ABSTRACT
OBJECTIVES: To evaluate the outcomes of chronic total occlusion (CTO) percutaneous coronary intervention (PCI) in patients with and without prior coronary artery bypass graft (CABG) surgery. BACKGROUND: Data on the outcomes of CTO PCI in patients with versus without CABG remains limited and with scarce representation from developing regions like Latin America. METHODS: We evaluated patients undergoing CTO PCI in 42 centers participating in the LATAM CTO registry between 2008 and 2020. Statistical analyses were stratified according to CABG status. The outcomes of interest were technical and procedural success and in-hospital major adverse cardiac and cerebrovascular events (MACCE). RESULTS: A total of 1662 patients were included (n = 1411 [84.9%] no-CABG and n = 251 [15.1%] prior-CABG). Compared with no-CABG, those with prior-CABG were older (67 ± 11 vs. 64 ± 11 years; p < 0.001), had more comorbidities and lower left ventricular ejection fraction (52.8 ± 12.8% vs. 54.4 ± 11.7%; p = 0.042). Anatomic complexity was higher in the prior-CABG group (J-CTO score 2.46 ± 1.19 vs. 2.10 ± 1.22; p < 0.001; PROGRESS CTO score 1.28 ± 0.89 vs. 0.91 ± 0.85; p < 0.001). Absence of CABG was associated with lower risk of technical and procedural failure (OR: 0.60, 95% CI: 0.43-0.85 and OR: 0.58, 95% CI: 0.40-0.83, respectively). No significant differences in the incidence of in-hospital MACCE (3.8% no-CABG vs. 4.4% prior-CABG; p = 0.766) were observed between groups. CONCLUSION: In a contemporary multicenter CTO-PCI registry from Latin America, prior-CABG patients had more comorbidities, higher anatomical complexity, lower success, and similar in-hospital adverse event rates compared with no-CABG patients.
Subject(s)
Coronary Occlusion , Percutaneous Coronary Intervention , Chronic Disease , Coronary Angiography , Coronary Artery Bypass/adverse effects , Coronary Occlusion/diagnostic imaging , Coronary Occlusion/surgery , Humans , Percutaneous Coronary Intervention/adverse effects , Registries , Risk Factors , Stroke Volume , Time Factors , Treatment Outcome , Ventricular Function, LeftABSTRACT
Aneurysmal coronary artery disease includes coronary artery aneurysms and ectasia; this condition has been associated with poor long-term outcomes. Few studies have explored myocardial blood flow 13N-ammonia PET/CT MPI added value. We present a 45-year-old man who came to the emergency department with chest pain. After a physical examination and laboratory studies, he was diagnosed with very high-risk unstable angina and referred to the catheterization laboratory. Coronary angiography showed the culprit lesion in the LCx and was treated by angioplasty and stent. LAD was found with coronary artery ectasia (TIMI 2 flow grade) and the RCA with aneurysmal disease in the proximal and middle segments (TIMI 3 flow grade). Medical treatment was decided for these findings and the patient was discharged. Two weeks later, we performed a 13N-ammonia PET/CT MPI founding apical, inferior, and inferoseptal severe ischemia, and reduced hyperemic coronary blood flow and coronary flow reserve in the RCA territory. Flow was normal in the LAD territory. Although coronary angiography remains the gold standard for evaluating these coronary abnormalities, it does not show the physiological compromise. Therefore 13N-ammonia PET/CT MPI should be performed as a complementary noninvasive imaging approach.
Subject(s)
Coronary Artery Disease , Ammonia , Coronary Angiography , Coronary Artery Disease/complications , Coronary Artery Disease/diagnostic imaging , Coronary Artery Disease/pathology , Coronary Circulation/physiology , Coronary Vessels , Dilatation, Pathologic/pathology , Humans , Male , Middle Aged , Positron Emission Tomography Computed TomographyABSTRACT
Outcomes of chronic total occlusion (CTO) percutaneous coronary intervention (PCI) have improved because of advancements in equipment and techniques. With global collaboration and knowledge sharing, we have identified 7 common principles that are widely accepted as best practices for CTO-PCI. 1. Ischemic symptom improvement is the primary indication for CTO-PCI. 2. Dual coronary angiography and in-depth and structured review of the angiogram (and, if available, coronary computed tomography angiography) are key for planning and safely performing CTO-PCI. 3. Use of a microcatheter is essential for optimal guidewire manipulation and exchanges. 4. Antegrade wiring, antegrade dissection and reentry, and the retrograde approach are all complementary and necessary crossing strategies. Antegrade wiring is the most common initial technique, whereas retrograde and antegrade dissection and reentry are often required for more complex CTOs. 5. If the initially selected crossing strategy fails, efficient change to an alternative crossing technique increases the likelihood of eventual PCI success, shortens procedure time, and lowers radiation and contrast use. 6. Specific CTO-PCI expertise and volume and the availability of specialized equipment will increase the likelihood of crossing success and facilitate prevention and management of complications, such as perforation. 7. Meticulous attention to lesion preparation and stenting technique, often requiring intracoronary imaging, is required to ensure optimum stent expansion and minimize the risk of short- and long-term adverse events. These principles have been widely adopted by experienced CTO-PCI operators and centers currently achieving high success and acceptable complication rates. Outcomes are less optimal at less experienced centers, highlighting the need for broader adoption of the aforementioned 7 guiding principles along with the development of additional simple and safe CTO crossing and revascularization strategies through ongoing research, education, and training.
Subject(s)
Coronary Occlusion/diagnostic imaging , Coronary Occlusion/surgery , Percutaneous Coronary Intervention/standards , Practice Guidelines as Topic/standards , Chronic Disease , Collateral Circulation/physiology , Coronary Angiography/methods , Coronary Angiography/standards , Coronary Vessels/diagnostic imaging , Coronary Vessels/surgery , Humans , Percutaneous Coronary Intervention/methods , Treatment OutcomeABSTRACT
This report describes a solution for a restenosis and for the fracture of a stent in the vertebral artery in a patient suffering from vertebrobasilar symptoms. Angiography demonstrates restenosis of a vertebral stent as well as its fracture and migration into the subclavian artery. This complication was managed percutaneously by passing a guide wire through the fractured stent. Pre-dilatation and kissing balloon techniques were applied in both the vertebral and subclavian arteries to modify the stent's dimensions and shape it into the form of a "ring." Postprocedural angiography demonstrated an excellent final result with the assistance of StentBoost visualization. Control angiography at six months also utilized StentBoost imaging and confirmed the patency of the bifurcation and that the stent was not displaced.
Subject(s)
Prosthesis Failure , Stents/adverse effects , Vertebrobasilar Insufficiency/surgery , Aged , Female , Foreign-Body Migration , Humans , Recurrence , Subclavian Artery , Vascular Surgical Procedures/methodsABSTRACT
Central venous catheterization is a common procedure in the emergency and intensive-care units. Rupture of the central catheter has been described as a rare complication in patients with permanent subclavian catheters. We report the case of a patient with rupture and central catheter and embolization secondary to intermittent mechanical compression by the subclavian and the first rib (pinch-off syndrome) and its resolution through a percutaneous device.
Subject(s)
Catheterization, Central Venous/adverse effects , Equipment Failure , Clavicle , Female , Humans , Middle Aged , Ribs , SyndromeABSTRACT
Chronic total occlusion (CTO) percutaneous coronary intervention is a complex procedure and is associated with considerable risk of complications. Several success and complication scores have been developed; however, data regarding their external validation in other populations such as Latin America are scarce. This study aimed to evaluate the accuracy of the main predictors of success and complications in a broad cohort of procedures in the Latin American (LATAM) CTO registry. From April 2008 to December 2023, 3,706 consecutive procedures listed in the LATAM CTO registry were screened. Of these, 2,835 procedures had sufficient information to analyze the Multicenter CTO Registry in Japan (J-CTO); Prospective Global Registry for the Study of Chronic Total Occlusion Intervention (PROGRESS); Ostial location, Rentrop grade, and Age (ORA); Clinical and Lesion-related Score (CL-score); and EuroCTO Score (CASTLE) success scores. The complication scores were PROGRESS (MACE, mortality, and pericardiocentesis) and Outcomes, Patient health status, and Efficiency iN Chronic Total Occlusion hybrid procedures (OPEN-CTO),OPEN-CLEAN. The J-CTO and CASTLE scores demonstrated the highest areas under the curve (AUC) of 0.718 and 0.703, respectively. The AUC value for the CL-score was 0.685, whereas the PROGRESS score had an AUC of 0.598 and the ORA AUC was 0.545. The level of agreement between scores was low; only 4% of the procedures were classified as difficult or very difficult by all scores and <1% were classified as easy by all 5 scores. Of the complication scores, PROGRESS mortality (AUC 0.651) and PROGRESS MACE (AUC 0.588) showed the best performance, identifying groups with >10% event rate. These results may improve the selection of revascularization techniques, especially for patient demographics that are historically underrepresented in CTO research.
ABSTRACT
OBJECTIVES: To evaluate the mid-term outcomes, and the aortic remodeling in Marfan syndrome (MFS) patients with type B dissection that were treated with endovascular repair. BACKGROUND: MFS is a relative contraindication to thoracic endovascular aortic repair (TEVAR). Mid-term aortic outcomes data in MFS after TEVAR are limited, and the occurrence of late events remains unclear. METHODS: Of 89 patients that underwent TEVAR between September 2002 and February 2011, 10 patients with mid-term follow-up fulfilled the Ghent criteria for MFS and complicated type B dissection. High risk for open surgery was documented in 90%. RESULTS: The mean age was 35.1 ± 9.4 years and all patients presented with acute aortic syndrome complicating a chronic type B dissection (DeBakey type IIIb). Five patients underwent a Bentall surgical procedure previous to endovascular repair, and in four patients initial TEVAR was followed by surgery of the ascending aorta. Treatment was limited to endovascular repair in only one patient. In-hospital mortality was 10%. At a mean follow-up of 59.6 ± 38.9 months, the cumulated mortality was of 20% and late mortality 11.1%. The rate of secondary endoleak was 44.4%, and late reintervention of 33.3%. Survival freedom from cardiovascular death at 8 years was 80.0%, and positive remodeling was documented in 37.5% of patients. CONCLUSIONS: Our results suggest that TEVAR is feasible, safe, and associated with a high reintervention rate and reduced rate of positive aortic remodeling in patients with Marfan syndrome. Survival at 8 years was comparable to contemporary series of open repair.
Subject(s)
Aorta, Thoracic/surgery , Aortic Aneurysm, Thoracic/surgery , Aortic Dissection/surgery , Blood Vessel Prosthesis Implantation , Endovascular Procedures , Marfan Syndrome/complications , Adult , Aortic Dissection/diagnosis , Aortic Dissection/etiology , Aortic Dissection/mortality , Aorta, Thoracic/diagnostic imaging , Aorta, Thoracic/pathology , Aortic Aneurysm, Thoracic/diagnosis , Aortic Aneurysm, Thoracic/etiology , Aortic Aneurysm, Thoracic/mortality , Aortography/methods , Blood Vessel Prosthesis Implantation/adverse effects , Blood Vessel Prosthesis Implantation/mortality , Chronic Disease , Dilatation, Pathologic , Endoleak/etiology , Endoleak/surgery , Endovascular Procedures/adverse effects , Endovascular Procedures/mortality , Female , Hospital Mortality , Humans , Kaplan-Meier Estimate , Magnetic Resonance Angiography , Male , Marfan Syndrome/diagnosis , Marfan Syndrome/mortality , Reoperation , Risk Factors , Time Factors , Tomography, X-Ray Computed , Treatment OutcomeABSTRACT
Venovenous extracorporeal membrane oxygenation (ECMO) has become a rescue therapy for acute respiratory distress syndrome (ARDS) secondary to COVID-19 for patients who are refractory to conventional therapy. However, this therapy comes with complications, and alternative cannulation strategies are needed to overcome these difficulties. In this article, we present a case of venovenous ECMO presenting with refractory hypoxemia and right ventricular dysfunction, which were corrected by cannulating the pulmonary artery. This situation is rarely reported in literature and may constitute an alternative for managing these patients.
ABSTRACT
OBJECTIVE: In recent years, transcatheter aortic valve replace (TAVR) has revolutionized the interventional treatment of aortic stenosis, however, only scarce evidence considers it as treatment for Aortic Regurgitation (AR). At present, the treatment of Pure AR of Native Valve with TAVR does not fall within the recommendations of international guidelines, as it poses multiple challenges with immediate and long-term variable and unpredictable results. The objective of this paper is to present the case of a patient with prohibitive operative risk that benefited of TAVR treatment for AR. MATERIALS AND METHODS: We present the case of a 79-year-old male patient who has severe Pure Native Aortic Valve Regurgitation, considered inoperable. Based on the heart team's decision, TAVR was planned with the use of an Edwards SAPIEN 3 valve. After TAVR, the patient developed complete heart block and a pacemaker was implanted. He improved to NYHA II functional class. At 15-month follow-up, he suffered intracranial hemorrhage and passed away. RESULTS AND CONCLUSIONS: Management of patients with severe symptomatic AR with high surgical risk continues to be a special challenge. They have high mortality if left untreated with valvular change, despite medical treatment. Even though it is strictly off-label, TAVR might be a reasonable solution for a select type of patients who are considered inoperable due to surgical high mortality risk.
OBJETIVO: En años recientes, el reemplazo valvular aórtico vía percutánea (TAVI) ha revolucionado el tratamiento de los pacientes con estenosis aórtica, sin embargo, poca evidencia la considera como opción de tratamiento en pacientes con insuficiencia aórtica (IA), especialmente en pacientes con Insuficiencia Aórtica Pura de Válvula Nativa (IAPVN), dado que esta patología confiere múltiples retos con resultados muy variables tanto a corto como a largo plazo. Dada su alta mortalidad en caso de permanecer sin tratamiento, la primera opción de tratamiento es la cirugía de cambio valvular. MATERIAL Y MÉTODOS: Presentamos el caso de un masculino de 79 años con IAPVN grave considerado inoperable dadas las comorbilidades. De acuerdo con la decisión del equipo de Cardiología, se decidió realizar TAVI con la colocación de una Válvula Edwards SAPIEN 3. El paciente desarrolló bloqueo AV completo como única complicación y se colocó marcapasos permanente. Permaneció en clase funcional NYHA II. A los 15 meses de seguimiento presentó hemorragia intracraneal y falleció. RESULTADOS Y CONCLUSIONES: El manejo de los pacientes con IAPVN grave sintomática con riesgo quirúrgico alto sigue siendo un reto especial. Tienen alta mortalidad si no se realiza cambio valvular a pesar de tratamiento médico. A pesar de que no se recomienda en las guías actuales, la TAVI puede ser una opción razonable para un grupo muy selecto de pacientes que son considerados inoperables.
Subject(s)
Aortic Valve Insufficiency , Heart Valve Prosthesis , Transcatheter Aortic Valve Replacement , Male , Humans , Aged , Aortic Valve Insufficiency/surgery , Off-Label Use , Aortic Valve/surgeryABSTRACT
A 62-year-old man was admitted to the hospital due to sepsis secondary to a hemodialysis catheter-related infection that, upon diagnostic evaluation, demonstrated to be caused by P. aeruginosa and was treated with meropenem. Eradication of the infectious episode was confirmed by blood workup, including cultures. One month after the initial episode, the patient was readmitted due to a symptomatic penetrating aortic ulcer, which was classified as a cardiovascular emergency. The patient underwent an aortic stent-graft placement. Four weeks later, he presented to the emergency department with a 2-hour onset of thoracic pain and massive hematemesis. The esophagus and aortic segment with aortic stent graft were resected en bloc after an aortoesophageal fistula was diagnosed.
Subject(s)
Aortic Aneurysm, Thoracic , Aortic Diseases , Blood Vessel Prosthesis Implantation , Esophageal Fistula , Vascular Fistula , Aortic Aneurysm, Thoracic/complications , Aortic Aneurysm, Thoracic/diagnostic imaging , Aortic Aneurysm, Thoracic/surgery , Aortic Diseases/diagnostic imaging , Aortic Diseases/etiology , Aortic Diseases/surgery , Blood Vessel Prosthesis Implantation/adverse effects , Esophageal Fistula/diagnostic imaging , Esophageal Fistula/etiology , Esophageal Fistula/surgery , Humans , Male , Middle Aged , Vascular Fistula/diagnostic imaging , Vascular Fistula/etiology , Vascular Fistula/surgeryABSTRACT
During the past decade, the treatment of choice for chronic coronary syndromes (CCS) has been a contentious issue. Whether revascularisation, either percutaneous or surgical, or optimal medical therapy, offers better prognosis in terms of mortality, MI, and symptom relief, has yet to be confirmed. The long-awaited and recently published International Study of Comparative Health Effectiveness with Medical and Invasive Approaches (ISCHEMIA) trial randomised more than 5,000 patients into a revascularisation plus optimal medical therapy group and an optimal medical therapy alone group. The authors analyse the trial, with particular emphasis on the incidence of MI. They propose a patient-centred approach to incorporate the results of the ISCHEMIA trial into daily practice and determine the best treatment strategy for patients with CCS.
ABSTRACT
BACKGROUND: PCI is an expensive procedure in our population and it implies a huge cost for the institutions and National Health Service. AIM OF THE STUDY: The main objective was to evaluate the technical and biological success of two stents designed in Mexico. METHODS: Ten York pigs, 4-6 months of age, underwent implantation of the bare metal INC-01 (10 stents) and INC-02 (6 stents) coronary stent in addition to a conventional commercial stent (10 stents). Technical success was evaluated immediately with angiography and Intravascular Ultrasound IVUS, continued by a mean follow-up of 4 month and a final angiographic, IVUS and histological evaluation. RESULTS: Initial technical success, angiography and IVUS between the three stents were not significant. One stent presented restenosis in follow-up (commercial stent), but all other stents presented excellent clinical outcome, satisfactory angiographic and IVUS results. Inflammation, proliferation and endothelialization between the stents had no major differences in histological analysis in a mean of 4 months follow-up. CONCLUSIONS: In this pig model, the INC 01 and INC 02 stents showed the same delivering technical success, angiographic and IVUS features, biological and histological response compared to commercial last generation stents.
Subject(s)
Myocardial Ischemia/surgery , Percutaneous Coronary Intervention/methods , Stents/standards , Animals , Humans , Metals , Middle Aged , Swine , Treatment OutcomeABSTRACT
BACKGROUND: Reclassification of a large thrombus burden is an independent predictor of major adverse cardiac events and no-reflow in patients with ST- segment elevation myocardial infarction (STEMI). Patients with a greater residual thrombus burden have worse microvascular dysfunction and greater myocardial damage. METHODS: A retrospective analysis was performed on 833 STEMI patients who underwent primary percutaneous coronary intervention. The final residual thrombus burden was reclassified after the lesion was wired, and a thrombus aspiration or balloon dilatation was performed to restore and stabilise a thrombolysis in myocardial infarction (TIMI) 2-3 flow. Deferred stenting (DEI) was compared with immediate stenting (ISI) group, and the primary outcome was the incidence of no-/slow-reflow (TIMI ≤ 2, or TIMI 3 with myocardial blush grade < 2). RESULTS: Overall, 47 patients (6.8%) had a residual large thrombus burden reclassified. The right coronary artery was the culprit vessel in 34 cases. More patients had coronary ectasia in the DSI group (P=.005). Fewer patients in the DSI had no-/slow-reflow (36% vs. 58%), and the myocardial blush grade 3 was more frequent in the DSI group (P=.005). After repeat coronary angiography in the DSI group, stenting was not performed in 56%, and oral anticoagulation was more frequent in the follow-up (P=.031). Major cardiac adverse events were similar between groups. There was a tendency to better left ventricular function in the DSI group (P=.056). CONCLUSIONS: Deferred stenting may be an efficient option in STEMI patients with a residual large thrombus burden reclassified after achieving a stable TIMI 2-3 flow.
Subject(s)
Coronary Angiography/methods , Coronary Thrombosis/therapy , Percutaneous Coronary Intervention/methods , ST Elevation Myocardial Infarction/therapy , Stents , Adult , Aged , Anticoagulants/administration & dosage , Coronary Thrombosis/diagnostic imaging , Female , Follow-Up Studies , Humans , Longitudinal Studies , Male , Middle Aged , Retrospective Studies , ST Elevation Myocardial Infarction/diagnostic imaging , ST Elevation Myocardial Infarction/physiopathology , Time Factors , Ventricular Function, LeftABSTRACT
Abstract Objective: In recent years, transcatheter aortic valve replace (TAVR) has revolutionized the interventional treatment of aortic stenosis, however, only scarce evidence considers it as treatment for Aortic Regurgitation (AR). At present, the treatment of Pure AR of Native Valve with TAVR does not fall within the recommendations of international guidelines, as it poses multiple challenges with immediate and long-term variable and unpredictable results. The objective of this paper is to present the case of a patient with prohibitive operative risk that benefited of TAVR treatment for AR. Materials and methods: We present the case of a 79-year-old male patient who has severe Pure Native Aortic Valve Regurgitation, considered inoperable. Based on the heart team's decision, TAVR was planned with the use of an Edwards SAPIEN 3 valve. After TAVR, the patient developed complete heart block and a pacemaker was implanted. He improved to NYHA II functional class. At 15-month follow-up, he suffered intracranial hemorrhage and passed away. Results and Conclusions: Management of patients with severe symptomatic AR with high surgical risk continues to be a special challenge. They have high mortality if left untreated with valvular change, despite medical treatment. Even though it is strictly off-label, TAVR might be a reasonable solution for a select type of patients who are considered inoperable due to surgical high mortality risk.
Resumen Objetivo: En años recientes, el reemplazo valvular aórtico vía percutánea (TAVI) ha revolucionado el tratamiento de los pacientes con estenosis aórtica, sin embargo, poca evidencia la considera como opción de tratamiento en pacientes con insuficiencia aórtica (IA), especialmente en pacientes con Insuficiencia Aórtica Pura de Válvula Nativa (IAPVN), dado que esta patología confiere múltiples retos con resultados muy variables tanto a corto como a largo plazo. Dada su alta mortalidad en caso de permanecer sin tratamiento, la primera opción de tratamiento es la cirugía de cambio valvular. Material y Métodos: Presentamos el caso de un masculino de 79 años con IAPVN grave considerado inoperable dadas las comorbilidades. De acuerdo con la decisión del equipo de Cardiología, se decidió realizar TAVI con la colocación de una Válvula Edwards SAPIEN 3. El paciente desarrolló bloqueo AV completo como única complicación y se colocó marcapasos permanente. Permaneció en clase funcional NYHA II. A los 15 meses de seguimiento presentó hemorragia intracraneal y falleció. Resultados y Conclusiones: El manejo de los pacientes con IAPVN grave sintomática con riesgo quirúrgico alto sigue siendo un reto especial. Tienen alta mortalidad si no se realiza cambio valvular a pesar de tratamiento médico. A pesar de que no se recomienda en las guías actuales, la TAVI puede ser una opción razonable para un grupo muy selecto de pacientes que son considerados inoperables.
Subject(s)
Vena Cava Filters , Vena Cava, Inferior/abnormalities , Venous Thrombosis/therapy , Adult , Female , HumansABSTRACT
ABSTRACT Background: The cost of performing a percutaneous coronary intervention is considerably high for the patient as well as for health systems, which have promoted the development of local technology to help meet the need for these devices. Methods: The INC-01 bare-metal stent was developed at the National Institute of Cardiology in Mexico City and was first implanted on porcine models with technical success in 100% of the evaluated parameters. Presentation of Cases: We present the first three cases of patients with ischemic heart disease, to whom the INC-01 bare-metal stent was implanted. Intracoronary ultrasonography was performed post-stent implantation, showing all the characteristics of implant success during evaluation and clinical follow-up. Conclusions: Angiography and intracoronary ultrasound were carried out demonstrating that the INC-01 bare-metal stent has physical, biological, and histological characteristics similar to those found in commercial metallic stents.
Subject(s)
Humans , Male , Adult , Middle Aged , Aged , Prosthesis Design , Stents , Myocardial Ischemia/surgery , Pilot Projects , Follow-Up Studies , Ultrasonography , Treatment Outcome , Myocardial Ischemia/physiopathology , Myocardial Ischemia/diagnostic imaging , MexicoABSTRACT
Abstract Introduction: A drug-eluting coronary stent is being developed at the National Institute of Cardiology of Mexico for the treatment of ischemic heart disease. Objective: To establish the best animal model for the tests, to show the advances in the drug-eluting stent prototype, to assess two drugs antiproliferative activity and histological results. Method: Smooth muscle cell culture tests were performed in order to assess sirolimus and paclitaxel antiproliferative properties. The drugs were encapsulated inside the polymeric matrix of the stents. Rabbits and pigs were used as animal models. Results: Sirolimus and paclitaxel showed an inhibitory effect, which was higher for the latter. Infrared spectroscopy and light and optical microscopy showed that the drug/polymer layer properly adhered to the stent. At a four-week follow-up, both animal models showed satisfactory clinical evolution and adequate histological response, although the porcine model was shown to be more suitable for future protocols. Conclusions: Preliminary tests of the drug-eluting stent provided bases for the development of a study protocol with an adequate number of pigs and with clinical angiographic and histopathological three-month follow-up.
Resumen Introducción: En el Instituto Nacional de Cardiología de México se desarrolla una endoprótesis (stent) coronaria liberadora de fármacos para el tratamiento de la cardiopatía isquémica. Objetivo: Establecer el mejor modelo animal para las pruebas, mostrar los avances en el prototipo del stent liberador de fármacos, evaluar la actividad antiproliferativa de dos fármacos y los resultados histológicos. Método: Se realizaron cultivos de células de músculo liso para evaluar las propiedades antiproliferativas de sirolimus y paclitaxel. Los fármacos fueron encapsulados en el interior de la matriz polimérica de los stents. Se emplearon conejos y cerdos como modelos animales. Resultados: Sirolimus y paclitaxel mostraron efecto inhibitorio, mayor en el segundo. La espectroscopia infrarroja y la microscopia óptica y electrónica mostraron que la capa del polímero con el fármaco se adhería adecuadamente al stent. A las cuatro semanas de seguimiento, ambos modelos animales mostraron evolución clínica satisfactoria y adecuada respuesta histológica, si bien el modelo porcino resultó más conveniente para protocolos futuros. Conclusiones: Las pruebas preliminares del stent liberador de fármaco brindó bases para desarrollar el protocolo con un número adecuado en cerdos y con seguimiento clínico angiográfico e histopatológico a tres meses.