Seguimiento clínico en pacientes con buena capacidad metabólica en la prueba de esfuerzo con SPECT miocárdico / Follow-up of patients with good exercise capacity in stress test with myocardial single-photon emission computed tomography (SPECT)

Background: The evaluation of coronary artery disease (CAD) can be performed with stress test and myocardial SPECT tomography. Aim: To assess the predictive value of myocardial SPECT using stress test for cardiovascular events in patients with good exercise capacity. Material and Methods: We included 102 males aged 56 ± 10 years and 19 females aged 52 ± 10 years, all able to achieve 10 METs and ≥ 85% of the theoretical maximum heart rate and at least 8 min in their stress test with gated 99mTc-sestamibi SPECT. Eighty two percent of patients were followed clinically for 33 ± 17 months. Results: Sixty seven percent of patients were studied for CAD screening and the rest for known disease assessment. Treadmill stress test was negative in 75.4%; 37% of patients with moderate to severe Duke Score presented ischemia. Normal myocardial perfusion SPECT was observed in 70.2%. Reversible defects appeared in 24.8% of cases, which were of moderate or severe degree (> 10% left ventricular extension) in 56.6%. Only seven cases had coronary events after the SPECT. Two major (myocardial infarction and emergency coronary revascularization) and 5 minor events (elective revascularization) ere observed in the follow-up. In a multivariate analysis, SPECT ischemia was the only statistically significant parameter that increased the probability of having a major or minor event. Conclusions: Nearly a quarter of our patients with good exercise capacity demonstrated reversible defects in their myocardial perfusion SPECT. In the intermediate-term follow-up, a low rate of cardiac events was observed, being the isotopic ischemia the only significant predictive parameter.

Perfusión y función ventricular en SPECT cardiaco y coronariografía del mismo día según localización en enfermedad de un vaso / Single-photon emission computed tomography for the assessment of ventricular perfusion and function

Single-photon emission computed tomography (SPECT) can be used as a non-invasive tool for the assessment of coronary perfusion. Aim: To assess ventricular perfusion and function by SPECT in patients with single vessel coronary artery disease. Material and Methods: Among patients with indications for a coronary artery angiography, those with significant lesions in one vessel, were selected for the study. Within 24 hours, cardiac SPECT examinations on basal conditions and after high doses of dipyridamole, were performed. SPECT data from 38 patients with a low probability of coronary artery disease was used for comparisons. Results: Ten patients aged 61 ± 8 years (seven men) were studied. Visual analysis of SPECT revealed signs suggestive of ischemia in eight patients. The remaining two patients did not have perfusion disturbances. SPECT detected eight of ten abnormal vessels reported in the coronary artery angiography. There were two false negative results Summed stress, summed rest and summed difference scores were 9.78 ± 6.51, 3.22 ± 5.07 and 6.33 ± 4.97, respectively. The ejection fractions under stress and at rest were 53 ± 11.7% and 61 ± 15.7% respectively (p < 0.01). The figures for the control group were 69.1 ± 13.5% and 75.2 ± 12.04% respectively (significantly different from patients). Two patients had a summed motion score above 14.9. Likewise, two patients had a summed thickening score above 10.9. Conclusions: SPECT detected 80% of coronary lesions found during coronary artery angiography. Visual analysis of perfusion is highly reliable for diagnosis. Quantitative parameters must be considered only as reference parameters.

Seguimiento a cinco años en pacientes diabéticos sin síntomas cardíacos estudiados con perfusión miocárdica / Myocardial perfusion studies in asymptomatic patients with diabetes mellitus are controversial

Antecedentes: El rendimiento del estudio de perfusión miocárdica en pacientes con Diabetes Mellitus (DM) y sin síntomas coronarios es controvertido. Objetivo: Efectuar un seguimiento a 5 años para eventos cardíacos mayores en DM asintomáticos estudiados con SPECT miocárdico en esfuerzo. Método: Se estudiaron 40 pacientes asintomáticos coronarios, con DM conocida por >5 años, >45 años de edad, con >2 factores de riesgo cardiovascular (FRCV) y electrocardiograma basal normal o con alteraciones inespecíficas. Todos efectuaron una prueba de esfuerzo (PE) adecuada y se estudiaron con Sestamibi-Tc99m repetido en 32 casos al 3° año. Además, se evaluó a 36 controles no diabéticos con >2 FRCV. El seguimiento fue de 64+/-11 meses. Resultados: En el grupo DM, 48 por ciento tenía Hba1c>7.5 por ciento; en ellos el SPECT mostró isquemia silente (IS) en 30 por ciento y la PE en 18 por ciento del total. No hubo variaciones significativas en SPECT al 3° año. Hubo una muerte no cardíaca en el 2° año; en el 4° año, se produjo una muerte por infarto agudo de miocardio, con mínima isquemia septal y otra asociada a miocardiopatía e insuficiencia cardíaca, con defecto de predominio fijo, ambos con PE negativa. En el grupo control, el 11 por ciento tuvo SPECT anormal y 8 por ciento PE positiva; hubo una muerte no cardíaca. El Odds Ratio para isquemia fue 3.42 [IC=0.99-11.85] entre DM vs controles y el Hazard Ratio para eventos cardíacos 6.75 [IC=0.40-108.2]. Conclusiones: En DM asintomáticos coronarios el riesgo de IS en SPECT fue mayor que en controles sin DM y con FRCV. Los eventos cardiacos mayores fueron más frecuentes, aunque no significativamente, en DM que en controles. Ello deberá reevaluarse conocidos los resultados del estudio multicéntrico.

The clinical value of myocardial perfusion studies in cardiac asymptomatic patients with Diabetes Mellitus (DM) is controversial. Aim: To conduct a 5 year follow-up study to detect major adverse cardiac events in asymptomatic DM patients using exercise stress and SPECT myocardial perfusion imaging. Methods: 40 patients with known DM for at least 5 years and without evidence of coronary artery disease, older than 45 years of age with >2 cardiovascular risk factors (CVRF) and either normal or minimally altered ECG underwent adequate exercise testing (ET) and 99mTc Sestamibi, repeated 3 years later in 32 cases. We also assessed 36 non-diabetic control patients, with >2 CVRF. Mean follow up was 64+/-11 months. Results: 48 percent of DM patients had HbA1c >7.5 percent; in them, the SPECT showed silent ischemia (SI) in 30 percent and positive ET in 18 percent. There were no significant variations in SPECT at 3 years. There was 1 non-cardiac death in the 2nd year and 2 deaths, one from acute myocardial infarction associated to minimal septal ischemia and another associated with cardiomyopathy and heart failure, with a fixed perfusion defect. Both patients had a negative ET. In the control group, 11 percent had abnormal SPECT and 8 percent positive ET and no cardiac deaths were observed. The Odds ratio for ischemia between DM and controls was 3.42 [CI=0.99-11.85 ] and the Hazard Ratio for cardiac events was 6.746 [CI=0.4205-108.2]. Conclusions: In asymptomatic coronary DM patients, the presence of SPECT ischemia detect was higher than in non-DM controls with CVRF. The incidence of major cardiac events was higher, although not significantly, in DM than control patients. This finding should be re-evaluated in the multicenter study.

Utilidad del estudio PET con FDG en la evaluación de sarcomas de diverso origen y de tumores no sarcoma-no epiteliales / Positron emission tomography with fluorine-deoxyglucose in sarcomas and non-sarcoma non-epithelial tumors

Background: The usefulness of positron emission tomography (PET) with fluorine-deoxyglucose (FDG) in sarcomas and non-sarcoma non-epithelial (NSNE) tumors is not clearly defined. Aim: To report a Chilean experience with NSNE tumors evaluated using PET with FDG. Material and Methods: Retrospective review of the database of a PET laboratory. Demographic data, indications and metabolic findings were compared with conventional imaging in 88 adults and children with diverse bone and soft tissue sarcomas as well as 24 gastrointestinal stromal tumors (GIST), 6 pleural malignant mesotheliomas in adults, and 9 medulloblastomas in children. Results: FDG showed good concordance with conventional imaging in NSNE tumors. It was helpful for staging, restaging, follow-up after treatment and for the detection of new not previously suspected lesions. Conclusions: PET with FDG could have a prognostic role and help in patient management, mainly in musculos-keletal and high grade or less differentiated sarcomas. In GIST, it was a good tool for immunotherapy control.

Daño vascular asociado a uso de cocaína: Caso clínico / Cocaine-induced vascular damage: Report of one case

Background: Cocaine abuse is associated with an increased risk of cardiac and cerebrovascular events, such as myocardial infarction, sudden cardiac death, and ischemic stroke. The underlying mechanisms leading to these complications are not fully understood although intravascular thrombus formation and accelerated atherosclerosis are prominent findings. We report a 39-year-old male addicted to cocaine, who presented with three consecutive ischemic events characterized by an acute myocardial infarction and two ischemic strokes complicated by cardiac failure and severe neurological sequelae. The pathophysiology of cocaine-induce vascular damage and the management of the ischemic complications are discussed.

Cardiología nuclear: actualización en diagnóstico y evaluación de enfermedad coronaria / Nuclear cardiology: updates in diagnosis and evaluation of coronary disease

En esta revisión se entrega una visión general de la situación de la cardiología nuclear en diagnóstico y evaluación de la enfermedad coronaria de una manera global y relativamente simple. Se revisa el rendimiento, las indicaciones y la correlación con otras técnicas disponibles.

This review provides an overview of the status of nuclear cardiology regarding diagnosis and evaluation of coronary artery disease in a comprehensive and relatively simple way. Overall accuracy, indications and the correlation with other available techniques are presented.

Valor del índice de excentricidad del ventrículo izquierdo con tomografía spect de perfusión miocárdica en diversas condiciones / Value of eccentricity index of left ventricle with miocardial SPECT perfusion tomography in several conditions

Introducción: El índice de excentricidad (IE) obtenido con SPECT miocárdico permite evaluación de esfericidad ventricular izquierda en remodelación patológica. Objetivo: conocer IE en adultos con diversas condiciones cardíacas. Método: Grupo I: Controles (n=44) con >2 factores de riesgo cardiovascular exceptuando Diabetes Mellitus (DM); Grupo II: DM 2 (n=41). Ambos grupos asintomáticos sin enfermedad coronaria conocida. Grupo III: Con alteración de motilidad segmentaria y/o infarto de miocardio (n=64). Grupo IV: Dilatados (n=21) con alteraciones de motilidad difusa o miocardiopatías. Se utilizó Sestamibi-Tc99m y procesamiento QGS. (IE esfera valor

Background: The Eccentricity Index (EI) obtained with myocardial SPECT allows adequate assessment of left ventricular shape in pathological myocardial remodeling. Aim: To compare EIs in adults with different cardiac conditions. Methods: 170 patients were studied. Group I (n=44) were control subjects with >2 cardiovascular risk factors not including Diabetes Mellitus (DM); Group II (n=41) had type II DM. Patients in both groups were asymptomatic without known coronary artery disease or wall motion abnormalities. Group III (n=64) had seg-mental wall motion abnormality and/or myocardial infarction; Group IV (n=21) included patients with dilated ventricles and diffuse abnormal wall motion. We used gated 99mTc Sestamibi SPECT and QGS processing (EI sphere