RESUMO
Stent thrombosis remains an important problem after the implantation of different stent types. A potential solution to this problem may be vasoactive agents with dual effects on different cell types like C-type natriuretic peptide (CNP). Therefore, in vitro and in vivo effects of CNP were investigated in a porcine restenotic model. Gene transfer of CNP in cultures of porcine vascular cells revealed up to 30% reduction of growth of smooth muscle cells (p<.05), but no suppression of endothelial growth using CNP. Applied in vivo, angiography revealed a trend of reduced restenosis formation in balloon-injured porcine arteries treated with CNP gene or beta-galactosidase (beta-Gal) control gene after three months (2.59 +/- 2.04-fold reduction, p = n.s.). Histologically, morphometry revealed significantly reduced neointima formation after treatment with CNP plasmid (7.26 +/- 1.44-fold reduction, p < .05). Evans blue staining demonstrated complete endothelial repair already 3 weeks after intervention using CNP. Transfer of CNP gene resulted in a significant inhibition of neointima formation without compromising endothelial repair. Therefore, use of the CNP gene may offer a solution to suppress restenosis formation while preventing subacute or late thrombosis.
Assuntos
Angioplastia com Balão/efeitos adversos , Técnicas de Transferência de Genes , Peptídeo Natriurético Tipo C/administração & dosagem , Peptídeo Natriurético Tipo C/genética , Trombose/prevenção & controle , Angiografia , Animais , Artérias/citologia , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Corantes/metabolismo , Constrição Patológica , DNA/genética , Modelos Animais de Doenças , Células Endoteliais/citologia , Células Endoteliais/efeitos dos fármacos , Endotélio Vascular/fisiopatologia , Azul Evans/metabolismo , Expressão Gênica , Imuno-Histoquímica , Músculo Liso Vascular/citologia , Músculo Liso Vascular/efeitos dos fármacos , Suínos , Fatores de Tempo , Transfecção , Túnica Íntima/efeitos dos fármacosRESUMO
Coronary stent thrombosis remains an important problem after the implantation of different stent types. This study investigates the risk of stent thrombosis associated with the use of drug-eluting stents (DESs), bare-metal stents (BMSs) compared to balloon angioplasty. A meta-analysis of 28 randomized trials involving 5612 versus 7639 versus 2994 patients with coronary heart disease treated with DES, BMS, or balloon angioplasty was therefore performed. Comparing the implantation of DES versus BMS, DES was not found to increase the hazard for thrombosis up to 15 months (odds ratio [OR] = 0.86, 95% confidence interval [CI] 0.58 to 1.3, p < .48). There was also no significant difference in the hazard for subacute thrombosis (SAT) or late stent thrombosis (LST) in the DES versus BMSs group (OR = 0.86, 95% CI 0.50 to 1.5, p < .6 and OR = 0.92, 95% CI 0.50 to 1.68, p < .78, respectively). Comparing incidences of stent thromboses in patients receiving balloon angioplasty or implantation of BMS, the rate of SAT in the balloon angioplasty group (1.7% SAT) versus BMS group (1.8% SAT) was also similar (OR = 0.93, 95% CI 0.61 to 1.4, p < .71). Finally, there was no significant difference in the occurrence of stent thrombosis for the different coatings of DESs. In conclusion, the use of DES was not observed to have a significant effect on stent thrombosis events, compared with the implantation of BMS or balloon angioplasty.
