Análise comparativa do segmento de "ovelapping" dos stents liberadores de sirolimus e paclitaxel / Comparative analysis of the overlapping segment of sirolimus-versus paclitaxel-eluting stents

RESUMO

Introdução: No tratamento de obstruções coronárias longas e complexas recomenda-se cobertura total da lesão. Quando mais de um stent é implantado, torna-se mandatário um "overlapping" ou sobreposição dos stents para evitar espaços não cobertos entre eles. Há pouca evidência na literatura sobre a eficácia e segurança de se realizar sobreposição de stents liberadores de sirolimus (Cypher, SES) e paclitaxel (Taxus, SEP). Objetivo: Avaliar, por meio de estudo seriado com ultra-sonografia intravascular (USIC), a eficácia na redução da proliferação neointimal e as mudanças na parede vascular no segmento com sobreposição de stents farmacológicos SES e SEP. Método: Um total de 52 pacientes (72 lesões) foram prospectivamente incluídos nesta análise e randomizados para tratamento percutâneo com implante de SES ou SEP. Cartoze pacientes do grupo SES e 12 do grupo SEP apresentaram segmentos de sobreposição. Angiografia Coronária quantitativa e USIC foram realizados imediatamente após o implante dos stents e repetidos após oito meses. Resultados: Ambos os grupos apresentavam características clínicas e angiográficas basais...

ABSTRACT

Introduction: To treat long complex coronary obstructions, total lesion coverage is recommended. When more than one stent is deployed an overlap segment is mandatory to avoid uncovered gaps between stents. There is no data comparing Sirolimus- (SES) versus Paclitaxel-eluting stents (PES) at overlapping segments in regards to neointimal inhibition or toxic effects on the vessel wall. Objective: To evaluate, by means of serial intravascular ultrasound (IVUS), the efficacy in reducing neointimal proliferation and the vessel changes in the overlapping segment comparing these two drug-eluting stents. Method: Fifty-two patients with 72 de novo coronary lesions were randomized for SES or PES. Fourteen patients in the SES Group and twelve in the PES Group had overlapping segments. Quantitative coronary angiography and IVUS were performed at the time of the procedure and at 8 months follow-up. Results: No significant baseline differences were identified between the 2 groups. The mean stent/lesion ratios were similar (1.74 ± 0.89 for SES vs. 2.01 ± 0.92 for PES; p= 0.47). SES and PES were comparable in reducing neointima hyperplasia in the overlapping zone (neointima volume 2.24 ± 0.9 mm3 after SES vs. 2.53 ± 1.5 mm3 after PES; p=0.1 and % neointima obstruction of 18.15 ± 8.5% after SES vs. 26.7 ± 16.8% after PES; p=0.1). There was no positive remodeling in the overlapping segment for both groups (expansion ratio 0.74 ± 0.18 vs. 0.76 ± 0.14, respectively; p=0.74). Other IVUS volumetric measurements were also equivalent between the two cohorts. Conclusion: In our preliminary experience, overlapping of DESs proved...