution of Killip classification nor culprit lesion was different between the two groups. In patients treated with the TVAC system, the procedure was successful in 39/40 patients (98%) and there were no procedure-related complications. In the final coronary angiogram, TIMI-3 (Thrombolysis in Myocardial Infarction) flow was obtained in 37/40 (93%) in patients treated with the TVAC system and 43/50 (86%) in control patients. Electrocardiograms before and after coronary intervention were analyzed in patients with ST elevation AMI (35 patients treated with the TVAC system and 41 control patients). ST elevation recovery >50% of the initial value was observed after coronary intervention in 26/35 (74%) in patients treated with the TVAC system and 26/41 (63%) in control patients (P = 0.33). In the case of anterior AMI, ST elevation recovery >50% of the initial value was observed in 13/17 (76%) in patients treated with the TVAC system and 8/20 (40%) in control patients (P = 0.045). Thus, thrombectomy using a TVAC system is feasible, safe, and may have the potential to enhance ST-segment resolution in patients with anterior AMI.

Rheolytic Thrombectomy during Percutaneous Coronary Intervention Improves Long-Term Outcome in High-Risk Patients with Acute Myocardial Infarction

OBJECTIVES

Aim of the present study was to compare the immediate and long-term effects of AngioJet rheolytic thrombectomy performed in the setting of a percutaneous coronary angioplasty (PTCA) with those of conventional PTCA in patients with acute myocardial infarction (AMI) and angiographic evidence of high intracoronary thrombus burden.

BACKGROUND

Plaque rupture, with subsequent exposure to the flowing bloodstream of high thrombotic materials often leads to intravascular thrombosis, representing the main pathophysiological event of acute coronary syndromes. PTCA is the first-choice treatment for these patients in hospitals with cardiac catheterization facilities. However, distal embolization of thrombotic material, fibrin, and other fragments from atherosclerotic plaques might lead to procedural failure.

METHODS

Immediate and 1-year follow-up results of a group of 30 consecutive patients, presenting with AMI and angiographic evidence of high thrombus burden, who underwent rheolytic thrombectomy and PTCA were compared with those of 30 consecutive patients with similar clinical presentation, risk profile, and angiographic picture, and treated with standard PTCA procedure.

RESULTS

After the procedure, angiographic analysis showed a higher incidence of final thrombolysis in myocardial infarction (TIMI) flow grade 3 in the AngioJet group (93.3% vs 83.3%, P = 0.034). In addition, mean corrected TIMI frame count (cTFC) was significantly lower in the AngioJet group (22.4 vs 32.4, P = 0,0004). At 1-year follow-up, patients treated with AngioJet showed a significantly lower incidence of death (3.33% vs 13.33%,P < 0.001), major adverse cardiac events (MACE: 10% vs 30%, P = 0.026), and need of revascularization (6.67% vs 20%, P = 0.013).

CONCLUSIONS

Data of the present study highlight that AngioJet thrombectomy in selected AMI patients at high risk for distal thrombotic embolization results not only in immediately improved angiographic results as compared to conventional PTCA but, indeed, seems to be associated with a significantly better long-term clinical outcome.

Topographic association of angioscopic yellow plaques with coronary atherosclerotic plaque: assessment with quantitative colorimetry in human coronary artery autopsy specimens

Yellow plaques seen during coronary angioscopy are thought to be the surrogates for superficial intimal lipids in coronary plaque. Given diffuse and heterogeneous nature of atherosclerosis, yellow plaques in coronaries may be seen as several yellow spots on diffuse coronary plaque. We examined the topographic association of yellow plaques with coronary plaque. In 40 non-severely stenotic ex-vivo coronary segments (average length: 52.2 +/- 3.1 mm), yellow plaques were examined by angioscopy with quantitative colorimetry. The segments were cut perpendicular to the long axis of the vessel at 2 mm intervals, and 1045 slides with 5 microm thick tissue for whole segments were prepared. To construct the plaque surface, each tissue slice was considered to be representative of the adjacent 2 mm. The circumference of the lumen and the lumen border of plaque were measured in each slide, and the plaque surface region was constructed. Coronary plaque was in 37 (93%) of 40 segments, and consisted of a single mass [39.9 +/- 3.9 (0-100) mm, 311.3 +/- 47.4 (0.0-1336.2) mm2]. In 30 (75%) segments, multiple (2-9) yellow plaques were detected on a mass of coronary plaque. The number of yellow plaques correlated positively with coronary plaque surface area (r = 0.77, P < 0.0001). Yellow plaques in coronaries detected by angioscopy with quantitative colorimetry, some of them are associated with lipid cores underneath thin fibrous caps, may be used to assess the extent of coronary plaque. Further research using angioscopy could be of value to study the association of high-risk coronaries with acute coronary syndromes.

Quantitative colorimetry of atherosclerotic plaque using the L*a*b* color space during angioscopy for the detection of lipid cores underneath thin fibrous caps

OBJECTIVES

Yellow plaques seen during angioscopy are thought to represent lipid cores underneath thin fibrous caps (LCTCs) and may be indicative of vulnerable sites. However, plaque color assessment during angioscopy has been criticized because of its qualitative nature. The purpose of the present study was to test the ability of a quantitative colorimetric system to measure yellow color intensity of atherosclerotic plaques during angioscopy and to characterize the color of LCTCs.

METHODS

Using angioscopy and a quantitative colorimetry system based on the L*a*b* color space [L* describes brightness (-100 to +100), b* describes blue to yellow (-100 to +100)], the optimal conditions for measuring plaque color were determined in three flat standard color samples and five artificial plaque models in cylinder porcine carotid arteries. In 88 human tissue samples, the colorimetric characteristics of LCTCs were then evaluated.

RESULTS

In in-vitro samples and ex-vivo plaque models, brightness L* between 40 and 80 was determined to be optimal for acquiring b* values, and the variables unique to angioscopy in color perception did not impact b* values after adjusting for brightness L* by manipulating light or distance. In ex-vivo human tissue samples, b* value >/=23 (35.91 +/- 8.13) with L* between 40 and 80 was associated with LCTCs (fibrous caps <100 mum).

CONCLUSIONS

Atherosclerotic plaque color can be consistently measured during angioscopy with quantitative colorimetry. High yellow color intensity, determined by this system, was associated with LCTCs. Quantitative colorimetry during angioscopy may be used for detection of LCTCs, which may be markers of vulnerability.

Update on coronary angioscopy: review of a 20-year experience and potential application for detection of vulnerable plaque

Predicting the occurrence of future acute coronary syndromes remains an important challenge of contemporary cardiology. It is thought that detecting the individual vulnerable plaques in patients can be an important step to preventing myocardial infarction and sudden cardiac death. Coronary angioscopy can provide detailed information of the luminal surface of plaque, such as color, thrombus, or disruption, and is one of a few possibly useful imaging modalities for identifying vulnerable plaques. During its 20-year history, coronary angioscopy has been used as a diagnostic tool or to guide coronary angioplasty, and has contributed to our understanding of the pathophysiology of coronary artery disease. Yellow plaques seen during angioscopy seem to have many characteristics of high risk or vulnerable plaques, most consistent with the thin-cap fibroatheroma. Moreover, differences in yellow color have been reported to reflect differences in the structure or composition of plaques. Development of quantitative methods to assess plaque color and histopathologic correlations in conjunction with prospective natural history studies may lead to advances in vulnerable plaque detection by coronary angioscopy. Although current angioscopic devices are limited by the need to displace the column of blood in order to see the vessel wall, and by the lack of quantitative colorimetric methods, advances in technology may lead to new device versions that could be practical for expanded clinical use.

Number of yellow plaques detected in a coronary artery is associated with future risk of acute coronary syndrome: detection of vulnerable patients by angioscopy

OBJECTIVES

We sought to test whether the risk of acute coronary syndrome (ACS) can be estimated by angioscopy.

BACKGROUND

Disruption of vulnerable plaque and subsequent thrombosis is regarded as a major mechanism of ACS. Although yellow plaques are supposedly vulnerable, the association between angioscopically determined extent of coronary atherosclerosis and risk of ACS events has not been reported.

METHODS

Patients (n = 552) who received catheterization and angioscopic examination for the diagnosis of coronary artery diseases were prospectively included and followed up for new onset of ACS events. Yellow color intensities of all detected yellow plaques were graded as 1, 2, or 3 according to the standard colors. Number of yellow plaques (NYP) in a coronary artery and maximum color grade of detected yellow plaques (maxYP) were determined. Association between the incidence of ACS events and angioscopic findings were analyzed.

RESULTS

Follow-up interval was 57.3 +/- 22.1 months. Acute coronary syndrome events were detected in 39 patients (7.1%). Although maxYP was not statistically different (2.0 +/- 0.7 vs. 1.8 +/- 0.9; p = 0.18), NYP was higher in the patients with an ACS event than those without the event (3.1 +/- 1.8 vs. 2.2 +/- 1.5; p = 0.008). Patients with NYP > or =2 and those with NYP > or =5 had 2.2- and 3.8-fold higher event rates, respectively, than those with NYP 0 or 1 (9.0% and 15.6%, respectively, vs. 4.1%; p = 0.02). Multivariate logistic regression analysis revealed NYP and multivessel disease as the independent risk factors of ACS events.

CONCLUSIONS

Patients with multiple yellow plaques per vessel have a higher risk of suffering ACS events than those with NYP 0 or 1. Angioscopy would be useful to detect vulnerable patients.

Distal Myocardial Protection During Percutaneous Coronary Intervention

The discrepancy between angiographic success and microvascular perfusion has been recognized for some time. In the face of an open artery, the degree of microvascular perfusion determines post-infarct prognosis. Despite successful epicardial recanalization, tissue perfusion may be absent in up to 25% patients with acute myocardial infarction. Historically associated with saphenous vein graft intervention, embolization is increasingly recognized in native coronary arteries, particularly in patients undergoing primary percutaneous coronary intervention (PCI). With more than two million PCI procedures performed worldwide each year, there is enormous interest in protecting the left ventricular myocardium from embolization during PCI. This article reviews the evidence for distal myocardial protection and discusses the relative merits of the different available techniques.

Relationship between myocardial injury and soluble P-selectin in non-ST elevation acute coronary syndromes

BACKGROUND

The relationships among troponin concentration, early phase coagulation activation and soluble P-selectin concentration was evaluated in this study.

METHODS AND RESULTS

Troponin-l, soluble P-selectin, von Willebrand factor (vWF), fibrinogen, plasminogen, plasminogen activator inhibitor 1 (PAI-1) and tissue plasminogen activator (t-PA) concentrations of 202 consecutive patients with non-ST elevation acute coronary syndrome (NSTE-ACS) were measured at the time of admission. Patients were classified into 2 groups as troponin-negative (<0.2 ng/ml, n=129) or positive (>or=0.2 ng/ml, n=73). Soluble P-selectin concentrations were found to be higher (p<0.001) and correlated with troponin concentrations (r=0.313, p<0.005) in troponin-positive patients with NSTE-ACS. In these patients fibrinogen (p<0.001), plasminogen (p<0.001) and PAI-1 (p<0.026) concentrations were higher and t-PA concentrations were lower (p<0.013) and all these parameters correlated with P-selectin concentrations (p<0.001). There was no difference between the groups according to vWF concentrations (p=0.379). Soluble P-selectin concentrations were found to be an independent predictor of troponin positivity (beta=0.295, odds ratio =1.05, p<0.001). Analysis of regression revealed a significant effect of troponin on soluble P-selectin concentrations (r=0.52, r2=0.27, p<0.001).

CONCLUSIONS

The results suggest that higher soluble P-selectin concentrations might be involved in increased coagulation activation and myocardial injury development in patients with NSTE-ACS.

Association between cardiac troponin T elevation and angioscopic morphology of culprit lesion in patients with non-ST-segment elevation acute coronary syndrome

BACKGROUND

It is well known that cardiac troponin T (TnT) elevation on admission indicates a high-risk subgroup among patients with non-ST-segment elevation acute coronary syndrome (NSEACS). Although the mechanism of TnT elevation is speculated to be the microthromboembolism from unstable plaques, it has not been clarified. The aim of this study is to clarify the association between the serum TnT elevation and the angioscopically evaluated morphology of culprit lesion in the patients with NSEACS.

METHODS

Among 113 patients with NSEACS who had significant coronary stenosis, 62 patients with successful angioscopic examination were prospectively and consecutively enrolled from October 2001 to August 2002. Patients were divided into 2 groups according to the serum TnT level measured before percutaneous coronary intervention: TnT-positive or TnT-negative group. Thrombus and plaque color at culprit lesion were evaluated by angioscopy and were compared between the groups. Plaque color was determined as yellow or white, and thrombus as none, small, or large. Three different definitions for TnT-positive (> or =0.1, > or =0.03, and > or =0.01 ng/mL) were used and the sensitivity and specificity for detecting thrombus was compared.

RESULTS

Prevalence of thrombus, large thrombus, and yellow plaque were all higher in TnT-positive than in TnT-negative group for 3 different cutoff values of TnT. Angiographic slow-flow occurred more frequently after percutaneous coronary intervention in TnT-positive than in TnT-negative group for 3 different cutoff values of TnT. Sensitivity/specificity of detecting large thrombus were 33%/100%, 44%/91%, and 56%/83% when TnT-positive was defined as TnT > or = 0.1, > or =0.03, and > or =0.01 ng/mL, respectively.

CONCLUSIONS

Serum TnT level was significantly associated with the prevalence of thrombus and yellow plaque at the culprit lesions of NSEACS. Troponin T, when positive was defined as > or =0.01 ng/mL, still have a high specificity for detecting intracoronary thrombus.

Detection of coronary plaque by computed tomography with a novel plaque analysis system, 'Plaque Map', and comparison with intravascular ultrasound and angioscopy

BACKGROUND

Previous reports suggest that plaque may be characterized by the computed tomography (CT) number, but there is not a comprehensive method for evaluating the gray-scale CT image of the coronary artery obtained by multi-detector row CT (MDCT).

METHODS AND RESULTS

Forty-five patients with acute coronary syndrome (ACS) underwent MDCT either 3-4 weeks after the onset of acute myocardial infarction (n=24) or within 1 week after percutaneous coronary intervention in patients with unstable angina (UA; n=21). The cross-sections obtained at intervals of 5 mm were converted to numerical data and a 'plaque map' was drawn using the color-based isometric line method and bird's eye view. 'Plaque map' was compared with the findings of intravascular ultrasound (IVUS) and angioscopy. Of 662 slices of 78 vessels, soft, intermediate or calcified plaque was detected in 144, 134, and 84 slices, respectively. Compared with IVUS, the sensitivities were 92%, 87%, and 89%, respectively, and compared with angioscopy, sensitivity was 80% and specificity was 87%.

CONCLUSIONS

MDCT with the 'Plaque Map' system can noninvasively characterize plaque in patients with ACS.

Assessment of plaque vulnerability by angioscopic classification of plaque color

BACKGROUND

The disruption of yellow plaque and subsequent thrombosis is regarded as the mechanism of acute coronary syndrome. However, there are limited reports on the assessment of plaque vulnerability. Therefore, we tested whether the angioscopically determined yellow color intensity of plaque is associated with the prevalence of thrombosis on the plaque.

METHODS

The angioscopic images of 843 patients who underwent catheterization and angioscopic examination from November 1999 to July 2003 for the diagnosis of coronary artery diseases were analyzed. Suspected culprit vessel was observed by angioscopy, and the yellow color intensity (1, light yellow; 2, yellow; 3, intensive yellow) of all yellow plaques (n = 1253) detected in the nonstenotic (diameter stenosis <50%) coronary segments was determined, as well as whether there was thrombosis on the plaques.

RESULTS

The number of detected yellow plaques was 345, 721, and 187 for color grade 1, 2, and 3, respectively. The prevalence of thrombosis detected by angioscopy (15%, 26%, and 52% on the plaque of color grade 1, 2, and 3, respectively, P <.0001) was significantly higher on the plaque of higher yellow color grade.

CONCLUSIONS

The yellow color intensity of plaque determined by angioscopy was strongly related with the prevalence of thrombosis on the plaque. The yellow color intensity may be a marker of plaque vulnerability.

Atheromatous plaque cap thickness can be determined by quantitative color analysis during angioscopy: implications for identifying the vulnerable plaque

BACKGROUND

Coronary angioscopy in acute myocardial infarction has frequently revealed disrupted yellow lesions. Furthermore, postmortem studies have demonstrated that these lesions have thin collagenous caps with underlying lipid-rich cores.

HYPOTHESIS

We hypothesized that the yellow color is due to visualization of reflected light from the lipid-rich yellow core through a thin fibrous cap. Thus, quantification of yellow color saturation may estimate plaque cap thickness and identify vulnerable plaques.

METHODS

To test this hypothesis, the feasibility of detecting cap thickness was tested using both a model of lipid-rich plaque and human atherosclerotic plaque. The model was constructed by injecting a yellow beta-carotene-lipid emulsion subendothelially into normal bovine aorta. Human plaque was obtained from cadaver aorta. Digitized images were obtained by angioscopy, and percent yellow saturation was analyzed using a custom computer program. Plaque cap thickness was measured by planimetry of digitized images on stained tissue sections. Percent yellow saturation was then correlated with plaque cap thickness.

RESULTS

In the bovine model, plaque cap thickness and percent yellow saturation correlated inversely (r2 = 0.91; p = 0.0001). In human plaques, yellow saturation was significantly greater in atheromatous than in white plaques (p < 0.0004). Also, there was a high correlation between plaque cap thickness and yellow saturation at various angles of view between 40 degrees and 90 degrees, the greatest between 50 degrees and 80 degrees (r2 = 0.75 to 0.88).

CONCLUSION

Plaque cap thickness is a determinant of plaque color, and this can be assessed by quantitative colorimetry. Thus, plaque color by angioscopy may be useful for detecting vulnerable plaques.

Morphologic changes in infarct-related plaque after coronary stent placement: a serial angioscopy study

OBJECTIVES

The aim of this study was to investigate the morphologic changes in infarct-related lesions after stenting in acute or recent myocardial infarction (MI) with coronary angioscopy.

BACKGROUND

There is no information on the serial morphologic changes, which occur after stenting, and the time course of neointimal coverage of stents for disrupted unstable plaques.

METHODS

Forty-three patients with MI within seven days of onset were examined. Angioscopy was serially performed for the infarct-related lesions at baseline (n = 43), after balloon angioplasty (n = 35), and after stenting following balloon angioplasty (n = 39) and at one (n = 36) and six months (n = 30) after stenting.

RESULTS

At baseline, most of the lesions had complex morphology, yellow plaque color, and protruding thrombus (96%, 96%, and 74%, respectively). Although balloon angioplasty reduced the protruding thrombus, it remained in 37%, and an intimal flap was observed in 89% of the lesions. After stenting, the protruding thrombus and intimal flap disappeared, with an increased luminal size obtained in all lesions. At one-month follow-up, an irregular and yellow surface, along with a lining thrombus, was still observed, with partial neointimal stent coverage in most of the lesions. At six-month follow-up, the neointima was found to have sufficiently formed over the stent. The plaque shape and color were almost all classified as smooth (97%) and white (93%).

CONCLUSIONS

These results suggest that a stent not only compressed and covered a disrupted plaque with a protruding thrombus and intimal flap, leading to a wide vessel lumen, but also helped to seal the unstable plaque through neointimal proliferation.

Changes in coronary plaque color and morphology by lipid-lowering therapy with atorvastatin: serial evaluation by coronary angioscopy

OBJECTIVES

Changes in coronary plaque color and morphology by statin therapy were evaluated using coronary angioscopy.

BACKGROUND

Coronary plaque stabilization by statin therapy has not been clarified in humans.

METHODS

Thirty-one patients with coronary artery disease were divided into either the comparison group (n = 16) or the atorvastatin group (n = 15). Before treatment and 12 months after, the color and complexity of 145 coronary plaques were determined according to angioscopic findings. The yellow score of the plaque was defined as 0 (white), 1 (light yellow), 2 (yellow), or 3 (dark yellow), and its disrupted score was defined as 0 (smooth surface) or 1 (irregular surface) and as 0 (without thrombus) or 1 (with thrombus). In each patient, the mean yellow score and mean disrupted score were calculated.

RESULTS

Mean low-density lipoprotein cholesterol (LDL-C) decreased by 45% in the atorvastatin group, whereas an increase of 9% was seen in the comparison group. The mean yellow score decreased from 2.03 to 1.13 in the atorvastatin group, whereas it increased from 1.67 to 1.99 in the comparison group. There was a good correlation between the change in the mean yellow score and the change in LDL-C levels (r = 0.81, p < 0.0001). The change in the mean yellow score and mean disrupted score differed significantly between the two groups (p = 0.002 and p = 0.03, respectively).

CONCLUSIONS

This is the first report clarifying detailed changes in coronary plaque by statin in humans. This study indicated that lipid-lowering therapy changes plaque color and morphology and should then lead to coronary plaque stabilization.

Plaque disruption and thrombus in Ambrose's angiographic coronary lesion types

Lesion eccentricity with irregularities on coronary angiography is associated with ruptured plaques and thrombus based on postmortem and clinical angiographic studies. However, the predictive value of such angiographic markers of plaque disruption and thrombus remains to be determined in vivo. The purpose of this study was to establish whether Ambrose's angiographic coronary lesion types and other angiographic criteria predict the presence of disrupted plaques and thrombus using intracoronary angioscopy. Angioscopy was performed before angioplasty in 60 patients with various coronary syndromes and culprit lesions that were not totally occlusive. Lesions were classified angiographically according to Ambrose's criteria as concentric, type I and II eccentric, and multiple irregularities, or as complex or noncomplex, and then compared with the corresponding angioscopic findings. Disruption and/or thrombus were seen in 17 of 19 type II eccentric lesions and 21 of 23 angiographically complex lesions and had the highest positive predictive value to detect complicated atherosclerotic plaques (type II eccentric lesions: positive predictive value 89%, 95% confidence intervals 67% to 99%; complex lesions: 91%, 95% confidence intervals 72% to 99%). We conclude that Ambrose's type II eccentric stenoses and angiographically complex lesions are strongly associated with disrupted plaques and/or thrombus as assessed by angioscopy in patients and represent unstable plaque substrates.

Safety and efficacy of a novel device for treatment of thrombotic and atherosclerotic lesions in native coronary arteries and saphenous vein grafts: results from the multicenter X-Sizer for treatment of thrombus and atherosclerosis in coronary applications trial (X-TRACT) study

Intervention in thrombotic lesions and diseased saphenous vein grafts frequently results in thromboembolic complications, including no-reflow, distal branch occlusion, periprocedural MI, and death. The utility of a novel thromboatherectomy device, the X-Sizer, was tested in 50 consecutive patients at nine U.S. centers. A total of 61 lesions were treated in 31 vein grafts and 19 native coronary arteries; thrombus was present in 78% of lesions, and TIMI 0-1 flow in 21%. TIMI 3 flow improved from 57% at baseline to 94% postprocedure. No patient developed visible distal thromboemboli, side-branch occlusion, or reduced antegrade flow. Thirty-day events included one death (2.0%), Q- or non-Q-wave MI in 4.0%, TVR in 6.0%, and any MACE in 6.0%. We conclude that the use of the X-Sizer prior to percutaneous intervention is safe in high-risk vein grafts and thrombotic lesions and results in a low rate of adverse events compared to historical controls.

Angioscopy and ischemic heart disease

Angioscopy allows direct visualization of the coronary artery lumen and provides detailed information regarding the surface characteristics of the vessel wall and specific lesions causing acute coronary syndromes. Disruption of a plaque, ulceration, tears, fissures, lipid-rich or fibrous lesions, and luminal or mural thrombus can be readily detected in vivo. Characterization of culprit lesions in various coronary syndromes reveals the different mechanisms of ischemia. The predominant lesion in acute myocardial infarction is an ulcerated, yellow plaque with thrombus. In unstable angina, different substrates can be seen, from the lipid-rich lesion with thrombus to the fibrous smooth plaque, reflecting a varied physiopathology. Because of its ability to detect superficial lipid pools, angioscopy may be valuable for the detection of vulnerable plaques.

AngioJet thrombectomy and stenting for reperfusion in acute MI complicated with cardiogenic shock

AngioJet thrombectomy (AJ) has been shown to be safe and effective in treatment of acute myocardial infarction (AMI). However, use of AJ has not been studied extensively in AMI with cardiogenic shock (CS). Clinical outcomes in 19 patients with CS and treated with AJ were retrospectively analyzed. Immediate stenting was also performed. Procedure success (final diameter stenosis < 50% and TIMI flow > or = 2) was achieved in 95%, with final TIMI 3 flow in 89%. Clinical success (procedure success without major in-hospital cardiac events) was achieved in 68%. There were five in-hospital deaths and no patients experienced stroke or required emergent bypass surgery. At 30-day follow-up, there were no additional deaths or stroke, and two patients had undergone target vessel revascularization. AJ is relatively safe and effective in the setting of AMI complicated with CS, allowing for immediate definitive treatment. This strategy may offer improved mortality in these high-risk patients.

In vitro bleeding test with PFA-100-aspects of controlling individual acetylsalicylic acid induced platelet inhibition in patients with cardiovascular disease

OBJECTIVES

This study investigated the usefulness and practicability of a platelet function analyzer (PFA-100(TM), DADE-Behring, Germany) to determine individual platelet inhibition in patients treated with acetylsalicylic acid (ASA).

BACKGROUND

Patients with coronary artery disease (CAD) routinely and during angioplasty (PTCA) receive standard doses of ASA to avoid acute coronary syndromes and abrupt vessel closures without information of the individual efficacy of platelet inhibition.

METHODS

With the PFA-100(TM) a standardized bleeding time is measured. Whole-blood anticoagulated with 3.2% sodium citrate is aspirated through a capillary ( solidus in circle 200 microm) and through an aperture ( solidus in circle 147 microm). The time until occlusion of the aperture (closure time, CT) by a stable platelet plug induced by shear stress, collagen and epinephrine (COLL/EPI-CT) or shear stress, collagen and adenosine 5'-diphosphate (COLL/ADP-CT) is determined. To examine the usefulness of the PFA-100(TM) as a rapid bedside test and the individual effect of ASA, closure time was measured in healthy individuals (n=17), in patients with stable CAD (n=19) and in patients undergoing PTCA (n=8).

RESULTS

Patients with stable CAD and regular medication with 100 mg ASA per day for at least 3 month showed shorter COLL/ADP-CT in comparison to healthy individuals who took only one single dose of 100 mg ASA. Of the patients with CAD 63% had a COLL/EPI-CT within normal range suggesting a low or no response to ASA. Also only 50% of the patients undergoing PTCA reached the expected COLL/EPI-CT>300 s after an additive single dose of 500 mg ASA intravenously. Neither heparin, phenprocoumon, sex nor different blood sampling methods seem to influence the measurements relevantly.

CONCLUSIONS

This pilot study indicates that with the PFA-100(TM) test device a simple and quick measurement of an in vitro bleeding time is possible. It is able to detect an increase in the bleeding time after a single dose of ASA 100 mg in healthy subjects, reflecting a sensitive detection of ASA induced changes in platelet inhibition respective activation. Differences in the individual response to ASA could be observed in healthy subjects, patients with stable CAD and patients undergoing PTCA. Further studies should validate the PFA-100(TM) with standard methods to determine ASA response in patients with cardiovascular disease and investigate implications for treatment and outcome in this patient group.

The healing process of infarct-related plaques. Insights from 18 months of serial angioscopic follow-up

OBJECTIVES

To clarify the healing process of disrupted culprit plaques of acute myocardial infarction (MI), we serially observed the culprit plaques for 18 months after the onset of acute MI by angioscopy.

BACKGROUND

Although it has been reported that disruption of the yellow plaque and subsequent thrombosis cause acute MI and that the thrombogenicity of the plaque lasts for a month, the healing process of the plaque after disruption has not been clarified.

METHODS

Eighty-five patients with acute MI were prospectively and consecutively enrolled. Angioscopic studies were performed immediately and at 1, 6 and 18 months after successful reperfusion. The prevalence of yellow plaques and thrombus was examined. The color grade of the plaque was determined as 0 (white), 1 (light yellow), 2 (yellow) or 3 (bright yellow).

RESULTS

Although yellow plaque was present at the culprit lesion in most patients throughout follow-up, its color grade was reduced from one to six months (1.9 +/- 0.6 vs. 1.1 +/- 0.7, p = 0.0003) after reperfusion, especially in the patients without hyperlipidemia (HL). The incidence of thrombus was 92.5% immediately after reperfusion, which was reduced significantly to 63.8%, 4.8% and 11.8% at 1, 6 and 18 months, respectively. The incidence of thrombus (77.8% vs. 45.0%, p = 0.03) at one month was higher in the patients with diabetes mellitus (DM).

CONCLUSIONS

The healing process of yellow plaques at the culprit lesions of MI was detected by angioscopy as reductions of color grade and thrombogenicity at six months and partially at one month after the onset of acute MI. This healing process appears to deteriorate by complicating cases of DM or HL.

Extensive development of vulnerable plaques as a pan-coronary process in patients with myocardial infarction: an angioscopic study

OBJECTIVES

To test our hypothesis that the development of vulnerable plaques is not limited to the culprit lesions, but is a pan-coronary process, we directly observed all three major coronary arteries by angioscopy and evaluated the prevalence of yellow plaques in patients with myocardial infarction (MI).

BACKGROUND

Although pathologic studies have suggested that the disruption of atheromatous plaque plays a major role in the development of acute MI, the prevalence of yellow plaques in the whole coronary arteries of patients with MI has not been clarified.

METHODS

Thirty-two patients undergoing follow-up catheterization one month after the onset of MI were prospectively and consecutively enrolled in this study. The prevalence of yellow plaques and thrombus in the major coronary arteries was successfully evaluated in 20 patients (58 coronary arteries, 21 culprit lesions) by coronary angioscopy. The diameter stenosis (DS) of the culprit lesions and the maximal diameter stenosis (maxDS) of nonculprit segments were angiographically measured for each coronary artery.

RESULTS

The DS of the culprit lesions and maxDS were 27 +/- 17% and 19 +/- 13%, respectively. Yellow plaques and thrombus were detected in 19 (90%) and 17 (81%) of 21 culprit lesions, respectively. Yellow plaques were equally prevalent in the infarct-related and non-infarct-related coronary arteries (3.7 +/- 1.6 vs. 3.4 +/- 1.8 plaques/artery). However, thrombus was only detected in the nonculprit segments of one (2%) coronary artery.

CONCLUSIONS

In patients with MI, all three major coronary arteries are widely diseased and have multiple yellow though nondisrupted plaques. Acute MI may represent the pan-coronary process of vulnerable plaque development.

Histopathologic validation of in-vivo angioscopic observation of coronary thrombus after angioplasty in a porcine model

BACKGROUND

Coronary angioscopy has been reported to be superior to angiography and intravascular ultrasound for detecting intracoronary thrombus. However, in-vivo histopathologic validation of angioscopic detection of intracoronary thrombus had not been performed.

OBJECTIVE

To perform histopathologic validation of in-vivo angioscopic detection of coronary thrombus.

DESIGN

An experimental, blinded comparison of angioscopy and histopathology.

METHODS

Coronary angioscopy was performed from 0 to 14 days after angioplasty in 39 porcine coronary arteries. When thrombus was detected by angioscopy, it was subclassified into white, mixed red-white, or red thrombus according to color. By histopathology the presence of thrombus was determined and subclassified into platelet-rich, mixed platelet-erythrocyte, or erythrocyte-rich thrombus.

RESULTS

Angioscopy correctly classified 19 of 21 coronary thrombi (sensitivity 90%) but incorrectly classified nine of 18 arteries without formation of thrombus as having a thrombus (specificity 50%). Positive and negative predictive values were 68 and 82%, respectively. The angioscopic subclassification of thrombus into white, mixed red-white, or red thrombi was not correlated to the corresponding histopathologic morphology (platelet-rich, mixed platelet-erythrocyte, or erythrocyte-rich) of the observed thrombi (chi2 test: P = 0.5).

CONCLUSIONS

Angioscopic detection of thrombus in vivo had high sensitivity and negative predictive value but low-to-moderate specificity and positive predictive value. Visual assessment of color of angioscopically detected thrombi seemed not to reflect histopathologic morphology of thrombus according to the definitions used in the present study.

Coronary microcirculatory vasoconstriction during ischemia in patients with unstable angina

OBJECTIVE

To verify the behavior of coronary microvascular tone during spontaneous ischemia in patients with unstable angina (UA).

BACKGROUND

In UA, the pathogenetic role of vasoconstriction is classically confined at the stenotic coronary segment. However, microcirculatory vasoconstriction has been also suggested by previous experimental and clinical studies.

METHODS

The study included 10 patients with UA (recent worsening of anginal threshold and appearance of angina at rest) and single-vessel CAD. Blood flow velocity was monitored by a Doppler catheter in the diseased artery. Transstenotic pressure gradient was monitored by aortic and distal coronary pressure monitoring. Stenosis resistance was calculated as the ratio between pressure gradient and blood flow, microvascular resistance as the ratio between distal pressure and blood flow. Measurements were obtained at baseline, following intracoronary adenosine (2 mg) and during transient ischemia. Aortic and distal coronary pressures were also measured during balloon coronary occlusion.

RESULTS

Adenosine did not affect stenosis resistance, while it decreased (p < 0.05) microvascular resistance to 52 +/- 22% of baseline. Angina and ischemic ST segment shift were associated with transient angiographic coronary occlusion in 7 of 10 patients; however, in no case was ischemia associated with interruption of flow. Despite markedly different flow values, distal coronary pressure was similar during adenosine and during spontaneous ischemia (48 +/- 15 vs. 46 +/- 20 mm Hg, respectively, NS). During ischemia, a marked increase in the resistance of both coronary stenosis and coronary microcirculation was observed (to 1,233% +/- 1,298% and 671% +/- 652% of baseline, respectively, p < 0.05). Distal coronary pressure was markedly reduced during balloon coronary occlusion (14 +/- 7 mm Hg, p < 0.05 vs. both adenosine and ischemia), suggesting the absence of significant collateral circulation.

CONCLUSIONS

In patients with UA, transient myocardial ischemia is associated with vasoconstriction of both stenotic arterial segment and downstream microcirculation.

Changes of hemostasis, endogenous fibrinolysis, platelet activation and endothelins after percutaneous transluminal coronary angioplasty in patients with stable angina

OBJECTIVES

This study investigated parameters of endogenous fibrinolysis, activation of coagulation and platelets, and endothelin levels before and after elective percutaneous transluminal coronary angioplasty (PTCA) in patients with stable coronary artery disease (CAD).

BACKGROUND

Abrupt vessel closure is a serious short-term complication after PTCA and is often unforeseeable. Detailed insight into the effect of PTCA on hemostasis, platelets and the release of vasoconstrictive substances, which are among the mainly discussed mechanisms of abrupt vessel closure, is needed to enhance the safety of coronary intervention.

METHODS

Plasma levels of markers of platelet activity, coagulation, endogenous fibrinolysis and endothelins were determined in 20 patients with stable CAD undergoing elective PTCA. The blood specimens were drawn before, immediately after, 1 h after intervention and on the next morning.

RESULTS

All patients showed an initially uncomplicated PTCA. Regarding the efficacy of anticoagulation after receiving 15.000 IU heparin during PTCA, two groups were compared. In eight patients with ineffective anticoagulation production of thrombin and platelet activation directly after and 1 h after PTCA was significantly higher compared with 12 patients with effective anticoagulation. Despite the strong activation of coagulation, only a low fibrinolytic response could be observed. Endothelins rose significantly after PTCA in both groups but stayed longer on higher levels in patients with distinct thrombin generation. Three of the eight patients without sufficient heparin treatment suffered abrupt vessel closure.

CONCLUSIONS

Initially uncomplicated dilation of coronary arteries leads to systemically measurable activation of coagulation and platelets in patients with ineffective doses of heparin and release of endothelins in all patients. Therefore, individual adjustment of anticoagulation and platelet inhibition in combination with effective antivasospastic substances are needed in every patient before, during and after initially uncomplicated PTCA to prevent this serious complication.

Interventional Cardiology: Advances in Percutaneous Techniques for the Treatment of Cardiac Disease

The field of interventional cardiology began in the late 1970s and consisted primarily of balloon catheter angio plasty until the early 1990s. Although understanding of the process of coronary angioplasty has evolved signifi cantly, restenosis still remains the Achilles' heel of the interventional cardiologist. This article reviews the cur rent issues involved in interventional cardiology for coronary disease from patient selection, anticoagulant therapy, restenosis, current interventional devices (stent mania), and future devices (intracoronary radiation). Noncoronary interventional procedures, vaivuloplasty, and atrial septal defect closure are also reviewed to provide an overview of cardiac interventional proce dures for the anesthesiologist.

Characterization of the unstable lesion by angiography, angioscopy, and intravascular ultrasound

Acute coronary syndromes are a spectrum of clinical presentations with various pathophysiologic substrates. As such, there is not one single type of lesion responsible for stable or unstable angina, acute myocardial infarction, and sudden cardiac death. Most of the information regarding the characteristics of culprit lesions derives from histopathologic studies, whether postmortem or from atherectomy samples, and from studies using angiography, angioscopy, and intravascular ultrasound. Characterization of the unstable coronary lesion is key to understanding the pathophysiology of coronary artery disease, this knowledge will allow clinicians to individualize treatment according to specific lesion types, and more importantly, will lead to strategies to identify atherosclerotic lesions in their early stages and implement preventive therapies.

Detecting and differentiating white from red coronary thrombus by angiography in angina pectoris and in acute myocardial infarction

To determine the ability to detect thrombus by angiography, angioscopy was performed before angiography in patients undergoing interventional procedures and the data collected in a blinded fashion. These data demonstrated that the sensitivity of angiography to detect white thrombus was 50% and the specificity was 95%, whereas the sensitivity and specificity to detect red thrombus was 100%, respectively; the positive and negative predictive value of detecting thrombus in general was 89% and 83%, respectively.

Pathology of unstable plaque: correlation with the clinical severity of acute coronary syndromes

OBJECTIVES

The aim of this study was to relate the various clinical presentations of acute coronary syndromes to the underlying plaque morphology as assessed from histopathologic analysis of plaque fragments obtained by directional coronary atherectomy (DCA).

BACKGROUND

Autopsy studies have shown that unstable angina and infarction are related to plaque instability and involve events such as fissure or rupture of the fibrous cap, thrombosis and inflammation. The clinical severity and prognosis of acute coronary syndromes can be estimated by the Braunwald classification of unstable angina. Whether plaque morphology can be related to the Braunwald classification has not been evaluated.

METHODS

Plaque fragments were obtained by DCA in 75 patients: 38 with unstable angina, 19 with stable angina and 18 with no symptoms after infarction. The presence of fibrous tissue, thrombus, high cellularity, inflammatory cells, atheroma, neovessels and "stellar-shaped" smooth muscle cells was evaluated in 7-micron thick sections by appropriate staining. The patients were classified according to clinical presentation without knowledge of the results of pathologic examination, and a plaque instability score was assigned. The risk of further cardiac events was classified as low, medium or high.

RESULTS

Increasing severity of the score of unstable angina was associated with increasing prevalence of thrombus, high cellularity, atheroma and neovessels. Plaque from patients with unstable angina considered to be at low risk of further events appeared very similar to that of patients with stable angina, whereas the specific morphologic characteristics of plaque instability were more frequently observed as the clinical score and the risk of further events increased. After thrombolyzed infarction, plaque morphology depends on the delay between the acute event and DCA. Within 1 week after infarction, plaque still showed the morphologic characteristics of instability, whereas late DCA provided samples with morphologic features similar to those observed in patients with stable angina.

CONCLUSIONS

The morphologic features of plaque fragments vary at different stages of acute coronary disease. The specific features of plaque instability correlate with the clinical scoring system of the Braunwald classification.

Improving the results of coronary angioplasty

Coronary angioplasty has changed dramatically in the past three years with major reductions in suboptimal results and restenosis rates, and improvements in safety, efficacy and cost-effectiveness. Intracoronary stent implantation with optimisation of strut expansion and the abandonment of anticoagulants after deployment, have led to less entry-site complications, facilitated early hospital discharge, virtually abolished subacute stent thrombosis and resulted in a 50% reduction in target vessel revascularisation. Adjuvant medical treatment with anti-platelet agents, including glycoprotein IIb/IIIa receptor inhibitors, improves the safety of angioplasty and may further reduce the restenosis rate. Selective use of debulking devices has extended the indications for angioplasty. High resolution fluoroscopy, quantitative coronary angiography and intracoronary ultrasound leading to improved diagnosis, equipment selection and treatment have contributed to better outcomes. Further clinical trials will compare angioplasty and stent implantation with coronary bypass surgery in patients with multivessel coronary disease, and may extend the indications for percutaneous transluminal coronary angioplasty (PTCA) to selected patients with three vessel disease.

Angioscopy variables predictive of early angiographic outcome after excimer laser-assisted coronary angioplasty

This study attempted to determine whether anatomic findings at angioscopy were associated with adverse early angiographic outcomes following excimer laser-assisted coronary angioplasty. Predictive factors of either coronary abrupt vessel closure or early (< or =24 hours) restenosis after percutaneous coronary angioplasty, including clinical and angiographic variables, have been widely evaluated. The role of angioscopic findings may contribute to identification of patients at risk for early poor outcome. Thirty-seven patients with severe lesions, including 23 total occlusions which underwent successful percutaneous transluminal coronary angioplasty (PTCA) with laser irradiation and adjunctive balloon dilatation (n = 35), or stand alone laser (n = 2), had concomitant angioscopic imaging of the target vessel. All patients had a 24-hour angiographic follow up. Early unfavorable outcome (n = 15) was defined as abrupt vessel closure or restenosis (> or = 50% stenosis) at 24 hours. By multivariate logistic regression analysis, immediate post-PTCA residual percent stenosis was associated with a poor outcome (restenosis: 33 +/- 22% vs no restenosis: 21 +/- 14%, p = 0.05). Angioscopic red thrombus aspect was the most significant correlate for early closure or restenosis (7 of 15 patients with unfavorable outcome vs 2 of 22 patients with favorable outcome, odds ratio, 22.9; p < 0.01) and was associated with a significantly higher early minimal lumen diameter loss (1 +/- 0.8 mm in the presence of a red thrombus vs 0.3 +/- 0.5 mm without thrombus, p < 0.005). Red thrombus appearance is associated with an unfavorable early angiographic outcome in patients who undergo laser-assisted coronary angioplasty.