Comparative pathological findings between coronary bare-metal stent implantation and balloon angioplasty over 16 years.

A 68-year old man underwent bare metal stent (BMS; Palmaz-Shatz stent) implantation in the distal right coronary artery (RCA; #4PL) and balloon angioplasity (BA) in the proximal left circumflex coronary artery (LCX; #11) for stable angina. After 5 years after initial stent implantation, de novo lesion located in mid RCA was treated by BMS (NIR stent) implantation additionally. After 16 years from first BMS implantation, the patient died from heart failure due to cardiac amyloidosis, and pathologic examination was performed for the specimen of stented RCA segment and LCX BA segment. An autopsy demonstrated that the lesions of stented site at RCA and BA site LCX were histopathologically different. In the stented segment, severe luminal stenosis is observed due to marked proliferation of the neointima in all stented sites. In addition, neovascularization and spotty calcification with mild lymphocyte infiltration were observed especially around the struts. In contrast, at the BA site of the proximal LCX lesion, in the neointima, the smooth muscle cells were rather atrophic and abundant collagen fibers were evident in the intercellular spaces, which showed very stable findings. Compared with these BMS implanted portions, the site of BA was associated with a trend for smaller late lumen loss. These findings suggested that in the stented site, chronic inflammatory reaction to the stent struts could evoke continuous proliferation of neointima resulting in severe late lumen loss. .

Clinical impact of pathology-proven etiology of severely stenotic aortic valves on mid-term outcomes in patients undergoing surgical aortic valve replacement.

BACKGROUND: The use of transcatheter or surgical aortic valve replacement (AVR) for severe aortic stenosis (AS) has considerably increased in recent years. However, the association between AS etiology and mid-term clinical outcomes after surgical AVR has not been fully investigated. METHODS AND RESULTS: We retrospectively included 201 patients (mean age, 75 years; 43%, men) who underwent surgical AVR for severe native AS (aortic valve area ≤1.0 cm2 on preoperative transthoracic echocardiography examination). The following valve etiologies were postoperatively identified on pathological examination: post-inflammatory (n = 28), congenital (n = 35), and calcific/degenerative (n = 138). The median follow-up interval was 4.1 years following surgical AVR. Of the 201 patients, 27% were asymptomatic, 40% had a history of heart failure, and 11% underwent previous heart surgery. The cumulative incidence of cardiac events (all-cause death, aortic valve deterioration requiring repeated AVR, and hospitalization for heart failure) and combined adverse events, which included non-fatal stroke, unplanned coronary revascularization, pacemaker implantation, and gastrointestinal bleeding along with cardiac events, was significantly higher in the calcific/degenerative group (p = 0.02 and p = 0.02, respectively). In multivariate analysis adjusted for age, sex, renal function, heart failure, atrial fibrillation, concomitant surgical procedures, and EuroSCORE II, AS etiology was independently associated with an increased risk of combined adverse events (congenital vs. post-inflammatory: hazard ratio [HR], 4.13; p = 0.02 and calcific/degenerative vs. post-inflammatory: HR, 5.69; p = 0.002). CONCLUSIONS: Pathology-proven AS etiology could aid in predicting the mid-term outcomes after surgical AVR, supporting the importance of accurate identification of severe AS etiology with or without postoperative pathological examination.

Two rare cases of congenital aortic stenosis showing a discrepancy between preoperative imaging diagnosis, intraoperative findings, and histopathological diagnosis.

Unicuspid aortic valve (UAV) is an extremely rare congenital heart valve abnormality while bicuspid valve (BAV) has been reported as one of the most common cardiac anomalies. With a UAV usually showing similar presentations to a BAV, such as aortic regurgitation or aortic stenosis (AS), it is challenging to differentiate them from each other in clinical settings. Despite some features shared between both valve disorders, there can be a clinical significance in distinguishing UAV from BAV for the management of patients with these heart anomalies. Herein, we describe two cases where patients with hemodynamically severe AS were diagnosed with BAV and UAV, respectively based on preoperative examinations and intraoperative findings, but subsequent pathological examinations confirmed the opposite diagnosis in both cases. .

Histological Evaluation of a Self-Expanding Stent-Graft 23 Months After Implantation in the Superficial Femoral Artery.

PURPOSE: To report histological examination of a Viabahn stent-graft implanted in the superficial femoral artery (SFA) for nearly 2 years. CASE REPORT: A 78-year-old man with peripheral artery disease was treated successfully with a 6.0×250-mm Viabahn self-expanding stent-graft in the right SFA, relieving his lower limb claudication. The patient died suddenly due to acute myocardial infarction 23 months later. Histological evaluation of the stent-graft implantation site revealed moderate neointimal proliferation at both proximal and distal edges of the device. In the middle part of the stent, significant macrophages and multinucleated foreign body giant cells had accumulated, although the stent was entirely patent. Furthermore, no endothelial cell coverage was found. CONCLUSION: Judging from these features, it might be necessary to continue dual antiplatelet therapy after stent-graft implantation over the long term to prevent thrombosis and subsequent restenosis or reocclusion.

Pathology of Neointimal Calcification in Very Late Restenosis After Bare Metal Stent Implantation for Superficial Femoral Artery.

A 60-year-old man, who had claudication in his right limb due to total occlusion of the right superficial femoral artery, received bare metal stents. Although the bare metal stents in the superficial femoral artery did not show restenosis 5 years after stent implantation, angiography revealed significant in-stent restenosis when he developed right critical limb ischemia at 8 years post implantation. Ballooning for in-stent lesions did not result in full expansion. His right limb was amputated above the knee due to progressive limb ischemia. In the pathological findings in the superficial femoral artery, marked calcification was observed in the entire circumference of the luminal surface of the neointima. However, lipid core formation was not identified in the neointima. Although several cracks following balloon angioplasty were observed at the superficial calcified layers, injury to neointimal tissue such as compression was not observed. The neointima exhibited heavy calcification in the very late phase of in-stent restenosis after bare metal stent implantation in superficial femoral artery. Therefore, balloon angioplasty in the very late phase of in-stent restenosis potentially results in underexpansion.

Oropharyngeal Dysphagia in Dermatomyositis: Associations with Clinical and Laboratory Features Including Autoantibodies.

OBJECTIVE: Dysphagia develops with low frequency in patients with dermatomyositis. Our objective was to determine the clinical and laboratory features that can estimate the development of dysphagia in dermatomyositis. METHODS: This study included 92 Japanese patients with adult-onset dermatomyositis. The associations between dysphagia and clinical and laboratory features including disease-specific autoantibodies determined by immunoprecipitation assays were analyzed. RESULTS: Videofluoroscopy swallow study (VFSS) was performed for all patients with clinical dysphagia (n = 13, 14.1%) but not for patients without clinical dysphagia. Typical findings of dysphagia (pharyngeal pooling, n = 11 and/or nasal regurgitation, n = 4) was detected by VFSS in all patients with clinical dysphagia. Eleven patients with dysphagia (84.6%) had anti-transcription intermediary factor 1γ (TIF-1γ) antibody. By univariate analysis, the average age and the male to female ratio, internal malignancy, and anti-TIF-1γ antibody were significantly higher and the frequency of interstitial lung diseases and manual muscle testing (MMT) scores of sternomastoid and dertoid muscles were significantly lower in patients with dysphagia than in patients without dysphagia. Among patients with anti-TIF-1γ antibody, the mean age, the ratios of male to female and internal malignancy were significantly higher and mean MMT scores of sternomastoid muscle were significantly lower in patients with dysphagia compared with patients without dysphagia. By multivariable analysis, the risk of dysphagia was strongly associated with the existence of internal malignancy and ant-TIF-1γ antibody and was also associated with reduced scores of manual muscle test of sternomastoid muscle. Dysphagia was markedly improved after the treatment against myositis in all 13 patients. CONCLUSION: These findings indicate that dysphagia can develop frequently in patients with internal malignancy, anti-TIF-1γ antibody, or severe muscle weakness of sternomastoid muscle.

Calcification around the Struts of a Sirolimus-eluting Stent Approximately 16 Months after Implantation in an Autopsy Case.

Drug-eluting stents (DES) are widely used for the treatment of coronary artery disease, and a sirolimus-eluting stent (SES; Cypher) was the first DES introduced into clinical practice. Although pathological reactions of coronary arteries to SES have been described in autopsy cases, there are few reports regarding calcification of the coronary arteries after SES implantation. The present report describes the findings of an autopsy conducted 16 months after SES implantation that showed remarkable persistent calcification. In addition, previously reported pertinent pathological findings are also described.

Giant vein graft aneurysm complicated by Loeys-Dietz syndrome.

Loeys-Dietz syndrome (LDS) is a recently reported autosomal dominant aortic aneurysm syndrome with widespread systemic involvement. Although connective tissue diseases carry a theoretical risk of aneurysmal degeneration in vein grafts, there are no reports of vein graft aneurysm (VGA) in patients with connective tissue disease. We herein report the first case of a giant VGA that was manifested 5 years after the reconstruction of a popliteal artery aneurysm associated with LDS. A pathologic examination of the VGA revealed high proteoglycan deposition and medial degeneration of the diffuse type in the VGA; these findings conformed to LDS.

Reduction of endoplasmic reticulum stress inhibits neointima formation after vascular injury.

Endoplasmic reticulum (ER) stress and inappropriate adaptation through the unfolded protein response (UPR) are predominant features of pathological processes. However, little is known about the link between ER stress and endovascular injury. We investigated the involvement of ER stress in neointima hyperplasia after vascular injury. The femoral arteries of 7-8-week-old male mice were subjected to wire-induced vascular injury. After 4 weeks, immunohistological analysis showed that ER stress markers were upregulated in the hyperplastic neointima. Neointima formation was increased by 54.8% in X-box binding protein-1 (XBP1) heterozygous mice, a model of compromised UPR. Knockdown of Xbp1 in human coronary artery smooth muscle cells (CASMC) in vitro promoted cell proliferation and migration. Furthermore, treatment with ER stress reducers, 4-phenylbutyrate (4-PBA) and tauroursodeoxycholic acid (TUDCA), decreased the intima-to-media ratio after wire injury by 50.0% and 72.8%, respectively. Chronic stimulation of CASMC with PDGF-BB activated the UPR, and treatment with 4-PBA and TUDCA significantly suppressed the PDGF-BB-induced ER stress markers in CASMC and the proliferation and migration of CASMC. In conclusion, increased ER stress contributes to neointima formation after vascular injury, while UPR signaling downstream of XBP1 plays a suppressive role. Suppression of ER stress would be a novel strategy against post-angioplasty vascular restenosis.

Impact of clinical and echocardiographic characteristics on occurrence of cardiac events in cardiac amyloidosis as proven by endomyocardial biopsy.

BACKGROUND: Although patients with immunoglobulin light chain (AL) cardiac amyloidosis exhibit worse outcomes than those with transthyretin (TTR) cardiac amyloidosis, few data exist regarding the occurrence of cardiac events and the echocardiographic indices in endomyocardial biopsy (EMBx) proven amyloidosis. METHODS: From November 2007 to October 2012, we identified 33 patients with EMBx-proven amyloidosis. There were 12 patients (8 men; mean age: 66 years) with AL and 21 patients (20 men; mean age: 78 years) with TTR. We performed serial echocardiography and observed the patients during follow-up; defining all-cause mortality as the primary endpoint and hospitalization for heart failure as the secondary endpoint. RESULTS: The survival rates at 12 months were 20.8% and 85.7% in AL and TTR, respectively (p<0.001). The cumulative incidences of the composite of death or readmission for heart failure at 12 months were 91.7% and 51.3% in AL and TTR, respectively (p<0.001). A multivariate analysis showed that the AL type amyloid was the powerful predictor of mortality (hazard ratio: 8.50, 95% confidence interval: 1.79 to 40.57, p<0.05). Under these conditions, the E/e' in AL tended to increase from 23±13 to 28±11 (p=0.06) with marked increases in B-type natriuretic peptide (779±456 pg/ml to 1576±895 pg/ml, p<0.05), although these remained unchanged in TTR, which exhibited significantly increased left ventricular end-diastolic dimensions from 40±4 mm to 42±4 mm (p<0.05). CONCLUSIONS: The survival rate was generally worse in AL cardiac amyloidosis, although the readmission for heart failure remains high in TTR cardiac amyloidosis with the occurrence of left ventricular dilatation.

Sirolimus-eluting stent implantation for ostial right coronary artery lesions: five-year outcomes from the j-Cypher registry.

Ostial right coronary artery (RCA) lesions are associated with a high restenosis rate after bare-metal stent implantation. However, long-term outcomes after drug-eluting stent (DES) implantation for ostial RCA lesions have not been adequately evaluated. Among 12824 patients enrolled in the j-Cypher registry, 5-year outcomes were compared between 397 patients with ostial RCA lesions, and 3716 patients with non-ostial RCA lesions treated with sirolimus-eluting stents (SES). Through 5-year follow-up, patients with ostial RCA lesions had a significantly higher cumulative incidence of target lesion revascularization (TLR) (28.2 versus 13.7 %, P < 0.0001) than those with non-ostial RCA lesions. After adjusting for confounders, excess TLR risk of the ostial group relative to the non-ostial group was significant for both early TLR within 1-year and late TLR beyond 1-year (HR 2.14 [95 % CI 1.59-2.84], P < 0.0001, and HR 1.58 [95 % CI 1.06-2.26], P = 0.02, respectively). Although the cumulative incidence of death was also significantly higher in the ostial group than in the non-ostial group (25.7 versus 14.4 %, P < 0.0001), the excess risk of the ostial group relative to the non-ostial group was no longer significant after adjusting for confounders (HR 1.25 [95 % CI 0.99-1.57], P = 0.07). SES implantation for ostial RCA lesions was associated with higher risk for TLR as compared with that for non-ostial RCA lesions. Restenosis, both early and late, remains an issue in coronary DES implantation for ostial RCA lesions.

Myocardial expression level of neural cell adhesion molecule correlates with reduced left ventricular function in human cardiomyopathy.

BACKGROUND: Recently, we screened for cardiac genes induced by metabolic stress and identified neural cell adhesion molecule (NCAM) as a candidate. This study aimed to clarify the expression pattern of NCAM in human cardiomyopathy. METHODS AND RESULTS: A total of 64 cardiac tissue samples of patients with dilated cardiomyopathy were dichotomized according to the immunohistochemically determined signal intensity of NCAM staining (NCAM-high and NCAM-low groups). Clinical and hemodynamic data of the patients were compared between the 2 groups. Fibrosis area, left ventricular end-diastolic volume index, and left ventricular diastolic pressure were greater in the NCAM-high group (22.8% versus 11.6%, P<0.05; 130.3±57.6 versus 104.8±31.7 mL/m(2), P<0.05; 14.3±8.0 versus 8.8±4.7 mm Hg, P<0.005; respectively). Incidence of cardiac death and admission for worsening heart failure was higher in the NCAM-high group during a follow-up of 6.3 years (log-rank P<0.05). Another 18 tissue samples were analyzed to determine the relationships between expression level of NCAM and major metabolic genes as well as hemodynamic parameters. The mRNA level of NCAM correlated with the serum (r=0.58; P=0.01) and mRNA levels (r=0.61; P=0.008) of brain-derived natriuretic peptides. It was also correlated with the mRNA levels of proliferator-activated receptor-γ coactivator-1 α (r=0.69; P=0.002) and the nuclear respiratory factor 1 (r=0.74; P<0.001). CONCLUSIONS: Expression of NCAM was associated with worsening hemodynamic parameters and major metabolic genes. Together with our previous findings, these data support the involvement of NCAM in left ventricular remodeling, revealing new insights into the pathophysiology of heart failure.

Percutaneous coronary intervention in patients with previous coronary artery bypass grafting (from the j-Cypher Registry).

A paucity of data is available from large-scale studies evaluating the long-term outcomes of percutaneous coronary intervention in patients who had previously undergone coronary artery bypass grafting (CABG) in the drug-eluting stent era. Of 12,812 patients who had undergone sirolimus-eluting stent implantation in the j-Cypher registry, 919 (7.2%) had a history of CABG and had significantly higher crude 5-year mortality (19.9% vs 14.0%, p <0.001). After adjusting for confounders, the excess risk of death was no longer significant (hazard ratio 0.99, 95% confidence interval 0.83 to 1.18, p = 0.90), and the adjusted risk of target lesion revascularization was significantly higher in patients with previous CABG than in those without (hazard ratio 1.25, 95% confidence interval 1.06 to 1.47, p = 0.01). Of the patients with previous CABG, those who had undergone ≥1 saphenous vein graft intervention had significantly higher adjusted risks of cardiac death (hazard ratio 2.21, 95% confidence interval 1.26 to 3.76, p = 0.01), myocardial infarction (hazard ratio 2.56, 95% confidence interval 1.10 to 5.60, p = 0.03), target lesion revascularization (hazard ratio 2.65, 95% confidence interval 1.82 to 3.81, p <0.001), and definite stent thrombosis (hazard ratio 7.70, 95% confidence interval 1.99 to 29.1, p = 0.004) compared with those who underwent percutaneous coronary intervention only for the native coronary artery. In conclusion, the adjusted mortality was similar between patients with and without previous CABG, despite a significantly different risk of target lesion revascularization. Among the patients with previous CABG, those with saphenous vein graft intervention using a first-generation drug-eluting stent had worse clinical outcomes than those with a native coronary artery target only.

[Effectiveness of acupuncture and moxibustion therapy for the treatment of refractory interstitial cystitis].

The efficacy of acupuncture and moxibustion treatment was examined on eight female patients with refractory interstitial cystitis (IC) who had been treated conservatively with hydrodistension, intravesical instillation of dimethyl sulfoxide, or oral medication. These patients had received hydrodistension on an average of 2.3±1.8 times. Moxa needles were applied to Ciliao in bladder meridian 32 and Xialiao in bladder meridian 34, and electroacupuncture was performed on Zhongliao in bladder meridian 33 at 3 Hz for 20 min once a week. The bladder condition was assessed by the visual analogue scale (VAS) score, the O'Leary-Sant Interstitial Cystitis Symptom Index (ICSI), the Interstitial Cystitis Problem Index (ICPI), and the maximum voided volume (MVV). After 3 months, patients who showed a reduction of >2 in their VAS score, reduction of <30% of ICSI and ICPI, and increase of >100 ml MVV were considered responders. There were three responders, and after repeated therapy to maintain these effects, they no longer required hydrodistension. Two responders had no recurrence for 48 months or more. Acupuncture and moxibustion resulted in improvement in 38% of the patients (3/8) with refractory IC, and repeated therapy maintained the therapeutic effects. This therapy is traditional and relatively noninvasive. Although its precise mechanism of action is unclear, this study suggests that acupuncture and moxibustion treatment may be a complementary and alternative therapeutic option for refractory IC.

Vascular responses to a biodegradable polymer (polylactic acid) based biolimus A9-eluting stent in porcine models.

AIMS: The time-dependent changes in endothelial and healing properties of coronary arteries implanted with a biodegradable polymer-based biolimus A9-eluting stent (BioPol-BES) have not been investigated. We evaluated the short-term and the long-term in vivo response of BioPol-BES, as compared to a permanent polymer-based sirolimus-eluting stent (PermPol-SES), and a bare metal stent (BMS). METHODS AND RESULTS: Overlapping stents were placed in 33 swine (n=11 for BES, SES, and BMS, respectively) for two and four weeks and single stents in 30 miniature pigs (n=18 for BES, n=9 for SES, n=3 for BMS) for three, nine and 15-month evaluations. The vessel patency, arterial healing and endothelialisation were assessed by angiography, histopathology and scanning electron microscopy. At four weeks, the endothelialisation at overlapping stent regions was greater with BioPol-BES (87.8±3.7%) and BMSs (98.0±0.4%) than with PermPol-SES (66.4±3.2%). The inflammation score in vessels implanted with single BioPol-BES increased slightly from three to 15 months (0.00±0.00 to 0.28±0.14), while this increase was more pronounced with PermPol-SES (0.11±0.07 to 1.56±0.68). Compared to BMS moderate lymphocyte infiltration was seen with BioPol-BES, and marked granulomatous formation with PermPol-SES. CONCLUSIONS: The level of endothelial coverage in BioPol-BES was comparable to BMS at four weeks, with no significant increase of inflammatory reaction up to 15 months.

Left atrium volume index and pathological features of left atrial appendage as a predictor of failure in postoperative sinus conversion.

BACKGROUND: Previous studies showed that some parameters, including left atrium diameter and left atrium volume index (LAVI), predicted the success of sinus conversion. However, no previous studies have investigated the association of sinus conversion with LAVI and histopathological findings. This study was designed to investigate the relationship among LAVI, pathological assessment, and failure in sinus conversion after surgery for valvular atrial fibrillation (AF). METHODS AND RESULTS: A total of 78 patients with left atrium enlargement and valvular AF who underwent maze procedure concomitantly with various cardiac surgeries were classified into one of two groups: those who successfully underwent sinus conversion (Group 1; n=40) and those who did not achieve sinus conversion (Group 2; n=38). Histopathological assessment was performed in 9 cases using tissues derived from the left atrial appendage (LAA). The degree of histopathological change was classified into 1 of 4 grades. LAVI was significantly less in Group 1 than in Group 2 (81 + or - 22 ml/m(2) vs. 122 + or - 49 ml/m(2), p<0.001). Preoperative LAVI predicted 100% failure of sinus conversion after surgery with a cut-off value of 135 ml/m(2). Histopathological analyses clearly showed that the grades for intercellular fibrosis, fatty infiltration, endocardial thickening, and nuclear enlargement/abnormalities were significantly and positively correlated with LAVI (r=0.75, p<0.05; r=0.74, p<0.05; r=0.69, p<0.05; r=0.77, p<0.05, respectively). CONCLUSIONS: LAVI associated with histopathological features of the resected LAA is a predictor of failure in sinus conversion following surgical intervention in patients with valvular AF.

Progranulin expression in advanced human atherosclerotic plaque.

BACKGROUND: Progranulin (PGRN) is a unique growth factor that plays an important role in cutaneous wound healing. It has an anti-inflammatory effect and promotes cell proliferation. However, when it is degraded to granulin peptides (GRNs) by neutrophil proteases, a pro-inflammatory reaction occurs. Since injury, inflammation and repair are common features in the progression of atherosclerosis, it is conceivable that PGRN plays a role in atherogenesis. RESULTS: Immunohistochemical analysis of human carotid endoatherectomy specimens indicated that vascular smooth muscle cells (vSMCs) in the intima expressed PGRN. Some macrophages in the plaque also expressed PGRN. We assessed the effect of PGRN on a human monocytic leukemia cell line (THP-1) and human aortic smooth muscle cells (HASMCs). PGRN alone had no effect on HASMC or THP-1 proliferation or migration. However, when THP-1 cells were stimulated with MCP-1, the number of migrated cells decreased in a PGRN-dose-dependent manner. TNF-alpha-induced HASMC migration was enhanced only at 10nM of PGRN. Interleukin-8 (IL-8) secretion from HASMCs was reduced by forced expression of PGRN and increased by RNAi-mediated knockdown of PGRN. While exogenous treatment with recombinant PGRN decreased IL-8 secretion, degraded recombinant GRNs increased IL-8 secretion from HASMCs. CONCLUSIONS: The expression of PGRN mainly reduces inflammation and its degradation into GRNs enhances inflammation in atherosclerotic plaque and may contribute to the progression of atherosclerosis.

SNPs in BRAP associated with risk of myocardial infarction in Asian populations.

Myocardial infarction is a common disease and among the leading causes of death in the world. We previously reported association of variants in LGALS2, encoding galectin-2, with myocardial infarction susceptibility in a case-control association study in a Japanese population. Here we identify BRAP (BRCA1-associated protein) as a galectin-2-binding protein. We report an association of SNPs in BRAP with myocardial infarction risk in a large Japanese cohort (P = 3.0 x 10(-18), OR = 1.48, 2,475 cases and 2,778 controls), with replication in additional Japanese and Taiwanese cohorts (P = 4.4 x 10(-6), 862 cases and 1,113 controls and P = 4.7 x 10(-3), 349 cases and 994 controls, respectively). BRAP expression was observed in smooth muscle cells (SMCs) and macrophages in human atherosclerotic lesions. BRAP knockdown by siRNA using cultured coronary endothelial cells suppressed activation of NF-kappaB, a central mediator of inflammation.

Pathological finding of sirolimus-eluting stent (SES) restenosis lesion with black hole appearance on intravascular ultrasound.

Restenosis still occurs, even with the sirolimus-eluting stent (SES), and the precise mechanisms have not yet been elucidated. In the present case, focal in-stent stenosis was discovered on angiography 16 months after SES implantation. Intravascular ultrasound revealed an echolucent homogeneous zone, which has been termed "black hole". A sample of stenotic tissue retrieved by aspiration revealed neointimal hyperplasia, composed of proteoglycans and smooth muscle cells with scanty cellularity. Furthermore, infiltration of many macrophages and T lymphocytes coexisted in the restenotic tissue. These findings suggest that delayed healing is 1 of the mechanisms of SES restenosis.

CCN1 knockdown suppresses neointimal hyperplasia in a rat artery balloon injury model.

OBJECTIVE: CCN1 (Cyr61) is an extracellular matrix-associated protein involved in cell proliferation and survival. CCN1 is bound to vascular smooth muscle cells (VSMCs) via integrins and is expressed in VSMCs in atherosclerotic lesions, suggesting involvement in the regulation of vascular smooth muscle cell (VSMC) proliferation and atherosclerosis. We hypothesized that knockdown of CCN1 may inhibit VSMC proliferation and suppress neointimal hyperplasia. METHODS AND RESULTS: We examined the effect of the knockdown of CCN1 using rat cultured VSMCs and a rat balloon injury model. CCN1 stimulated adhesion and migration of VSMCs in a dose-dependent manner, and this was blocked by an antibody for integrin alpha(6)beta(1). Moreover, knockdown of endogenous CCN1 by lentiviral delivery of siRNA significantly inhibited proliferation of VSMCs and the uptake of 5-bromo-2'-deoxyuridine (BrdU). Replenishment with recombinant CCN1 reversed the effect of siRNA knockdown. Interestingly, knockdown of CCN1 significantly suppressed neointimal hyperplasia in a rat carotid artery balloon injury model at days 14 and 28 after injury. Gene transfer of CCN1 to smooth muscle reversed the effect of CCN1 knockdown on neointimal formation. These results suggest that endogenous CCN1 regulates proliferation of VSMCs and neointimal hyperplasia. CONCLUSIONS: Inhibition of CCN1 may provide a promising strategy for the prevention of restenosis after vascular interventions.