[Considerations on the new Chilean law about rights and duties of patients]. / Reflexiones en torno a la ley N° 20.584 y sus implicancias para la investigación biomédica en Chile.

After years of discussion by the Chilean legislature, the Law Nº 20.584, which regulates health care related rights and duties of people, entered into force in Chile in October 2012. This bill represents an important step in the recognition and protection of health care related rights, welfare, dignity and duties of persons. It also intends to protect potential participants in clinical research. However such protective measures include explicit prohibitions such as the review of clinical records or the inclusion of people with mental or psychological handicaps as research participants. We herein discuss the implications of this law in medical research.

Reflexiones en torno a la ley N° 20.584 y sus implicancias para la investigación biomédica en Chile / Considerations on the new Chilean law about rights and duties of patients

After years of discussion by the Chilean legislature, the Law Nº 20.584, which regulates health care related rights and duties of people, entered into force in Chile in October 2012. This bill represents an important step in the recognition and protection of health care related rights, welfare, dignity and duties of persons. It also intends to protect potential participants in clinical research. However such protective measures include explicit prohibitions such as the review of clinical records or the inclusion of people with mental or psychological handicaps as research participants. We herein discuss the implications of this law in medical research.

¿Cuál es la utilidad del test de inhibidores de la bomba de protones en el dolor torácico no cardíaco? / What is the utility of proton pump inhibitor testing in non-cardiac chest pain?

FUNDAMENTOS Y OBJETIVO: El dolor torácico no cardíaco (DTNC) representa frecuentemente un problema diagnóstico y terapéutico complejo. Dado que la enfermedad por reflujo gastroesofágico (ERGE) es la causa más frecuente de DTNC, se ha propuesto la estrategia clínica de tratar con doble dosis de inhibidores de la bomba de protones (IBP) a todos los pacientes con DTNC, y reservar el estudio funcional únicamente para los pacientes que no respondan al tratamiento antisecretor. El objetivo del presente estudio es aportar evidencias de la utilidad clínica del test con doble dosis de pantoprazol en pacientes con DTNC. Pacientes y métodos: Estudio de rendimiento diagnóstico con diseño de cohortes en pacientes con DTNC remitidos por el Servicio de Cardiología. A todos los pacientes se les realizó endoscopia digestiva alta, manometría esofágica y pHmetría esofágica de 24 h antes del test de IBP con pantoprazol 40 mg cada 12 h durante un mes. Antes y después del tratamiento se evaluó la severidad (intensidad y frecuencia) del dolor torácico, la calidad de vida y la ansiedad y depresión mediante cuestionarios. El diagnóstico de ERGE se basó en la pHmetría de 24 h y se estableció por el criterio del porcentaje total de tiempo con un pH < 4 superior al 4,2% Se consideró respondedor al test de IBP si la mejoría del dolor torácico después de un mes de tratamiento con IBP fue > 50% respecto a la puntuación basal. Resultados: Se incluyeron 30 pacientes consecutivos (17 hombres/13 mujeres) con una media de edad de 49 años. Presentaban ERGE 20 de los 30 pacientes con DTNC (67%; IC 95%: 47-83%). Fueron respondedores al tratamiento con IBP 13 de los 30 (43%) pacientes con DTNC: 11 de los 20 (55%) pacientes del grupo ERGE-positivo y 2 de los 10 (20%) del grupo ERGE-negativo. La sensibilidad, la especificidad, el valor predictivo positivo, el valor predictivo negativo y la precisión del test de IBP fue del 55, del 80, del 85, del 47 y del 63%, respectivamente. El grupo ERGE-positivo con respecto al grupo ERGE-negativo presentó una reducción significativa del dolor torácico postratamiento con pantoprazol (p = 0,003) y una mejoría en la ansiedad y depresión que no alcanzó la significación estadística. La calidad de vida no se vio afectada. Conclusiones: En el DTNC, el test de IBP con pantoprazol tiene una baja sensibilidad para el diagnóstico de la ERGE y cuestiona reservar el estudio funcional únicamente para los pacientes que no respondan al tratamiento antisecretor. El estudio funcional permitiría un diagnóstico inicial más preciso y ofrecer un tratamiento dirigido más adecuado a todos los pacientes con DTNC

BACKGROUND AND AIMS: Noncardiac chest pain (NCCP) often represents a diagnostic and therapeutic challenge. Given that gastroesophageal reflux disease (GERD) is the most common cause of NCCP, initial treatment with proton-pump inhibitors (PPI) has been proposed for all patients (PPItesting), reserving esophageal function testing solely for non-responders. The aim of the present study was to provide evidence on the clinical utility of PPI testing with high-dose pantoprazole in patients with NCCP.PATIENTS AND METHODS: We carried out a study of diagnostic performance with a cohort design in patients with NCCP, who had been assessed by the Cardiology Service. All patients underwent upper endoscopy, esophageal manometry, and 24h esophageal pH monitoring before PPI testing with pantoprazole 40mg every 12h for 1month. Before and after treatment, we assessed the severity (intensity and frequency) of chest pain, quality of life, and anxiety and depression by means of specific questionnaires. The diagnosis of GERD was based on a pathological finding of esophageal pH monitoring. A positive response to PPI testing was defined as an improvement in chest pain >50% compared with the baseline score after 1month of PPI therapy. RESULTS: We included 30 consecutive patients (17men/13women) with a mean age of 49years. Of these 30 patients, 20 with NCCP had GERD (67%, 95%CI: 47%-83%). A positive response to PPI therapy was observed in 13 of the 30 (43%) patients with NCCP: 11 of the 20 (55%) patients in the GERD-positive group and 2 of the 10 (20%) in the GERD-negative group. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of PPI testing was 55%, 80%, 85%, 47% and 63%, respectively. A significant reduction in chest pain after pantoprazole therapy (P=.003) and a slight non significant improvement in anxiety and depression was achieved in the GERD-positive group as compared to the GERD-negative group. Conclusions: In NCCP, PPI testing with pantoprazole has a low sensitivity for the diagnosis of GERD, placing in doubt the strategy of reserving functional study to non-responders to antisecretory therapy. Esophageal function testing and accurate diagnosis would allow appropriate targeted therapy for all patients with NCCP

[What is the utility of proton pump inhibitor testing in non-cardiac chest pain?]. / ¿Cuál es la utilidad del test de inhibidores de la bomba de protones en el dolor torácico no cardíaco?

BACKGROUND AND AIMS: Noncardiac chest pain (NCCP) often represents a diagnostic and therapeutic challenge. Given that gastroesophageal reflux disease (GERD) is the most common cause of NCCP, initial treatment with proton-pump inhibitors (PPI) has been proposed for all patients (PPI testing), reserving esophageal function testing solely for non-responders. The aim of the present study was to provide evidence on the clinical utility of PPI testing with high-dose pantoprazole in patients with NCCP. PATIENTS AND METHODS: We carried out a study of diagnostic performance with a cohort design in patients with NCCP, who had been assessed by the Cardiology Service. All patients underwent upper endoscopy, esophageal manometry, and 24h esophageal pH monitoring before PPI testing with pantoprazole 40 mg every 12h for 1 month. Before and after treatment, we assessed the severity (intensity and frequency) of chest pain, quality of life, and anxiety and depression by means of specific questionnaires. The diagnosis of GERD was based on a pathological finding of esophageal pH monitoring. A positive response to PPI testing was defined as an improvement in chest pain >50% compared with the baseline score after 1 month of PPI therapy. RESULTS: We included 30 consecutive patients (17 men/13 women) with a mean age of 49 years. Of these 30 patients, 20 with NCCP had GERD (67%, 95%CI: 47%-83%). A positive response to PPI therapy was observed in 13 of the 30 (43%) patients with NCCP: 11 of the 20 (55%) patients in the GERD-positive group and 2 of the 10 (20%) in the GERD-negative group. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of PPI testing was 55%, 80%, 85%, 47% and 63%, respectively. A significant reduction in chest pain after pantoprazole therapy (P=.003) and a slight non significant improvement in anxiety and depression was achieved in the GERD-positive group as compared to the GERD-negative group. CONCLUSIONS: In NCCP, PPI testing with pantoprazole has a low sensitivity for the diagnosis of GERD, placing in doubt the strategy of reserving functional study to non-responders to antisecretory therapy. Esophageal function testing and accurate diagnosis would allow appropriate targeted therapy for all patients with NCCP.

Prueba de esfuerzo submáxima y atropina en la SPECT de perfusión miocárdica / Submaximal exercise testing plus atropine in myocardial perfusion SPECT

Introducción y objetivos. El objetivo de este estudio es evaluar la eficacia diagnóstica de la tomografía computarizada por emisión monofotónica (SPECT) de perfusión miocárdica con la administración de atropina intravenosa al final de una prueba de esfuerzo con insuficiente taquicardización. Métodos. A 172 pacientes que, a pesar de realizar una prueba ergométrica limitada por síntomas, no alcanzaron un 80% de taquicardización, sin presentar angina ni descenso del segmento ST >= 1 mm, se les administró 1 mg de atropina intravenosa al final del esfuerzo. A 23 de estos pacientes con criterios de isquemia gammagráfica en la SPECT con atropina, y en el curso de 1 semana, se les practicó una segunda SPECT sin la administración de atropina con la finalidad de comparar la presencia y la gravedad de la isquemia gammagráfica entre los dos estudios (suma puntuación diferencial [SPD]). Resultados. De los 172 pacientes, 75 (43,6%) presentaron angina (n = 56) o descenso del segmento ST (n = 30) con la administración de atropina. De los 23 pacientes en los que se hicieron ambas pruebas, 8 (35%) tuvieron isquemia (SPD >= 2) únicamente en la prueba con atropina. Además, la SPD fue significativamente superior en las imágenes de SPECT con atropina (5,6 ± 4,5 frente a 3,1 ± 2,8; p = 0,0001). Conclusiones. La administración de atropina al final de una prueba de esfuerzo insuficiente permite obtener criterios gammagráficos de isquemia en una tercera parte de los casos en que no se habría obtenido sin la administración del fármaco (AU)

Introduction and objectives. The aim of this study was to determine the diagnostic value of using myocardial perfusion single-photon emission computed tomography (SPECT) with intravenous atropine administration at the end of submaximal exercise testing. Methods. One milligram of atropine was administered intravenously at the end of exercise testing to 172 patients who underwent a symptom-limited ergometric test but did not reach 80% of their peak heart rate without exhibiting angina or an ST-segment depression >=1 mm. Within 1 week, 23 patients who satisfied scintigraphic criteria for ischemia during SPECT with atropine underwent SPECT for a second time without atropine administration with the aim of comparing the presence and severity of scintigraphic ischemia between the two studies (SDS: summed difference score). Results. Of the 172 patients, 75 (43.6%) developed angina (n=56) or ST-segment depression (n=30) during atropine administration. Eight of the 23 patients (35%) who underwent two tests exhibited scintigraphic ischemia (SDS >=2) on only the test with atropine. Furthermore, the SDS was significantly greater on SPECT imaging with atropine (5.6±4.5 vs. 3.1±2.8; P=.0001). Conclusions. One-third of patients who met scintigraphic criteria for ischemia at the end of submaximal exercise testing and after atropine administration would not have met those criteria without administration of the drug (AU)

Submaximal exercise testing plus atropine in myocardial perfusion SPECT.

INTRODUCTION AND OBJECTIVES: The aim of this study was to determine the diagnostic value of using myocardial perfusion single-photon emission computed tomography (SPECT) with intravenous atropine administration at the end of submaximal exercise testing. METHODS: One milligram of atropine was administered intravenously at the end of exercise testing to 172 patients who underwent a symptom-limited ergometric test but did not reach 80% of their peak heart rate without exhibiting angina or an ST-segment depression ≥1 mm. Within 1 week, 23 patients who satisfied scintigraphic criteria for ischemia during SPECT with atropine underwent SPECT for a second time without atropine administration with the aim of comparing the presence and severity of scintigraphic ischemia between the two studies (SDS: summed difference score). RESULTS: Of the 172 patients, 75 (43.6%) developed angina (n=56) or ST-segment depression (n=30) during atropine administration. Eight of the 23 patients (35%) who underwent two tests exhibited scintigraphic ischemia (SDS ≥2) on only the test with atropine. Furthermore, the SDS was significantly greater on SPECT imaging with atropine (5.6 ± 4.5 vs. 3.1 ± 2.8; P=.0001). CONCLUSIONS: One-third of patients who met scintigraphic criteria for ischemia at the end of submaximal exercise testing and after atropine administration would not have met those criteria without administration of the drug.

Normal myocardial perfusion SPECT database for the Spanish population.

INTRODUCTION AND OBJECTIVES: The aims of this study were to create a Spanish database of normal myocardial perfusion SPECT (single-photon emission computed tomography) data, termed the normal Spanish database, and to compare it with a database of normal data from the North American population. METHODS: We selected 104 healthy volunteers (45 female, mean age 42+/-14 years) who underwent SPECT during stress and at rest. The findings were analyzed using the 4DM-SPECT commercial software package. The resulting normal Spanish database for males and females was compared with the North American population database (from 70 men and 60 women) provided with the 4DM-SPECT software. RESULTS: In the Spanish database, the highest percentage uptake during both stress and rest was observed in medial-lateral region and the lowest, in the basal-septal region. The percentage uptake in the anterior-medial region was significantly lower in women than men, while uptake in the inferior, medial-septal and apical regions was lower in men than women. Data values in the Spanish database were significantly lower for the majority of heart regions than those in the database with the 4DM-SPECT software. CONCLUSIONS: A Spanish database of normal myocardial perfusion SPECT data was created and included separate data for men and women. Significant differences were observed between this database and a commercial North American database that is commonly used in semiquantitative studies.

Base de datos de normalidad de la SPECT de perfusión miocárdica en la población española / Normal myocardial perfusion SPECT database for the spanish population

Introducción y objetivos. El objetivo de este estudio ha sido crear una base de datos española (BDE) de normalidad de la SPECT ( single photon emission computed tomography) de perfusión miocárdica y compararla con una base de datos de normalidad de población norteamericana. Métodos. Se seleccionó a 104 voluntarios sanos (45 mujeres, media de edad, 42 ± 14 años) a los que se practicó una SPECT de estrés y reposo, procesándose los estudios en el programa comercial 4DM-SPECT. La BDE de normalidad generada para varones y mujeres se comparó con la base de datos de la población norteamericana (70 varones y 60 mujeres) que proporciona el programa 4DM-SPECT. Resultados. En la BDE el mayor porcentaje de captación correspondió a la región lateral-medial, y el menor, a la región septal-basal, tanto en estrés como en reposo. En las mujeres el porcentaje de captación de la región anterior-medial fue significativamente más bajo que en los varones, mientras que en éstos se observó una menor captación en las regiones inferiores, septal medial y apical con respecto a las mujeres. Los valores de la BDE fueron significativamente más bajos que los de la 4DMSPECT en la mayoría de las regiones. Conclusiones. Se ha creado una base de datos de normalidad española para mujeres y varones por separado de la SPECT de perfusión miocárdica, y se ha observado que hay diferencias significativas con una base de datos comercial de origen norteamericano que suele utilizarse en estudios semicuantitativos (AU)

Introduction and objectives. The aims of this study were to create a Spanish database of normal myocardial perfusion SPECT (single-photon emission computed tomography) data, termed the normal Spanish database, and to compare it with a database of normal data from the North American population. Methods. We selected 104 healthy volunteers (45 female, mean age 42±14 years) who underwent SPECT during stress and at rest. The findings were analyzed using the 4DM-SPECT commercial software package. The resulting normal Spanish database for males and females was compared with the North American population database (from 70 men and 60 women) provided with the 4DM-SPECT software. Results. In the Spanish database, the highest percentage uptake during both stress and rest was observed in medial-lateral region and the lowest, in the basal-septal region. The percentage uptake in the anterior-medial region was significantly lower in women than men, while uptake in the inferior, medial-septal and apical regions was lower in men than women. Data values in the Spanish database were significantly lower for the majority of heart regions than those in the database with the 4DM-SPECT software. Conclusions. A Spanish database of normal myocardial perfusion SPECT data was created and included separate data for men and women. Significant differences were observed between this database and a commercial North American database that is commonly used in semiquantitative studies (AU)