Increased expression of angiopoietin-like protein 4 regulates matrix metalloproteinase-13 expression in Porphyromonas gingivalis lipopolysaccharides-stimulated gingival fibroblasts and ligature-induced experimental periodontitis.

BACKGROUND: Angiopoietin-like protein 4 (ANGPTL4) is produced in chronic or acute inflammation. Although ANGPTL4 increases in the periodontal ligament fibroblasts during hypoxia, the involvement and role of ANGPTL4 in periodontitis have not been elucidated. OBJECTIVE: In this study, we investigated whether ligature-induced experimental periodontitis and/or Porphyromonas gingivalis lipopolysaccharides (Pg-LPS) would upregulate ANGPTL4 expression and whether ANGPTL4 would somehow involve in the expression of matrix metalloproteinases (MMPs) which are key molecules in the process of periodontal tissue destruction. METHODS: Experimental periodontitis was induced in 6-week-old male Sprague-Dawley rats by placing a nylon suture around the neck of the maxillary second molar. Two weeks after the induction of periodontitis, the periodontal tissue was excised and analyzed by histological/immunohistochemical staining and gene expression analyses. Human gingival fibroblasts (hGFs) were stimulated with Pg-LPS. The gene expression of ANGPTLs and receptors involved in ANGPTL4 recognition were observed. We also confirmed the changes in gene expression of MMPs upon stimulation with human ANGPTL4. Furthermore, we downregulated ANGPTL4 expression by short interfering RNA in hGFs and investigated the effect of Pg-LPS on MMP production. RESULTS: Induction of periodontitis significantly increased the expression of ANGPTL4 in the gingiva. Pg-LPS significantly increased the gene and protein expression of ANGPTL4 in hGFs but not the gene expression of other ANGPTLs or ANGPTL receptors. Recombinant human ANGPTL4 significantly increased MMP13 gene expression in hGFs. We also confirmed that MMP13 expression was increased in the gingiva during experimental periodontitis. Pg-LPS induced MMP13 gene expression in hGFs. These results suggest the pivotal role of ANGPTL4 in periodontitis. CONCLUSION: Periodontitis increases ANGPTL4 expression in the gingiva, further suggesting that increased ANGPTL4 may be a factor involved in enhancing MMP13 expression.

Clinical Outcomes and Predictors of All-Cause Mortality After Complex High-Risk and Indicated Revascularization Using Percutaneous Coronary Intervention.

The concept of complex and high-risk indicated procedures using percutaneous coronary intervention (CHIP-PCI) has recently been defined. However, few studies have investigated the prognosis of patients after CHIP-PCI. We enrolled 322 consecutive patients who underwent CHIP-PCI. CHIP-PCI was defined as a procedure satisfying at least one criterion each for both patient and procedure characteristics, as follows: patient characteristics [age ≥ 75 years old, low left ventricular ejection fraction (LVEF), diabetes mellitus, acute coronary syndrome, previous coronary artery bypass surgery, peripheral arterial disease, severe chronic kidney disease (CKD), chronic obstructive pulmonary disease (COPD), and severe valvular disease] and procedure characteristics [unprotected left main disease, degenerated saphenous or radial artery grafts, severely calcified lesions, last patent conduit, chronic total occlusions, multivessel disease, and use of mechanical circulatory support]. On Kaplan-Meier analysis, 1-, 2-, and 3-year survival rates following CHIP-PCI was 93.8%, 89.2%, and 85.4%, respectively. Moreover, on Cox multivariate hazard analysis, age (≥ 75 years old) (hazard ratio: 4.01, 95% confidence interval: 1.92-8.38, P < 0.01), COPD (hazard ratio: 2.95, 95% confidence interval: 1.38-6.32, P < 0.01), low LVEF (hazard ratio: 3.35, 95% confidence interval: 1.55-7.22, P < 0.01), severe CKD (hazard ratio: 3.02, 95% confidence interval: 1.44-6.36, P < 0.01), and use of mechanical circulatory support (hazard ratio: 5.97, 95% confidence interval: 2.72-13.10, P < 0.01) remained significant predictors of mortality. In conclusion, we revealed the clinical outcomes after CHIP-PCI. The presence of advanced age, COPD, low LVEF, severe CKD, and mechanical circulatory support use might lead to worse clinical outcomes.

Impacts of Glucose-Dependent Insulinotropic Polypeptide on Orthodontic Tooth Movement-Induced Bone Remodeling.

Glucose-dependent insulinotropic polypeptide (GIP) exerts extra-pancreatic effects via the GIP receptor (GIPR). Herein, we investigated the effects of GIP on force-induced bone remodeling by orthodontic tooth movement using a closed-coil spring in GIPR-lacking mice (GIPRKO) and wild-type mice (WT). Orthodontic tooth movements were performed by attaching a 10-gf nickel titanium closed-coil spring between the maxillary incisors and the left first molar. Two weeks after orthodontic tooth movement, the distance of tooth movement by coil load was significantly increased in GIPRKO by 2.0-fold compared with that in the WT. The alveolar bone in the inter-root septum from the root bifurcation to the apex of M1 decreased in both the GIPRKO and WT following orthodontic tooth movement, which was significantly lower in the GIPRKO than in the WT. The GIPRKO exhibited a significantly decreased number of trabeculae and increased trabecular separation by orthodontic tooth movement compared with the corresponding changes in the WT. Histological analyses revealed a decreased number of steady-state osteoblasts in the GIPRKO. The orthodontic tooth movement induced bone remodeling, which was demonstrated by an increase in osteoblasts and osteoclasts around the forced tooth in the WT. The GIPRKO exhibited no increase in the number of osteoblasts; however, the number of osteoclasts on the coil-loaded side was significantly increased in the GIPRKO compared with in the WT. In conclusion, our results demonstrate the impacts of GIP on the dynamics of bone remodeling. We revealed that GIP exhibits the formation of osteoblasts and the suppression of osteoclasts in force-induced bone remodeling.

Porphyromonas gingivalis Lipopolysaccharides Promote Proliferation and Migration of Human Vascular Smooth Muscle Cells through the MAPK/TLR4 Pathway.

Atherosclerosis is a major cause of mortality worldwide. The initial change in atherosclerosis is intimal thickening due to muscle cell proliferation and migration. A correlation has been observed between periodontal disease and atherosclerosis. Here, we investigated the proliferation and migration of human aortic smooth muscle cells (HASMCs) using Porphyromonas gingivalis-derived LPS (Pg-LPS). To elucidate intracellular signaling, toll-like receptor 4 (TLR4) and myeloid differentiation factor 88 (MyD88) of HASMCs were knocked down, and the role of these molecules in Pg-LPS-stimulated proliferation and migration was examined. The role of mitogen-activated protein kinase (MAPK) in HASMC proliferation and migration was further elucidated by MAPK inhibition. Pg-LPS stimulation increased the proliferation and migration of HASMCs and activated the TLR4/MyD88 pathway. TLR4 knockdown inhibited Pg-LPS stimulated HASMCs proliferation and migration. Pg-LPS stimulation led to the phosphorylation of P38 MAPK, JNK, and ERK, and MyD88 knockdown inhibited the phosphorylation of P38 MAPK and JNK but not ERK. P38 MAPK and SAPK/JNK inhibition did not suppress the proliferation of HASMCs upon Pg-LPS stimulation, but ERK inhibition significantly inhibited proliferation. SAPK/JNK and ERK inhibition suppressed Pg-LPS-stimulated migration of HASMCs. In conclusion, our findings suggest that Pg-LPS may promote atherosclerosis via the activation of MAPK through TLR4.

Impact of the clinical frailty scale on clinical outcomes and bleeding events in patients with ST-segment elevation myocardial infarction.

The Clinical Frailty Scale (CFS) is a simple tool to assess patients' frailty and may help to predict adverse outcomes in elderly patients. The aim of the present study was to examine the impact of CFS on clinical outcomes and bleeding events after successful percutaneous coronary intervention (PCI) in ST-segment elevation myocardial infarction (STEMI). We enrolled 266 consecutive patients with STEMI who underwent primary PCI in between January 2015 and June 2018. Patients were categorized into two groups based on the CFS stages: CFS 1-3 and CFS ≥ 4. We collected the data and evaluated the relationship between the CFS grade and the incidence of major adverse cardiovascular events (MACE) and Bleeding Academic Research Consortium 3 or 5 bleeding events. Of these patients, CFS ≥ 4 was present in 59 (22.2%). During the follow-up, 37.3% in the CFS ≥ 4 group and 8.2% in the CFS 1-3 group experienced MACE. In Kaplan-Meier analysis, the proportion of MACE-free survival for 4 years was significantly lower in the CFS ≥ 4 group (log-rank P < 0.001). Additionally, the proportion of bleeding event-free survival was significantly lower in the CFS ≥ 4 group (log-rank P < 0.001). The CFS (per 1-grade increase) remained an independent significant predictor of MACE on multivariate Cox proportional hazard analysis [hazard ratio 1.39 (95% confidence interval: 1.08 to 1.79, P = 0.01)]. In conclusion, CFS was an independent predictor of future adverse cardiac events in patients with STEMI. Therefore, the assessment of CFS is crucial in this population.

The Effects of Insulin on Immortalized Rat Schwann Cells, IFRS1.

Schwann cells play an important role in peripheral nerve function, and their dysfunction has been implicated in the pathogenesis of diabetic neuropathy and other demyelinating diseases. The physiological functions of insulin in Schwann cells remain unclear and therefore define the aim of this study. By using immortalized adult Fischer rat Schwann cells (IFRS1), we investigated the mechanism of the stimulating effects of insulin on the cell proliferation and expression of myelin proteins (myelin protein zero (MPZ) and myelin basic protein (MBP). The application of insulin to IFRS1 cells increased the proliferative activity and induced phosphorylation of Akt and ERK, but not P38-MAPK. The proliferative potential of insulin-stimulated IFRS1 was significantly suppressed by the addition of LY294002, a PI3 kinase inhibitor. The insulin-stimulated increase in MPZ expression was significantly suppressed by the addition of PD98059, a MEK inhibitor. Furthermore, insulin-increased MBP expression was significantly suppressed by the addition of LY294002. These findings suggest that both PI3-K/Akt and ERK/MEK pathways are involved in insulin-induced cell growth and upregulation of MPZ and MBP in IFRS1 Schwann cells.

Direct Comparison of Therapeutic Effects on Diabetic Polyneuropathy between Transplantation of Dental Pulp Stem Cells and Administration of Dental Pulp Stem Cell-Secreted Factors.

Stem cell transplantation is a potential novel therapy for diabetic polyneuropathy. Dental pulp stem cells (DPSCs) are attractive stem cell sources because DPSCs can be isolated from extracted teeth and cryopreserved while retaining viability. In this study, we directly compared the efficacy of the transplantation of DPSCs and the administration of the secreted factors from DPSCs (DPSC-SFs) on diabetic polyneuropathy. Eight weeks after streptozotocin injection, DPSCs (1.0 × 106 cells/rat) or DPSC-SFs (1.0 mL/rat) were administered into the unilateral hindlimb skeletal muscles of diabetic Sprague-Dawley rats. DPSC transplantation and DPSC-SF administration did not affect blood glucose levels and body weights in the diabetic rats. Both DPSC transplantation and DPSC-SF administration significantly ameliorated sciatic nerve conduction velocity and sciatic nerve blood flow, accompanied by increases in muscle bundle size, vascular density in the skeletal muscles and intraepidermal nerve fiber density in the diabetic rats, while there was no difference between the results for DPSCs and DPSC-SFs. These results suggest that the efficacy of both DPSC transplantation and DPSC-SF administration for diabetic polyneuropathy four weeks after transplantation/administration was mainly due to the multiple secretomes secreted from transplanted DPSCs or directly injected DPSC-SFs in the early phase of transplantation/administration.

Role of poly(ADP-ribose) polymerase activation in the pathogenesis of periodontitis in diabetes.

AIM: The aetiology of progressive periodontitis in diabetes has not yet been elucidated. We previously demonstrated that nitrosative stress is increased in diabetic rats with periodontitis. Nitrosative stress induces poly(ADP-ribose) polymerase (PARP) activation. Here, we demonstrated the involvement of PARP activation in diabetic periodontitis and detailed the therapeutic effects of PARP inhibitor. MATERIALS AND METHODS: Experimental periodontitis was induced by placing a nylon thread ligature. Half of the normal and diabetic rats received the PARP inhibitor, 1,5-isoquinolinediol, for 2 weeks. Gingival PARP activation was detected by immunostaining for poly(ADP-ribose). Periodontitis was evaluated by gingival inflammatory cell infiltration, inflammatory gene expressions and micro-CT analyses. RESULTS: Although both periodontitis and the presence of diabetes increased PARP activation in the gingiva, diabetic rats with periodontitis had the highest activation of PARP. Diabetic rats with periodontitis also showed significant increases in monocyte/macrophage invasion into the gingiva, inflammatory gene expressions, nitrotyrosine-positive cells in the gingiva and alveolar bone loss, all of which were suppressed by treatment with the PARP inhibitor. CONCLUSIONS: These results indicate the involvement of PARP activation in the pathogenesis and aggravation of periodontal disease in diabetes and suggest the therapeutic potential of PARP inhibition for treating periodontal disease, especially in patients with diabetes.

Impact of Coronary Stent Fracture on Restenotic Neointimal Tissue Characterization After Drug-Eluting Stent Implantation.

Although drug-eluting stents (DESs) reduce the rates of in-stent restenosis (ISR) and subsequent target lesion revascularization, stent fracture (SF) after DES implantation has become an important concern because of its potential association with restenosis and stent thrombosis. We aimed to assess the pathogenic impact of SF on in-stent restenotic neointimal tissue components after DES implantation. We analyzed 43 consecutive patients (14 with SF and 29 without SF) with ISR requiring revascularization after DES implantation between January 2008 and March 2014. For evaluation of in-stent tissue components, integrated backscatter intravascular ultrasound (IB-IVUS) was performed. SF was defined as complete or partial separation of stent segments observed using plain fluoroscopy or intravascular ultrasound. On volumetric IB-IVUS analyses, patients with SF had a significantly higher percentage of lipid tissue volume within the neointima and a significantly lower percentage of fibrous tissue volume than those without (37.3 ± 18.9% versus 24.9 ± 12.4%, P = 0.02, and 61.2 ± 18.3 versus 72.6 ± 12.1%, P = 0.04, respectively). Moreover, SF was positively correlated with the percentage of lipid volume on multiple linear regression analysis after adjustment for confounding factors (ß = 0.36, P = 0.03). The interval from stent implantation was similar in both groups (47.0 ± 28.7 versus 37.7 ± 33.3 months; P = 0.39). In conclusion, SF is associated with larger lipid tissue volume within the neointima after DES placement, suggesting a contribution to the development of neoatherosclerosis and vulnerable neointima. Thus SF might lead to future adverse coronary events.

Epigenome-wide association study suggests that SNPs in the promoter region of RETN influence plasma resistin level via effects on DNA methylation at neighbouring sites.

AIMS/HYPOTHESIS: To investigate epigenetic regulation of the plasma concentration of resistin, we performed an epigenome-wide association study for this variable and DNA methylation (DNAm) in an elderly Japanese cohort and then assessed the relation of single nucleotide polymorphisms (SNPs) associated with the plasma resistin concentration to DNAm level at identified sites. METHODS: The association of plasma resistin level with DNAm status was examined in 191 nondiabetic elderly men with the Illumina Infinium HumanMethylation450 BeadChip array. The association between DNAm status at specific sites in the flanking region of the resistin gene (RETN) and RETN mRNA abundance was then evaluated with a public data set for 1202 monocyte samples from a multi-ethnic cohort. Finally, the association of DNAm status and SNPs in the promoter region of RETN was assessed in two cohorts comprising a total of 478 Japanese individuals. RESULTS: DNAm status at cg02346997 located in the RETN promoter region showed a negative genome-wide significant association with the plasma resistin level (p = 6.02 × 10(-10)). Four DNAm sites in the RETN promoter region including cg02346997 (p = 4.23 × 10(-70)) showed a negative genome-wide significant association with RETN mRNA abundance in monocytes. Furthermore, the number of minor alleles of the RETN promoter SNPs rs34861192 and rs3219175 was negatively associated with DNAm level at cg02346997 (p = 4.43 × 10(-17)). CONCLUSIONS/INTERPRETATION: Our results suggest that RETN promoter SNPs might influence the circulating resistin level through an effect on DNAm at cg02346997 and on RETN mRNA abundance in monocytes.

Assessment of In-Stent Restenosis Using High-Definition Computed Tomography With a New Gemstone Detector.

BACKGROUND: Until now, there have been few reports on the accuracy of in-stent restenosis (ISR) detection using high-definition computed tomography (HDCT). The purpose of this study was to assess ISR using HDCT with a new gemstone detector and to examine the diagnostic accuracy compared with invasive coronary angiography. METHODS AND RESULTS: We evaluated 162 consecutive patients with 316 stents and the image quality (IQ) scores used to assess ISR, and analyzed whether stent strut thickness and diameter affected IQ score and assessability. In the 316 stents, 278 were diagnosed as assessable with HDCT (88.0%). IQ score for stent diameter ≥3 mm was significantly higher than that for stent diameter <3 mm, for stents with both thick struts ≥140 µm in thickness (mean IQ: 2.04±0.97 vs. 2.83±1.06, P<0.001) and thin struts <140 µm (mean IQ: 1.92±0.87 vs. 2.64±0.96, P=0.01). Assessability for stent diameter ≥3 mm was significantly higher than that for stent diameter <3 mm only for stents with thick struts (92.8% vs. 76.1%, P<0.001). Stent strut thickness, however, was not statistically significantly associated with either IQ score or assessability. CONCLUSIONS: In-stent lumens have high HDCT assessability, and HDCT is useful to evaluate thick-strut stents with diameter <3 mm.

Long-term effects of spironolactone in peritoneal dialysis patients.

ESRD treated with dialysis is associated with increased left ventricular hypertrophy, which, in turn, is related to high mortality. Mineralocorticoid receptor antagonists improve survival in patients with chronic heart failure; however, the effects in patients undergoing dialysis remain uncertain. We conducted a multicenter, open-label, prospective, randomized trial with 158 patients receiving angiotensin-converting enzyme inhibitor or angiotensin type 1 receptor antagonist and undergoing peritoneal dialysis with and without (control group) spironolactone for 2 years. As a primary endpoint, rate of change in left ventricular mass index assessed by echocardiography improved significantly at 6 (P=0.03), 18 (P=0.004), and 24 (P=0.01) months in patients taking spironolactone compared with the control group. Rate of change in left ventricular ejection fraction improved significantly at 24 weeks with spironolactone compared with nontreatment (P=0.02). The benefits of spironolactone were clear in patients with reduced residual renal function. As secondary endpoints, renal Kt/V and dialysate-to-plasma creatinine ratio did not differ significantly between groups during the observation period. No serious adverse effects, such as hyperkalemia, occurred. In this trial, spironolactone prevented cardiac hypertrophy and decreases in left ventricular ejection fraction in patients undergoing peritoneal dialysis, without significant adverse effects. Further studies, including those to determine relative effectiveness in women and men and to evaluate additional secondary endpoints, should confirm these data in a larger cohort.

Impact of Admission Anemia on Coronary Microcirculation and Clinical Outcomes in Patients With ST-Segment Elevation Myocardial Infarction Undergoing Primary Percutaneous Coronary Intervention.

Microvascular dysfunction after primary percutaneous coronary intervention (PCI) augments myocardial damage and prognosis in acute myocardial infarction. However, the relationship between baseline anemia and coronary microcirculation in patients with ST-segment elevation myocardial infarction (STEMI) remains unclear. We performed primary PCI in 337 consecutive patients with STEMI. Anemia was defined as a hemoglobin level < 13 g/dL in men and < 12 g/dL in women. Admission anemia was present in 17.5% of the patients enrolled. Data on epicardial coronary flow, STsegment resolution (STR) on electrocardiography, myocardial injury, and the incidence of adverse cardiac events defined as cardiac death or hospitalization for congestive heart failure were analyzed. The median follow-up period was 54.8 months. Despite comparable epicardial coronary flow, the rate of STR ≥ 50% was lower in anemic patients compared with non-anemic patients (55.9% versus 71.2%, P = 0.02). On multivariate logistic regression analysis, baseline anemia was an independent negative predictor of STR ≥ 50% (odds ratio, 0.53; 95% confidence interval: 0.31-0.92, P = 0.03). Moreover, anemic patients had higher maximum creatine kinase levels normalized for body surface area (2,215 ± 1,318 IU/L/m(2) versus 1,797 ± 1,199 IU/L/m(2), P = 0.047). Anemia remained an independent significant predictor of adverse events on multivariate Cox proportional hazard analysis (hazard ratio, 2.34; 95% confidence interval: 1.01-5.64, P = 0.048). In conclusion, admission anemia was related to microcirculatory dysfunction and poor prognosis in patients with STEMI. The decreased oxygen delivery might exacerbate microvascular function.

Iron-catalyzed directed alkylation of aromatic and olefinic carboxamides with primary and secondary alkyl tosylates, mesylates, and halides.

Alkenes, arenes, and heteroarenes possessing an 8-quinolylamide group as the directing group are alkylated with primary and secondary alkyl tosylates, mesylate, and halides in the presence of Fe(acac)3/diphosphine as a catalyst and ArZnBr as a base. The reaction proceeds stereospecifically for alkene substrates and takes place without loss of regiochemical integrity of the starting secondary tosylate, but with loss of the stereochemistry of the chiral center.

Synthesis of anthranilic acid derivatives through iron-catalyzed ortho amination of aromatic carboxamides with N-chloroamines.

Arenes possessing an 8-quinolinylamide group as a directing group are ortho aminated with N-chloroamines and N-benzoyloxyamines in the presence of an iron/diphosphine catalyst and an organometallic base to produce anthranilic acid derivatives in high yield. The reaction proceeds via iron-catalyzed C-H activation, followed by the reaction of the resulting iron intermediate with N-chloroamine. The choice of the directing group and diphosphine ligand is crucial for obtaining the anthranilic acid derivative with high yield and product selectivity.

Prognostic impact of lipid contents on the target lesion in patients with drug eluting stent implantation.

We sought to determine the morphologic predictors of major adverse cardiac events (MACEs) after successful percutaneous coronary intervention (PCI) with drug-eluting stents (DES), using integrated backscatter intravascular ultrasound (IB-IVUS). Conventional IVUS and IB-IVUS were performed in 260 consecutive patients who underwent PCI with DES. Three-dimensional analyses were performed to determine plaque volume and the volume of each plaque component (lipid, fibrous, and calcification). Patients were divided into two groups according to the median lipid volume (LV) in the target lesion. MACEs were defined as death, nonfatal myocardial infarction, and any repeat revascularization. The median follow-up interval was 1285 days. MACEs were observed in 64 patients (24.6 %). Patients having a larger LV compared with their counterparts had worse long-term clinical outcomes regarding mortality (3.8 vs. 0 %, P = 0.02) and MACEs (31.5 vs. 17.7 %, P = 0.008) by log-rank test. After adjustment for confounders, large LV (odds ratio 1.95, 95 % confidence interval 1.14-3.33, P = 0.02) was significantly and independently associated with MACEs. The assessment of coronary plaque characteristics in the target lesion may be useful to predict long-term outcome following successful coronary intervention.

A genome-wide association study of a coronary artery disease risk variant.

Although over 30 common genetic susceptibility loci have been identified to be independently associated with coronary artery disease (CAD) risk through genome-wide association studies (GWAS), genetic risk variants reported to date explain only a small fraction of heritability. To identify novel susceptibility variants for CAD and confirm those previously identified in European population, GWAS and a replication study were performed in the Koreans and Japanese. In the discovery stage, we genotyped 2123 cases and 3591 controls with 521 786 SNPs using the Affymetrix SNP Array 6.0 chips in Korean. In the replication, direct genotyping was performed using 3052 cases and 4976 controls from the KItaNagoya Genome study of Japan with 14 selected SNPs. To maximize the coverage of the genome, imputation was performed based on 1000 Genome JPT+CHB and 5.1 million SNPs were retained. CAD association was replicated for three GWAS-identified loci (1p13.3/SORT1 (rs599839), 9p21.3/CDKN2A/2B (rs4977574), and 11q22.3/ PDGFD (rs974819)) in Koreans. From GWAS and a replication, SNP rs3782889 showed a strong association (combined P=3.95 × 10(-14)), although the association of SNP rs3782889 doesn't remain statistically significant after adjusting for SNP rs11066015 (proxy SNP with BRAP (r(2)=1)). But new possible CAD-associated variant was observed for rs9508025 (FLT1), even though its statistical significance did marginally reach at the genome-wide a significance level (combined P=6.07 × 10(-7)). This study shows that three CAD susceptibility loci, which were previously identified in European can be directly replicated in Koreans and also provides additional evidences implicating suggestive loci as risk variants for CAD in East Asian.

Renal dysfunction and atherosclerosis of the neointima following bare metal stent implantation.

BACKGROUND: Recently, neoatherosclerosis within the neointima after bare metal stent (BMS) implantation, which could cause late restenosis and very late stent thrombosis, has been a cause of concern. Renal dysfunction has been related to late cardiovascular events after coronary intervention. The present study was conducted focusing on the relationship between renal dysfunction and neointimal tissue characteristics with BMS restenosis using integrated backscatter intravascular ultrasound (IB-IVUS). METHODS: We prospectively performed IB-IVUS in 80 consecutive patients requiring target lesion revascularization after BMS implantation; the patients were divided into two groups according to the estimated glomerular filtration [eGFR: ≥60 (n = 49) and <60 ml/min/1.73 m(2) (n = 31)]. RESULTS: Patients with eGFR <60 ml/min/1.73 m(2) had a significantly higher percentage of lipid tissue volume within the neointima and a lower percentage of fibrous tissue volume than those with eGFR ≥60 ml/min/1.73 m(2) (23.2 ± 9.4 vs. 18.0 ± 7.0%, p = 0.005, and 75.3 ± 9.3 vs. 80.4 ± 7.0%, p = 0.007, respectively). Using logistic regression analysis, eGFR <60 ml/min/1.73 m(2) and duration from stent implantation ≥48 months were independent predictors of increased lipid tissue volume within the neointima (odds ratio, 3.93; 95% confidence interval, 1.15-13.46, p = 0.03, and odds ratio, 7.56; 95% confidence interval, 2.02-28.30, p = 0.003, respectively). CONCLUSIONS: Lower eGFR levels were associated with greater lipid tissue volume within the neointima after BMS deployment, suggesting the development of atherosclerosis. Renal dysfunction may affect neointimal tissue characteristics and thus leading to an increased risk of late stent failure.

Post-stress perfusion abnormalities detected on myocardial perfusion single-photon emission computed tomography predict long-term mortality after elective abdominal aortic aneurysm repair.

BACKGROUND: After abdominal aortic aneurysm (AAA) repair, relatively low survival during long-term follow-up remains an unresolved issue. Stress myocardial perfusion single-photon emission computed tomography (SPECT) well predicts future mortality overall, as well as providing diagnoses of coronary artery disease. The prognostic value of myocardial SPECT findings after AAA repair, however, remains unclear. METHODS AND RESULTS: This study followed 285 patients, all undergoing preoperative pharmacologic stress myocardial perfusion SPECT to determine summed stress score (SSS), then elective AAA repair by open AAA repair or endovascular aneurysm repair. The endpoint of the study was cardiac death. The median follow-up duration was 925 days (range, 541-1,095 days). Twenty-four (8%) died during follow-up. Kaplan-Meier analysis showed that patients with SSS≥9 had a significantly poorer prognosis than those with SSS<9 (76% vs. 93%, P=0.003). Multivariate Cox proportional hazards analysis indicated that SSS≥9, diabetes, and chronic kidney disease≥stage 3 could significantly and independently predict long-term cardiovascular mortality in patients after AAA repair (hazard ratio [HR], 4.2; 95% confidence interval [CI]: 1.8-9.7, P=0.001; HR, 3.0; 95% CI: 1.2-7.4, P=0.020; and HR, 4.1; 95% CI: 1.7-10.1, P=0.029, respectively). CONCLUSIONS: Preoperative pharmacologic stress myocardial perfusion SPECT is a useful method to predict long-term cardiovascular mortality for patients undergoing elective AAA repair.