Abstract Background: There have been scattered reports indicating the possibility that applied magnetic fields can lower human blood viscosity, which has been considered as encouraging for decreasing blood pressure as a result of greater fluidity. Additional motivation comes from partial studies in animals showing some response of vascular variables to magnetic fields. Recently developed FeNbB magnets enable topical application to appropriate sites of much stronger permanent magnetic fields than previously available. Objectives: To establish whether powerful magnetic fields permanently applied along important arteries of the human body can lower blood pressure and, if so, to what extent. Methods: Ambulatory blood pressure tests were performed on 70 patients, half of them wearing real magnets, while the other 35 patients were wearing a similar placebo. Magnets or placebo devices were assigned at random. Each patient underwent two consecutive ambulatory 24-hour blood pressure (BP) tests; the first without a device and the second one with a device. Results: Results were compiled and analyzed only after the last measurement was completed. Individual responses, average values, standard deviations, information content, and Student's t test showed that no difference was found between measurements in either group. Conclusion: Permanent strong magnetic fields applied along the main arteries of the human body do not alter blood pressure. This was observed both in statistical terms and in individuals as well.

Background: Atrial fibrillation (AF) is the most common cardiac arrhythmia and is associated with high rates of death, ischemic stroke and systemic embolism (SE). There is scarce information about clinical characteristics and use of anti-thrombotic therapies in Chilean patients with non-valvular AF. Aim: To describe the characteristics and 1-year outcomes of patients with recently diagnosed AF recruited in Chile into the prospective global GARFIELD-AF registry. Material and Methods: Between 2011-2016, we prospectively registered information of 971 patients recruited at 15 centers, 85% of them from the public system and 15% from the private sector. Demographics, clinical characteristics and use of antithrombotic therapies were recorded for all patients. Adverse clinical outcomes were analyzed in 711 patients with 1-year follow-up. Results: The mean age was 71.5 years (66-79), 50% were men. Mean CHAD2S2 Vasc and HAS BLED scores for stroke risk were 3.3 (2.0-4.0) and 1.5 (1.0-2.0) respectively. Oral anticoagulants were prescribed in 82% of patients. Seventy percent received Vitamin K antagonists, 10% novel direct anticoagulants or antiplatelet therapy and only 8% did not receive any antithrombotic therapy. Mean time in optimal therapeutic range (an international normalized ratio of 2 to 3), was achieved in only 40.7% (23.0-54.8) of patients receiving Vitamin K antagonists. One year rates of death, stroke/systemic embolism and bleeding were 4.75 (3.36-6.71), 2.40 (1.47-3.92) and 1.64% (0.91-2.97) per 100 person-years. Ischemic stroke occurred in 1.8% and hemorrhagic stroke in 0.8% of patients at 1-year of follow up. Conclusions: Although the use of vitamin K antagonists at baseline was high, the mean time in optimal therapeutic range was low. Mortality and stroke rates are higher than those reported in other contemporary registries.

Background: Low C-HDL level has been associated to an increased incidence of atrial fibrillation (AF) and cardiovascular mortality. Previously, we have observed that low C-HDL had the same type of association with post operative AF (POAF) and mortality following surgery for coronary artery disease. Aim: to evaluate whether a low C-HDL level is a predictor of POAF and mortality following revascularization surgery in a controlled study. Method: A prospective observational study included 100 consecutive patients undergoing revascularization surgery for stable coronary artery disease (CAD) in sinus rhythm and no prior AF. POAF was defined as AF sustained for more than 5 min or the occurrence of 5 or more episodes of AF extending for more than 5 seconds during the first 5 post operative days. A value <30 mg/dl was considered low C-HDL. Patients were followed for one year. Uni and multivariate analysis were used to identify predictors of POAF and mortality. Results: 31 patients developed POAF. A significant (p=0.017) OR of 5.01 (95% CI 1.3 - 18.8) between low C-HDL and POAF was shown. A similar association linked low serum albumin level to POAF (OR 6.4, C.I. 1.6 - 26). After 14.1 ± 1.7 months of follow-up global mortality was 6%. Low C-HDL turned out to be a significant predictor of mortality (H.R. 11.1, C.I. 1.1 - 38.4, p=0.04). Conclusion: Low C-HDL is an independent predictor of POAF and mortality after coronary artery revascularization surgery.

Introducción: Se ha demostrado que bajos niveles de colesterol HDL (C-HDL) se asocian a una mayor incidencia de fibrilación auricular y de mortalidad global y cardiovascular. En un estudio observacional previo en nuestro centro, encontramos que un bajo nivel de C-HDL se asoció a mayor riesgo de fibrilación auricular postoperatoria (FAPO) en pacientes sometidos a cirugía de revascularización miocárdica (CRM). Objetivo: Evaluar si el bajo nivel de C-HDL se asocia a mayor incidencia de FAPO y mortalidad en un seguimiento a un año en un estudio controlado. Método: Se realizó un estudio observacional prospectivo que incluyó a 100 pacientes consecutivos sometidos a CRM por enfermedad coronaria estable sin antecedentes de FA y que ingresaron a la UCI Cardio-quirúrgica en ritmo sinusal. Se definió FAPO como FA con duración mayor a 5 minutos o 5 episodios de FA mayores a 30 segundos de duración en los primeros 5 días post operatorios. Se consideró bajo nivel de C-HDL a un valor < 30mg/dL. Los pacientes se siguieron por un año. Se utilizó un análisis univariado y multivaria-do para identificar factores predisponentes de FAPO y mortalidad. Resultados: 31 pacientes presentaron FAPO. El análisis multivariado mostró un incremento de FAPO con C-HDL <30mg/dL (OR 5.01, IC95% 1.3-18.8, p=0,017) y con albúmina <3,5 gr/dL (OR 6.42, IC95% 1.58-26.0, p=0,009). En un seguimiento de 14.1±1.7 meses. La mortalidad global fue 6% y un C-HDL <30mg/dL resultó ser un predictor independiente (HR 11.1, IC95% 1.1-38.4, p=0,039). Conclusión: En nuestra serie un C-HDL menor a 30mg/dL es un predictor independiente de FAPO y mortalidad posterior a la CRM.

Introduction: The association between coronary artery (CAD) and dysglicemia is well established. Diabetes (DM) is recognized as one of the most important coronary risk factors, but the association of CAD and metabolic syndrome (MS) is less well defined. Our objective was to evaluate the degree of coronary atherosclerotic disease in relation to the presence of MS and DM . Patients and Method: The data of 413 patients electively studied with coronary angiography over a period of one year was analyzed. Patients were divided into three groups: Patients with DM, patients with MS (without DM) and patients without a metabolic disorder (no DM, no MS). The severity of CAD was measured by the Gensini Score. Results: Mean age was 63,8 ±11,17 years. The prevalence of patients with MS was 38% (n=158), with DM 45% (n=186) and without a metabolic disorder 17% (n=69). The global prevalence of CAD was 52,7%. The prevalence of CAD in the different groups was as follows: Absence of metabolic disease 33.9%, patients with MS 52.2% and patients with DM 62.2% (p< 0.001). Conclusions: This observational study suggests that, compared to subjects without metabolic disease, the prevalence and severity of CAD are higher in patients with MS and even higher in patients with DM

Introducción: La asociación entre cardiopatía coronaria (CC) y estados de disglicemia está bien establecida. Sin embargo, aún cuando la diabetes mellitus (DM) corresponde a uno de los principales factores de riesgo para CC, la asociación con el síndrome metabólico (SM) parece menos clara. Nuestro objetivo fue evaluar el grado de compromiso aterosclerótico del árbol coronario de acuerdo a la existencia de SM y DM. Pacientes y método: Se analizó los datos de 413 pacientes sometidos a coronariografía electiva en el período de un año. Se dividió la muestra en 3 grupos: pacientes diabéticos, pacientes con SM (no diabéticos) y pacientes sin enfermedad metabólica (no SM, no DM). Se consideró como portador de CC a todo paciente con estenosis >50% en cualquier arteria coronaria, la severidad de la enfermedad coronaria fue medida por el Score de Gensini. Se utilizó análisis de varianza (Barlett) con comparación múltiple de Scheffe y prueba no paramétrica de Krus-kal-Wallis en aquellos grupos con varianzas distintas. El protocolo fue aprobado por el Comité Ético Científico del Servicio de Salud Araucanía Sur. Resultados: La edad promedio fue 63.8 ± 11,17 años. La prevalencia de SM fue 38% (n=158), DM 45% (n=186) y no tenían alteraciones metabólicas 17% de los pacientes (n=69). La prevalencia global de enfermedad coronaria fue 52,7%. La prevalencia en los distintos grupos fue 33.9% en aquellos sin enfermedad metabólica, 52.2% en los portadores de SM y 62.2% en los pacientes con DM (p=0.001). En cuanto a la severidad de la CC, el score de Gensini fue 18, 22,04 y 29,6 respectivamente (p=0,04). Conclusiones: Este estudio observacional sugiere que, comparados con sujetos sin enfermedad metabólica tanto la prevalencia de CC, como su severidad son mayores en pacientes con SM aislado y mayores aún en portadores de DM.

Background: Implementation of health programs to reduce cardiovascular risk, are needed for secondary prevention of cardiovascular diseases. Aim: To evalúate achievements of secondary prevention goals, pharmacologic prescription and major cardiovascular events in patients with coronary artery disease. Material and Methods: Patients who had a first event of acute coronary syndrome, angioplasty or revascularization surgery, between January 2008 and June 2010, were contacted for a clinical and laboratory evaluation between June and October 2011. Results: Seven hundred and two medical records were reviewed and 245 eligible patients were identified. Ofthese, we assessed 202 patients aged 64 ± 10 years (70% males). Sixty seven percent had two ormore cardiovascular riskfactors. A goal ofHDL cholesterol level over 40 mg/dL was achieved in 91 % of patients, smoking cessation in 84% and a total cholesterol < 200 mg/dL in 66%. A blood pressure below 130/85 mm Hgwas achieved in 30% of patients, a normal BMI in 19% and LDL cholesterol levels below 70 mg/dL in 18%. At the moment of assessment, 87%> were using aspirin, 78%> statins, 74% angiotensin converting enzyme inhibitors or angiotensin II receptor antagonists and 66%o were using β - blockers. Twenty two percent of patients had a major cardiovascular event during the follow up, which lasted 28 ± 8 months. Conclusions: A low percentage of cardiovascular goals achievement was observed in this sample of patients, with a high prevalence of overweight and obesity. A high percentage quit smoking after their first cardiovascular event. Despite the high percentage of drug prescription, hypertension and dyslipidemia were not fully controlled.

Background: Mortality due to infective endocarditis (IE) in Chile is close to 30%. Aim: To report the experience with patients admitted with the diagnosis of IE in a regional tertiary hospital. Material and Methods: Retrospective study of 107 patients aged 50 ± 16years (75% males) discharged with a definitive diagnosis of IE according to modified DUKE criteria, between years 2003 and 2010. Demographic variables, severity scores, clinical characteristics, bacteriology and hospital evolution were recorded. Results: Fifty nine percent of patients had concomitant cardiovascular problems. APACHE II and Sequential Organ Failure Assessment (SOFA) scores on admission were 8.4 ± 4.7 and 2.7 ± 2.8 respectively. Native valves were affected in 91% of cases (aortic and mitral valves in 62% and 50% of cases respectively). Prosthetic valves were affected in 9.3% of cases. Rheumatic heart disease was the predominant primary lesion in 10% of patients. Antibiotics were used in 45.1% before blood cultures were performed. In 68% of patients blood cultures were positive. S. viridans (30.8%), S.aureus (18.6%) and coagulase negative Streptocicci (5.6%) were the identified microorganisms. Intensive care unit admission was required in 48% of patients. Renal, heart and neurological deterioration was observed in 53, 34 and 14% of patients, respectively. Twenty percent of patients developed systemic embolism and 37% required heart surgery. Mean hospital stay was 28.3 ± 19.1 days and 27% of patients died. Conclusions: In this series of patients, IE has a high mortality. Most patients studied were admitted in bad conditions.

Background: Guidelines for the management of unstable angina (UA) and non ST elevation myocardial infarction (NSTEMI) have been issued, however cu-rrent practices are unknown in Chile. Aitn: To evalúate in a prospective cohort of NSTEMI patients the current practices, treatments and risk factors. Material and Methods: Oneyear prospective International non interventional registry, conducted in Chile between January 2005 and November 2006. Results: Two hundred thirty three Chilean NSTEMI patients were enrolled. Mortality was 5.5% at the end ofthe follow-up. Mean age was 61.6 years, and 30.6% were female. Most of the patients had at least one risk factor (98%): hypertension (84%), previous myocardial infarction (33%), dyslipidemia (54%), diabetes (33%), current smoking (30%). Main procedures duringthe hospitalization were coronary angiogram (67%), angioplasty (33%; 88% with stent) and coronary bypass surgery (7%). Duringprocedures, 31% of patients received clopidogrel, and 4.2% glycoprotein Ilb/IIIa antagonists. Medical management was selected for 60% of patients. In comparison to men, women received less interventional procedures despite havingmore risk factors. Treatments prescribed at discharge were aspirin (97%), clopidogrel (49%), beta blockers (78%), diuretics (21%), lipid lowering agents (78%), oral hypoglycemic agents (13%) and insulin (9%). At the end ofthe 1-year follow-up, treatments were aspirin (84%), beta blockers (72%), diuretics (19%), and dual antiplatelet therapy with clopidogrel (16%). Conclusions: A high prevalence of múltiple risk factors for cardiovascular disease in Chilean patients with NSTEMI was observed. More aggressive primary and secondary preventive measures are urgently needed. Use of therapies proposed in the guidelines is high, but dual antiplatelet therapy is less than 50% at discharge and decreases during the one year-follow-up.

Background: The mainstay of cholesterol reduction therapy is the diet. But the lack of compliance and prescription problems limit its usefulness. Aim: To compare the effectiveness of a nutritional intervention given by a nutritionist with the usual recommendations given by a physician to reduce the LDL cholesterol levels in patients with coronary artery disease, treated at the Regional public hospital in Temuco. Material and Methods: One hundred and forty patients with coronary heart disease (last acute episode at least three months before), without nutritional interventions nor cholesterol-lowering drugs, who gave informed consent, were randomized to receive either instructions by their physician or to take part in a nutritional program. The nutritional intervention consisted in five educational sessions, adapted from the NCEP and from a program of the Nutrition Department of the Catholic University of Chile. Patients randomized to the medical intervention received the standard written recommendations about diet. Lipid profile was measured before the intervention and after a three and twelve months follow up. Results: After one year the group on the nutritional program reduced LDL cholesterol by 11.1% (p=0.03). There were no changes in the medical group. However, only 10% patients on the nutritional intervention group and 8% of those with medical recommendations achieved LDL cholesterol levels less than 100 mg/dl. There were no changes in triglycerides, weight or body mass index during the period. Conclusions: Although this nutritional intervention proved to be more effective than usual medical instructions, most patients on secondary prevention did not achieve acceptable LDL cholesterol levels (Rev Méd Chile 2004; 132: 1457-65)

Background: From January 2000 to June 2002, the first Chilean registry of unstable angina was carried out, with the participation of 15 hospitals. Aim: To report the clinical and demographic features of 600 patients with unstable angina, their risk profile and prognosis. Material and methods: The inclusion criteria for this prospective registry were a history of recent onset of chest pain (<48 hours) or a change in the character of previous angina, associated to ischemic electrocardiographic changes and/or positive markers of myocardial damage. Results: Mean age of the patients was 65 years and 37% were women. Among coronary risk factors, 63% had hypertension, 27% had diabetes, 52% had dyslipidemia, 31% smoked and 21% had a family history of atherosclerosis. On admission 94% of patients had chest pain, associated to ST segment depression in 44%, negative T waves in 28% and positive markers of myocardial damage in 30%. Fifty seven percent received intravenous nitroglycerin, 47% received oral nitrates, 69% beta blockers and 15%, calcium antagonists. Antithrombotic therapy included aspirin in 96%, heparin in 74%, ticlodipine or clopidogrel in 19% and IIb/IIIa inhibitors in 12%. A coronary angiogram was performed in 52%, angioplasty in 25% and coronary bypass surgery in 13%. Hospital mortality was 2.6%. The incidence of new ischemic events was: myocardial infarction in 2.8% recurrent ischemia in 9.5% and refractory ischemia in 2%. The incidence of adverse events increased according to a higher risk profile. Conclusions: The demographic and clinical features, treatment and mortality of these patients are similar to those reported in international registries, with a low mortality rate (Rev Méd Chile 2004; 132: 135-43)

An analysis of health research in Chile is made, considering factors like exaggerated professional training during undergraduate studies and clinical residencies, and displacement of professionals from academic activities to more remunerative positions. Additionally, the limited role of the Ministry of Health in research promotion, evidenced by the almost absent participation of public hospitals in clinical research is discussed. Research investment, among a 0.6 to 0.8% of the GNP, is far from developed countries and Chile has not defined relevant health problems where a search effort would have an impact in public health. The marked centralism of the country attempts against regional application to financed projects. The following suggestions are made: to increase the financing for investigation, to reassign resources allowing the access of regional institutions, to financing, to discuss in the Chilean Association of Medical Faculties (ASOFAMECH) the creation of an academic degree by means of a thesis during the professional studies and to give facilities to develop research during clinical residencies. Also, the Ministry of Health should be involved, creating a national agenda or research priorities and increasing its association with Universities. Also training programs for professionals with a special interest in investigation should be devised (Rev Méd Chile 2000; 128: 1389-95).