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Nakazawa G, Vorpahl M, Finn AV, Narula J, Virmani R. One step forward and two steps back with drug-eluting-stents: from preventing restenosis to causing late thrombosis and nouveau atherosclerosis. JACC Cardiovasc Imaging 2009; 2:625-8. [PMID: 19442951 DOI: 10.1016/j.jcmg.2009.01.011] [Citation(s) in RCA: 130] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/06/2009] [Accepted: 01/09/2009] [Indexed: 10/20/2022]
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Finn AV, Kramer MCA, Vorpahl M, Kolodgie FD, Virmani R. Pharmacotherapy of coronary atherosclerosis. Expert Opin Pharmacother 2009; 10:1587-603. [DOI: 10.1517/14656560902988494] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Finn AV, Nakazawa G, Kolodgie F, Virmani R. Drug eluting or bare metal stent for acute myocardial infarction: an issue of safety? Eur Heart J 2009; 30:1828-30. [PMID: 19515688 DOI: 10.1093/eurheartj/ehp237] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Finn AV, Oh JS, Hendricks M, Daher M, Cagliero E, Byrne RM, Nadelson J, Crimins J, Kastrati A, Schömig A, Bruskina O, Palacios I, John MC, Gold HK. Predictive factors for in-stent late loss and coronary lesion progression in patients with type 2 diabetes mellitus randomized to rosiglitazone or placebo. Am Heart J 2009; 157:383.e1-8. [PMID: 19185649 DOI: 10.1016/j.ahj.2008.11.013] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/15/2008] [Accepted: 11/18/2008] [Indexed: 11/26/2022]
Abstract
BACKGROUND Type 2 diabetics (DM2) are at increased risk for restenosis as well as nonculprit coronary artery lesion (NCCL) progression. Rosiglitazone (RSG) favorably modifies many of the altered biologic processes in DM2, although recent reports have questioned its safety. We conducted a double-blind randomized trial to assess the effects of RSG versus placebo on in-stent late lumen loss (LL) and angiographic progression of NCCL. METHODS A total of 65 DM2 were randomized to RSG (4 mg/d) (n = 32) or placebo (n = 33) at the time of stenting and underwent clinical and laboratory analysis at 1 and 4 months and 8-month angiography (n = 46 patients). Rapid angiographic progression (RAP) was defined as > or =20% diameter reduction of preexisting NCCL by quantitative coronary angiography, or a new narrowing > or =30%. RESULTS Mean LL in RSG (n = 33 lesions) was not different from that of placebo (0.62 +/- 0.59 vs 0.70 +/- 0.67, P = NS). Seven (13.5%) of 52 NCCLs have RAP in RSG versus 9 (16.1%) of 56 in placebo (P = NS). High-sensitivity C-reactive protein (hs-CRP) was the only predictor of RAP. Patients with a 120-day hs-CRP > or =75th percentile had an OR of 7.35 (95% CI 2.35-23) for RAP versus those below. Although RSG treatment also lowered log (hs-CRP) at 4 months (RSG 0.10 +/- 0.37 vs placebo 0.26 +/- 0.49, P = .06), it did not decrease the likelihood of plaque progression while also raising LDL and N-terminal brain naturetic peptide. CONCLUSIONS Rosiglitazone appears not to lower LL or reduce angiographic progression of NCCL in DM2 and had complex effects on markers of cardiac risk.
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Virmani R, Finn AV, Kolodgie FD. Carotid plaque stabilization and progression after stroke or TIA. Arterioscler Thromb Vasc Biol 2009; 29:3-6. [PMID: 19092135 DOI: 10.1161/atvbaha.108.177659] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Joner M, Morimoto K, Kasukawa H, Steigerwald K, Merl S, Nakazawa G, John MC, Finn AV, Acampado E, Kolodgie FD, Gold HK, Virmani R. Site-Specific Targeting of Nanoparticle Prednisolone Reduces In-Stent Restenosis in a Rabbit Model of Established Atheroma. Arterioscler Thromb Vasc Biol 2008; 28:1960-6. [DOI: 10.1161/atvbaha.108.170662] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Jaffer FA, Vinegoni C, John MC, Aikawa E, Gold HK, Finn AV, Ntziachristos V, Libby P, Weissleder R. Real-time catheter molecular sensing of inflammation in proteolytically active atherosclerosis. Circulation 2008; 118:1802-9. [PMID: 18852366 DOI: 10.1161/circulationaha.108.785881] [Citation(s) in RCA: 147] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND To enable intravascular detection of inflammation in atherosclerosis, we developed a near-infrared fluorescence (NIRF) catheter-based strategy to sense cysteine protease activity during vascular catheterization. METHODS AND RESULTS The NIRF catheter design was based on a clinical coronary artery guidewire. In phantom studies of NIRF plaques, blood produced only a mild (<30%) attenuation of the fluorescence signal compared with saline, affirming the favorable optical properties of the NIR window. Catheter evaluation in vivo used atherosclerotic rabbits (n=11). Rabbits received an injection of a cysteine protease-activatable NIRF imaging agent (Prosense750; excitation/emission, 750/770 nm) or saline. Catheter pullbacks through the blood-filled iliac artery detected NIRF signals 24 hours after injection of the probe. In the protease agent group, the in vivo peak plaque target-to- BACKGROUND <0.05). Ex vivo fluorescence reflectance imaging corroborated these results (target-to- BACKGROUND <0.01). In the protease group only, saline flush-modulated NIRF signal profiles further distinguished atheromata from normal segments in vivo (P<0.01). Good correlation between the in vivo and ex vivo plaque target-to- BACKGROUND =0.82, P<0.01). Histopathological analyses demonstrated strong NIRF signal in plaques only from the protease agent group. NIRF signals colocalized with immunoreactive macrophages and the cysteine protease cathepsin B. CONCLUSIONS An intravascular fluorescence catheter can detect cysteine protease activity in vessels the size of human coronary arteries in real time with an activatable NIRF agent. This strategy could aid in the detection of inflammation and high-risk plaques in small arteries.
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John MC, Wessely R, Kastrati A, Schömig A, Joner M, Uchihashi M, Crimins J, Lajoie S, Kolodgie FD, Gold HK, Virmani R, Finn AV. Differential Healing Responses in Polymer- and Nonpolymer-Based Sirolimus-Eluting Stents. JACC Cardiovasc Interv 2008; 1:535-44. [DOI: 10.1016/j.jcin.2008.08.004] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/12/2008] [Revised: 07/10/2008] [Accepted: 08/14/2008] [Indexed: 10/21/2022]
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Fan D, Makaryus AN, Hamik A, Finn AV, Isselbacher EM. Prosthetic Valve Dysfunction Presenting as Intermittent Acute Aortic Regurgitation. Echocardiography 2008; 25:925-7. [DOI: 10.1111/j.1540-8175.2008.00693.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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Nakazawa G, Finn AV, Joner M, Ladich E, Kutys R, Mont EK, Gold HK, Burke AP, Kolodgie FD, Virmani R. Delayed arterial healing and increased late stent thrombosis at culprit sites after drug-eluting stent placement for acute myocardial infarction patients: an autopsy study. Circulation 2008; 118:1138-45. [PMID: 18725485 DOI: 10.1161/circulationaha.107.762047] [Citation(s) in RCA: 470] [Impact Index Per Article: 29.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
BACKGROUND The long-term safety of drug-eluting stents (DES) for acute myocardial infarction (AMI) remains uncertain. Using autopsy data, we evaluated the pathological responses of the stented segment in patients treated with DES for AMI and compared with patients with stable angina. METHODS AND RESULTS From the CVPath Registry of 138 DES autopsies, we identified 25 patients who presented with AMI and had an underlying necrotic core with a ruptured fibrous cap. Twenty-six patients who had stable angina with thick-cap fibroatheroma treated by DES were selected as controls. Histomorphometric analysis was performed in patients with >30-day stent duration. We compared the response to stenting at the culprit site in these 2 groups and to nonculprit sites within each stent. Late stent thrombosis was significantly less frequent in stable (11%) than in AMI (41%; P=0.04) patients. Although neointimal thickness in the AMI culprit site was significantly less (median, 0.04 mm; interquartile range [IQR], 0.02 to 0.09 mm), the prevalence of uncovered struts (49%; IQR, 16% to 96%), fibrin deposition (63+/-28%), and inflammation (35%; IQR, 27% to 49%) were significantly greater compared with the culprit site in stable patients (neointimal thickness: 0.11 mm [IQR, 0.07 to 0.21 mm], P=0.008; uncovered struts: 9% [IQR, 0% to 39%], P=0.01; fibrin: 36+/-27%, P=0.008; inflammation, 17% [IQR, 7% to 25%], P=0.003) and the nonculprit site within each stent. CONCLUSIONS Vessel healing at the culprit site in AMI patients treated with DES is substantially delayed compared with the culprit site in patients receiving DES for stable angina, emphasizing the importance of underlying plaque morphology in the arterial response to DES. Our data suggest an increased risk of thrombotic complications in patients treated with DES for AMI.
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Nakazawa G, Ladich E, Finn AV, Virmani R. Pathophysiology of vascular healing and stent mediated arterial injury. EUROINTERVENTION 2008; 4 Suppl C:C7-C10. [PMID: 19202684] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Drug eluting stents (DES) have expanded the use of stents for the treatment of coronary atherosclerotic disease with significant reduction in restenosis rates. However, DES have been associated with late stent thrombosis (LST), especially when used for "off-label" indications. Although similar cellular processes control the early response after both bare metal (BMS) and DES placement, the more chronic response and time course of healing is markedly different between BMS and DES. There is persistence of fibrin beyond the 12-month period and re-endothelialisation is incomplete with some struts remaining uncovered beyond the 2-year period, a strong predictor for LST. While vessel wall injury correlated with restenosis in the BMS era, its impact has been minimised by the use of DES, which is likely related to the use of powerful antiproliferatives with prolonged release kinetics which profoundly inhibit the reparative response to arterial injury. However, at the same time, vessel injury secondary to drug toxicity or inflammation caused by polymer is observed following DES implantation. Nonerodable polymers induce granulomatous and hypersensitivity reactions in animal models and this has been observed exclusively with the use of Cypher stents in man. On the other hand the Taxus stent is associated with medial necrosis, positive remodelling and excessive fibrin deposition, all likely cytotoxic effects of paclitaxel. Both may lead to late stent thrombosis. Other factors that increase risk are penetration of the necrotic core, bifurcation stenting and malapposition.
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Joner M, Nakazawa G, Finn AV, Quee SC, Coleman L, Acampado E, Wilson PS, Skorija K, Cheng Q, Xu X, Gold HK, Kolodgie FD, Virmani R. Endothelial cell recovery between comparator polymer-based drug-eluting stents. J Am Coll Cardiol 2008; 52:333-42. [PMID: 18652940 DOI: 10.1016/j.jacc.2008.04.030] [Citation(s) in RCA: 502] [Impact Index Per Article: 31.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/02/2007] [Revised: 04/23/2008] [Accepted: 04/29/2008] [Indexed: 10/21/2022]
Abstract
OBJECTIVES The purpose of this study was to assess trends in endothelial coverage and recovery among leading polymer-based drug-eluting stents (DES). BACKGROUND Autopsy studies of human U.S. Food and Drug Administration (FDA)-approved DES implanted coronary arteries suggest that complications of late stent thrombosis are associated with incomplete endothelial coverage of struts. METHODS Rabbits received sirolimus-eluting stents (SES), paclitaxel-eluting stents (PES), zotarolimus-eluting stents (ZES), and everolimus-eluting stents (EES) for 14 or 28 days along with MULTI-LINK (ML) Vision control stents. Endothelial coverage above and between struts was measured by morphometric analysis of images acquired through en face scanning electron microscopy. Dual fluorescent immunolabeling was performed for platelet-endothelial cell adhesion molecule (PECAM)-1 and thrombomodulin (TM), factors involved in cell-to-cell contact and thrombogenicity, respectively. In a separate analysis, the endothelial mitogen, vascular endothelial growth factor (VEGF), was also assessed. RESULTS Varying rates of endothelialization among comparator DES were most notable at 14 days, where coverage above struts remained poor in SES, PES, and ZES (<or=30%) relative to EES and ML Vision controls (>or=70%), whereas no significant differences were observed at 28 days. Select DES with poor endothelialization showed a further reduced expression of PECAM-1. All DES showed an absence or weak expression of the antithrombotic cofactor TM. Incomplete endothelialization in select DES was further associated with increased VEGF secretion and messenger ribonucleic acid levels at 14 days, providing evidence of a transitional healing surface. CONCLUSIONS The present study marks the first comparator analysis of endothelial coverage in leading polymeric DES, supporting disparities in arterial healing based on endothelial regrowth and recovery, favoring newer designs over the current generation of FDA-approved stents.
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Nakazawa G, Finn AV, Virmani R. Drug-eluting stent pathology—should we still be cautious? ACTA ACUST UNITED AC 2008; 5:1. [DOI: 10.1038/ncpcardio1093] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Finn AV, Gold HK. Total erythrocyte membrane cholesterol: a marker of plaque instability? NATURE CLINICAL PRACTICE. CARDIOVASCULAR MEDICINE 2007; 4:646-7. [PMID: 17768403 DOI: 10.1038/ncpcardio0986] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2007] [Accepted: 07/11/2007] [Indexed: 05/17/2023]
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Nakazawa G, Finn AV, John MC, Kolodgie FD, Virmani R. The significance of preclinical evaluation of sirolimus-, paclitaxel-, and zotarolimus-eluting stents. Am J Cardiol 2007; 100:36M-44M. [PMID: 17950831 DOI: 10.1016/j.amjcard.2007.08.020] [Citation(s) in RCA: 96] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Comparative preclinical histologic studies remain the most effective method for assessing the healing characteristics of vascular stents. The 2 most commonly used animal models to assess vascular responses to stent implantation are the porcine coronary artery and the rabbit iliac artery. Neither model alone is comparable to the human response to the implantation of a drug-eluting stent (DES). In the rabbit model at 28 days, the pathologies of the zotarolimus-eluting stent (ZES), the paclitaxel-eluting stent (PES), the sirolimus-eluting stent (SES), and a bare metal stent (BMS) were assessed. There was less inflammation with the ZES than with the SES or PES, and there were uncovered struts with the SES and PES but not with the ZES and BMS. In the pig model at 30, 90, and 180 days, the pathologies of the ZES, SES, and BMS were assessed. At 30 days, the thickness of neointima and the grade of inflammation were less with the SES than with the ZES and BMS, but at 90 and 180 days, the measures increased for the SES and were greater than those with the ZES and BMS, whereas the measures for the ZES and BMS did not change over time. In the rabbit model, the endothelialization of overlapping the SES, PES, and ZES was assessed. There was significantly greater endothelialization in the area above stent struts in the overlapping segment for the ZES than for the SES (p = 0.028). The level of endothelialization for the PES was less than that for the ZES, but the difference was not significant. Because arterial healing is multifactorial, it is extremely important that the next generation of DESs undergo preclinical testing in pig and rabbit models to examine endothelialization, inflammation, release kinetics, and neointimal reduction to establish the safety of these devices in humans.
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Jain RK, Finn AV, Kolodgie FD, Gold HK, Virmani R. Antiangiogenic therapy for normalization of atherosclerotic plaque vasculature: a potential strategy for plaque stabilization. ACTA ACUST UNITED AC 2007; 4:491-502. [PMID: 17712362 DOI: 10.1038/ncpcardio0979] [Citation(s) in RCA: 87] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2006] [Accepted: 06/01/2007] [Indexed: 11/09/2022]
Abstract
Angiogenesis within human atherosclerotic plaques has an important role in plaque progression as immature blood vessels leak red blood cells and inflammatory mediators into the plaque center. Accumulation of free cholesterol from red blood cell membranes potentially increases the size of the necrotic core and triggers a chain of events that promote plaque destabilization. Antiangiogenic agents have been shown to prune some tumor vessels and 'normalize' the structure and function of the remaining vasculature, thereby improving the access of chemotherapeutic agents to tumors. We propose that antiangiogenic therapy can similarly stabilize vulnerable 'rupture-prone' plaques by pruning and normalizing immature intraplaque vessels, preventing further intraplaque hemorrhage. This normalization would limit necrotic core enlargement, further luminal narrowing and the degree of inflammation. Such normalization has been realized using vascular endothelial growth factor antagonists for the treatment of cancer and age-related macular degeneration. The development of this novel approach to prevent plaque progression might add to the armamentarium of preventive measures for acute myocardial infarction, stroke and sudden cardiac death.
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Cheruvu PK, Finn AV, Gardner C, Caplan J, Goldstein J, Stone GW, Virmani R, Muller JE. Frequency and Distribution of Thin-Cap Fibroatheroma and Ruptured Plaques in Human Coronary Arteries. J Am Coll Cardiol 2007; 50:940-9. [PMID: 17765120 DOI: 10.1016/j.jacc.2007.04.086] [Citation(s) in RCA: 286] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/22/2006] [Revised: 03/13/2007] [Accepted: 04/03/2007] [Indexed: 12/22/2022]
Abstract
OBJECTIVES Our purpose was to quantify the frequency and distribution of suspected vulnerable lesions, defined as thin-capped fibroatheroma (TCFA) and ruptured plaque, in human coronary artery autopsy specimens. BACKGROUND Most acute coronary events and sudden death are believed to arise from rupture of a TCFA followed by thrombosis. Although there is general agreement that clinical events are usually caused by focal lesions, there is considerable debate over the relative importance of focal versus systemic factors in the pathogenesis of atherosclerosis. METHODS We longitudinally sectioned coronary arteries from 50 whole hearts taken from patients (mean age 73 years, 64% men) dying of cardiovascular (n = 33), noncardiovascular (n = 13), and unknown (n = 4) causes. A total of 3,639 longitudinal segments of length 3 mm were sectioned from 148 arteries, accounting for 10.9 m of total tissue length. Specimens were classified on the basis of histology and computer-aided morphometry. RESULTS Twenty-three TCFA and 19 ruptured plaques were found (mean +/- SD: 0.46 +/- 0.95 and 0.38 +/- 0.70 per heart, respectively), and these lesions accounted for only 1.6% and 1.2%, respectively, of the total length of the coronary tree examined in patients dying of cardiovascular causes. The majority of TCFA and ruptured plaque localized in the proximal third of the major coronary arteries, and in 92% of cases these lesions clustered within 2 or fewer nonoverlapping 20-mm segments. CONCLUSIONS The suspected precursors of rupture-mediated thrombosis occur in a limited, focal distribution in the coronary arteries.
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Finn AV, Nakazawa G, Joner M, Kolodgie FD, Mont EK, Gold HK, Virmani R. Vascular Responses to Drug Eluting Stents. Arterioscler Thromb Vasc Biol 2007; 27:1500-10. [PMID: 17510464 DOI: 10.1161/atvbaha.107.144220] [Citation(s) in RCA: 709] [Impact Index Per Article: 41.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Polymer-based sirolimus- (Cypher) and paclitaxel-eluting (Taxus) drug eluting stents have become the treatment of choice for patients with symptomatic coronary artery disease undergoing percutaneous coronary intervention (PCI). Although these stents reduce rates of restenosis compared with bare metal stents (BMS), late thrombosis, a life threatening complication, has emerged as a major safety concern. Our understanding of the pathophysiology of late DES thrombosis is derived from animal and human pathologic samples taken after implantation of these devices. These data indicate that both DES cause substantial impairment in arterial healing characterized by lack of complete reendothelialization and persistence of fibrin when compared with BMS. This delayed healing is the primary substrate underlying all cases of late DES thrombosis at autopsy. Several additional risk factors for late stent thrombosis such as penetration of necrotic core, malapposition, overlapping stent placement, excessive stent length, and bifurcation lesions represent additional barriers to healing and should be avoided if DES are to be used to minimize the risk of late thrombosis. Because the time course of complete healing with DES in man is unknown, the optimal duration of antiplatelet treatment remains to be determined.
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Ribichini F, Joner M, Ferrero V, Finn AV, Crimins J, Nakazawa G, Acampado E, Kolodgie FD, Vassanelli C, Virmani R. Effects of Oral Prednisone After Stenting in a Rabbit Model of Established Atherosclerosis. J Am Coll Cardiol 2007; 50:176-85. [PMID: 17616304 DOI: 10.1016/j.jacc.2007.03.031] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/27/2006] [Revised: 03/02/2007] [Accepted: 03/06/2007] [Indexed: 11/20/2022]
Abstract
OBJECTIVES The aim of this study was to compare the effects of systemic prednisone in combination with a bare-metal stent (BMS) or a paclitaxel-eluting stent (Taxus, Boston Scientific Corp., Natick, Massachusetts) on neointimal inhibition and vessel healing in an atherosclerotic rabbit model. BACKGROUND Inflammation plays a critical role in neointimal formation after coronary artery stenting. The efficacy of immunosuppressive doses of oral prednisone to inhibit in-stent neointimal proliferation was compared with BMS and with a commercially available paclitaxel-eluting stent (Taxus) in a rabbit model of established atherosclerosis. METHODS Bilateral iliac artery injury in atherosclerotic New Zealand White rabbits fed an atherogenic diet was followed by stent implantation. Animals randomly received Taxus stents, BMS (Express, Boston Scientific Corp.) and placebo, or BMS and oral prednisone (2.1 mg/kg/day for the first 7 days, followed by 1.4 mg/kg/day for 14 days and 0.7 mg/kg/day for 21 days). Stented arterial segments were harvested at 42 days and processed for light microscopy, immunohistochemistry, and organoid culture. RESULTS Compared with control subjects, prednisone-treated animals showed a 30% reduction in percent stenosis (p = 0.009), a 35% decrease in neointimal area (p < 0.003), and a 66% decrement in neointimal thickness (p < 0.001). Taxus stents also reduced all 3 parameters significantly (-34%, -39%, and -83%, respectively), but showed significantly more inflammatory cells and fibrin deposition and less endothelialization compared with the other 2 groups. Plaque burden was equal among groups, as shown by the identical stent and vessel area, and no remodeling was observed. CONCLUSIONS Systemic prednisone treatment and Taxus stents reduce neointimal formation compared with BMS. The extent of neointimal reduction is similar between prednisone- and Taxus stent-treated animals; however, Taxus stents resulted in a significantly greater delay in healing. Targeting of inflammatory pathways after percutaneous coronary intervention may be an efficacious way to prevent restenosis without the long-term risk of late thrombosis.
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Abstract
Polymer-based sirolimus- (Cypher) and paclitaxel-eluting stents (Taxus), so-called drug-eluting stents (DES), have become the treatment of choice for patients with symptomatic coronary artery disease undergoing percutaneous coronary revascularization (PCI). While these stents have reduced rates of restenosis and late lumen loss compared to bare-metal stents (BMS), late thrombosis, a life-threatening complication of this technology, has emerged as a major concern. Our understanding of the pathophysiology of late DES thrombosis is derived from animal and human pathologic samples taken after implantation of these devices. These data indicate that the DES cause substantial impairment in arterial healing characterized by lack of complete reendothelialization and persistence of fibrin when compared to BMS. This so-called delayed healing is "identified as" the primary substrate of an underlying cause of late DES thrombosis at autopsy. Several additional risk factors for late stent thrombosis include penetration of necrotic core, malapposition, overlapping stent placement, excessive stent length, and bifurcation lesions. These represent additional barriers to healing and should be avoided if DES are to be used in order to minimize the late thrombotic risks of these devices. Since the time course of complete healing with DES is unknown, the optimal duration of antiplatelet treatment remains to be determined.
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Nakazawa G, Finn AV, Virmani R. Morphologic Predictors of Drug-eluting Stent Thrombosis. US CARDIOLOGY REVIEW 2007. [DOI: 10.15420/usc.2007.4.1.75] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
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Finn AV, Joner M, Nakazawa G, Kolodgie F, Newell J, John MC, Gold HK, Virmani R. Pathological Correlates of Late Drug-Eluting Stent Thrombosis. Circulation 2007; 115:2435-41. [PMID: 17438147 DOI: 10.1161/circulationaha.107.693739] [Citation(s) in RCA: 998] [Impact Index Per Article: 58.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background—
Late stent thrombosis (LST) after Cypher and Taxus drug-eluting stent placement has emerged as a major concern. Although the clinical predictors of LST have been reported, specific morphological and histological correlates of LST remain unknown.
Methods and Results—
From a registry totaling 81 human autopsies of drug-eluting stents, 46 (62 lesions) had a drug-eluting stent implanted >30 days. We identified 28 lesions with thrombus and compared those with 34 of similar duration without thrombosis using computer-guided morphometric and histological analyses. LST was defined as an acute thrombus within a coronary artery stent in place >30 days. Multiple logistic generalized estimating equations modeling demonstrated that endothelialization was the best predictor of thrombosis. The morphometric parameter that best correlated with endothelialization was the ratio of uncovered to total stent struts per section. A univariable logistic generalized estimating equations model of occurrence of thrombus in a stent section versus ratio of uncovered to total stent struts per section demonstrated a marked increase in risk for LST as the number of uncovered struts increased. The odds ratio for thrombus in a stent with a ratio of uncovered to total stent struts per section >30% is 9.0 (95% CI, 3.5 to 22).
Conclusions—
The most powerful histological predictor of stent thrombosis was endothelial coverage. The best morphometric predictor of LST was the ratio of uncovered to total stent struts. Heterogeneity of healing is a common finding in drug-eluting stents with evidence of LST and demonstrates the importance of incomplete healing of the stented segment in the pathophysiology of LST.
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Kolodgie FD, Narula J, Yuan C, Burke AP, Finn AV, Virmani R. Elimination of Neoangiogenesis for Plaque Stabilization. J Am Coll Cardiol 2007; 49:2093-101. [PMID: 17531658 DOI: 10.1016/j.jacc.2006.10.083] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/08/2006] [Revised: 10/18/2006] [Accepted: 10/30/2006] [Indexed: 11/25/2022]
Abstract
Emerging data suggest that intraplaque hemorrhage is critical in promoting atherosclerotic lesion instability. Because red blood cell membranes are a rich source of free cholesterol and accumulated red blood cells within plaques promote inflammation, intraplaque hemorrhage is associated with expansion of the necrotic core. Plaque hemorrhage results from the development of immature neointimal vasa vasorum. Therefore, it is proposed that molecular therapies designed to eliminate pathologic neovascularization within developing lesions will interrupt the process of hemorrhage and decrease the rate of necrotic core expansion. The elimination of intraplaque neovascularization would involve targeting of pre-existing and new vessel development. The concept of vascular regression has met some success in other neovascular-dependent diseases, including macular degeneration and malignancies. The efficacy of this novel approach is dependent on gaining critical knowledge of the environment required to support development and maturation of the vasa vasorum within varying plaque types. A multitargeted approach involving selective local antiangiogenic agents should contribute to prevention of plaque progression and its clinical consequences.
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