Ayaka Murakami

Ruptured plaque and large plaque burden are risks of distal embolisation during percutaneous coronary intervention: evaluation by angioscopy and virtual histology intravascular ultrasound imaging.

AIMS Slow flow and no flow phenomena have been associated with distal embolisation, especially of plaque debris, and with unfavourable clinical outcomes. However, patients at high risk of distal embolisation for whom distal protection might be beneficial have not been adequately identified. We examined the frequency of distal embolisation and its predicting factors, including both ACS and non-ACS patients. METHODS AND RESULTS Consecutive patients (n=98) with or without ACS who had received PCI with a filter-type distal protection device and successful angioscopic and VH-IVUS examination were prospectively enrolled. The presence of yellow plaque and plaque rupture was evaluated by angioscopy. Tissue classification and plaque burden was evaluated by VH-IVUS. Distal embolisation was evaluated by pathological examination of material collected in the filter. Distal embolisation of plaque debris was more frequently detected in patients with ACS (48% vs. 25%, p=0.02), in those with ruptured plaque (86% vs. 13%, p<0.001), in those with large (>75%) plaque burden (50% vs. 23%, p=0.006), and in those with grade 2/3 yellow plaque (52% vs. 7%, p<0.001), as compared to those without it. CONCLUSIONS The presence of ruptured yellow plaque and of large plaque burden, rather than the setting of ACS, was highly predictive of distal embolisation of plaque debris.

Chronic Kidney Disease and Coronary Artery Vulnerable Plaques

BACKGROUND AND OBJECTIVES Chronic kidney disease (CKD) is a risk factor of cardiovascular disease. The number of yellow plaques is a predictor of future cardiovascular events. We assumed that CKD might raise the risk of cardiovascular events by increasing the number of yellow plaques. Therefore, we compared the number of yellow plaques between patients with and without CKD. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS Consecutive 136 patients with acute myocardial infarction who received percutaneous coronary intervention (PCI) and angioscopic examination were analyzed. The infarct-related artery was angioscopically examined. The number of yellow plaques, maximum yellow color grade of detected yellow plaques, and prevalence of disrupted yellow plaques in nonculprit segments were compared between patients with and without CKD. RESULTS The number of yellow plaques was significantly larger in CKD than in non-CKD patients (median [interquartile range]: 4.0 [2.0 to 6.0] versus 2.0 [1.0 to 4.0], P = 0.001). Maximum yellow color grade and prevalence of disrupted plaques in the nonculprit segments were not different between patients with and without CKD. Multivariate logistic regression analysis revealed CKD as an independent risk of multiple yellow plaques per vessel (odds ratio 3.49, 95% confidence interval 1.10 to 11.10, P = 0.03). CONCLUSION CKD was an independent risk factor of multiple coronary yellow plaques, suggesting that patients with CKD would have a higher risk of coronary events because they had more yellow plaques than patients without CKD.

Risk of in-stent thrombus formation at one year after drug-eluting stent implantation

INTRODUCTION Although very late stent thrombosis is an important problem with drug-eluting stents, risks for in-stent thrombus formation have not been clarified. Therefore, we examined the risks among patient and lesion characteristics by direct visualization of the stented lesion by angioscopy. MATERIALS AND METHODS Consecutive patients (n=118) who received successful angioscopic examination of drug-eluting (sirolimus- or paclitaxel-eluting) stents at 1-year after implantation were included. Presence or absence of thrombus directly on the area of each condition determined by the combination of lesion color (white or yellow) and neointima coverage (grade 0-2) was evaluated for each stent; and the factors associated with the presence of thrombus were analyzed. RESULTS Multivariate logistic regression analysis revealed lesion color (=yellow; odds ratio [OR] 5.5, 95% confidence interval [CI] 3.0-10, p<0.001), neointima coverage (=grade 0 or 1; OR 5.5, 95% CI 2.4-13, p<0.001), and stent type (=paclitaxel-eluting stent; OR 7.6, 95% CI 3.9-15, p<0.001) as independent contributors for in-stent thrombus formation. CONCLUSION Yellow color of the lesion, poor neointima coverage, and use of paclitaxel-eluting stent were the risks of in-stent thrombus formation at 1 year after DES implantation.

Comparison of angioscopic findings among second-generation drug-eluting stents

BACKGROUND First-generation drug-eluting stents (DES) have reduced short-term stent failure as compared to bare-metal stents due to the inhibition of neointima hyperplasia, but instead increased the risk of very-late stent failure. Although better outcomes have been reported for second-generation DES than for first-generation DES, the difference in the angioscopic findings at 1-year follow-up has not been adequately elucidated among second-generation DES. METHODS Consecutive 161 patients who received angioscopic examination at 1 year after implantation of second-generation DES, i.e. Nobori biolimus-eluting stents (Terumo, Tokyo, Japan) (N-BES, n=25), Xience everolimus-eluting stents (Abbot Vascular, Santa Clara, CA, USA; X-EES, n=95), or Resolute zotarolimus-eluting stents (Resolute Integrity; Medtronic, Minneapolis, MN, USA; R-ZES, n=41), in de novo native coronary lesions were analyzed. RESULTS Maximum neointima coverage grade (N-BES, 0.9±0.3; X-EES, 1.2±0.4; R-ZES, 1.5±0.5; p<0.001) was the highest in R-ZES and lowest in N-BES. Heterogeneity score was higher in R-ZES than in N-BES (N-BES, 0.8±0.4; X-EES, 0.9±0.4; R-ZES, 1.1±0.5; p=0.007). Maximum yellow color grade and prevalence of thrombus were not different. Multivariate analysis demonstrated that only stent type was associated with maximum neointima coverage grade; stent type and total stent length were associated with heterogeneity score; and stenting for acute coronary syndrome (ACS) and total stent length were associated with maximum yellow color grade. CONCLUSIONS Neointima coverage and heterogeneity were mainly determined by stent type even among second-generation DES, while yellow color was determined mainly by whether target lesion was of ACS.

Angioscopic Comparison of Resolute and Endeavor Zotarolimus-Eluting Stents.

BACKGROUND Drug-eluting stents (DES) have reduced late loss and target lesion revascularization through the inhibition of neointimal hyperplasia, but instead increased the risk of very late stent failure due to incomplete neointimal coverage and neoatherosclerosis. Although newer DES are more effective and safer than the first-generation DES, the difference in the condition of the stented lesions between Resolute zotarolimus-eluting stents (R-ZES) and Endeavor zotarolimus-eluting stents (E-ZES) on angioscopy has not been reported. METHODSANDRESULTS Consecutive patients who received R-ZES (n=46) or E-ZES (n=46) for de novo lesion of native coronary artery and had 1-year follow-up angioscopy were examined. Yellow color (grade 0-3), neointimal coverage (grade 0-2), heterogeneity score (maximum-minimum neointimal coverage grade) and thrombus (presence or absence) at stented lesion were evaluated. The maximum yellow color grade (1.2±0.9 vs. 0.7±1.0, P=0.005) was higher in R-ZES than in E-ZES. The maximum (1.9±0.3 vs. 1.5±0.5, P<0.001) and minimum (1.1±0.7 vs. 0.4±0.5, P<0.001) coverage grade was higher in E-ZES than in R-ZES. The heterogeneity score was higher in R-ZES than in E-ZES (1.0±0.5 vs. 0.7±0.7, P=0.007). Prevalence of thrombus was not different between the 2 stents (6.5% vs. 2.2%, P=0.4). CONCLUSIONS E-ZES had better neointimal coverage with less yellow plaque and lower heterogeneity score than R-ZES. The lesions with E-ZES appeared more stable than those with R-ZES. (Circ J 2016; 80: 650-656).

Bacterial Contamination During Pacemaker Implantation Is Common and Does Not Always Result in Infection

BACKGROUND Bacterial cultures of cardiovascular implantable electronic devices removed from patients without clinical infection are often positive, and the cultured bacteria are different from those at the time of clinical infection. This discrepancy has not been adequately explained. We hypothesized that the cause is bacterial contamination at operation and compared the results of bacterial cultures between patients with de novo pacemaker implantation and those with pacemaker replacement. METHODS AND RESULTS We prospectively enrolled consecutive 100 patients who underwent cardiac pacemaker implantation (49 de novo implantations, 51 replacements). We took swab cultures from inside the generator pocket (1) immediately after the creation of new pocket or removal of old generator, (2) after connection of leads to new generator, and (3) after pocket lavage. Swab cultures were positive in 272 (45%) of 600 samples. The majority of the cultured bacteria were Propionibacterium species. No statistical difference was detected between de novo implantations and replacements in the positive ratio of swab cultures. The positive ratio was not correlated with the number of previous device replacements. CONCLUSIONS The positive ratio of swab cultures was not different between new implantations and replacements, suggesting that a positive culture merely indicates contamination of bacteria during operation rather than colonization.

Detection of angioscopic yellow plaque by intracoronary near-infrared spectroscopy.

Angioscopy can detect vulnerable, lipid-rich coronary plaques (LRPs), but it requires removal of blood plus expert technique and interpretation [(1,2)][1]. We studied the use of a near-infrared spectroscopy (NIRS) intravascular ultrasound (IVUS) catheter [(3)][2], which does not require blood

A higher colour grade yellow plaque was detected at one year after implantation of an everolimus-eluting stent than after a zotarolimus-eluting stent

Objective Neoatherosclerosis or atherosclerosis progression is one of the mechanisms of long-term stent failure. Yellow plaque detected by angioscopy has been associated with advanced atherosclerosis and the future risk of a coronary event. We compared the yellow colour of the stented segment between zotarolimus-eluting stents (ZES) and everolimus-eluting stents (EES) at 1 year after implantation. Design Cross-sectional study. Patients Consecutive patients underwent angioscopic examination 1 year after the implantation of ZES (n=45) or EES (n=45) at a de novo native coronary lesion. Main outcome measures The maximum yellow colour grade (grade 0–3) of the stented segment, maximum and minimum neointima coverage grade (grade 0–2) and the presence of thrombus were examined. The neointima heterogeneity index was calculated as maximum − minimum coverage grade. Results Maximum yellow colour grade was higher in EES than in ZES (1.3±0.9 vs 0.4±0.8, p<0.001) and maximum (2.0±0.2 vs 1.2±0.5, p<0.001) and minimum (1.5±0.6 vs 0.7±0.5, p<0.001) coverage grade was higher in ZES than in EES. The neointima heterogeneity index was not different between ZES and EES (0.4±0.5 vs 0.5±0.6, p=0.42). The incidence of thrombus was very low and was not different between ZES and EES (2% vs 4%, p=0.55). Conclusions Although both ZES and EES had good healing with homogeneous neointima coverage and a low incidence of thrombus, EES had more advanced atherosclerosis as shown by the presence of higher grade yellow plaque than ZES at 1 year after implantation.

The level of blood thrombogenicity was not elevated in stable patients with disrupted coronary plaque

BACKGROUND Although extremely high blood thrombogenicity has been reported in patients with acute myocardial infarction, it has not been clarified if the increased blood thrombogenicity is a cause of acute myocardial infarction or a mere result induced by thrombus formation at the disrupted plaque. Therefore, we examined if blood thrombogenicity is extremely increased as in acute myocardial infarction patients when disrupted plaque is present in patients with stable coronary artery disease. METHODS AND RESULTS Consecutive patients (n=38) with stable coronary artery disease who received angioscopic examination were included. Patients were divided into two groups according to presence or absence of disrupted plaque that accompanied thrombus. Blood thrombogenicity was evaluated by blood vulnerability index and compared between the patients with and without disrupted plaque. Among 38 study patients, 16 had disrupted plaque and 22 did not. Blood vulnerability index was not different between the patients with and without disrupted plaque (2395 ± 612 vs. 3013 ± 1476, p=0.12). Multivariate analysis revealed no significant association between blood vulnerability index and the presence of disrupted plaque. CONCLUSION The presence of disrupted plaque, in comparison with its absence, was not associated with higher blood thrombogenicity evaluated by blood vulnerability index.

Systemic and local factors associated with coronary plaque disruption

INTRODUCTION Yellow plaques are regarded vulnerable; and disrupted yellow plaques are the major cause of acute coronary syndrome. We examined the factors associated with the disruption of yellow plaques among patients and lesion characteristics. MATERIALS AND METHODS Consecutive 161 patients with ischemic heart diseases who received coronary angioscopic examination were analyzed. Yellow plaques in the segments to which intervention had never been performed were included, and their yellow color grade and presence/ absence of disruption were examined. Associated factors for plaque disruption were examined among patients and lesion characteristics. RESULTS In 161 patients, 392 yellow plaques were included for analysis and 70 of them were disrupted. Frequency of plaque disruption (=disrupted / all yellow plaques) was significantly higher at the segments of severer stenosis (stenosis≥75% vs. 75-25% vs. <25%: 34% vs. 21% vs. 14%, p=0.006). Multivariate analysis revealed angiographic stenosis (odds ratio [OR], 1.014; 95% confidence interval [CI], 1.005-1.023; p=0.003), yellow color grade (OR, 3.297; 95% CI, 2.062-5.273, p<0.001), LDL-cholesterol (OR, 1.012; 95% CI, 1.004-1.020, p=0.003), male gender (OR, 3.608; 95% CI, 1.538-8.465; p=0.003), and hypertension (OR, 2.552; 95% CI, 1.094-5.953; p=0.030) as significant associated factors for plaque disruption. CONCLUSION Angiographic stenosis, yellow color grade, LDL-cholesterol, male gender, and hypertension were significantly associated with the disruption of yellow plaques.