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Plaque rupture (PR), characterized by a disruption of the fibrous cap of lipid-rich plaques, is the major etiology of ST-segment elevation myocardial infarction (STEMI). Dyslipidemia is a well-known risk factor for PR. Nonetheless, the impact of detailed atherogenic lipid profiles, including small dense low-density lipoprotein cholesterol (sd-LDL-C) and triglyceride-rich lipoproteins (TRLs), on PR has not yet been investigated.To elucidate the impact of sd-LDL-C and TRL levels on PR in patients with STEMI using optical coherence tomography (OCT).A total of 106 consecutive statin-naive patients with STEMI were enrolled. The PR in culprit lesions was assessed on pre-intervention OCT images, and serum samples were collected immediately before coronary angiography. Sd-LDL-C was directly measured using a homogeneous assay. TRL-cholesterol (TRL-C) was estimated by subtracting the LDL-C level from the non-high-density lipoprotein cholesterol level. Clinical characteristics and lipid profiles were compared between the PR and intact fibrous cap (IFC).No difference in LDL-C levels was observed between the PR (n=64) and IFC (n=42) groups (120.0 mg/dL vs. 129.5 mg/dL, p=0.97); however, sd-LDL-C levels were significantly higher in the PR group (38.9 mg/dL vs. 32.4 mg/dL, p=0.04). Similarly, the PR group had higher TRL-C (24.0 mg/dL vs. 18.0 mg/dL, p=0.01) and triglyceride (130.0 mg/dL vs. 100.3 mg/dL, p=0.03) levels than the IFC group. Multivariate logistic regression analysis showed that sd-LDL-C was an independent factor determining PR (odds ratio, 1.53 per 10 mg/dL; p=0.04).Only sd-LDL-C levels were significantly associated with PR in culprit lesions in patients with STEMI.

The presence of cholesterol crystals (CCs) is recognized as a component of vulnerable atherosclerotic plaques at risk of rupture. The phagocytosis of atherogenic lipid factors by macrophages precedes and promotes the formation of vulnerable plaques, but it is not clear how these factors affect the formation of CC.This study aimed to evaluate the relationship between lipid biomarkers such as small dense low-density lipoprotein cholesterol (sd-LDL-c) and CC detected by optical coherence tomography (OCT) in patients with acute coronary syndrome (ACS).Serum samples were collected immediately before coronary angiography in consecutive 174 patients with ACS who did not take statins and underwent OCT imaging of the culprit lesion. The sd-LDL-c levels were measured using a direct homogenous assay. CC was defined as a thin linear structure with high reflectivity and low signal attenuation on the OCT images.CC was identified in 85 patients (48.9%). The prevalence of CC was significantly higher in lesions with ruptured plaques and greater macrophage grade. The sd-LDL-c levels were significantly higher in the patients with CC (41.6 vs. 31.2 mg/dL, p = 0.01) although there were no significant differences in the levels of LDL-c and apolipoprotein B. The CC group also had higher levels of apolipoprotein C3 and HbA1c levels. In multiple logistic regression analysis, sd-LDL-c was an independent risk factor of CC (odds ratio, 1.19 per 10 mg/dL; p = 0.03).sd-LDL may play an important role in the presence of CC in patients with ACS.

A recent thinner strut drug-eluting stent might facilitate early strut coverage after its placement. We aimed to investigate early vascular healing responses after the placement of an ultrathin-strut bioresorbable-polymer sirolimus-eluting stent (BP-SES) compared to those with a durable-polymer everolimus-eluting stent (DP-EES) using optical coherence tomography (OCT) imaging.This study included 40 patients with chronic coronary syndrome (CCS) who underwent OCT-guided percutaneous coronary intervention (PCI). Twenty patients each received either BP-SES or DP-EES implantation. OCT was performed immediately after stent placement (baseline) and at 1-month follow-up.At one month, the percentage of uncovered struts reduced significantly in both the BP-SES (80.9 ± 10.3% to 2.9 ± 1.7%; P < 0.001) and DP-EES (81.9 ± 13.0% to 5.7 ± 1.8%; P < 0.001) groups, and the percentage was lower in the BP-SES group than in the DP-EES group (P < 0.001). In the BP-SES group, the percentage of malapposed struts also decreased significantly at 1 month (4.9 ± 3.7% to 2.6 ± 3.0%; P = 0.025), which was comparable to that of the DP-EES group (2.5 ± 2.2%; P = 0.860). The optimal cut-off value of the distance between the strut and vessel surface immediately after the placement to predict resolved malapposed struts was ≤ 160 μm for BP-SES and ≤ 190 μm for DP-EES.Compared to DP-EES, ultrathin-strut BP-SES demonstrated favorable vascular responses at one month, with a lower rate of uncovered struts and a comparable rate of malapposed struts.

Recent clinical studies suggest that newer-generation drug-eluting stents that combine ultrathin struts and nanocoating (biodegradable polymer sirolimus-eluting stents, BP-SES) could improve long-term clinical outcomes in patients with ST-elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PCI). However, the early vascular response to BP-SES in these patients has not been investigated so far.We examined this response in 20 patients with STEMI caused by plaque rupture using frequency-domain optical coherence tomography (OCT) to understand the underlying mechanisms. Plaque rupture was diagnosed by OCT before PCI with BP-SES implantation was performed. OCT was again performed before the final angiography (post-PCI) and after 2 weeks (2W-OCT).BP-SES placement caused protrusion of atherothrombotic material into the stent lumen and incomplete stent apposition in all patients. After 2 weeks, incomplete stent apposition was significantly reduced (% malapposed struts: post-PCI 4.7 ± 3.3%; 2W-OCT 0.9 ± 1.2%; P < 0.0001), and the percentage of uncovered struts also significantly decreased (% uncovered struts: post-PCI; 69.8 ± 18.3%: 2W-OCT; 29.6 ± 11.0%, P < 0.0001). The maximum protrusion area of the atherothrombotic burden was significantly reduced (post-PCI 1.36 ± 0.70 mm2; 2W-OCT 0.98 ± 0.55 mm2; P = 0.004).This study on the early vascular responses following BP-SES implantation showed rapid resolution of atherothrombotic material and progression of strut apposition and coverage. (UMIN000041324).

Although balloon angioplasty for femoropopliteal artery lesions has been associated with restenosis rates of up to 60% at 12 months, the mechanism of restenosis has not been fully evaluated. The aim of this study was to evaluate the relationship between the vascular features observed on optical frequency domain imaging (OFDI) before and after balloon angioplasty of femoropopliteal artery lesions, and restenosis at 6 months. This study was a prospective multicenter single arm study. OFDI was performed before and after balloon angioplasty and plaque characteristics and vascular features, along with de novo lesions, were assessed. The primary outcome was the presence or absence of restenosis 6 months after balloon angioplasty. Residual platelet reactivity was assessed according to VerifyNow platelet reactivity units (PRUs). The number of patients completing 6 months of follow-up was 47, of which 14 had developed restenosis. Maximum thickness of the dissection flap (odds ratio (OR) 2.71; 95% confidence interval [0.9–8.0]; p = 0.071) and lesion length were identified as risk factors for restenosis (OR 1.015; 95% confidence interval [0.001–0.029]; p = 0.039). The mean PRU at the time of treatment in patients with restenosis was significantly higher than in those without restenosis (286.3 ± 82.6 vs. 208.5 ± 03.6, p = 0.026). Long lesions and major dissection on OFDI after balloon angioplasty for femoropopliteal artery lesions increase restenosis at 6 months. In addition, high residual platelet reactivity at the time of EVT may also be a risk factor for restenosis. Clinical Trial Registration Number UMIN000021120.

Pathological reports have shown that plaque erosion (PE), a common cause of acute coronary syndrome (ACS), can form in both fibrous plaque and lipid-rich plaque (LRP). In plaque rupture (PR), which is the main cause of ACS, the underlying plaque is LRP with a thin fibrous cap. In this study, we aimed to investigate the clinical features and lipid profiles of PE with or without LRP in comparison with those of PR.A total of 166 patients with ACS, who underwent percutaneous coronary intervention using optical coherence tomography (OCT) and met the criteria for PR or PE, were included. LRP was defined as plaque with a maximal lipid arc (180°). Culprit lesions were categorized into PR and PE with/without LRP [PEThe prevalence of PR, PEThe clinical features and lipid profiles are substantially different between PE

Although balloon angioplasty for femoropopliteal artery lesions has been associated with restenosis rates of up to 60% at 12 months, the mechanism of restenosis has not been fully evaluated. The aim of this study was to evaluate the relationship between the vascular features observed on optical frequency domain imaging (OFDI) before and after balloon angioplasty of femoropopliteal artery lesions, and restenosis at 6 months. This study was a prospective multicenter single arm study. OFDI was performed before and after balloon angioplasty and plaque characteristics and vascular features, along with de novo lesions, were assessed. The primary outcome was the presence or absence of restenosis 6 months after balloon angioplasty. Residual platelet reactivity was assessed according to VerifyNow platelet reactivity units (PRUs). The number of patients completing 6 months of follow-up was 47, of which 14 had developed restenosis. Maximum thickness of the dissection flap (odds ratio (OR) 2.71; 95% confidence interval [0.9-8.0]; p = 0.071) and lesion length were identified as risk factors for restenosis (OR 1.015; 95% confidence interval [0.001-0.029]; p = 0.039). The mean PRU at the time of treatment in patients with restenosis was significantly higher than in those without restenosis (286.3 ± 82.6 vs. 208.5 ± 03.6, p = 0.026). Long lesions and major dissection on OFDI after balloon angioplasty for femoropopliteal artery lesions increase restenosis at 6 months. In addition, high residual platelet reactivity at the time of EVT may also be a risk factor for restenosis.Clinical Trial Registration Number UMIN000021120.

This paper presents a new diagnostic method for evaluating the penetration strength of a rubber sheet based on electromagnetic induction phenomena. This method was established on the basis of the experimental results of impact tests of specimens when small impactors collided with rubber sheets. The impactor behavior, impact force, and specimen deflection were analyzed based on the electromotive force generated in a coil near the specimens when the impactors containing a neodymium magnet collided with the specimens because the intensity of the electromotive force is proportional to the impactor velocity and because its variation is solely dependent on the position of the impactor. The validity of the analyzed impact force and specimen deflection was confirmed by considering the impactor behavior, which was observed using a high-speed camera, and the external work of the impactors evaluated from the analyzed results. The penetration strength of the rubber sheet was determined from the impact-force history and the impact force-specimen deformation curve based on the analyzed impactor behavior during the collision.

Background: The impact of antiplatelet drug effects on mid-term local arterial responses following percutaneous coronary intervention (PCI) remains uncertain. We evaluated the impact of the platelet reactivity of prasugrel on mid-term vascular healing between acute coronary syndrome (ACS) and stable coronary artery disease (CAD). Methods and Results: We conducted a prospective, 12-center study in 125 patients with ACS and 126 patients with stable CAD who underwent PCI with an everolimus-eluting stent (EES) and received dual antiplatelet therapy (DAPT) with prasugrel and aspirin. Serial optical coherence tomography (OCT) was performed immediately after PCI and at the 9-month follow-up to assess the association of P2Y12reaction units (PRU) with the frequency of malapposed or uncovered struts and intrastent thrombi (IST). The incidence of abnormal mid-term OCT findings did not different between the ACS and CAD arms, regardless of clinical presentation, except that uncovered struts were more frequent in the ACS than CAD arm. PRU at PCI was significantly associated with the frequency of IST at follow-up, but not with uncovered and malapposed struts. PRU at PCI was the only independent predictor of IST detected at follow-up (odds ratio 1.009).Conclusions: In patients undergoing EES implantation and receiving prasugrel, achieving an adequate antiplatelet effect at the time of stent implantation may regulate thrombus formation throughout the follow-up period.

Docetaxel, a taxane derivative, is frequently used for the treatment of advanced breast cancer, non-small cell lung cancer, and metastatic prostate cancer. Clinical reports demonstrated that docetaxel-based chemotherapy often induces anorexia, but the etiology is not completely understood. To elucidate possible mechanisms, we investigated the involvement of central interleukin (IL)-1β, cyclooxygenase (COX)-2, and pro-opiomelanocortin (POMC) in the development of docetaxel-induced anorexia in rats. Rats received docetaxel (10mg/kg, i.p.) with or without pretreatment with selective COX-2 inhibitors, NS-398 (10 and 30 mg/kg, i.g.) or celecoxib (10 and 30 mg/kg, i.g.), and a non-selective COX inhibitor, indomethacin (10mg/kg, i.g.), then food intake was monitored for 24h after administration. We also examined expression of IL-1β, COX-2, and POMC mRNA in hypothalamus of docetaxel-treated rats and the effect of a COX-2 inhibitor on docetaxel-induced POMC mRNA expression. Food consumption in rats was significantly decreased 24h after administration of docetaxel and anorexia was partially reversed by all COX inhibitors. Administration of docetaxel increased IL-1β, COX-2, and POMC mRNA expression in the hypothalamus of rats. The time required to increase these gene expressions was comparable to the latency period of docetaxel-induced anorexia in rats. In addition, pretreatment with COX-2 inhibitors suppressed docetaxel-induced expression of POMC mRNA. These results suggest that IL-1β and COX-2 mRNA expression and subsequent activation of POMC in the hypothalamus may contribute to the development of docetaxel-induced anorexia in rats.

Introduction We have reported that pica, kaolin ingestion behavior, correlates with nausea and vomiting in rats and the amount of kaolin intake is related to the severity of symptoms. However, the time course of the behavior is still unclear, because kaolin intake has been measured 24 h after administration of an emetic stimulus. It is quite difficult and troublesome to determine kaolin intake manually at short time intervals without affecting the animal's behavior. In the present study, we investigated the time course of radiation or chemotherapeutic agent-induced pica in rats using an automatic feeding monitoring system (FDM700SW). Methods Rats received total body X-ray irradiation (4 Gy), or i.p. administration of cisplatin (6 mg/kg) or cyclophosphamide (120 mg/kg) with or without pretreatment of 5-HT 3 receptor antagonist, granisetron (0.1 mg/kg, i.p.), then their kaolin and food intake were monitored hourly for 24 h after the emetic stimuli. Results Total body irradiation and i.p. injection of cisplatin or cyclophosphamide induced pica within 3 h of the administration and the pica persisted for 12, 8 and 16 h after the emetic stimuli, respectively. Granisetron delayed the latency and inhibited the amount of kaolin intake. X-ray and chemotherapeutic agents induced anorexia in all rats, but anorexia was not recovered by pretreatment with granisetron. Discussion These results suggested that both the latency and the duration of pica are similar to the clinical evidence of radiation or chemotherapy-induced nausea and vomiting in human patients and this monitoring system is useful to evaluate the emetogenic potential of drugs and other medical intervention in preclinical studies.