Thierry Colman

Stenting the Stent: Initial Results and Long-Term Clinical and Angiographic Outcome of Coronary Stenting for Patients With In-Stent Restenosis

Stent restenosis constitutes a therapeutic challenge affecting an increasing number of patients. Conventional angioplasty and debulking techniques are currently used in these patients. However, the potential role of a second stent implantation in this setting (stenting the stent) remains unknown. Therefore, 65 consecutive patients (12 women, aged 62 +/- 11 years) undergoing stent implantation (42 elective and 23 unplanned) for the treatment of in-stent restenosis (diffuse [> 10 mm] in 39 [60%]) were studied. Angiographic success was obtained in all patients. Three patients developed hospital complications: 1 died from refractory heart failure and 2 suffered non-Q-wave myocardial infarctions. During follow-up (mean 17 +/- 11 months) 1 patient died (noncardiac cause) and only 9 (14%) required target vessel revascularization. Kaplan-Meier event-free survival (freedom from death, myocardial infarction, and target vessel revascularization) at 1 year was 84%. Using Cox analysis, patients with unstable symptoms, a short time to stent restenosis, nonelective stenting, and B2-C lesions tended to have poorer prognosis. After adjustment, nonelective stenting was associated (adjusted RR 2.9, 95% confidence interval [CI] 0.82 to 10.3, p = 0.09) with an adverse clinical outcome. On quantitative angiography (core lab) restenosis was found in 13 of 43 patients (30%) (75% of those eligible). Logistic regression analysis identify restenosis length (adjusted RR 1.43, 95% CI 1.04 to 2.14, p = 0.04), and time to restenosis (adjusted RR 0.67, 95% CI 0.47 to 0.94, p = 0.01) as the only independent predictors of recurrent restenosis. Thus, repeat coronary stenting is a safe and efficacious strategy for the treatment of patients with in-stent restenosis. Both elective and nonelective stenting provide excellent initial results. The long-term clinical and angiographic outcome of these patients is also favorable.

Virtual Histology Intravascular Ultrasound Assessment of Cardiac Allograft Vasculopathy From 1 to 20 Years After Heart Transplantation

BACKGROUND Cardiac allograft vasculopathy (CAV) is the main cause of graft loss and death in heart transplant (HTx) recipients surviving >1 year. There is a dual etiology for coronary disease in HTx: classic atherosclerosis and an immunologically mediated disease. Intravascular ultrasound (IVUS) is highly sensitive for CAV detection; however, gray-scale IVUS is of limited value for identification of specific plaque components. We sought to characterize graft coronary artery disease by means of IVUS-virtual histology (IVUS-VH) at different time-points of follow-up and to correlate plaque composition with clinical factors. METHODS In our study we included 67 patients, who were 7.6 +/- 5.7 years post-HTx. IVUS gray-scale evaluation was performed on all patients. IVUS-VH analysis was done in those patients showing intimal thickening >0.5 mm at the three more significant lesions (three cross-sections for each) of the left anterior descending artery. RESULTS IVUS-VH analysis was obtained done on 58 patients (86.5%). We found a significant correlation between time of HTx and IVUS gray-scale parameters (plaque area and plaque burden), with both increasing over time. We also found a significant correlation between time and IVUS-VH-derived plaque components, necrotic core and calcium, which increased with time, and fibrous and fibrofatty components, both decreased at follow-up. IVUS-VH results were also related to donor age and cardiovascular risk factors. CONCLUSIONS We observed a time-related change in IVUS-VH-derived plaque composition. Necrotic core and calcium, typical atheromatous components, become more prevalent with time after HTx, especially when influenced by cardiovascular risk factors. The presence of a necrotic core in the early stages was linked to older donor age.

Evaluation of direct stent implantation without predilatation by intravascular ultrasound

The present study shows that direct stent implantation without predilatation in selected lesions provides angiographic and ultrasonographic results that could be comparable to those expected with conventional stenting. These results may even safely improve if a balloon-artery ratio of 1.1 to 1.2 is used in combination with implantation pressures of 12 to 16 atm.

Resultados iniciales y seguimiento clínico a 6 meses tras el implante de un stent coronario recubierto de carburo de silicio

Introduccion y objetivos Presentar la experiencia inicial en Espana con el stent coronario Tenax, de acero inoxidable 316L recubierto de una capa de carbono de silicio amorfo rico en hidrogeno. Pacientes y metodos Desde julio de 1998 a julio de 1999 se implantaron 231 stents Tenax® en 206 pacientes de 9 centros (62 ± 5 anos) como unico procedimiento revascularizador. La indicacion clinica mas frecuente fue la angina inestable (66%), siendo la mayoria de las lesiones complejas (clases B2 y C). La arteria mas revascularizada fue la descendente anterior (51%). La fraccion de eyeccion fue inferior a 0,5 en 19% de casos. El resultado inmediato se valoro con angiografia cuantitativa y el seguimiento a 6 meses fue clinico. Resultados La revascularizacion fue completa en el 70%, electiva en el 80% y con implante directo en el 25% de los casos. El stent se desplego con exito en todos los pacientes. La estenosis disminuyo del 62 ± 16 al 16 ± 10% y el diametro luminal minimo aumento de 0,81 ± 0,40 a 2,61 ± 0,59. El flujo TIMI, comprometido en un 30% de casos, se normalizo en todos menos un caso. La incidencia de acontecimientos cardiacos fue minima: una trombosis aguda (0,5%) resuelta con nueva angioplastia y un infarto agudo de miocardio sin onda Q (0,5%). A los 6 meses reaparecio angina mayor de clase II en el 10% de los pacientes y se realizo una nueva angioplastia en el 1,9% de los casos. Conclusiones Los datos clinicos y angiograficos sugieren que el recubrimiento del stent coronario Tenax con carburo de silicio hidrogenado posiblemente desempena un papel beneficioso en el porvenir de los pacientes, aunque requiere una evaluacion en estudios clinicos prospectivos.

Aplicación prospectiva de un valor de corte de área luminal mínima por ecografía intravascular en la evaluación de lesiones intermedias del tronco

Introduccion y objetivos La angiografia presenta limitaciones importantes para definir la severidad de las lesiones intermedias del tronco comun. La ecografia endovascular (EEV) permite realizar una evaluacion precisa, pero no hay consenso respecto a los valores de area luminal minima (ALM) que indican significacion. El objetivo de este estudio es evaluar la seguridad a largo plazo de la aplicacion de un valor de corte de 6 mm2 para el ALM en el tronco. Metodos Se ha incluido a pacientes con lesiones intermedias (25-50%) de tronco no protegido, sin datos previos indicativos de isquemia atribuible. Se realizo estudio con EEV y se indico revascularizacion en los pacientes con ALM ≤ 6 mm2. Resultados En el periodo 2000-2005 se ha incluido a 79 pacientes, en 31 (39%) el ALM fue ≤ 6 mm2 y recibieron revascularizacion del tronco, en los restantes 48 (61%) el ALM fue > 6 mm2 y solo se actuo sobre otras lesiones (n = 37) o continuaron con tratamiento medico (n = 11). En un seguimiento de 40 ± 17 meses se han producido 4 muertes cardiacas (8,3%), que ocurrieron en casos con un ALM de 9-10 mm2 en el estudio basal. Solo en 2 casos (4,2%) fue preciso efectuar procedimientos de revascularizacion del tronco que consistieron en cirugias electivas tras mas de 2 anos del estudio inicial. Conclusiones La evaluacion con EEV de las lesiones intermedias de tronco y la consideracion de un valor de corte de 6 mm2 para el ALM resulta segura a largo plazo, siempre que se consideren unos criterios clinicoangiograficos de aplicabilidad como los considerados en este estudio.

Stent directo sin predilatación. Experiencia en 300 lesiones

Introduccion y objetivos La tecnica de stent directo consiste en la implantacion del stent sin predilatacion pretendiendo con ello reducir los costes y tiempos de procedimiento. Otros potenciales beneficios serian evitar la oclusion aguda tras angioplastia con balon y una probable reduccion en la tasa de reestenosis al provocar menor trauma arterial. Presentamos nuestra experiencia con esta tecnica en un amplio numero de pacientes. Pacientes y metodos. Se incluyeron 230 pacientes remitidos a nuestra unidad con 300 lesiones estenoticas no oclusivas (50-99%) sin excesiva tortuosidad, calcificacion, longitud o angulacion y con un diametro luminal de referencia 3 2,5 mm. Se intento la implantacion directa del stent , evaluandose los resultados angiograficos inmediatos y las complicaciones derivadas de los procedimientos. Resultados Se logro la implantacion directa en 256 de las 300 lesiones tratadas (85%). En 43 (14,3%) fue precisa la predilatacion y en un unico caso fue imposible la colocacion del stent . En 27 de los 256 stents (10,5%) colocados sin predilatar se efectuo sobredilatacion al apreciarse una expansion no optima. Se produjeron 5 perdidas de stent recuperandose 4 y sin consecuencias clinicas. Los mejores resultados se obtuvieron en las estenosis no subtotales ni bifurcadas de tipo A o B1 sin moderada calcificacion, tortuosidad o angulacion. Conclusiones La implantacion directa del stent es viable en un amplio numero de casos y puede abordarse con exito muy elevado tras una seleccion adecuada. Las lesiones mas idoneas serian aquellas con estenosis £ 90% no bifurcada de tipo A o B1 sin moderada calcificacion, tortuosidad o angulacion.

Treatment of Lesions With a High Risk of Stenosis. Comparative Study in 300 Patients of Rapamycin- and Paclitaxel-Eluting Polymer-Based Stents, and Bare Metal Stents

INTRODUCTION AND OBJECTIVES Rapamycin- and taxol-eluting stents have been shown to reduce restenosis, but there are no large-scale studies of their usefulness in lesions with a high risk of restenosis, or of the relative merits of the two devices. This prospective study compared their safety and efficacy in lesions with a high risk of restenosis. PATIENTS AND METHOD We included consecutive patients with lesions to treat that met at least one of the following criteria: a) in-stent restenosis; b) diffuse (>20 mm) restenosis; c) small vessel (< or =2.5 mm) restenosis; or d) total occlusion. Patients received different devices along three consecutive study periods: bare metal (conventional) stents, sirolimus-eluting (rapamycin) stents and paclitaxel-eluting (taxol) stents. RESULTS One hundred patients in each group were included, for a total of 300 patients. In the sirolimus group, after 8.5+/-2 months of follow-up, there were 2 late thromboses (2%) and only 1 patient (1%) required target lesion revascularization. In the paclitaxel group 2 patients (2%) had in-hospital stent thrombosis (1 acute, 1 subacute), and after 9+/-2.5 months of follow-up only 1 patient (1%) needed target lesion revascularization. In the conventional group, after 8+/-2 months of follow-up, there was 1 subacute thrombosis (1%) and 15 patients (15%) had clinical restenosis requiring target lesion revascularization. Event-free survival curves were significantly better with drug-eluting stents (P<.01 vs conventional stents). CONCLUSION Rapamycin- and taxol-eluting stents were safe for lesions with a high risk of restenosis. These stents were associated with a lower rate of target lesion revascularization during follow-up compared to bare metal stents.

Prospective Use of an Intravascular Ultrasound-Derived Minimum Lumen Area Cut-Off Value in the Assessment of Intermediate Left Main Coronary Artery Lesions

BACKGROUND AND OBJECTIVES Angiographic assessment of the severity of intermediate lesions in the left main coronary artery (LMCA) is subject to significant limitations. Intravascular ultrasound (IVUS) can provide accurate measurement, but there is no agreement on the minimum lumen cross-sectional area (MLA) that indicates significant disease. The aim of this study was to determine the long-term safety of applying a cut-off value of 6 mm2 for the MLA in the LMCA. METHODS The study included patients with intermediate lesions (i.e., 25-50%) in unprotected LMCAs, with no previous evidence of associated ischemia. An IVUS examination was carried out and revascularization was indicated when the MLA was < or =6 mm2. RESULTS In total, 79 patients were recruited between 2000-2005. In 31 (39%), the MLA was < or =6 mm2, and they underwent LMCA revascularization; in the remaining 48 (61%), the MLA was >6 mm2, and patients either underwent angioplasty for other lesions (n=37) or continued medical treatment (n=11). In a follow-up period of 40 [17] months, four patients (8.3%) died from heart disease, all of whom had an MLA between 9-10 mm2 in the baseline study. Revascularization of the LMCA was necessary in only two patients (4.2%), both of whom had elective surgery more than 2 years after the initial study. CONCLUSIONS Intravascular ultrasound assessment of intermediate LMCA lesions using an MLA cut-off value of 6 mm2 appears safe over the long term provided the clinical and angiographic criteria applied to patient selection are similar to those used in this study.

[Two-year clinical follow-up in 200 patients receiving sirolimus-eluting stents in lesions at a high risk of restenosis].

INTRODUCTION AND OBJECTIVES Sirolimus-eluting stents (SESs) have been shown to reduce the rate of restenosis significantly in all types of coronary lesion. However, reports of late cases of thrombosis and restenosis have raised questions about long-term outcome in patients treated with these stents. Our aim was to evaluate long-term outcome in patients undergoing SES placement in lesions at a high risk of restenosis. PATIENTS AND METHOD Since SESs became available, we have used them to treat lesions at risk of restenosis. We studied clinical outcomes in consecutive patients treated with SESs who were followed up for more than 2 years. RESULTS The study included 200 patients (age 60[11] years, 22% diabetics) who were treated between June 2002 and April 2003 for 309 lesions: 16% were total occlusions, 16.8% in-stent restenoses, 28% diffuse lesions, and 30% small-vessel lesions. The total stent length per patient was 29 (16) mm and the mean diameter was 2.78 (0.27) mm. In a mean clinical follow-up period of 29 (3.2) months (range 24-34 months), there were four deaths, two (1%) of which were cardiac, four (2%) non-fatal infarctions, four (2%) in-stent thromboses (all occurred late, at 3, 7, 26 and 31 months), four (2%) cases requiring target lesion revascularization (at 3, 5, 14 and 15 months), and six (3%) requiring revascularization of a new lesion. CONCLUSIONS Long-term follow-up of patients undergoing SES placement in lesions at a high risk of restenosis revealed a very low restenosis rate. However, the incidence of late thrombosis appeared to be elevated and warrants further evaluation in larger studies.

Isquemia sintomática en un paciente con coronaria derecha única sin lesiones

Las anomalias congenitas de las coronarias son infrecuentes y la coronaria derecha unica es probablemente una de las mas raras. Ha sido incluida dentro de las potencialmente malignas por su ocasional asociacion con infartos o muerte subita. Presentamos el caso de una paciente que referia dolores toracicos, que realizo una ergometria electricamente positiva y en la que en la coronariografia se observo una coronaria derecha unica sin lesiones estenosantes. Discutimos la fisiopatologia e implicaciones clinico-terapeuticas.