[Comparative analysis of intimal hyperplasia after sirolimus-eluting stent and thin-strut bare-metal stent implantation in small coronary arteries]. / Análise comparativa da hiperplasia intimal após o implante de stents com e sem sirolimus em artérias coronárias de pequeno calibre.

OBJECTIVE: This study aimed at evaluating reduction in intimal hyperplasia volume following angioplasty using sirolimus-eluting stents (Cypher) compared with thin-strut bare-metal stents (Pixel) in patients with small vessels. METHODS: Eighty patients with coronary artery disease were prospectively included in two consecutive series, the first using sirolimus-eluting stents (50) and the second using bare-metal stents (30). RESULTS: The use of sirolimus-eluting stents reduced: in-stent net volume obstruction [5.0% (SE = 0.77) x 39.0% (SE = 4.72), p < 0.001], in-stent late loss [0.25 mm (SE = 0.03) x 1,11 mm (SE = 0.13), p < 0.001], in-segment late loss [0.30 mm (SE = 0.04) x 0.83 mm (SE = 0.11), p < 0.001], in-stent restenosis (0% x 33.3%, p < 0.001) and in-segment restenosis (4% x 36.7%, p < 0.001). The event-free survival rate was 96% in the sirolimus-eluting stent group versus 86.7% in the bare-metal stent group (BMS) (p = 0.190). CONCLUSION: Sirolimus-eluting stents are superior to thin-strut bare-metal stents in reducing intimal hyperplasia (less in-stent obstruction and less late lumen loss) in patients with small vessels. The use of these stents significantly reduced angiographic restenosis at eight months.

Análise comparativa da hiperplasia intimal após o implante de stents com e sem sirolimus em artérias coronárias de pequeno calibre / Comparative analysis of intimal hyperplasia after sirolimus-eluting stent and thin-strut bare-metal stent implantation in small coronary arteries

OBJETIVO: Avaliar a redução do volume de hiperplasia intimal após angioplastia com stents com sirolimus (Cypher®) comparados com os stents não-recobertos de estrutura metálica fina (Pixel®) em pacientes com vasos pequenos. MÉTODOS: Oitenta pacientes com doença arterial coronariana foram prospectivamente incluídos em duas séries consecutivas de tratamento, sendo a primeira empregando stents com sirolimus (50) e a segunda stents não-recobertos de estrutura metálica fina (30). RESULTADOS: Os resultados foram: menor porcentual de obstrução da prótese através do ultra-som intracoronário [5,0 por cento (EP = 0,77) x 39,0 por cento (EP = 4,72), p < 0,001], menor perda tardia intra-stent [0,25 mm (EP = 0,03) x 1,11 mm (EP = 0,13), p < 0,001] e no segmento do vaso [0,30 mm (EP = 0,04) x 0,83 mm (EP = 0,11), p < 0,001], e também menor reestenose intra-stent (0 por cento x 33,3 por cento, p < 0,001) e no segmento do vaso (4 por cento x 36,7 por cento, p < 0,001) com os stents com sirolimus. A sobrevivência livre de eventos foi de 96 por cento com os stents com sirolimus x 86,7 por cento com os stents não-recobertos (p = 0,190). CONCLUSÃO: Os pacientes com vasos de pequeno calibre após o implante de stents com sirolimus evoluem com menor hiperplasia intimal (menor porcentual de obstrução intra-stent e menor perda tardia) do que quando são utilizados stents não-recobertos de estrutura metálica fina. Isto resultou em redução significativa da reestenose angiográfica aos oito meses de evolução.

Pilot study with an intensified oral sirolimus regimen for the prevention of in-stent restenosis in de novo lesions

This pilot study evaluated the safety and efficacy of an intensified oral sirolimus regimen

(15-mg loading dose 24 hr before PCI, followed by a daily dose of 5 mg for

4 weeks) in 15 patients subjected to elective bare metal coronary stent implantation

patients. The reference diameter was 3.04 6 0.38 mm, and the lesion length was

14 6 2 mm. Angiographic and volumetric intravascular ultrasound (IVUS) analyses were

performed in all patients at 6.0 6 0.2 months. Two patients (13%) met the definition of

in-segment binary restenosis; in-stent and in-segment angiographic late loss was 0.61 6

0.31 mm and 0.67 6 0.45 mm, respectively, and the percent neointimal volume was

infarctions, or target lesion revascularizations were detected. Mean sirolimus

blood level was 13 6 7 ng/ml. No correlations were found between drug levels and late

loss (r = 0.15, P = 0.59) or IVUS percent neointimal volume (r = 0.23, P = 0.47). Side

effects were frequent (80%), leading to dose reductions in four and drug discontinuation

in one patient. The results of this pilot study suggest that an intensified 5-mg oral

sirolimus regimen resulted in no relevant improvements in the angiographic and IVUS

encourage further trials evaluating the current protocol for the prevention of in-stent

for de novo lesions. Mean patient age was 59 6 9; 73% were male, and 13% were diabetic

parameters of restenosis after stent implantation in de novo lesions when compared

with historic controls. Considering the efficacy/safety balance, our results do not

Pilot study with an intensified oral sirolimus regimen for the prevention of in-stent restenosis in de novo lesions: a serial intravascular ultrasound study.

This pilot study evaluated the safety and efficacy of an intensified oral sirolimus regimen (15-mg loading dose 24 hr before PCI, followed by a daily dose of 5 mg for 4 weeks) in 15 patients subjected to elective bare metal coronary stent implantation for de novo lesions. Mean patient age was 59+/-9; 73% were male, and 13% were diabetic patients. The reference diameter was 3.04+/-0.38 mm, and the lesion length was 14+/-2 mm. Angiographic and volumetric intravascular ultrasound (IVUS) analyses were performed in all patients at 6.0+/-0.2 months. Two patients (13%) met the definition of in-segment binary restenosis; in-stent and in-segment angiographic late loss was 0.61+/-0.31 mm and 0.67+/-0.45 mm, respectively, and the percent neointimal volume was 28.5+/-15.8%. At adjacent reference segments, there was neither significant plaque increase nor constrictive vascular remodeling. At 24-month follow-up no deaths, myocardial infarctions, or target lesion revascularizations were detected. Mean sirolimus blood level was 13+/-7 ng/ml. No correlations were found between drug levels and late loss (r=0.15, P=0.59) or IVUS percent neointimal volume (r=0.23, P=0.47). Side effects were frequent (80%), leading to dose reductions in four and drug discontinuation in one patient. The results of this pilot study suggest that an intensified 5-mg oral sirolimus regimen resulted in no relevant improvements in the angiographic and IVUS parameters of restenosis after stent implantation in de novo lesions when compared with historic controls. Considering the efficacy/safety balance, our results do not encourage further trials evaluating the current protocol for the prevention of in-stent restenosis.

Reperfusão mecânica no infarto agudo do miocárdio / Percutaneous coronary intervention in acute myocardial infarction

A recanalização da artéria epicárdica culpada foi o grande avanço no tratamento do infarto agudo do miocárdio. A estratégia farmacológica com fibrinolíticos permitiu a obtenção de amplo benefício clínico, documentado pela redução da mortalidade em diversos estudos. A utilização endovenosa dessas drogas, entretanto, também exibe limitações, entre outras o baixo porcentual de patência do vaso culpado, com fluxo veloz e persistente. A obtenção desse fluxo TIMI 3 correlaciona-se diretamente com maior sobrevida, adquirindo grande importância em qualquer estratégia de reperfusão no infarto agudo do miocárdio. Paralelamente, a estratégia mecânica de reperfusão no infarto agudo do miocárdio demonstrou sua vantagem em relação aos fibrinolíticos, já na angioplastia com balão, nos estudos clínicos da década de 90. Assim sendo, a intervenção percutânea, nessa condição, promove maior sobrevida, menor reinfarto e menor necessidade de nova revascularização, com maior segurança. A incorporação dos stents coronarianos ampliou tais benefícios, tanto pelo alto perfil de segurança de implante como pela redução da reestenose. Mais recentemente, atenção especial foi dada à microcirculação e à reperfusão tecidual completa no infarto agudo do miocárdio, permitindo a introdução de novos fármacos (inibidores da glicoproteína IIb/IIIa), que, com sinergismo, potencializaram a vantagem da angioplastia primária, na otimização dos resultados apresentados. Recentemente, com o estudo CADILLAC, a Cardiologia Intervencionista sintetiza a estratégia mecânica de reperfusão no infarto agudo do miocárdio, que, no momento, direciona nossas condutas.

Manuseio Percutâneo das lesöes coronarias >20mm através dos stents. Existe uma estratégia de primeira escolha? / Percutaneous handling of coronary lesions >20mm through stents. Is there a first choice strategy?

OBJECTIVE - This study compared the early and late results of the use of one single stent with those of the use of multiple stents in patients with lesions longer than 20mm. METHODS - Prospective assessment of patients electively treated with stents, with optimal stent deployment and followed-up for more than 3 months. From February '94 to January '98, 215 patients with lesions >20mm were treated. These patients were divided into 2 groups as follows: Group A - 105 patients (49 percent) with one stent implanted; Group B - 110 patients (51 percent) with multiple stents implanted. RESULTS - The mean length of the lesions was 26mm in group A (21-48mm) versus 29mm in group B (21-52mm) (p=0.01). Major complications occurred in one patient (0.9 percent) in group A (subacute thrombosis, myocardial infarctionand death) and in 2 patients (1.8 percent) in group B (one emergency surgery and one myocardial infarction) (p=NS). The results of the late follow-up period (6 months) were similar for both groups (group A = 82 percent vs group B = 76 percent; p=NS), and we observed an event-free survical in 89 percent of the patients in group A and in 91 percent of the patients in group B (p=NS). Angina (group A = 11 percent vs group B =7percent) and lesion revascularization (group A = 5 percent vs group B = 6 percent; p=NS) also occurred in a similar percentage. No infarction or death was observed in the late follow-up period; restenosis was identified in 33 percent and 29 percent of the patients in groups A and B, respectively (p=NS). CONCLUSION - The results obtained using one stent and using multiple stents were similar; the greater cost-effectiveness of one stent implantation, however, seems to make this strategy the first choice