Stents libertadores de sirolimus com e sem cobertura polimérica: análise seriada com angiografia e ultrassom intracoronariano tridimensional / Sirolimus-eluting stents with and without polymeric coating: serial angiography and three-dimensional intravascular ultrasound analysis

RESUMO

Introdução: A presença de polímeros sintéticos em contato com a parede vascular tem sido associada a intensaresposta inflamatória local e a eventos adversos tardios. Entretanto, sua ausência pode comprometer a eficácia dos stents farmacológicos em suprimir a hiperplasia intimal. Avaliamos, com angiografia coronariana quantitativa (ACQ) e ultrassom intracoronariano (USIC), a eficácia do stent Vestasync™ (VES), liberador não-polimérico de sirolimus em baixa dose (55 µg), e do stent CypherTM (CYP), liberador de sirolimus polimérico em alta dose (140 µg). Método: Quinze pacientes com lesões primárias < 14 mm, em artérias coronárias nativas de 2,5 mm a 3,5 mm, foram tratados com VES e comparados a uma coorte histórica de 15 pacientes tratados com CYP. ACQ e USIC foram realizados pós-procedimento, aos 4 e 12 meses. Desfechos primários foram perda tardia intrastent e porcentual de obstrução volumétrica intrastent. Resultados: As características clínicas eram semelhantes. O grupo VES tinha vasos menores (2,67 ± 0,32 mm vs. 2,98 ± 0,4 mm; P = 0,02). Aos 4 meses, o grupo VES mostrou tendência a maior perda tardia intrastent (0,30 ± 0,25 mm vs. 0,10 ± 0,3 mm; P = 0,06), mas porcentual de obstrução volumétrica intrastent similar ao do grupo CYP (2,8 ± 2,2% vs. 2,2 ± 3,8%; P = 0,60). Aos 12 meses, a perda tardia intrastent foi de 0,37 ± 0,24 mm no grupo submetido a implante de stent VES vs. 0,16 ± 0,36 mm no grupo submetido a implante de stent CYP (P = 0,074), e o porcentual de obstrução volumétrica intrastent foi de 4,0 ± 2,2% no grupo que recebeu stent VES vs. 2,4 ± 3,9% no grupo que recebeu stent CYP (P = 0,17). Não houve casos de reestenose binária...

ABSTRACT

Background: The long-term presence of the stent polymer in contact with the vessel wall has been associated to intense inflammatory response and late adverse events. However, absence of the stent polymer may compromise drug dose and drug delivery kinetics, leading to some efficacy issues. We aimed to compare, by means of serial quantitative coronary angiography (QCA) and intravascular ultrasound (IVUS), the efficacy of the novel nonpolymeric low-dose (55 µg) VESTAsync™ (VES) sirolimus-eluting stent, with the permanent polymer, high-dose (140 µg) Cypher™ sirolimus-eluting stent (CYP). Methods: Fifteen patients with single, de novo lesions < 14 mm, in native vessels of 2.5 mm to 3.5 mm diameter, were treated with VES and compared to a paired historical cohort of 15 patients treated with CYP. QCA and IVUS data were obtained post-procedure and at 4 and 12-month follow-up. Primary endpoints were the comparison of in-stent late luminal loss and percentage of intimal hyperplasia obstruction. Results: Clinical characteristics were similar between groups. The VES group had smaller vessels (2.67 ± 0.32 mm vs. 2.98 ± 0.4 mm; P = 0.02). At 4 months, the VES group had a tendency towards a higher in-stent late luminal loss (0.30 ± 0.25 mm vs. 0.10 ± 0.3 mm; P = 0.06) but similar IVUS % of intimal hyperplasia obstruction (2.8 ± 2.2% vs. 2.2 ± 3.8%; P = 0.60). At 12-months, in-stent late luminal loss was 0.37 ± 0.24 mm (VES) vs. 0.16 ± 0.36 mm (CYP), P = 0.074, and the IVUS % of intimal hyperplasia obstruction was 4.0 ± 2.2% (VES) vs. 2.4 ± 3.9% (CYP), P = 0.17. There were no cases of binary restenosis...