Intravascular ultrasound and 3D angle measurements of coronary bifurcations

Objective: To standardize the intravascular ultrasound (IVUS) analysis of coronary bifurcations. Background: Percutaneous treatment of bifurcation lesions is difficult particularly at the side branch ostium. Imaging techniques may improve our understanding of treatment options. There is no established IVUS methodology to assess the bifurcation. The present study aims to develop standards for bifurcation imaging. Methods: Quantitative IVUS analysis and 3D bifurcation angle measurements were performed in 34 patients who were selected from the Washington Hospital Center Database. Patients were included if both left anterior descending (LAD) and first diagonal (DX) pullbacks in the same procedure were done. Angiograms were available in 27 patients to measure the 3D bifurcation angle using specialized software. Pullbacks were analyzed proximal and distal to the bifurcation, and at the bifurcation. Results: Prox_LAD versus Prox_LAD(DX) were similar for vessel area (15.5 ± 4.6 mm² vs. 15.9 ± 4.0 mm², P = 0.19), lumen area (8.3 ± 3.6 mm² vs. 8.6 ± 3.3 mm², P = 0.25), and plaque area (7.2 ± 2.0 mm² vs. 7.3 ± 1.9 mm², P = 0.55). However, Bifurcation_LAD was larger than Bifurcation_DX for vessel area (17.3 ± 4.0 mm² vs. 16.6 ± 3.9 mm², P = 0.0083). The 3D angiographic bifurcation angle was 50° ± 13° (range of 26°–84°), and did not affect the IVUS measurements. IVUS analysis showed that bifurcation lesions did obey Murray's Law, as Prox_LAD lumen area measured 36.7 ± 25.1 mm³ versus Dist_LAD/Dist_DX measured 38.0 ± 29.1 mm³, P = 0.56. Conclusions: Two IVUS pullbacks should be performed for a complete assessment of the bifurcation and comparison with Murray's Law. The proposed IVUS analysis was not influenced by the bifurcation angle. © 2009 Wiley‐Liss, Inc.     

Virtual histology by intravascular ultrasound study on degenerative aortocoronary saphenous vein grafts

Data of virtual histology (VH) acquired by intravascular ultrasound (IVUS) on saphenous vein graft (SVG) lesions is lacking. This study sought to report the VH IVUS findings in degenerative aortocoronary SVG lesions and correlate various types of plaque compositions (fibrous, fibro-fatty, dense calcium, and necrotic core) with different clinical and lesion characteristics. Virtual histology IVUS was performed on SVG in 38 symptomatic patients with a history of coronary artery bypass grafting, who underwent percutaneous coronary intervention on either native vessels or SVG. Measurements were made at the image slice with the smallest lumen. A total of 54 SVG lesions were analyzed; the mean graft age was 13.7 ± 4.0 years. The mean vessel size was 5.0 ± 1.0 mm; plaque area was 13.4 ± 7.3 mm², and plaque burden was 63.0% ± 15.0%. Fibrous tissue represented the major plaque component (62.1% ± 17.1%). Lesions with a plaque burden of ≥70% were associated with positive remodeling, larger vessel size, higher percentage of fibro-fatty tissue, but lower percentage of dense calcium. Plaque burden was found to be positively correlated with remodeling index (r = 0.37, P = 0.01) and % fibro-fatty tissue (r = 0.49, P < 0.001) but negatively correlated with % dense calcium (r= −0.31, P = 0.03). The severity of SVG atherosclerosis paralleled with a proportional increase in fibro-fatty tissue. Unstable plaques in SVG were associated with positive remodeling, lipid-rich atheroma, and less calcium deposition, similar to the VH IVUS findings in native coronary arteries.     

Serial intravascular ultrasound analysis comparing double kissing and classical crush stenting for coronary bifurcation lesions

Background : Compared with the classical crush, double kissing (DK) crush improved outcomes in patients with coronary bifurcation lesions. However, there is no serial intravascular ultrasound (IVUS) comparisons between these two techniques. Objectives : This study aimed to analyze the mechanisms of the two crush stenting techniques using serial IVUS imaging. Methods : A total of 54 patients with IVUS images at baseline, post‐stenting and eight‐month follow‐up were classified into classical (n = 16) and DK (n = 38) groups. All patients underwent final kissing balloon inflation (FKBI). Unsatisfactory kissing (KUS) was defined as the presence of wrist or >20% stenosis during FKBI at the side branch (SB) ostium. The vessels at bifurcation lesions were divided into the proximal main vessel (MV) stent, the crushed segment, the distal MV stent, the SB ostium and the SB stent body. Results : KUS and incomplete crushing were commonly observed in the classical group (62.5%, 81.3%), compared with DK group (18.0%, 39.5%, P < 0.001 and P = 0.004). The post‐stenting stent symmetry in the classical group was 71.85 ± 7.69% relative to 85.93 ± 6.09% in DK group (P = 0.022), resulting in significant differences in neointimal hyperplasia (NIH, 1.60 ± 0.21 mm² vs. 0.85 ± 0.23 mm², P = 0.005), late lumen loss (1.31 ± 0.81 mm² vs. 0.55 ± 0.70 mm², P = 0.013), and minimal lumen area (MLA, 3.57 ± 1.52 mm² vs. 4.52 ± 1.40 mm^2, P = 0.042) at the SB ostium between two groups. KUS was positively correlated with the incomplete crush and was the only predictor of in‐stent‐restenosis (ISR) at the SB ostium. Conclusion : DK crush was associated with improved quality of the FKBI and larger MLA. KUS predicted the occurrence of ISR. © 2011 Wiley Periodicals, Inc.     

Impact of Nonobstructive Left Main Coronary Artery Atherosclerosis on Long-Term Mortality

BackgroundAlthough the presence of severe stenosis in the left main coronary artery (LMCA) is a well-established predictor of mortality, whether this extends to nonobstructive atherosclerosis in the LMCA is unknown.ObjectivesThe aim of this study was to evaluate the association between LMCA disease by intravascular ultrasound (IVUS) and long-term mortality.MethodsBetween 2005 and 2013, 3,239 patients with LMCA IVUS imaging without LMCA revascularization (either before angiography or scheduled based on index angiography or IVUS) were included. The primary and secondary endpoints were all-cause and cardiac mortality at a minimum of 5 years obtained from the National Death Index.ResultsThe IVUS-measured LMCA minimum lumen area (MLA) and plaque burden were 13.1 ± 5.0 mm² and 41.7% ± 15.6%, respectively. The median follow-up was 8.2 years. The Kaplan-Meier estimated 12-year all-cause and cardiac death rates were 37.5% and 17.0%, respectively. Greater plaque burden (unadjusted HR per 10%: 1.17; 95% CI: 1.12-1.22; P < 0.0001) and smaller IVUS MLA (unadjusted HR per 1 mm²: 0.98; 95% CI: 0.96-0.99; P = 0.0008) were associated with all-cause death. After adjusting for clinical, angiographic, and IVUS factors, plaque burden (adjusted HR per 10%: 1.12; 95% CI: 1.04-1.21; P = 0.003) but not MLA (adjusted HR per 1 mm²: 1.02; 95% CI: 0.99-1.04; P = 0.18) was associated with long-term all-cause death. These findings were also consistent for long-term cardiac mortality.ConclusionsIn the present large-scale study with a 12-year follow-up, increasing LMCA plaque burden was associated with long-term all-cause and cardiac mortality in patients not undergoing LMCA revascularization, even when the lumen area was preserved.     

Prediction of the no-reflow phenomenon during percutaneous coronary intervention using coronary computed tomography angiography

Coronary computed tomography angiography (CTA) can assess plaque characteristics and plaque size noninvasively. The purpose of this study was to investigate whether coronary CTA before percutaneous coronary intervention (PCI) can predict the no-reflow phenomenon during PCI. Seventy-eight patients [acute coronary syndrome (ACS) = 43, stable angina pectoris (SAP) = 35, male/female = 72/6, age: 65 ± 10 years] who underwent 16- or 64-slice CTA in the 4 weeks before PCI were enrolled. The low attenuation plaque size on CTA was compared between patients with (NR+) and without the no-reflow phenomenon (NR−). No-reflow phenomenon was observed in 11 patients, including 10 patients with ACS and 1 patient with SAP. Low attenuation plaque was detected in 9 (82%) NR(+) lesions and 35 (52%) NR(−) lesions. The length of low attenuation plaque was significantly longer in NR(+) than in NR(−) patients (9.0 ± 6.5 vs. 1.6 ± 2.7 mm, p < 0.0001). On step-wise regression analysis, ACS (p = 0.036, 95% CI = 0.009–0.258) and the presence of low attenuation plaque with a length >4.7 mm (p < 0.001, 95% CI = 0.447–0.778) were significant independent predictors of NR(−) no-reflow phenomenon. Low attenuation plaque with lesion length of >4.7 mm on coronary CTA and ACS were the significant predictors for the no-reflow phenomenon during PCI. Coronary CTA assessment before PCI would be useful to predict coronary events during PCI in advance.     

Analysis of left main coronary artery bifurcation lesions treated with biolimus‐eluting DEVAX AXXESS plus nitinol self‐expanding stent: Intravascular ultrasound results of the AXXENT trial

Objective: To assess the efficacy of the AXXESS stent on the treatment of left main coronary artery (LMCA) bifurcation lesions using IVUS. Background: The treatment of LMCA bifurcation lesions remains challenging even with the use of drug‐eluting stents. The AXXESS system is a biolimus A9‐eluting self‐expanding stent, dedicated to the treatment of bifurcation lesions. Methods: Data were obtained from the AXXENT trial, a prospective, single‐arm, multicenter study designed to evaluate the efficacy of the AXXESS stent on the treatment of LMCA bifurcation lesions. IVUS was available in 26 cases at 6‐months follow‐up. Volumetric and cross‐sectional analyses within the AXXESS stent, and cross‐sectional analyses at the ostia of left anterior descending (LAD) and left circumflex coronary arteries (LCX) were performed. Results: Within the AXXESS stent, percent neointimal volume obstruction was (3.0 ± 4.1)% with a minimal lumen area of 10.3 ± 2.6 mm². AXXESS stent volume showed an 12.4% increase at follow‐up compared with postprocedure (P = 0.04). Lumen area was significantly smaller in the LCX ostium compared with the LAD ostium at follow‐up (3.6 ± 1.3 mm² vs. 5.5 ± 2.0 mm², P = 0.0112). There was greater neointimal formation in the LCX ostium compared with the LAD ostium (1.37 ± 1.20 mm² vs. 0.30 ± 0.36 mm², P = 0.0003). Conclusions: The AXXESS stent in the LMCA showed enlargement through 6‐months follow‐up and significant neointimal suppression. Greater neointimal formation and relatively inadequate stent expansion may contribute to luminal narrowing in the LCX ostium. © 2008 Wiley‐Liss, Inc.     

Improved left ventricular function after transplantation of microspheres and fibroblasts in a rat model of myocardial infarction

As a novel and promising therapeutic strategy for heart failure, the application of different cell types is the subject of increasing research interest. In this study we investigated the effect of several cell types and microspheres (uniform polystyrene microspheres, 10 μm diameter) transplanted 4 weeks after induction of myocardial infarction in a rat model. Eight weeks after intramyocardial application of fibroblasts and microspheres, left ventricular function was significantly improved as demonstrated by isolated heart studies (Langendorff) and echocardiographic findings (LVDP fibroblasts 129 ± 32.9 mmHg, LVDP microspheres 119.2 ± 24.1 mmHg, fractional shortening (FS) microspheres 38.9 ± 4.6%, FS fibroblasts 36.84 ± 6.05%) in contrast to injection of macrophages or medium alone (LVDP medium 67 ± 22.6 mmHg, LVDP macrophages 75.9 ± 24.8 mmHg, FS macrophages 29.16 ± 8.7%, FS medium 27.2 ± 7.2%, P < 0.05). Signals of Bromodesoxy-Uridine (BrdU) labeled transplanted fibroblasts were detected in infarcted areas. Microspheres were recorded abundantly by autofluorescence. Significantly more apoptotic cells were observed in infarcted areas of macrophage (328.6 ± 37.4 cells/mm²) and medium (338.7 ± 16.5 cells/mm²; P < 0.05) treated hearts compared to microsphere (233.2 ± 16.8 cells/mm²) and fibroblast (232.2 ± 19.1 cells/mm²) injected hearts. Neovascularization, as reflected by the density of CD 31 positive vessels in the infracted area, did not differ between the four groups studied. The increased number of macrophages in infarcted areas after fibroblast and microsphere injection (fibroblasts 94.7 ± 7.1 cells/mm², microspheres 82.2 ± 3.0 cells/mm², macrophages 56.02 ± 9.93 cells/mm², medium 46.35 ± 9.03 cells/mm², P < 0.05) suggests that the underlying mechanism of augmented left ventricular function might be based on inflammatory processes. Returned for 1. Revision: 10 March 2008 1. Revision received: 11 September 2008 Returned for 2. Revision: 15 October 2008 2. Revision received: 28 October 2008 Dr. A. Schuh and Dr. E.A. Liehn equally contributed to this paper.     

Intravascular ultrasound assessment of coronary artery involvement in Fabry disease

Summary Aim  We used intravascular ultrasound (IVUS) to characterize coronary artery involvement in patients with Fabry disease (FD). Methods  Nine FD patients (5 women) were matched to 10 control patients (5 women) chosen from our IVUS database. Standard volumetric IVUS analyses were performed along with assessment of plaque echodensity. Results  Plaques in FD patients were diffuse and hypoechogenic compared with more focal and more echogenic lesions in control patients. Echogenicity of plaques was significantly lower in FD patients (median 30.7  ±  12.9 vs 55.9  ±  15.7, p  =  0.0052, mean 37.2  ±  15.6 vs 66.2  ±  13.3, p  =  0.0014). Diffusiveness was assessed as differences between mean and median plaque burden versus the plaque burden in each of the analysed cross-sections. These differences were lower in FD vs controls (5.8  ±  4.8 vs 8.7  ±  6.6, p  <  0.001 for mean, and 5.8  ±  4.9 vs 8.8  ±  7.3, p  <  0.001 for median) indicating a more diffuse involvement. The occurrence of lipid cores was significantly higher in FD patients than in controls (2.4  ±  1.5 vs 1.0  ±  0.94, p  =  0.02). Conclusion  IVUS showed diffuse hypoechogenic plaques in patients with FD. The explanation may be higher lipid content in plaques and accumulation of glycosphingolipid in smooth-muscle and endothelial cells. Competing interests: None declared References to electronic databases: Fabry disease: OMIM +301500.     

Discrimination of early/intermediate and advanced/complicated coronary plaque types by radiofrequency intravascular ultrasound analysis

Radiofrequency intravascular ultrasound (IVUS-RF) analysis, as an extension of conventional IVUS imaging, may provide more accurate plaque discrimination. Thirty-two autopsy atherosclerotic coronary arteries were investigated. Corresponding sectors in different plaques were matched by histologic and RF analysis. Histologic analysis utilized the American Heart Association plaque classification. The backscattered ultrasound RF signal was analyzed by fast-Fourier transform, providing the underlying frequency components of its power spectrum. The normalized backscattered signal power (in decibels [dB]) for frequencies between 15.3 and 40.3 MHz was then measured for plaque discrimination. Advanced/complicated plaque types showed a higher signal power at all frequencies than early/intermediate lesion types (p <0.001 to p = 0.005). Discrimination of advanced/complicated lesion types was best at 15.3 MHz, with a cut-off point of 2.5 dB (sensitivity 93%, specificity 79%), and second best at 17.6 MHz (sensitivity 87%, specificity 71%, cut-off point 1.9 dB). With conventional IVUS, plaque discrimination was weaker; the best sensitivity for diagnosing early/intermediate lesion types was reached for “soft plaque” (sensitivity 63%, specificity 73%). Compared with conventional IVUS, IVUS-RF can discriminate between advanced/complicated and early/intermediate coronary atherosclerotic lesions with relatively high sensitivity and specificity in vitro.     

Clinical significance of non-slip element balloon angioplasty for patients of coronary artery disease: A preliminary report

BackgroundRecent advances in drug-eluting stent (DES) technology have succeeded in reducing restenosis. However, the use of DES is reportedly equivalent to bare metal stents in terms of long-term survival. In addition, stent materials represent foreign bodies, which if possible should not ideally be left within the patient. On these bases, an investigation was performed into the feasibility of a new approach, ‘stentless’ percutaneous coronary intervention (PCI), using a Lacrosse^® non-slip element (NSE) balloon (Goodman Co., Ltd., Nagoya, Japan).Methods and resultsIn our ‘stentless’ approach, the NSE balloon is used for target lesion dilation in patients with low risk factors and simple target lesions. No stenting was performed once an optimal dilatation result was achieved, as evaluated by intravascular ultrasound (IVUS). In a total of 340 lesions in 304 patients, in whom the follow-up study was completed, the ‘stentless’ PCI by NSE balloon alone was achieved in 52 lesions (15%). Target lesion revascularization (TLR) was performed for 5 (9.6%) of the 52 ‘stentless’ lesions. In the comparison between the 52 ‘stentless’ lesions and the 31 DES lesions selected under the statistical matching of the patient profiles and baseline lesion characteristics, the TLR rate (9.6% vs 6.5%, p = 0.616) and late lumen loss (0.52 ± 0.26 mm vs 0.48 ± 0.21 mm, p = 0.347) were similar. In the 52 ‘stentless’ lesions, IVUS parameters such as vessel area, minimal lumen area, and plaque area at both before and immediately after PCI were similar between the 5 TLR lesions and the 47 non TLR lesions.ConclusionsIt is believed that the ‘stentless’ approach is applicable even in the DES era.     

Intravascular ultrasound findings after excimer laser coronary angioplasty

Intravascular ultrasound (IVUS) was used to study 104 lesions in 98 patients after excimer laser coronary angioplasty (ELCA). Lesion site external elastic membrane (EEM) and lumen cross-sectional areas (CSA) were measured; plaque + media (P + M = EEM − lumen) CSA and percentage of cross-sectional narrowing (CSN = P + M CSA/EEM CSA) were calculated; and the results were compared to a reference site. The lumen CSA (2.6 ± 1.0 mm²) averaged 24% larger than the cross-sectional area of the largest laser catheter used, and 64 lesions (62%) fit the definition of arterial expansion (lesion EEM CSA > reference site EEM CSA). The residual percentage of cross-sectional narrowing averaged 83.8 ± 8.8%. Dissections were present in 44% of lesions, and were more common in lesions with superficial calcium (59%) than in lesions with only deep calcium (31%) or no calcium (20%, P = 0.0102). Dissections of superficial calcified plaque had an unusual “shattered” or “fragmented” appearance. These findings suggest that excimer laser angioplasty causes forced vessel expansion with dissection, but limited atheroablation. © 1996 Wiley-Liss, Inc.     

Heterogeneity of Plaque Structural Stress Is Increased in Plaques Leading to MACE: Insights From the PROSPECT Study

ObjectivesThis study sought to determine if plaque structural stress (PSS) and other plaque stress parameters are increased in plaques that cause future major adverse cardiovascular event(s) (MACE) and if incorporating these parameters improves predictive capability of intravascular ultrasonography (IVUS).BackgroundLess than 10% of coronary plaques identified as high-risk by intravascular imaging result in subsequent MACE. Thus, more specific measurements of plaque vulnerability are required for effective risk stratification.MethodsPropensity score matching in the PROSPECT (Providing Regional Observations to Study Predictors of Events in the Coronary Tree) study plaque cohort resulted in 35 nonculprit lesions (NCL) associated with future MACE and 66 matched NCL that remained clinically silent. PSS was calculated by finite element analysis as the mechanical loading within the plaque structure in the periluminal region.ResultsPSS was increased in the minimal luminal area (MLA) regions of NCL MACE versus no MACE plaques for all plaques (PSS: 112.1 ± 5.5 kPa vs. 90.4 ± 3.3 kPa, respectively; p = 0.001) and virtual histology thin-cap fibroatheromas (VH-TCFAs) (PSS: 119.2 ± 6.6 kPa vs. 95.8 ± 5.0 kPa, respectively; p = 0.005). However, PSS was heterogeneous over short segments, and PSS heterogeneity index (HI) was markedly greater in NCL MACE than in no-MACE VH-TCFAs (HI: 0.43 ± 0.05 vs. 0.29 ± 0.03, respectively; p = 0.01). Inclusion of PSS in plaque assessment improved the identification of NCLs that led to MACE, including in VH-TCFAs (p = 0.03) and plaques with MLA ≤4 mm² (p = 0.03). Incorporation of an HI further improved the ability of PSS to identify MACE NCLs in a variety of plaque subtypes including VH-TCFA (p = 0.001) and plaques with MLA ≤4 mm² (p = 0.002).ConclusionsPSS and variations in PSS are increased in the peri-MLA regions of plaques that lead to MACE. Moreover, longitudinal heterogeneity in PSS is markedly increased in MACE plaques, especially VH-TCFAs, potentially predisposing to plaque rupture. Incorporation of PSS and heterogeneity in PSS may improve the ability of IVUS to predict MACE.     

Intracoronary ultrasound before coronary interventions: A prospective comparison of two different catheters

Intravascular ultrasound (IVUS) provides unique information about the coronary arterial wall that can be used to guide transcatheter therapy. In this prospective study, two different IVUS systems were compared with respect to feasibility of imaging before intervention and angiographic changes induced by the simple advancement of the catheter across the lesion. Eighty-five patients (mean age 59 ± 10 yr, 11 female) were studied with IVUS before intervention. In 34 patients, a 4.8F (1.6-mm) IVUS catheter was used (Group I), whereas in the remaining 51 patients a 3.5F (1.2-mm) IVUS catheter was used (Group II). Quantitative angiography was performed before and after the IVUS study to determine potential changes in lumen diameter. Clinical and angiographic characteristics were similar in the two groups. A successful IVUS interrogation of the target lesion was obtained more frequently in Group II (45/51 (88%) vs. 19/34 (56%) patients, P < 0.01). After the IVUS study, a change in minimal lumen diameter was seen in Group I (baseline 0.84 ± 0.2 vs. Final 1.17 ± 0.2 mm, P < 0.001) and Group II patients (baseline 0.80 ± 0.3 vs. final 1.03 ± 0.4 mm, P < 0.01). In the 64 lesions successfully crossed, the absolute gain in lumen diameter was significantly higher in Group I (0.40 + 0.2 vs. 0.23 ± 0.2 mm, P < 0.05). In addition, an inverse correlation was found between baseline minimal lumen diameter and the absolute lumen gain induced by the IVUS study in Group I (r = −0.47, P < 0.05) but not in Group II patients (r = −0.16, NS). Neither angiographic nor echogenic lesion characteristics were associated with the change in lumen diameter. When multivariate analysis was applied, catheter size was the only independent predictor of lumen gain induced by IVUS after adjustment. Thus, the advancement of IVUS catheters across severe coronary lesions induces significant angiographic changes consistent with plaque remodeling and a Dotter effect. The use of smaller catheters not only allows a higher number of lesions to be studied before intervention, but also lessens the mechanical disruption of the plaque, yielding a more accurate and veracious picture of baseline plaque characteristics. Cathet Cardiovasc Diagn 40:33–39, 1997. © 1997 Wiley-Liss, Inc.     

Effectiveness and safety of optical coherence tomography-guided PCI in Indian patients with complex lesions: A multicenter,prospective registry

BackgroundOptical coherence tomography (OCT) is reported to be a feasible and safe imaging modality for the guidance of percutaneous coronary intervention (PCI) of complex lesions.MethodsThis multicenter, prospective registry assessed the minimum stent area (MSA) achieved under OCT guidance. A performance goal of 24% improvement in MSA over and above the recommendation set by the European Association of Percutaneous Cardiovascular Interventions Consensus 2018 (4.5 mm² MSA for non-left main and 3.5 mm² for small vessels). The incidence of contrast-induced nephropathy was also assessed. Core lab analysis was conducted.ResultsFive hundred patients (average age: 59.4 ± 10.1 years; 83% males) with unstable angina (36.8%), NSTEMI (26.4%), and STEMI (22%) were enrolled. The primary endpoint was achieved in 93% of lesions with stent diameter ≥2.75 mm (average MSA: 6.44 mm²) and 87% of lesions with stent diameter ≤2.5 mm (average MSA: 4.56 mm²). The average MSA (with expansion ≥80% cutoff) was 6.63 mm² and 4.74 mm² with a stent diameter ≥2.75 mm and ≤2.5 mm, respectively. According to the core lab analysis, the average MSA achieved with a stent diameter ≥2.75 mm and ≤2.5 mm was 6.23 mm² and 3.95 mm², respectively (with expansion ≥80% cutoff). Clinically significant serum creatinine was noted in two patients (0.45%). Major adverse cardiac events at 1 year were noted in 1.2% (n = 6) of the patients; all were cardiac deaths.ConclusionPCI under OCT guidance improves procedural and long-term clinical outcomes in patients with complex lesions not just in a controlled trial environment but also in routine clinical practice.     

Intravaskul?rer Ultraschall zur Erkennung atherosklerotischer Plaques und der Plaquekomposition

Coronary atherosclerosis including acute coronary syndrome (ACS) is the leading cause of death in the western world and in the majority of patients is caused by plaque rupture in flow-limiting and non-flow-limiting angiographically intermediate stenoses. Histopathologic analyses have shown the relationship of plaque composition to acute clinical events and therefore to the vulnerability of coronary lesions. Knowledge of remodeling processes of the coronary artery has focused interest on non-flow-limiting lesions of the coronary tree. Intravascular ultrasound (IVUS) can demonstrate discrepancies between the extent of coronary atherosclerosis and angiographic imaging by in vivo plaque imaging. In addition the spectral analysis of IVUS-derived radiofrequency (RF) data enables more precise analysis of the plaque composition and plaque type.As IVUS is best able to assess stent underexpansion and malapposition the guidance of catheter-based coronary interventions plays a major role in angiographically unclear lesions even in the drug-eluting stent era. In the field of percutaneous coronary interventions (PCI) IVUS can influence the therapy and therefore optimize the stratification of patients.In terms of secondary prevention it is of great clinical importance to detect progression of coronary artery disease and moreover to predict coronary lesions with significant progression up to ACS. Coronary angiography and clinical parameters are poor surrogates to predict future events in a broad cohort of patients after PCI. In addition non-invasive imaging fails to identify coronary plaques with potential rupture and subsequent ACS. This highlights the need to identify potentially high risk lesions. However, prospective studies with IVUS-RF imaging to detect lesions that are considered to be prone to rupture showed no evidence for catheter-based invasive treatment of a non-flow-limiting high risk plaque.In the future the integrated combination of multiple technologies (e.g. IVUS-RF and optical coherence tomography) can further improve the accuracy of the analysis of high risk lesions.     

Comparison of the effects of nitroprusside versus nicorandil on the slow/no-reflow phenomenon during coronary interventions for acute myocardial infarction

Although slow/no-reflow is a serious problem complicating primary percutaneous coronary interventions (PCI) for acute myocardial infarction (AMI) and is associated with a poor prognosis, its efficacious treatment remains problematic. We compared the acute, in-hospital and long-term (1 year) effects of nitroprusside (NTP) with those of nicorandil (NC) on the slow/no-reflow phenomenon. Forty-nine of 442 consecutive patients with AMI who underwent primary PCI complicated by slow/no-reflow and who received intracoronary NTP (n = 25) or NC (n = 24) administration were studied. Both NTP and NC induced significant improvements in coronary flow, with increases in TIMI flow grade from 1.64 ± 0.62 to 2.74 ± 0.36 (p < 0.001) and 1.60 ± 0.86 to 2.23 ± 0.91 (p < 0.001), and in corrected TIMI frame count from 37.8 ± 15.1 to 13.7 ± 7.1 (p < 0.001) and 30.8 ± 20.7 to 19.3 ± 17.9 (p < 0.001), respectively. The degree of improvement in TIMI flow grade (post–pre/pre) and TIMI frame count (pre–post/pre) showed that NTP was more effective than NC (NTP vs. NC: 0.88 ± 0.79, 0.37 ± 0.37, p = 0.008; 0.59 ± 0.23, 0.36 ± 0.27, p = 0.003, respectively). Congestive heart failure did not tend to last beyond 3 days after onset in the NTP group, which was more than in the NC group, during hospitalization (1/25, 4/24, p = 0.143, respectively). At the 1-year follow-up, the NTP group tended to show more improvement than the NC group in MACE (5/25, 9/24, p = 0.175, respectively). NTP is a more effective treatment for slow/no-reflow associated with PCI in patients with AMI and may improve long-term clinical outcomes compared with NC.     

Decreased circulating lipoprotein-associated phospholipase A2 levels are associated with coronary plaque regression in patients with acute coronary syndrome

Objective

Lipoprotein-associated phospholipase A2 (Lp-PLA2) is a vascular-specific inflammatory enzyme, of which increases are associated with cardiovascular events. However, the relationship between circulating Lp-PLA2 levels and coronary plaque volume has not been clarified in patients with acute coronary syndrome (ACS).

Methods

We studied 40 patients with ACS (age, 61.4 ± 8.0 years; male, 87.5%; statin use, 45.0%) who had undergone successful percutaneous coronary intervention (PCI). Plaque volume (PV) in non-culprit sites of PCI lesions was precisely determined using grayscale intravascular ultrasound (IVUS) at onset and at six months later. We then analyzed associations among PV, lipid profiles and Lp-PLA2 levels.

Results

Circulating Lp-PLA2 levels and PV significantly decreased between baseline and six months of follow-up (458.6 ± 166.7 IU/L vs. 378.4 ± 158.5 IU/L, p < 0.001 and 82.2 ± 34.8 mm³ vs. 77.3 ± 33.1 mm³, p < 0.001, respectively). The % change in PV positively and significantly correlated with % change in LDL-C and in the LDL-C/HDL-C ratio (r = 0.444, p = 0.004 and r = 0.462, p = 0.003, respectively). Furthermore, % changes in Lp-PLA2 and in PV correlated even more closely (r = 0.496, p = 0.001). The absolute change in PV also significantly correlated with the change in Lp-PLA2 levels (r = 0.404, p = 0.009).

Conclusions

Circulating Lp-PLA2 levels are associated with changes in coronary plaque determined by IVUS in patients with ACS.     

First Report of Edge Vascular Response at 12 Months of Magmaris,A Second-Generation Drug-Eluting Resorbable Magnesium Scaffold,Assessed by Grayscale Intravascular Ultrasound,Virtual Histology,and Optical Coherence Tomography. A Biosolve-II Trial Sub-Study

Introduction and objectiveThe edge vascular response (EVR) remains unknown in second generation drug-eluting Resorbable Magnesium Scaffold (RMS), such as Magmaris. The aim of the study was to evaluate tissue modifications in the RMS edges over time, assessed by different invasive imaging modalities.MethodsThe patients treated with the device were assessed by optical coherence tomography (OCT), grayscale intravascular ultrasound (IVUS), and virtual histology IVUS at baseline and 12 months. The EVR study performed a segment- and frame-level analysis of the 5 mm segments proximal and distal of the actual RMS.ResultsThe segment-level grayscale IVUS (n = 10), virtual histology IVUS (n = 10), and OCT (n = 18) analysis did not show any significant changes after 12 months, except for a fibrous plaque area (FPA) reduction of 0.5mm² (p = 0.017) in the proximal segment compared to baseline. In the frame-level analysis, IVUS evaluation revealed a vessel area decreased 2.80 ± 1.43 mm² (p = 0.012) and 2.49 ± 1.53 mm² (p = 0.022) in 2 proximal frames. This was accompanied by plaque area reduction of 0.88 ± 0.70 mm² (p = 0.048) and a FPA decreased by 0.63 ± 0.48 mm² (p = 0.004) in one proximal frame. In 1 distal frame, there was a dense calcium area reduction of 0.10 ± 0.12 mm² (p = 0.045), FPA and fibrous fatty plaque increased 0.54 ± 0.53 mm² (p = 0.023) and 0.17 ± 0.16 mm² (p = 0.016), respectively. By OCT, there was a lumen area decrease of 0.76 ± 1.51 mm² (p = 0.045) in a distal frame.ConclusionAt 12 months, Magmaris EVR assessment does not show overall significant changes, except for a fibrous plaque area reduction in the proximal segment. This could be translated as a benign healing process at the edges of the RMS.SummaryThe edge vascular response (EVR) remains unknown in second generation drug-eluting absorbable metal scaffolds (RMS), such as Magmaris. Patients treated with the device were assessed by multi invasive imaging modalities [i.e. optical coherence tomography (OCT), grayscale intravascular ultrasound (IVUS), and virtual histology IVUS] evaluating the tissue changes over time in the segment- and frame-level analysis of the 5 mm segments proximal and distal of the actual RMS. As a result, after 12 months, Magmaris EVR assessment does not show overall significant changes, except for a fibrous plaque area reduction in the proximal segment, translating a benign healing process at the edges of the RMS.     

Atherosclerotic coronary lesions with inadequate compensatory enlargement have smaller plaque and vessel volumes: observations with three dimensional intravascular ultrasound in vivo

Objective—To compare vessel, lumen, and plaque volumes in atherosclerotic coronary lesions with inadequate compensatory enlargement versus lesions with adequate compensatory enlargement.
Design—35 angiographically significant coronary lesions were examined by intravascular ultrasound (IVUS) during motorised transducer pullback. Segments 20 mm in length were analysed using a validated automated three dimensional analysis system. IVUS was used to classify lesions as having inadequate (group I) or adequate (group II) compensatory enlargement.
Results—There was no significant difference in quantitative angiographic measurements and the IVUS minimum lumen cross sectional area between groups I (n = 15) and II (n = 20). In group I, the vessel cross sectional area was 13.3 (3.0) mm² at the lesion site and 14.4 (3.6) mm² at the distal reference (p < 0.01), whereas in group II it was 17.5 (5.6) mm² at the lesion site and 14.0 (6.0) mm² at the distal reference (p < 0.001). Vessel and plaque cross sectional areas were significantly smaller in group I than in group II (13.3 (3.0) v 17.5 (5.6) mm², p < 0.01; and 10.9 (2.8) v 15.2 (4.9) mm², p < 0.005). Similarly, vessel and plaque volume were smaller in group I (291.0 (61.0) v 353.7 (110.0) mm³, and 177.5 (48.4) v 228.0 (92.8) mm³, p < 0.05 for both). Lumen areas and volumes were similar.
Conclusions—In lesions with inadequate compensatory enlargement, both vessel and plaque volume appear to be smaller than in lesions with adequate compensatory enlargement.

     

Impact of intravascular ultrasound‐guided percutaneous coronary intervention on long‐term clinical outcomes in a real world population

Objectives : To compare long‐term clinical outcomes between intravascular ultrasound (IVUS)‐guided and angiography‐guided percutaneous coronary intervention (PCI) in a large “real world” registry. Background : The impact of IVUS‐guided PCI on clinical outcomes remains unclear. Methods : Between January 1998 and February 2006, 8,371 patients who underwent IVUS‐ (n = 4,627) or angiography‐ (n = 3,744) guided PCI were consecutively enrolled. Three‐year clinical outcomes were compared after adjustment for inverse‐probability‐of‐treatment weighting (IPTW) in the overall population and in separate populations according to stent type. Results : A crude analysis of the overall population showed that the 3‐year mortality rate was significantly lower in the IVUS‐guided group than in the angiography‐guided group (96.4% ± 0.3% vs. 93.6% ± 0.4%, log‐rank P < 0.001). When adjusted by IPTW, patients undergoing IVUS‐guided PCI remained at lower risk of mortality (hazard ratio [HR] 0.627; 95% CI 0.50–0.79, P < 0.001). Similarly, in the drug‐eluting stent (DES) population, the 3‐year risk of mortality was significantly lower in patients undergoing IVUS‐guided PCI (HR 0.46; 95% CI 0.33–0.66, P < 0.001). In contrast, IVUS‐guided PCI did not reduce the risk of mortality in the bare metal stent population (HR 0.82; 95% CI 0.60–1.10, P = 0.185). However, the risks of myocardial infarction (HR 0.95; 95% CI 0.63–1.44, P = 0.810), target vessel revascularization (HR 1.00; 95% CI 0.86–1.15, P = 0.944), and stent thrombosis (HR 0.82; 95% CI 0.53–1.07, P = 0.109) were not associated with IVUS guidance. Conclusions : IVUS‐guided PCI may reduce long‐term mortality when compared with conventional angiography‐guided PCI. This may encourage the routine use of IVUS for PCI in patients undergoing DES implantation. © 2012 Wiley Periodicals, Inc.