Resultados clínicos inmediatos y alejados del implante de stents metálicos no recubiertos: ¿Se justifica un reemplazo total por los stents liberadores de drogas? / Acute and long-term clinical results of bare metal coronary stenting

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 íeast one stent implanted. Twenty two percent were diabetic, 33 percent had recent myocardial infarction, 53 percent unstable angina and 22 percent stable angina. Angiographic and clinical success were 99.6 percent and 98.2 percent, respectively. In hospital death was 0.5 percent. During a mean follow-up of 19.1 months, all cause mortality was 3.9 percent, cardiac death 1.9 percent and survival free of major cardiac ischemic events was 85.3 percent. Only 6.4 percent of lesions underwent target vessel revascularization (TVR). Independent predictors of TVR were previous surgery, íeft 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.

Consideraciones sobre el uso de rayos X en la práctica médica convencional para la necesaria aplicación de normas básicas de seguridad / Considerations about the use of X-rays in the conventional medical practice for necesary aplication of basic security rules

The application maintained and increasing of the explorations with X-rays, consequence of significant development of the engineering together with evolved computacionals methodologies has allowed to reach to the great anatomical majority of locus where it seats the disease. The consequence immediate has been the increase of the exhibition of the patients to ionizing radiations. Different organizations, worried about the health publish, including with it to important societies of Radiology and also to tie international organizations directly related to the governments like the WHO and the OPS. They have emphasized the necessity to generateregulatory conducts destined to introduce the basic rules of the good medical practice. In our country a situation of smaller development in this particular area still persists. Contingencies experienced by general doctors in his professional practice in small town are described. Some situations derived from the use of conventional radiological procedures like mammography and axial computed tomography are presented commenting aspects that do necessary to prevent the doses that receive the patients in order to avoid the expression of stochasticor deterministic effects with high doses of radiation applied with medical intentions. General aspects of radiological procedures related to practices in pediatric patient emphasizing the conditions of increased risk for iatrogenic effects of radiation, particularly in those premature or new borns.

Estudio comparativo de la angioplastia coronaria en pacientes con diabetes: resultados clínicos y angiográficos inmediatos y evolución clínica en el primer año / Comparative study of coronary angioplasty in diabetic patients: clinical and angiographic results and clinical evolution at 1 year of follow up

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 percent in diabetics and 91.8 percent in non diabetics. Hospital mortality was 1.3 pecent in diabetics and 0.7 percent in non diabetics. Major complications occurred in 3.8 percent of diabetics and 3.2 percent in non diabetics. One year survival was 95.9 percent for diabetics and 98 percent 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 percent in diabetics and 8.3 percent in non diabetics. Event-free survival was 95.6 percent in diabetics and 89.2 percent in non diabetics. Conclusions: Results of angioplasty were similar in diabetic and non diabetic patients in terms of hospital outcome and late follow-up

Infarto agudo del miocardio por oclusión total del tronco común de arteria coronaria izquierda tratado con revascularización percutánea endoluminal: caso clínico / Acute myocardial infarction caused by total occlusion of the left main coronary artery treated with percutaneous endoluminal revascularization: report of case

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

Radiación ionizante secundaria generada en equipos de cineangiografía coronaria digital y analógica: influencia de los sistemas externos de protección radiológica / Secondary ionizing radiation generated by analog and digital coronary cineangiographic equipment: influence of external protection devices

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 ñ 337 and 364 ñ 222 µGray/h respectively (p<0.001). During fluoroscopy and with leaded protection generated radiation for groups 1 and 2 was 612 ñ 947 and 70 ñ 61 µGray/h respectively (p<0.001). For ALO projection, generated radiation for groups 1 and 2 was 105 ñ 47 and 71 ñ 192 µGray/h respectively (p<0.001). During filming the radiation for ALO projection for groups 1 and 2 was 7252 ñ 9569 and 1671 ñ 2038 µGray/h respectively (p = 0.03). Out of the protection zone, registered radiation during fluoroscopy for groups 1 and 2 was 2800 ñ 1741 and 1318 ñ 954 µGray/h respectively (p < 0.001); during filming, the figures were 15500 ñ 5840 and 18961 ñ 10599 µGray/h respectively (NS). Conclusions: Digital radiological equipment has a lower level of ionizing radiation emission than the analog equipment

Angioplastía en infarto agudo de miocardio: resultado inicial y seguimiento alejado / Angioplasty in acute myocardial infarction: early and late results

Background: The usefulness of angioplasty in the first hours of an acute myocardial infarction is widely demonstrated. However, its long term effects are less well known. Aim: To report the effects of coronary angioplasty on early and late outcome of patients with acute myocardial infarction. Patients and methods: A non-randomized, consecutive and retrospective analysis of the hospital and late outcome of 70 patients, aged 35 to 85 years, subjected to coronary angioplasty during an acute myocardial infarction. Patients were followed during 12 to 60 months. Results: Angioplasty was performed 5.3 ñ 5 hours after the initial symptoms. Anterior descendent artery was occluded in 63 percent of patients with a 99.5 percent luminal occlusion and TIMI 0-1 anterograde flow. An angiographic success was achieved in 83 percent of procedures with a residual stenosis of 32.3 percent. Recurrent ischemia was observed in 6 percent of patients, that were treated with a new revascularization procedure. Thirteen percent of patients died, all due to cardiogenic shock. Severe ventricular failure and failure of revascularization influenced mortality. During the first year of follow up there was a 3.3 percent mortality and 3.3 percent of patients required a new revascularization procedure. Eighty percent of patients were asymptomatic and event-free. Conclusion: Angioplasty was a useful therapeutic procedure in this group of patients

Impacto de la radiación secundaria en el operador durante la arteriografía coronaria selectiva / Secondary irradiation of operators during coronary arteriography

Background: The activity over cellular genetic pattern of ionizing radiation can produce stochastic and unspecific damages. Interventional cardiology operators have increasing exposure times to ionizing radiation and there is no information about the real protection conferred by simple radiological protection devices. Aim: To assess the magnitude of secondary ionizing radiation exposure of operators during conventional coronary arteriography, evaluating the radiation exposure during different beam projections and the usefulness of leaded aprons. Material and methods: Ionizing radiation received by operators during coronary arteriography was measured using a Geiger-Müller Victoreen model 490 counter. The device was placed in the ventral region, covered by the leaded apron and in the unprotected dorsal region. Radiation was measured in right and left projections during fluoroscopy and shooting. Results: In right projection, the intensity of ionizing radiation in ventral and dorsal regions was 1.24 ñ 1.1 and 2.9 ñ 4 mR/h respectively (p= 0.08). In left projection, the figures were 2.95 ñ 3 and 7.86 ñ 7.2 mR/h respectively (p= 0.001). During shooting in left projection the radiation exposure in ventral and dorsal regions was 9.66 ñ 6.7 and 32.8 ñ 27 mR/h respectively (p< 0.001). During shooting in right projection that figures were 10.1 ñ 16 and 20.7 ñ 39.8 mR/h respectively (p= 0.09). No correlation between radiation exposure and patients surface area was observed. Conclusions: Secondary radiation received by operators is higher during shooting and in left projections. Leaded apron confers a partial protection for ventral region, and great fluctuations in the magnitude of radiation exposure were recorded. Unprotected dorsal region receives a greater amount of radiation in left projections