Alfredo Ramírez N

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 (Rev Med Chile 2002; 130: 243-50).

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)

La clasificación de lesiones coronarias de la Society for Cardiac Angiography and Interventions predice mejor el éxito de la angioplastia coronaria que la del American College of Cardiology/American Heart Association

Background. The classification of coronary lesion complexity, using the American College of Cardiology/American Heart Association (ACC/AHA) is a predictor of balloon angioplasty success. Stents have improved results even in complex lesions. Aim. To compare the ACC/ AHA and the new Society for Cardiac Angiography (SCAeI) coronary lesion scores as predictors of angioplasty success. Patients and Methods. Ali consecutive angioplasty procedures (n=346, 456 lesions, 47% stents) were prospectively analized from August 1996 to March 1999. Coronary lesions were classified using the ACC/AHA and SCA&I scores. Angiographic success was assesed and its multivariate predictors determined with logistic regression analysis. Results. According to the ACC/AHA score, angiographic success was 97, 92.7, 93.3, and 82.3% in A, Bl, B2 and C lesions respectively (p=0.013). There only were significant differences in success between C and A, Bl or B2 lesions. According to the SCAeI score success was achieved in 97.3, 97.9, 75.8 and 33.3% in nonCP, CP, nonCO and CO lesions respectively (P<0.001). With the SCAeI score statistically significant differences in angiographic success were found for all lesion score comparisons, except between nonCP and CP lesions. No other variables had predictive value for angiographic success. Conclusions. Coronary angioplasty angiographic success is better predicted by the new SCAel lesion score than with the ACC/AHA lesion clasification in a group of patiens with frequent use of stents. (Rev Med Chile 2001,129: 605-10)

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).

Hidatidosis cardiaca: caso clínico

Background: Hydatidosis is an endemic zoonosis in Chile. We report a 48-year-old former slaughterman, with a previous history of pulmonary hydatidosis, who presented a stroke without associated cardiovascular symptoms. An echocardiogram revealed a tumor mass with cystic features in the left ventricle. The patient was operated and the cyst was successfully excised. During the follow up, the patient remains asymptomatic.

Captación miocárdica de pirofosfato en amiloidosis cardíaca: Caso clínico

We report a previously healthy 73 years old woman, who was hospitalised with increasing dyspnea and signs of congestive heart failure. Echocardiography showed a normal left ventricular cavity with increased echogenicity of its walls and severe pulmonary hypertension. A lung ventilation/perfusion scintigraphy concluded that there was a low probability for pulmonary embolism. Coronary angiography was normal. A restrictive cardiomyopathy due to amyloid deposits was suspected. Myocardial pyrophosphate scintigraphy showed intense pyrophosphate uptake in the left ventricle wall. An abdominal fat tissue biopsy was positive for amyloid deposits (Rev Med Chile 2002; 130: 315-8)

Tomografía SPECT con F18-fluorodeoxiglucosa en infarto reciente del miocardio.: Caso clínico

We report a 50-year-old woman with a recent myocardial infarction in whom a myocardial perfusion single photon emission computed tomography (SPECT) with Thallium201201Tl SPECT to study viability and a FDG-SPECT with a dual head high-energy collimator camera were done. Images, acquired 45 min after injection, were analyzed visually. In anterior and medial apical sectors, discordance between flux and metabolism, considered a classical mismatch, was observed. Echocardiographic hypokinesia disappeared three month after revascularization (Rev Med Chile 2000; 128: 1019-23).

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).