Gastón Dussaillant N

Frecuencia y características de la resistencia a aspirina en pacientes cardiovasculares chilenos

Background: Studies performed in Anglo-Saxon countries show that 5% of patients are resistant to the antiplatelet effects of aspirin. Aim: To assess the prevalence of aspirin resistance in a sample of Chilean cardiovascular patients and its association with clinical and laboratory characteristics. Patients and Methods: Ninety nine patients (30 women, 63±10 years) treated for stable cardiovascular diseases with aspirin 100325 mg/day were studied. Clinical and basic coagulation variables were assessed. Platelet aggregation was studied with platelet rich plasma using three different agonists in an optical aggregometer. Aspirin resistance was defined as an aggregation >20% with arachidonic acid and an aggregation >70% with ADP or collagen. Results: Eleven patients (11.11%, 95% CI= 4.95-17.27%) complied with both criteria and were classified as aspirin resistant. Current smoking was more common in aspirin resistant patients (63.6 vs 29.6%, p=0.039). Conclusions: Aspirin resistance was found in a significant proportion of cardiovascular patients and was more common among current smokers (Rev Med Chile 2005; 133: 409-17). (Key Words: Aspirin; Cardiovascular diseases; Platelet aggregation inhibitors)

Mortalidad post infarto del miocardio en Chile: Comparación de los registros de angioplastía primaria versus trombolisis

ResumenAntecedentes: Desde el ano 2005, se ha implementado en nuestro pais un conjunto de politicas publicas para permitir un acceso universal al tratamiento trombolitico a los pacientes con infarto agudo del miocardio (IAM). Para evaluar sus resultados es importante establecer los estandares locales de las distintas opciones de reperfusion. Objetivos: 1) Comparar la mortalidad precoz y alejada de los pacientes con IAM sometidos a angioplastia primaria (angioplastia) versus los sometidos a trombolisis, en Chile. 2) Establecer los factores de riesgo de mortalidad en estos pacientes. Metodos: Utilizando los registros nacionales de angioplastia (RENAC) y de IAM (GEMI), seleccionamos a todos los pacientes con IAM tratados con angioplastia o trombolisis, durante los anos 2003 y 2004. Entre ellos, comparamos mediante prueba de t de Student o chi-cuadrado, segun correspondiera, sus caracteristicas basales y su mortalidad hospitalaria, a 30 dias, y a 12 y 24 meses. Ademas se hizo analisis de regresion logistica multivariado para identificar

Fibrilación auricular focal. Características clínicas y resultado de la ablación con radiofrecuencia

Background: Atrial fibrillation can originate in arrhythmogenic foci coming from the pulmonary veins. Patients with atrial fibrillation, initiated from triggering foci, can be treated with radiofrequency ablation. Aim: To report the results of radiofrequency ablation in patients with focal atrial fibrillation. Patients and methods: Thirteen patients with focal atrial fibrillation (8 male, aged 19 to 60 years old) are reported. Twelve had frequent crises refractory to antiarrhythmic drugs. Two had also flutter and tachycardia. One had a permanent atrial fibrillation lasting five years. Two had ventricular dysfunction and left atrial dilatation. The triggering focus was identified during the electrophysiological study, by the precocity of the potential that initiated the atrial fibrillation. Results: All patients had early atrial extrasystolic beats, isolated or repetitives, that preceded atrial fibrillation. During the electrophysiological study, 18 foci (3 in the right and 15 in the left atrium all in pulmonary veins) were identified. Radiofrequency ablation had immediate success in 11 patients. In 5, a flutter was also ablated. One patient had a sinus dysfunction after the procedure and atrial fibrillation was not eliminated. In this and other patient in whom the procedure failed, a pacemaker was implanted and the atrioventricular node was blocked. In a follow up, ranging from 4 to 31 months, eight patients are asymptomatic and 3 recidivated. No complications have been detected. Conclusions: Patients with focal atrial fibrillation have common clinical and electrocardiographic features. Radiofrequency ablation of the triggering focus is possible and effective in most cases (Rev Med Chile 2002; 130: 482-94)

Práctica contemporánea de la angioplastia coronaria en Chile: Informe final del Registro Nacional de Angioplastia Coronaria (RENAC) 2001-2002

Background:Coronary angioplasty was introduced in Chile in 1982, but only after the introduction of stents it became commonplace. However, the results of this procedure at the national level remain largely unknown. Aim: To assess the results and characteristics of coronary angioplasty and develop a national registry in Chile (RENAC). Patients and Methods: All centers performing angioplasty were invited to contribute prospectively with the clinical, angiographic, procedural characteristics and results of all consecutive coronary angioplasty procedures attempted between June 2001 and October 2002. Results: In 10 centers, 1768 lesions were treated in 1484 procedures (22.98% in women). Mean age was 60.8±11.3 years old. Diabetes was found in 21.8%, hypertension in 60.2%, dyslipidemia in 52.0%, active smoking in 40.0%, renal failure in 6.2%. Myocardial infarction was recent in 28.4% and acute in 19.7%. Forty eight percent of patients had unstable angina and 15.5% had stable angina. Fifty three percent of patients had single vessel disease and 71%, normal left ventricular eyection fraction. One vessel was treated in 90.6% of patients and 81.7% of lesions were treated with stents, 17.9% only with baloon and in 0.4% with atherectomy. Angiographic success was obtained in 95.2%. Clinical success was obtained in 92.2%, and 95.1% in patients without acute myocardial infarction. Overall inhospital death was 2.2%. In patients without myocardial infarction, the figure was 1.1%. Conclusions: Coronary angioplasty in Chile is performed mostly for the treatment of acute coronary syndromes. Stents are the most frequently used devices. The high success, low mortality and complications observed are comparable to North American registries (Rev Med Chile 2004; 132: 913-22)Background: Coronary angioplasty was introduced in Chile in 1982, but only after the introduction of stents it became commonplace. However, the results of this procedure at the national level remain largely unknown. Aim: To assess the results and characteristics of coronary angioplasty and develop a national registry in Chile (RENAC). Patients and Methods: All centers performing angioplasty were invited to contribute prospectively with the clinical, angiographic, procedural characteristics and results of all consecutive coronary angioplasty procedures attempted between June 2001 and October 2002. Results: In 10 centers, 1768 lesions were treated in 1484 procedures (22.98% in women). Mean age was 60.8±11.3 years old. Diabetes was found in 21.8%, hypertension in 60.2%, dyslipidemia in 52.0%, active smoking in 40.0%, renal failure in 6.2%. Myocardial infarction was recent in 28.4% and acute in 19.7%. Forty eight percent of patients had unstable angina and 15.5% had stable angina. Fifty three percent of patients had single vessel disease and 71%, normal left ventricular eyection fraction. One vessel was treated in 90.6% of patients and 81.7% of lesions were treated with stents, 17.9% only with baloon and in 0.4% with atherectomy. Angiographic success was obtained in 95.2%. Clinical success was obtained in 92.2%, and 95.1% in patients without acute myocardial infarction. Overall inhospital death was 2.2%. In patients without myocardial infarction, the figure was 1.1%. Conclusions: Coronary angioplasty in Chile is performed mostly for the treatment of acute coronary syndromes. Stents are the most frequently used devices. The high success, low mortality and complications observed are comparable to North American registries (Rev Med Chile 2004; 132: 913-22). (Key Words: Coronary disease; Angioplasty, transluminal, percutaneous Coronary; Stents)BACKGROUND Coronary angioplasty was introduced in Chile in 1982, but only after the introduction of stents it became commonplace. However the results of this procedure at the national level remain largely unknown. AIM To assess the results and characteristics of coronary angioplasty and develop a national registry in Chile (RENAC). PATIENTS AND METHODS All centers performing angioplasty were invited to contribute prospectively with the clinical, angiographic, procedural characteristics and results of all consecutive coronary angioplasty procedures attempted between June 2001 and October 2002. RESULTS In 10 centers, 1768 lesions were treated in 1484 procedures (22.98% in women). Mean age was 60.8 +/- 11.3 years old. Diabetes was found in 21.8%, hypertension in 60.2%, dyslipidemia in 52.0%, active smoking in 40.0%, renal failure in 6.2%. Myocardial infarction was recent in 28.4% and acute in 19.7%. Forty eight percent of patients had unstable angina and 15.5% had stable angina. Fifty three percent of patients had single vessel disease and 71%, normal left ventricular eyection fraction. One vessel was treated in 90.6% of patients and 81.7% of lesions were treated with stents, 17.9% only with baloon and in 0.4% with atherectomy. Angiographic success was obtained in 95.2%. Clinical success was obtained in 92.2%, and 95.1% In patients without acute myocardial infarction. Overall inhospital death was 2.2%. In patients without myocardial infarction, the figure was 1.1%. CONCLUSIONS Coronary angioplasty in Chile is performed mostly for the treatment of acute coronary syndromes. Stents are the most frequently used devices. The high success, low mortality and complications observed are comparable to North American registries.

Resultados clínicos inmediatos y alejados del implante de stents metálicos no recubiertos: ¿Se justifica un reemplazo total por los stents liberadores de drogas?

Background: Since the introduction of stents in 1994, improved clinical results have boosted the development of coronary angioplasty in Chile. Drug eluting stents, that have a reduced rate of restenosis, are being increasingly used. Aim: To assess the acute and long-term results of bare metal stent implantation. Patients and Methods: Acute and long-term clinical, procedural and angiographic results were assessed in non acute myocardial infarction patients undergoing coronary stent implantation between August 1996 and December 2003. Results: During the study period, 932 patients aged 30 to 87 years (194 women) had at ieast one stent implanted. Twenty two percent were diabetic, 33% had recent myocardial infarction, 53% unstable angina and 22% stable angina. Angiographic and clinical success were 99.6% and 98.2%, respectively. In hospital death was 0.5%. During a mean follow-up of 19.1 months, all cause mortality was 3.9%, cardiac death 1.9% and survival free of major cardiac ischemic events was 85.3%. Only 6.4% of lesions underwent target vessel revascularization (TVR). Independent predictors of TVR were previous surgery, ieft anterior descending artery, small post stent minimum luminal diameter. Ostial location, in-stent restenosis, and younger age were non significant predictors. Conclusions: Acute and long-term results of bare metal stents in this population were excellent. An intriguingly low rate of TVR was seen. Selective bare metal stenting should continue in lesions and patients with a low risk of clinical restenosis

Infarto agudo del miocardio por oclusión total del tronco común de arteria coronaria izquierda tratado con revascularización percutánea endoluminal.: Caso clínico

We report a 43 years old female who developed an intense precordial pain and arterial hypotension. The patient was admitted to the emergency room in cardiogenic shock. An emergency angiography revealed a total occlusion of the left main coronary artery. An endoluminal coronary angioplasty with the placement of two stents was performed and coronary reperfusion TIMI III was achieved. The patient had a good evolution and one month later, a surgical revascularization was done, to avoid new occlusions. She was discharged in good conditions and in functional capacity I (Rev Med Chile 2001; 129: 773-9)

Estudio comparativo de la angioplastia coronaria en pacientes con diabetes.: Resultados clínicos y angiográficos inmediatos y evolución clínica en el primer año

Background: The success of revascularization procedures for coronary artery disease could be lower in diabetic patients. Aim: To report the results of coronary angioplasty in diabetic and non diabetic patients. Patients and methods: All angioplasty procedures performed between 1996 and 1999 were recorded. Demographic data, procedure details, hospital outcome and evolution at one year of follow up were analyzed. Results: During the study period, 358 patients were treated; of these, 79 were diabetics. Despite the greater severity of coronary lesions among diabetic patients the clinical success of the procedure was 92.4% in diabetics and 91.8% in non diabetics. Hospital mortality was 1.3% in diabetics and 0.7% in non diabetics. Major complications occurred in 3.8% of diabetics and 3.2% in non diabetics. One year survival was 95.9% for diabetics and 98% in non diabetics. There were five late cardiac deaths among non diabetics and 3 among diabetics during the year of follow up. The frequency of new revascularization procedures was 4.3% in diabetics and 8.3% in non diabetics. Event-free survival was 95.6% in diabetics and 89.2% in non diabetics. Conclusions: Results of angioplasty were similar in diabetic and non diabetic patients in terms of hospital outcome and late follow-up (Rev Med Chile 2001; 129: 861-70).

Radiación ionizante secundaria generada en equipos de cineangiografía coronaria digital y analógica: influencia de los sistemas externos de protección radiológica

Background: Exposure to ionizing radiation is a known hazard of radiological procedures. Aim: To compare the emission of secondary ionizing radiation from two coronary angiographic equipments, one with digital and the other with analog image generation. To evaluate the effectiveness of external radiological protection devices. Material and methods: Environmental and fluoroscopy generated radiation in the cephalic region of the patient was measured during diagnostic coronary angiographies. Ionizing radiation generated in anterior left oblique projection (ALO) and in anterior right oblique projection (ARO) were measured with and without leaded protections. In 19 patients (group 1), a digital equipment was used and in 21 (group 2), an analog equipment. Results: Header radiation for groups 1 and 2 was 1194 ± 337 and 364 ± 222 µGray/h respectively (p<0.001). During fluoroscopy and with leaded protection generated radiation for groups 1 and 2 was 612 ± 947 and 70 ± 61 µGray/h respectively (p<0.001). For ALO projection, generated radiation for groups 1 and 2 was 105 ± 47 and 71 ± 192 µGray/h respectively (p<0.001). During filming the radiation for ALO projection for groups 1 and 2 was 7252 ± 9569 and 1671 ± 2038 µGray/h respectively (p = 0.03). Out of the protection zone, registered radiation during fluoroscopy for groups 1 and 2 was 2800 ± 1741 and 1318 ± 954 µGray/h respectively (p < 0.001); during filming, the figures were 15500 ± 5840 and 18961 ± 10599 µGray/h respectively (NS). Conclusions: Digital radiological equipment has a lower level of ionizing radiation emission than the analog equipment. (Rev Med Chile 2000; 128: 853-62).