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Lakshmana K Pendyala,
Daisuke Matsumoto,
Toshiro Shinke,
Taizo Iwasaki,
Ryota Sugimoto,
Dongming Hou,
Jack P Chen,
Jaipal Singh,
Spencer B King,
Nicolas Chronos,
Jinsheng Li
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ABSTRACT: The current study sought to examine inflammation at the stented segments of Nobori (Terumo Corporation, Tokyo, Japan) and Cypher (Cordis, Miami, Florida) drug-eluting stents (DES), as well as free radical production and endothelial function of the adjacent nonstented segments in a pig coronary model.
Nobori is a novel DES, incorporating a biolimus A9-eluting biodegradable polymer coated only on the abluminal surface of the stent. These unique features may favorably affect inflammation and endothelial function, as compared to the currently marketed DES. Presently, pre-clinical data on direct comparison of the various generations of DES are not available.
A total of 18 DES were implanted in pig coronary arteries and subsequently explanted at 1 month. Stented segments were assessed by angiography and histology. Ex vivo vasomotor function and superoxide production in segments proximal and distal to the stent were determined. The vasoconstriction, endothelial-dependent relaxation, and endothelial-independent relaxation of proximal and distal nonstented segments were measured.
Histological evaluation revealed lower inflammatory response with Nobori than with Cypher DES. There is trend for lower angiographic percentage diameter stenosis in Nobori versus Cypher groups (p = 0.054). There was increased endothelium-dependent relaxation, decreased endothelin-1-mediated contraction, and less superoxide production in the vessel segments proximal and distal to Nobori versus Cypher stents.
Our data show significantly lower inflammatory response in the stented segments, and rapid recovery of endothelial function of peristent segments in the Nobori group compared with Cypher DES group at 1 month in porcine coronary artery model.
04/2012; 5(4):436-44. · 1.07 Impact Factor
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H Robert Superko,
Kathryn M Momary, Lakshmana K Pendyala,
Paul T Williams,
Steven Frohwein,
Brenda C Garrett,
Cathy Skrifvars,
Radhika Gadesam,
Spencer B King,
Steve Rolader,
Bill Meyers,
David Dusik,
Stoney Polite
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ABSTRACT: To determine the association of cardiovascular risk markers with noninvasive imaging of atherosclerosis in firefighters.
Cross-sectional investigation of subclinical atherosclerosis with metabolic, work related, and life-style variables in 296 professional firefighters.
Calcified coronary atherosclerosis (CAC), carotid arterial intimal thickness (CIMT), and electrocardiogram provided independent CVD assessments. Homeostatic Model Assessment (HOMA) concentrations were related to heart-rate-corrected QT (QTc) (slope ± SE: 2.16 ± 65, P = 0.001), average common CIMT (0.019 ± 0.005 mm, P = 0.0005), and total CAC lesions (0.269 ± 0.116, P = 0.02). Stepwise linear regression selected fasting insulin as the strongest predictor for QTc, HOMA as the strongest predictor of average CIMT, and fasting glucose as the strongest predictor of total coronary lesion number and score.
Firemen's HOMA and fasting insulin and glucose concentrations were significantly associated with three measures of CVD. Aspects of insulin resistance are related to CVD risk among firefighters.
Journal of occupational and environmental medicine / American College of Occupational and Environmental Medicine 06/2011; 53(7):758-64. · 1.88 Impact Factor
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ABSTRACT: Recently, a growing body of clinical data has shown that the first generation of drug-eluting stents (1st-gen DES) implantation could elicit coronary conduit artery vasomotor dysfunction at nonstented reference segments as late as 12 months after implantation compared with that seen with bare-metal stents. The mechanism of this phenomenon is still not fully understood. Pathological studies have implicated delayed arterial healing and poor re-endothelialization after the 1st-gen DES implantation. Given the vast use of DES globally, a thorough understanding of the early and long-term safety of these devices is paramount. Therefore, this article systematically reviews the current clinical, pathophysiological, and histopathological available data regarding 1st-gen DES-associated vascular endothelial dysfunction. Meanwhile, we will also review the newer generation of DES and emerging endothelial-friendly technology.
12/2009; 2(12):1169-77. · 1.07 Impact Factor
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ABSTRACT: Several definitions have been used to assess rates of contrast-induced nephropathy (CIN) in patients undergoing percutaneous coronary intervention (PCI). Whether the definition influences observed rates of CIN is unclear. The Oxilan Registry was the first-ever prospective analysis of the efficacy and safety of ioxilan (low-osmolar and low-viscosity contrast medium), including rates of CIN assessed by multiple definitions, in PCI. From July 2006 to June 2007, consecutive patients undergoing PCI using ioxilan were enrolled. Serum creatinine (SCr) and estimated glomerular filtration rate (eGFR) were assessed at baseline and 3 to 5 days after PCI. CIN was defined as SCr increase >or=0.5 mg/dl, eGFR decrease >or=25%, SCr increase >or=25%, or the composite. Of 400 patients (age 62 +/- 11 years), 19% were women, 37% were diabetic, 22% were anemic, and 8% had a history of congestive heart failure. Baseline SCr was 1.12 +/- 0.3 mg/dl and 24% had an eGFR <60 ml/min. CIN rates were 3.3% (SCr increase >or=0.5 mg/dl), 7.6% (eGFR decrease >or=25%), 10.2% (SCr increase >or=25%), and 10.5% (composite). Hospitalization was prolonged in 3.4% of patients with CIN and none required dialysis. There were no deaths or severe allergic reactions. Non-ST-elevation myocardial infarction and repeat revascularization each occurred in 0.8%. In conclusion, in this unselected population undergoing PCI, CIN ranged in frequency from 3.3% to 10.5% depending on the definition used and was not associated with in-hospital mortality or substantial morbidity, such as dialysis. The wide variation in CIN and its lack of association with adverse outcomes underscore the need for a standardized, clinically relevant definition.
The American journal of cardiology 06/2009; 103(12):1657-62. · 3.58 Impact Factor
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ABSTRACT: We sought to evaluate coronary epicardial and intramyocardial resistance, arterial vasomotor function, local inflammatory reaction, and superoxide anion (O(2)(.-)) production after overlapping paclitaxel-eluting stent (PES) implantation in a porcine model.
PES implantation has been shown to elicit coronary vasomotor dysfunction. However, underlying mechanisms remain largely unknown.
Nine pigs received overlapping PES and bare-metal stents (BMS) in the coronary arteries, and 3 sham animals were naïve. At 1 month, inflammatory response at the overlapped region was assessed by histopathology and scanning electron microscopy. Endothelial vasomotor function and O(2)(*-) at nonstented coronary reference segments were measured by angiography and organ chamber tensiometry, and lucigenin luminometry; vasomotor function of distal resistance arteries was measured by myography.
Paclitaxel-eluting stents showed reduced late lumen loss, but inflammation and luminal inflammatory cell adherence were higher than for BMS (p < 0.001) at overlapped segments. Endothelium-dependent relaxation to substance P was significantly impaired in PES at nonstented coronary reference segments (>or=15 mm proximally and distally) and perfusion bed resistance arteries (p < 0.05). In contrast, endothelium-independent relaxation to nitroglycerin and sodium-nitroprusside was similar between groups. Local O(2)(*-) production at both proximal and distal nonstented coronary reference segments was elevated for PES when compared with O(2)(*-) production in BMS and naïve arteries (p < 0.001).
Abnormal endothelium-dependent relaxation at both coronary conduit and resistance arteries was demonstrated after overlapping PES implantation. Profound localized inflammatory reaction, as well as enhanced local oxidative stress, may contribute to vasomotor dysfunction.
03/2009; 2(3):253-62. · 1.07 Impact Factor
