Comparação randomizada entre o stent eluidor de paclitaxel de nova geração sem polímero e o stent eluidor de paclitaxel com polímero durável em pacientes com doença arterial coronária: resultados da análise angiográfica e ultrassonográfica seriada do estudo PAX-A

Seguimento angiográfico e clínico tardio do novo stent farmacológico não-polimérico liberador de paclitaxel para o tratamento de lesões coronárias de novo: resultados do estudo PAX-B

“…[1][2][3][7][8][9][10][11][24][25][26][27][28] Notably, the angiographic findings in the long-term follow-up of the PAX-B study are similar to results reported with other previously tested non-polymeric paclitaxel-releasing stents, 6 which also confirms that the Amazonia PAX ® stent is less effective than the Taxus ® Liberté paclitaxel-releasing stent with durable polymer at suppressing neointimal proliferation. 19 In general, first-generation DES, such as Cypher ® (Cordis -Miami Lakes, USA) and Taxus ® , demonstrated remarkable and sustained clinical effectiveness. 29 However, the durable polymeric components used as drug carriers in these devices were shown to cause an intense local inflammatory response, 30,31 which has been associated with recurrence and late thrombotic phenomena.…”

“…It is noteworthy that the paclitaxel dose (or concentration) was 0.67 µg/cm 2 of the stent surface area, with 33%-52% of the drug being released within eight hours; 55%-75%, within a week; and 100%, in 45 days. 19 Thus, the kinetics of drug release appear to explain, at least in part, the greater efficacy observed with polymeric vs. non-polymeric DES, despite the use of the same drug (in this case, paclitaxel) and a reduced dose. 6,19 Greater efficacy has also been observed with stents releasing drugs from the 'limus' class.…”

“…The main exclusion criteria were acute myocardial infarction within < 72 hours of the index procedure; renal failure with basal serum creatinine ≥ 2 mg/ dL; previous percutaneous coronary intervention of the target lesion; previous coronary intervention of the target vessel within nine months of the index procedure; cardiogenic shock; cerebrovascular accident; lesions located in a coronary bifurcation, left main coronary artery or saphenous vein bypass graft; calcification and/or significant tortuosity; total occlusion; left ventricular ejection fraction of < 30%; and hypersensitivity or contraindication to aspirin and/or thienopyridine (clopidogrel). 19 According to the protocol, treatment of up to two lesions per patient was permitted, as long as a single lesion was treated per target vessel.…”

“…19 In summary, this device incorporates a low-profile metallic cobalt-chromium platform, with a thickness of 73 µm, an open-cell modular design, and an antiproliferative agent, paclitaxel, which is applied directly to the abluminal surface of the stent struts by a microdrop spray crystallisation process. This procedure only adds 5 µm to strut thickness and aims to ensure the integrity of the drug and a controlled release profile.…”

“…Recently published data from the initial study on the device (vs. Taxus ® Liberté DES, Boston Scientific -Natick, MA, USA) showed no significant differences in the occurrence of angiographic restenosis at four months or clinical events up to 12 months in a small sample of patients from a single-centre study. 19 However, the performance of the Amazonia PAX ® stent in more complex scenarios, with more patients and over longer angiographic follow-up has not been determined. The present study aimed to report the nine-month angiographic follow-up and the long-term clinical outcomes of patients treated with the Amazonia PAX ® stent in a prospective, multicentre study.…”