RESUMO
Optical coherence tomography (OCT) has become the invasive imaging modality of choice for coronary stent assessment due to its unmatched spatial resolution. Neointimal calcification (NC) is a rare finding, observed in 5-10% of in-stent restenosis (ISR) neointima. The impact of NC on percutaneous coronary intervention of ISR is unknown. We therefore present the outcome of six unique cases of ISR and NC in which OCT was used to evaluate the impact of NC on the quality of stent-in-stent deployment for the treatment of ISR. This series demonstrates for the first time the impact of NC on stent expansion, a finding which might help guiding percutaneous coronary intervention for ISR with NC.
Assuntos
Reestenose Coronária/diagnóstico por imagem , Neointima/diagnóstico por imagem , Stents , Calcificação Vascular/diagnóstico por imagem , Reestenose Coronária/terapia , Humanos , Stents/efeitos adversos , Tomografia de Coerência ÓpticaRESUMO
FUNDAMENTO: Não há consenso sobre o impacto do implante de stent sobre a função endotelial no longo prazo. Há relatos de disfunção endotelial aumentada com stent com sirolimus quando comparado com o stent metálico convencional (BMS). OBJETIVO: Este estudo visa a avaliar o impacto do BMS e o efeito do sirolimus por via oral sobre a função endotelial. MÉTODOS: Quarenta e cinco pacientes foram randomizados em três grupos: BMS + altas doses de sirolimus oral (dose inicial de 15 mg, seguida de 6 mg/dia durante quatro semanas); BMS + baixa dose de sirolimus (6 mg, seguida de 2 mg por dia durante quatro semanas) e BMS sem sirolimus. Mudanças na vasoconstrição ou vasodilatação, em um segmento de 15 milímetros começando pelo extremo distal do stent em resposta a acetilcolina e nitroglicerina, foram avaliadas por angiografia quantitativa. RESULTADOS: Os grupos apresentaram características angiográficas semelhantes. A variação percentual de diâmetro em resposta a acetilcolina foi semelhante em todos os grupos, nos dois momentos (p = 0,469). Quatro horas após o implante de stent, o segmento alvo apresentou uma disfunção endotelial que se manteve após oito meses em todos os grupos. Em todos os grupos, a vasomotricidade independente de endotélio em resposta a nitroglicerina foi semelhante, às quatro horas e aos oito meses, com diâmetro do segmento alvo aumentado após a infusão de nitroglicerina (p = 0,001). CONCLUSÃO: A disfunção endotelial esteve igualmente presente no segmento distal de 15 milímetros do segmento tratado, às 4 horas e aos 8 meses após implante do stent. O sirolimus administrado por via oral durante quatro semanas para evitar a reestenose não afetou o estado de vasomotricidade endotélio dependente e independente.
BACKGROUND: There is no consensus regarding the impact of stenting on long-term endothelial function. There have been reports of increased endothelial dysfunction with sirolimus-eluting stents as compared to bare metal stenting (BMS). OBJECTIVE: This study aims to assess the impact of BMS and the effect of oral sirolimus on endothelial function. METHODS: Forty-five patients were randomized into three groups: BMS + high-dose oral sirolimus (initial dose of 15 mg, followed by 6 mg/day for four weeks); BMS + low-dose sirolimus (6 mg followed by 2 mg daily for four weeks); and BMS without sirolimus. Changes in vasoconstriction or vasodilation in a 15 mm segment starting at the distal stent end in response to acetylcholine and nitroglycerin were assessed by quantitative angiography. RESULTS: The groups had similar angiographic characteristics. The percent variation in diameter in response to acetylcholine was similar in all groups at the two time points (p = 0.469). Four hours after stenting, the target segment presented an endothelial dysfunction that was maintained after eight months in all groups. In all groups, endothelium-independent vasomotion in response to nitroglycerin was similar at four hours and eight months, with increased target segment diameter after nitroglycerin infusion (p = 0.001). CONCLUSION: The endothelial dysfunction was similarly present at the 15 mm segment distal to the treated segment, at 4 hours and 8 months after stenting. Sirolimus administered orally during 4 weeks to prevent restenosis did not affect the status of endothelium-dependent and independent vasomotion.
Assuntos
Adulto , Feminino , Humanos , Pessoa de Meia-Idade , Vasos Coronários/efeitos dos fármacos , Endotélio Vascular/efeitos dos fármacos , Imunossupressores/farmacologia , Sirolimo/farmacologia , Stents/efeitos adversos , Sistema Vasomotor/efeitos dos fármacos , Administração Oral , Análise de Variância , Acetilcolina/farmacologia , Acetilcolina/uso terapêutico , Vasos Coronários/fisiopatologia , Endotélio Vascular/fisiopatologia , Imunossupressores/administração & dosagem , Nitroglicerina/farmacologia , Nitroglicerina/uso terapêutico , Sirolimo/administração & dosagem , Fatores de Tempo , Vasoconstrição/efeitos dos fármacos , Vasoconstrição/fisiologia , Vasodilatação/efeitos dos fármacos , Vasodilatação/fisiologia , Vasodilatadores/farmacologia , Vasodilatadores/uso terapêutico , Sistema Vasomotor/fisiopatologiaRESUMO
BACKGROUND: There is no consensus regarding the impact of stenting on long-term endothelial function. There have been reports of increased endothelial dysfunction with sirolimus-eluting stents as compared to bare metal stenting (BMS). OBJECTIVE: This study aims to assess the impact of BMS and the effect of oral sirolimus on endothelial function. METHODS: Forty-five patients were randomized into three groups: BMS + high-dose oral sirolimus (initial dose of 15 mg, followed by 6 mg/day for four weeks); BMS + low-dose sirolimus (6 mg followed by 2 mg daily for four weeks); and BMS without sirolimus. Changes in vasoconstriction or vasodilation in a 15 mm segment starting at the distal stent end in response to acetylcholine and nitroglycerin were assessed by quantitative angiography. RESULTS: The groups had similar angiographic characteristics. The percent variation in diameter in response to acetylcholine was similar in all groups at the two time points (p = 0.469). Four hours after stenting, the target segment presented an endothelial dysfunction that was maintained after eight months in all groups. In all groups, endothelium-independent vasomotion in response to nitroglycerin was similar at four hours and eight months, with increased target segment diameter after nitroglycerin infusion (p = 0.001). CONCLUSION: The endothelial dysfunction was similarly present at the 15 mm segment distal to the treated segment, at 4 hours and 8 months after stenting. Sirolimus administered orally during 4 weeks to prevent restenosis did not affect the status of endothelium-dependent and independent vasomotion.