[Transcatheter aortic valve implantation: experience in 17 patients]. / Implante valvular aórtico transarterial: experiencia en Chile.

BACKGROUND: Transcatheter aortic valve implantation (TAVI) is taking a leading role in the management of patients with severe aortic stenosis. Valve replacement surgery prolongs survival and is the technique of choice considering its historical background and long experience worldwide. Recently however, TAVI has positioned itself as the only standard therapy for symptomatic patients who are not candidates for surgery. AIM: To report the experience with this new technique comparing our results with those reported in the literature. MATERIAL AND METHODS: Between May 2010 and December 2011,17 patients aged 81 ± 7.3 years (58.8% men with an Euro SCORE 29 ± 22.4%) underwent a TAVI. RESULTS: The median transvalvular gradient was 54 ± 15.7 mmHg. All patients received a CoreValve™. Technical success was 100%, with a post implant gradient of 6.29 ± 3.3 mmHg. Residual aortic regurgitation was observed in 94%, none greater than grade II. There were no complications at the vascular access site. One patient developed cardiac tamponade during the procedure. Permanent pacemaker implantation was required in 35.2%. Hospital mortality rate was 5.8%, a figure that remained unchanged at 30 days of follow-up. CONCLUSIONS: In high-risk patients with aortic stenosis, TAVI has a high success rate and a low rate of complications. Besides an appropriate patient selection, a trained multidisciplinary team and technical conditions to solve possible complications of the procedure are required.

Implante valvular aórtico transarterial: experiencia en Chile / Transcatheter aortic valve implantation: Experience in 17 patients

Background: Transcatheter aortic valve implantation (TAVI) is taking a leading role in the management of patients with severe aortic stenosis. Valve replacement surgery prolongs survival and is the technique of choice considering its historical background and long experience worldwide. Recently however, TAVI has positioned itself as the only standard therapy for symptomatic patients who are not candidates for surgery. Aim: To report the experience with this new technique comparing our results with those reported in the literature. Material and Methods: Between May 2010 and December 2011,17patients aged 81 ± 7.3 years (58.8% men with an Euro SCORE 29 ± 22.4%) underwent a TAVI. Results: The median transvalvular gradient was 54 ± 15.7 mmHg. All patients received a CoreValveTM. Technical success was 100%, with a post implant gradient of 6.29 ± 3.3 mmHg. Residual aortic regurgita-tion was observed in 94%, none greater than grade II. There were no complications at the vascular access site. One patient developed cardiac tamponade during the procedure. Permanent pacemaker implantation was required in 35.2%. Hospital mortality rate was 5.8%, a figure that remained unchanged at 30 days offollow-up. Conclusions: In high-risk patients with aortic stenosis, TAVI has a high success rate and a low rate of complications. Besides an appropriate patient selection, a trained multidisciplinary team and technical conditions to solve possible complications of the procedure are required.

Spect de perfusión con²°¹Talio detecta enfermedad coronaria significativa en estenosis angiográfica entre 50 por ciento y 75 por ciento / ²°¹-Thallium perfusion scanning is able to detect significant coronary stenosis in the 50 to 75 percent range

Antecedentes: La angiografía coronaria es el estándar de oro para diagnosticar enfermedad coronaria. El objetivo de este trabajo fue comparar los resultados del SPECT con Talio 201 (²°¹ TI) con diversos valores de estenosis coronaria a la angiografía. Métodos: Se tabularon resultados de 145 pacientes. A todos ellos se les realizó un electrocardiograma (ECG) de esfuerzo, SPECT de perfusión miocárdica y angiografía coronaria. Para hacer la valorización se utilizaron 2 criterios angiográficos para estenosis coronaria: a) >50 por ciento y b) 75 por ciento, los que se aplicaron a los pacientes y vasos coronarios. Resultados: en la evaluación por pacientes la sensibilidad (S), especificidad (E) y exactitud (Ex) fue 87 por ciento, 57 por ciento y 81 por ciento, respectivamente, con criterio de estenosis de > 50 por ciento y de 93 por ciento, 51 por ciento y 79 por ciento usando criterio de > 75 por ciento, (NS). Al analizar los vasos individualmente la S, E y EX fue de 59 por ciento, 78 por ciento y 68 por ciento para criterio > 50 por ciento y de 70 por ciento, 75 por ciento y 74 por ciento para criterio > 75 por ciento (p<0.029 para S). Como era esperado a mayor severidad de estenosis, mayor incidencia de detección. Hubo 19 pacientes que presentaron estenosis entre 50 y 74 por ciento. De ellos 21 por ciento presentó ECG de estrés anormal y 58 por ciento SPECT de perfusión miocárdica anormal. Conclusión: Los resultados con el estudio de perfusión miocárdica con ²°¹TI avalan el uso de valor de 50 por ciento o más de estenosis angiográfica en el diagnóstico y evaluación de la enfermedad coronaria. En conjunto con la angiografía coronaria. El SPECT miocárdico ofrece una excelente estrategia para el manejo de los pacientes.

The predictive value of 201Tl rest-redistribution and 18F-fluorodeoxyglucose SPECT for wall motion recovery after recent reperfused myocardial infarction.

UNLABELLED: 201Tl and 18F-FDG are useful for acute myocardial infarction (MI) assessment. The goal of this study was to compare their predictive value for wall motion recovery in the culprit area after a recent reperfused MI using SPECT technique. METHODS: Forty-one patients (mean age: 56 +/- 12 years) were included, 81% of them male; all were studied within 1-24 days post MI. They underwent angioplasty in 27 cases (12 primary); bypass grafting in 10 cases and successful thrombolysis in 4. SPECT 201Tl injected at rest and redistribution (R-R) and also 18F-FDG, were performed on different days. Processed tomograms were interpreted blinded to clinical or angiographic data. Segmental wall motion assessed with echocardiography at baseline was compared with the 3 month follow up. RESULTS: Sensitivity [Confidence Interval] for 201Tl R-R was 74.6% [60.5-84.5], for FDG it was 82.1% [70.8-90.4]; specificities were 73% [64.3-80.5] and 54.8% [45.6-63.7], respectively. 18F-FDG tended to be more sensitive than 201Tl R-R, but the latter was more specific (p < 0.0004). Both 201Tl RR and 18F-FDG presented high negative predictive value (p: ns). CONCLUSION: In recent MI, SPECT 201Tl R-R is a valuable and widely available technique for viability detection, with similar sensitivity and significant better specificity than SPECT 18F-FDG.

FDG F18 / Rest Tl 201 SPECT patterns in recent myocardial infarction: predictive value for regional function recovery

Background. Detecting viability is important after recent myocardial infarction (MI). SPECT FDG/Tl flow-metabolism patterns for predicting functional recovery were analyzed in this setting. Method. Forty-one patients were studied (56ñ12 years; 80 percent males) with Tl 201 at rest and FDG F18 SPECT at a mean of 8.9 days post MI (range:1-24). All had baseline and 3 month follow-up echocardiography (ECHO) and initial coronary angiography. They were submitted to primary PTCA in 12 cases, late PTCA in 15 and bypass surgery in 10 and thrombolysis was performed in 4 patients as only procedure. A total of 345 culprit artery territory segments were interpreted by 3 nuclear independent observers. Analysis included segments with or without abnormal motion. Results. FDG/Tl 201 on patient basis, had: sensitivity 91percent; specificity 56 percent; positive predictive value 88 percent; negative predictive value (NPV) 63 percent and accuracy 83 percent. The analysis of segments with abnormal contractility showed values of 67 percent, 69 percent, 44 percent, 85 percent and 68 percent, respectively. Reverse mismatch with FDG/Tl appears to predict viability similarly to classical mismatch; severe or moderate match was highly associated with no functional recovery (NPV = 85 percent). Conclusion. Flow-perfusion patterns are variable in recent MI. FDG/Tl 201 SPECT has acceptable accuracy for predicting functional recovery and excellent NPV to further exclude viability

Streptokinase promotes development of dipeptidyl peptidase IV (CD26) autoantibodies after fibrinolytic therapy in myocardial infarction patients.

Dipeptidyl peptidase IV (DPP IV) (CD26) plays a critical role in the modulation and expression of autoimmune and inflammatory diseases. We recently reported that sera from patients with rheumatoid arthritis and systemic lupus erythematosus contained low levels of DPP IV and high titers of anti-DPP IV autoantibodies of the immunoglobulin A (IgA) and IgG classes and found a correlation between the low circulating levels of DPP IV and the high titers of anti-DPP IV autoantibodies of the IgA class. Since streptokinase (SK) is a potent immunogen and binds to DPP IV, we speculated that patients with autoimmune diseases showed higher DPP IV autoantibody levels than healthy controls as a consequence of an abnormal immune stimulation triggered by SK released during streptococcal infections. We assessed this hypothesis in a group of patients suffering from acute myocardial infarction, without a chronic autoimmune disease, who received SK as part of therapeutic thrombolysis. Concomitant with the appearance of anti-SK antibodies, these patients developed anti-DPP IV autoantibodies. These autoantibodies bind to DPP IV in the region which is also recognized by SK, suggesting that an SK-induced immune response is responsible for the appearance of DPP IV autoantibodies. Furthermore, we determined a correlation between high titers of DPP IV autoantibodies and an augmented clearance of the enzyme from the circulation. Serum levels of the inflammatory cytokines tumor necrosis factor alpha (TNF-alpha) and interleukin 6 (IL-6) increased significantly after 30 days of SK administration, while the levels of soluble IL-2 receptor remained unchanged during the same period, suggesting a correlation between the lower levels of circulating DPP IV and higher levels of TNF-alpha and IL-6 in serum in these patients.

[Performance of Thallium 201 rest-redistribution spect to predict viability in recent myocardial infarction]. / Rendimiento del SPECT talio201 reposo-redistribución para predecir viabilidad post infarto reciente del miocardio.

BACKGROUND: The detection of viability after acute myocardial infarction is primordial to select the most appropriate therapy, to decrease cardiac events and abnormal remodeling. Thallium201 SPECT is one of the radionuclide techniques used to detect viability. AIM: To evaluate the use of Thallium201 rest-redistribution SPECT to detect myocardial viability in reperfused patients after a recent myocardial infarction. PATIENTS AND METHODS: Forty one patients with up to of 24 days of evolution of a myocardial infarction were studied. All had angiographically demonstrated coronary artery disease and were subjected to a successful thrombolysis, angioplasty or bypass grafting. SPECT Thallium201 images were acquired at rest and after 4 h of redistribution. These results were compared with variations in wall motion score, studied at baseline and after 3 or 4 months with echocardiography. RESULTS: The sensitivity of rest-redistribution Thallium201 SPECT, to predict recovery of wall motion was 91% when patient analysis was performed and 79% when segmental analysis was done in the culprit region. The figures for specificity were 56 and 73% respectively. CONCLUSIONS: Rest-distribution Thallium201 SPECT has an excellent sensitivity to predict myocardial viability in recent myocardial infarction. The data obtained in this study is similar to that reported for chronic coronary artery disease.

Pautas para el diagnóstico y tratamiento de la Angina Inestable / Guidelines for the diagnosis and treatment of unstable angina

El presente artículo es una actualización de los principales métodos diagnósticos y terapéuticos para el manejo de la Angina Inestable. Presenta en forma clara y concisa tablas en las que se detallan las diferentes clasificaciones utilizadas. A pesar del avance de la tecnología sigue siendo crucial la anamnesis, antecedentes y el examen clínico, acompañado del ECG. Asimismo demuestra la utilidad que tiene los exámenes complementarios tales como las determinaciones de CK, CK-MB, Troponina y Mioglobina. El manejo clínico en las primeras horas del diagnóstico es vital, el objetivo del tratamiento de la angina inestable es estabilizar el cuadro clínico y prevenir que progrese hacia el infarto de miocardio. El tratamiento antiisquémico, utilizando diferentes medicamentos y reposos, así como la terapia antitrombótica son parte esencial del mismo. Se hace mención a nuevos fármacos antitrombóticos más específicos y más potentes como son los antagonistas de los receptores de membrana plaquetaria IIb-IIIa. Entre ellos figuran el Abciximab, la Intergrilina, el tirofiban y el Lamifiban. Finalmente se hace mención a los diferentes estudios (TIMI, VANQWISH, PRISM) en que se comparan conductas terapéuticas conservadoras vs. agresivas.

Eficacia de F18_fluorodeoxiglucosa SPECT para evaluar infarto reciente y viabilidad miocárdica / Efficacy of F18_fluorodeoxiglucose SPECT for recent infarction evaluation and myocardial viability

El mejor examen disponible para evaluar viabilidad miocárdica es el Fluor18-fluordeoxiglucosa (F18FDG) que mide metabolismo celular y utilización de glucosa como sustrato. Su asociación a marcadores de flujo miocárdico permiten conocer la existencia y extensión de tejido con función potencialmente recuperable. El objetivo de este trabajo fue evaluar el rendimiento del F18FDG SPECT en pacientes con infarto reciente de miocardio. Material y Método: Se estudiaron preliminarmente 23 pacientes (7M,16H), edad promedio 63 ñ 13 años (rango:40-85), con evolución promedio de 10 días postinfarto (rango:5-24). En 14 casos, el infarto fue anterior y en 9 casos inferior. Se realizó F18FDG en cámara ADAC doble cabezal con colimadores de 511 Kev, con dosis promedio de 211 MBq (rango: 52-444) , con adquisición de las imágenes a los 45 min postinyección. Contemporáneamente, se efectuó Tl201 SPECT reposo redistribución con dosis de 148 MBq y adquisición de imágenes a los 10 min y 3 hrs. Se realizó análisis visual de ambos estudios en forma independiente dividiendo el miocardio en 17 segmentos (total de segmentos: 391). Resultados: Tanto en el SPECT con Tl201 como en el con F18 FDG hubo 21/23 (91 por ciento) de casos con segmentos alterados, en que hubo concordancia de 83 por ciento. En el Tl201 reposo redistribución, se encontraron 32 por ciento de segmentos alterados y en el estudio conjunto Tl201 reposo F18 FDG, se observó un 34 por ciento de segmentos alterados del total de los analizados. En dichos segmentos, el Tl201 reposo redistribución mostró 65 por ciento de segmentos viables y el Tl201 F18 FDG 77 por ciento de segmentos con viabilidad. Conclusión: 1) Tanto el Tl201 como el estudio con F18 FDG tienen buena concordancia, tanto por pacientes como por segmentos, en el infarto reciente de miocardio. 2) El SPECT Tl201 asociado a F18 FDG detecta un mayor número de segmentos viables que el examen de Tl201 reposo- redistribución aislado

Inhibición de la respuesta depresora del miocardio inducida por frio: acción de nifedipina / Inhibition of myocardial depressor response induced by cold: action of nifedipine

Se estudian 15 pacientes portadores de Cardiopatía Isquémica reconocida por el antecedente de Infarto de Miocardio con evolución media de 6,1 mes desde el episodio agudo. Se realizó evaluación de la función ventricular con ventriculografia radioisotópica en condiciones basales y después de realizar Test presor con Frío. Según respuesta fueron didividos en: a) Grupo I: el cambio en la fracción de eyección inducido por el Test presor con frío es inferior o igual a 3% (No Reactivos). b) Grupo II: El cambio inducido por el test presor con frío en la fracción de eyección de ventrículo izquierdo es igual o superior a 4% (Reactivos). Después de administrar 20 mgrs. de Nifedipina por vía oral se repite ventriculografía isotópica evaluando respuesta al frío. El grupo reactivo deprime su fracción de eyección por influencia del Test con frío de 49,8% a 42,2%. Nifedipina impide se manifeste esta respuesta depresora de la función cardíaca inducida por el Test con frío encontrándose por la acción del fármaco una Fracción de eyección ventricular izquierda semejante en ambos grupos de pacientes y que no se modifica por influencia del frío