Espacios cardioprotegidos en México: acciones para prevenir la muerte súbita cardiaca. Una postura de profesionales de la salud.

La muerte súbita cardiaca es un problema de salud pública a nivel mundial. Aunque su incidencia no es conocida, se estima que causa hasta 50% de la mortalidad de origen cardíaco y hasta 20% de la mortalidad total en los adultos. En México, estimaciones previas sugieren que causa en promedio 33 000 muertes al año; sin embargo, los datos no son precisos. La  mitad de los eventos por muerte súbita cardiaca se deben a un paro cardiaco súbito extrahospitalario que, de no ser atendido oportunamente, deriva en una muerte súbita cardiaca. Por tanto, la capacidad de responder pronta y adecuadamente a estos eventos con las maniobras y equipos necesarios mejora la sobrevida de las víctimas. Para atender este problema, en algunos estados del país se han creado espacios cardioprotegidos que permiten realizar maniobras de reanimación cardiopulmonar y desfibrilación cardiaca de acceso público oportunamente. Como objetivo, los profesionales de la salud establecen la importancia de implementar espacios cardioprotegidos y crear políticas públicas al respecto en todo el país.

FASTING INSULIN AND ALANINE AMINO TRANSFERASE, BUT NOT FGF21, WERE INDEPENDENT PARAMETERS RELATED WITH IRISIN INCREMENT AFTER INTENSIVE AEROBIC EXERCISING.

BACKGROUND: Irisin is a protein cleaved from fibronectin type III domain-containing protein 5 and has been implicated in the beneficial effects of exercise. However, it is unknown which factors contribute to irisin increment after intensive exercising in humans. This study aimed to assess independent factors related with serum irisin after 2 weeks of supervised physical activity in young sedentary healthy women. DESIGN AND METHODS: We developed a comparative, interventional, longitudinal, and prospective study at a third-level specialty health center. Between March 2010 and August 2011, 82 sedentary young adult women, without chronic diseases or regular medical treatments, were recruited. A total of 38 women fulfilled selection criteria, and irisin concentrations were quantified before and after the intervention. Independent factors related with irisin increment were evaluated according to mild to moderate and vigorous intensity of physical activity. A supervised treadmill exercise test following the Bruce's protocol was conducted from Monday to Friday during 2 weeks. In addition, anthropometric measurements were taken, and fibroblast growth factor 21 (FGF21), glucose, insulin, and liver transaminases were measured. RESULTS: Intensity of exercising was directly related to irisin (p = 0.02) and FGF21 (p = 0.01) serum levels. However, an independent and significant relationship between FGF21 and irisin was not confirmed. A novel association was found between alanine aminotransferase (ALT) and irisin, showing a positive and significant correlation (r = 0.37, p = 0.02). The association was particularly strong with higher intensity of aerobic exercising (r = 0.64, p = 0.01). Linear regression model adjusted for glucose and body mass index confirmed an independent association between ALT and irisin and also between insulin and irisin (adjusted R² = 0.12, p = 0.04). Such association increased after grouping in moderate to vigorous physical activity intensity (adjusted R² = 0.46, F = 4.7, p = 0.03). CONCLUSIONS: Serum irisin and FGF21 levels significantly increased after 2 weeks of supervised physical activity. However, only fasting insulin and ALT, but not FGF21, were independent parameters explaining irisin increment, mainly after moderate to vigorous exercising.

I. THE ROLE OF RESEARCH ETHICS COMMITTEES IN OBSERVATIONAL STUDIES: EPIDEMIOLOGICAL REGISTRIES, CASE REPORTS, INTERVIEWS, AND RETROSPECTIVE STUDIES.

It is often unclear to the clinical investigator whether observational studies should be submitted to a research ethics committee (REC), mostly because, in general, no active or additional interventions are performed. Moreover, obtaining an informed consent under these circumstances may be challenging, either because these are very large epidemiological registries, or the subject may no longer be alive, is too ill to consent, or is impossible to contact after being discharged. Although observational studies do not involve interventions, they entail ethical concerns, including threats such as breaches in confidentiality and autonomy, and respect for basic rights of the research subjects according to the good clinical practices. In this context, in addition to their main function as evaluators from an ethical, methodological, and regulatory point of view, the RECs serve as mediators between the research subjects, looking after their basic rights, and the investigator or institution, safeguarding them from both legal and unethical perils that the investigation could engage, by ensuring that all procedures are performed following the international standards of care for research. The aim of this manuscript is to provide information on each type of study and its risks, along with actions to prevent such risks, and the function of RECs in each type of study.

Infective endocarditis: 10-year experience in a non-cardiovascular center.

BACKGROUND AND OBJECTIVE: Infective endocarditis (IE) is an infection with a poor prognosis, and an associated in-hospital mortality of at least 25%. Optimal therapy of IE requires long-term effective antibiotic therapy and valve surgery in many cases. The aim of this study was to review the demographics, bacteriology, and outcomes of patients with IE admitted to a tertiary referral center in Mexico City, over a 10-year period. METHODS: Retrospective cohort study of patients admitted at Instituto Nacional Salvador Zubiran with a new diagnosis of IE over a 10-year period, from January 2009 to January 2019. Patients who met the definition for definitive diagnosis of infective endocarditis according to the modified Duke criteria were included in the study. RESULTS: There were 62 patients (50.85 ± 17.46 years, 40.3% females) with IE. The culprit microorganism was identified in all cases, with Staphylococcus aureus being the most frequently found (34%). Valve surgery was performed in 58.1%, while 41.9% only received medical treatment. The mortality rate was 25.8% at 30 days and 41.9% at 12 months. Comparing the surgical and medical treatment groups, we found that 50% and 36% in each group, respectively, had died within 12 months of admission. CONCLUSIONS: Our center has a high prevalence of health care-associated endocarditis, mostly related to the presence of intravascular access devices. Most of the patients had a surgical indication. Patients with type 2 diabetes mellitus and decreased right ventricular systolic function had an increased mortality rate at 12 months.

Antecedentes y objetivo: La endocarditis infecciosa (EI) es una infección de mal pronóstico, con una mortalidad intrahospitalaria que va del 15-20%. La terapia óptima requiere antibioticoterapia efectiva por tiempo prolongado y cirugía valvular en algunos casos. El objetivo de este estudio fue revisar la epidemiología y desenlaces de pacientes con EI en un centro de referencia en la Ciudad de México. Métodos: Cohorte retrospectiva de pacientes admitidos al Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán con diagnóstico de EI en un periodo de 10 años, de enero de 2009 a enero de 2019. Se incluyeron a pacientes que cumplían la definición de diagnóstico definitivo de endocarditis infecciosa de acuerdo a los criterios modificados de Duke. Resultados: Se incluyeron a 62 pacientes (50.85 ± 17.46 años, 40.3% mujeres). Todos los casos tuvieron cultivos positivos, siendo S. aureus el microorganismo más frecuente (34%). El 58.1% de los pacientes recibió tratamiento quirúrgico y 41.9% recibió únicamente tratamiento médico. La mortalidad a 30 días fue de 25.8% y a 12 meses fue de 41.9%. Comparando los grupos de tratamiento médico y quirúrgico, se encontró que 50% y 36% de cada grupo, respectivamente, habían fallecido a los 12 meses. Conclusiones: Encontramos una alta prevalencia de EI asociada a los cuidados de la salud, principalmente en relación a accesos intravasculares. Casi todos los pacientes presentaban un criterio quirúrgico al momento del diagnóstico. Los pacientes con diabetes mellitus tipo 2 y función sistólica del ventrículo derecho disminuida presentaron una mayor mortalidad a 12 meses.

Adverse Effects Associated With the Use of Antimalarials During The COVID-19 Pandemic in a Tertiary Care Center in Mexico City.

Background: Antimalarial drugs were widely used as experimental therapies against COVID-19 in the initial stages of the pandemic. Despite multiple randomized controlled trials demonstrating unfavorable outcomes in both efficacy and adverse effects, antimalarial drugs are still prescribed in developing countries, especially in those experiencing recurrent COVID-19 crises (India and Brazil). Therefore, real-life experience and pharmacovigilance studies describing the use and side effects of antimalarials for COVID-19 in developing countries are still relevant. Objective: To describe the adverse effects associated with the use of antimalarial drugs in hospitalized patients with COVID-19 pneumonia at a reference center in Mexico City. Methods: We integrated a retrospective cohort with all adult patients hospitalized for COVID-19 pneumonia from March 13th, 2020, to May 17th, 2020. We compared the baseline characteristics (demographic and clinical) and the adverse effects between the groups of patients treated with and without antimalarial drugs. The mortality analysis was performed in 491 patients who received optimal care and were not transferred to other institutions (210 from the antimalarial group and 281 from the other group). Results: We included 626 patients from whom 38% (n = 235) received an antimalarial drug. The mean age was 51.2 ± 13.6 years, and 64% were males. At baseline, compared with the group treated with antimalarials, the group that did not receive antimalarials had more dyspnea (82 vs. 73%, p = 0.017) and cyanosis (5.3 vs. 0.9%, p = 0.009), higher respiratory rate (median of 28 vs. 24 bpm, p < 0.001), and lower oxygen saturation (median of 83 vs. 87%, p < 0.001). In the group treated with antimalarials, 120 patients had two EKG evaluations, from whom 12% (n = 16) prolonged their QTc from baseline in more than 50 ms, and six developed a ventricular arrhythmia. Regarding the trajectories of the liver function tests over time, no significant differences were found for the change in the mean value per day between the two groups. Among patients who received optimal care, the mortality was 16% (33/210) in those treated with antimalarials and 15% (41/281) in those not receiving antimalarials (RR 1.08, 95% 0.75-1.64, and adjusted RR 1.12, 95% CI 0.69-1.82). Conclusion: The adverse events in patients with COVID-19 treated with antimalarials were similar to those who did not receive antimalarials at institutions with rigorous pharmacological surveillance. However, they do not improve survival in patients who receive optimal medical care.

[Differential behaviour of blood pressure in patients with neurocardiogenic syncope during the initial stage of the tilt table test]. / Comportamiento diferencial de la tensión arterial de pacientes con síncope neuro-cardiogénico en la fase inicial de la prueba de inclinación.

UNLABELLED: Neurocardiogenic syncope (NCS) is diagnosed by means of a head-up tilt table tests (HUTT). This is a prolonged test although early outcome predictors are known. METHODS: We conducted a study among patients engaged in a syncope study protocol. We performed HUTT in all of them and compared the basal arterial pressure with the arterial pressure at the end of a the 70 degrees tilting. RESULTS: We performed 185 HUTT studies. Systolic blood pressure (BP) raised 0.9% among patients with a negative test, whereas patients with a positive HUTT showed a 2.3% decrease (p = 0.2) in the same measurement. Diastolic BP increased 34% among negative HUTT patients and 14.9% among patients with positive test (p = 0.02). We calculated a relative risk of 1.45 for positive test when the combination of systolic BD decrease and dyastolic increase was present, according to the percentage of change (IC95%: 1.1 to 7.8). CONCLUSIONS: The combination of systolic BP reduction and diastolic BP elevation at the end of the 70 degrees tilting is associated with an increased risk of having a positive HUTT. These changes might be related to differential sympathetic stimulation.

Impact of Body Mass Index >50 on Cardiac Structural and Functional Characteristics and Surgical Outcomes After Bariatric Surgery.

BACKGROUND: Body mass index (BMI) ≥50.0 kg/m2 has been associated with increased surgical complications and mortality. We assessed echocardiographic characteristics and bariatric surgery complications of patients with BMI ≥50.0 kg/m2 vs. those in less severe obesity. METHODS AND RESULTS: A retrospective analysis in patients who underwent gastric bypass was performed. Pre-surgery structural characteristics analyzed included left atrial dimension (LA), left ventricle mass (LVM), LVM indexed for height2.7 (LVMI), and LV hypertrophy (LVH). Functional characteristics included LV diastolic and systolic function. Degree of obesity was correlated with cardiac parameters, comorbidities, and surgical complications. Data on 312 patients (75.3 % women, age 39.3 ± 0.6 years, BMI 50.2 ± 0.5 kg/m2) were analyzed. Cardiac parameters on the basis of BMI (<50 kg/m2 vs. ≥50 kg/m2) were LA 39.6 ± 4.8 vs. 41.9 ± 5.2 mm, LVM 161 ± 46 vs. 194 ± 56 g, LVMI 43.6 ± 0.9 vs. 51.8 ± 1.3 g/ht2.7, and systolic pulmonary pressure 43.7 ± 10.1 vs. 50.5 ± 11.3 mmHg, respectively (all p < 0.001). LVMI was correlated with BMI (p < 0.001), 2-h glucose on a glucose tolerance test (p = 0.01), and ejection fraction (p = 0.01). Surgical complications were not different among groups. Presence of LVH was independently associated with BMI ≥50 kg/m2 and female sex, after adjusting for age, diabetes, hypertension, and pulmonary hypertension. CONCLUSION: Body mass index ≥50 kg/m2 was independently associated with female sex and LVH but not with hypertension, diabetes, or a higher rate of surgical complications.

Elevation of plasmatic endothelin in patients with heart failure.

BACKGROUND: Endothelin 1 is an autocrine and paracrine factor with vasoconstrictive, mitogenic, and inotropic activities in vascular and cardiac muscles. Its elevation has been reported in patients with chronic heart failure and its production may be conditioned by activation of other neurohumoral factors that are stimulated by the disease. METHODS: The objective of this study was to correlate level of endothelin (ET) with echocardiographic, clinical, and biochemical markers and to determine its role as an independent marker of severity. We included patients with congestive heart failure in whom echocardiographic evaluation had been done and serum markers measured. Serum endothelin 1 levels were determined by radioimmunoassay (RIA). Correlation between endothelin concentration, echocardiographic parameters, potentially confounding factors, and severity of heart failure was made. RESULTS: Patients with symptomatic heart failure and longer time of evolution had higher levels of endothelin unrelated to levels of troponin T, tumor necrosis factor, and atrial natriuretic peptide. There were no differences in levels of endothelin, independently of the etiology of cardiac failure. CONCLUSIONS: These results support the idea that endothelin plays an important independent role in the physiopathology of heart failure. It may be a severity marker and an attractive therapeutic target.

Abnormal SPECT myocardial perfusion imaging during periods of obstructive sleep apnea in morbid obese patients without known heart disease.

OBJECTIVE: Determine the myocardial perfusion characteristics in obstructive sleep apnea and its possible role in cardiovascular damage. METHODS AND PROCEDURES: Fourteen patients from the Obesity Clinic weighing less than 130 kg underwent myocardial perfusion studies using single photon emission computed tomography with technetium 99m-labeled sestamibi during nighttime polysomnographic recordings. Coronary angiograms were performed on patients with suspect of severe coronary obstruction according nighttime myocardial perfusion studies or pharmacological stress carried out during waking hours. RESULTS: All 14 patients manifested myocardial perfusion defects during sleep, affecting an average of 5.5 segments/patient, although only 8 presented ischemic ST segment changes and none demonstrated rhythm or conduction disturbances. Angiographic examination of the 10 patients with the most severe perfusion defects did not reveal significant coronary obstruction, and fewer perfusion defects were documented during daytime scintigraphy. DISCUSSION: In obese patients with obstructive sleep apnea, myocardial perfusion defects appear to occur with highest frequency and severity during nighttime sleep, justifying further investigation in a larger number of patients with obstructive sleep apnea and more significant obesity.

Fasting insulin and alanine amino transferase, but not FGF21, were independent parameters related with irisin increment after intensive aerobic exercising

Abstract Background Irisin is a protein cleaved from fibronectin type III domain-containing protein 5 and has been implicated in the beneficial effects of exercise. However, it is unknown which factors contribute to irisin increment after intensive exercising in humans. This study aimed to assess independent factors related with serum irisin after 2 weeks of supervised physical activity in young sedentary healthy women. Design and Methods We developed a comparative, interventional, longitudinal, and prospective study at a third-level specialty health center. Between March 2010 and August 2011, 82 sedentary young adult women, without chronic diseases or regular medical treatments, were recruited. A total of 38 women fulfilled selection criteria, and irisin concentrations were quantified before and after the intervention. Independent factors related with irisin increment were evaluated according to mild to moderate and vigorous intensity of physical activity. A supervised treadmill exercise test following the Bruce’s protocol was conducted from Monday to Friday during 2 weeks. In addition, anthropometric measurements were taken, and fibroblast growth factor 21 (FGF21), glucose, insulin, and liver transaminases were measured. Results Intensity of exercising was directly related to irisin (p = 0.02) and FGF21 (p = 0.01) serum levels. However, an independent and significant relationship between FGF21 and irisin was not confirmed. A novel association was found between alanine aminotransferase (ALT) and irisin, showing a positive and significant correlation (r = 0.37, p = 0.02). The association was particularly strong with higher intensity of aerobic exercising (r = 0.64, p = 0.01). Linear regression model adjusted for glucose and body mass index confirmed an independent association between ALT and irisin and also between insulin and irisin (adjusted R² = 0.12, p = 0.04). Such association increased after grouping in moderate to vigorous physical activity intensity (adjusted R² = 0.46, F = 4.7, p = 0.03). Conclusions Serum irisin and FGF21 levels significantly increased after 2 weeks of supervised physical activity. However, only fasting insulin and ALT, but not FGF21, were independent parameters explaining irisin increment, mainly after moderate to vigorous exercising.

I. The role of research ethics committees in observational studies: epidemiological registries, case reports, interviews, and retrospective studies

Abstract It is often unclear to the clinical investigator whether observational studies should be submitted to a research ethics committee (REC), mostly because, in general, no active or additional interventions are performed. Moreover, obtaining an informed consent under these circumstances may be challenging, either because these are very large epidemiological registries, or the subject may no longer be alive, is too ill to consent, or is impossible to contact after being discharged. Although observational studies do not involve interventions, they entail ethical concerns, including threats such as breaches in confidentiality and autonomy, and respect for basic rights of the research subjects according to the good clinical practices. In this context, in addition to their main function as evaluators from an ethical, methodological, and regulatory point of view, the RECs serve as mediators between the research subjects, looking after their basic rights, and the investigator or institution, safeguarding them from both legal and unethical perils that the investigation could engage, by ensuring that all procedures are performed following the international standards of care for research. The aim of this manuscript is to provide information on each type of study and its risks, along with actions to prevent such risks, and the function of RECs in each type of study.

Exercise increases serum fibroblast growth factor 21 (FGF21) levels.

BACKGROUND: Fibroblast growth factor 21 (FGF21) increases glucose uptake. It is unknown if FGF21 serum levels are affected by exercise. METHODOLOGY/PRINCIPAL FINDINGS: This was a comparative longitudinal study. Anthropometric and biochemical evaluation were carried out before and after a bout of exercise and repeated after two weeks of daily supervised exercise. The study sample was composed of 60 sedentary young healthy women. The mean age was 24±3.7 years old, and the mean BMI was 21.4±7.0 kg/m². The anthropometric characteristics did not change after two weeks of exercise. FGF21 levels significantly increased after two weeks of exercise (276.8 ng/l (142.8-568.6) vs. (460.8 (298.2-742.1), p<0.0001)). The delta (final-basal) log of serum FGF21, adjusted for BMI, showed a significant positive correlation with basal glucose (r = 0.23, p = 0.04), mean maximal heart rate (MHR) (r = 0.54, p<0.0001), mean METs (r = 0.40, p = 0.002), delta plasma epinephrine (r = 0.53, p<0.0001) and delta plasma FFAs (r = 0.35, p = 0.006). A stepwise linear regression model showed that glucose, MHR, METs, FFAs, and epinephrine, were factors independently associated with the increment in FGF21 after the exercise program (F = 4.32; r²â€Š= 0.64, p<0.0001). CONCLUSIONS: Serum FGF21 levels significantly increased after two weeks of physical activity. This increment correlated positively with clinical parameters related to the adrenergic and lipolytic response to exercise. TRIAL REGISTRATION: ClinicalTrials.gov NCT01512368.

Comportamiento diferencial de la tensión arterial de pacientes con síncope neuro-cardiogénico en la fase inicial de la prueba de inclinación / Differential behaviour of blood pressure in patients with neurocardiogenic syncope during the initial stage of the tilt table test

Neurocardiogenic syncope (NCS) is diagnosed by means of a head-up tilt table tests (HUTT). This is a prolonged test although early outcome predictors are known. METHODS: We conducted a study among patients engaged in a syncope study protocol. We performed HUTT in all of them and compared the basal arterial pressure with the arterial pressure at the end of a the 70 degrees tilting. RESULTS: We performed 185 HUTT studies. Systolic blood pressure (BP) raised 0.9% among patients with a negative test, whereas patients with a positive HUTT showed a 2.3% decrease (p = 0.2) in the same measurement. Diastolic BP increased 34% among negative HUTT patients and 14.9% among patients with positive test (p = 0.02). We calculated a relative risk of 1.45 for positive test when the combination of systolic BD decrease and dyastolic increase was present, according to the percentage of change (IC95%: 1.1 to 7.8). CONCLUSIONS: The combination of systolic BP reduction and diastolic BP elevation at the end of the 70 degrees tilting is associated with an increased risk of having a positive HUTT. These changes might be related to differential sympathetic stimulation.

Fibrilación auricular: nuevos aspectos sobre una vieja enfermedad / Atrial Fibrillation: new aspects of an old disease

La fibrilación auricular es la arritmia encontrada más frecuentemente en la clínica. Los principales problemas derivados de ella son los eventos trombóticos recurrentes y el deterioro de la clase funcional. La fibrilación auricular induce alteraciones de los canales iónicos, que la perpetoan. El tratamiento de la FA se encamina a corregir estas alteraciones y regresar al ritmo sinusal, al tiempo que se debe controlar la frecuencia cardiaca y prevenir eventos embólicos por medio de anticoagulación o tratamiento con antiagregantes plaquetarios. Actualmente existen recursos con antiarrítmicos de clase IC o clase III para intentar recuperar el ritmo sinusal. Las tasas de éxito son variables y las mejores se obtienen con flecainida o propafenona en los casos sin cardiopatía estructural y amiodarona cuando ésta existe. Las combinaciones de pacientes y fármacos son múltiples, cada caso debe ser individualizado. Los nuevos antiarrítmicos de clase III han mostrado eficacia pero con tasas relativamente altas de reacciones adversas como taquicardia helicoidal. La anticoagulación sería el tratamiento preferido para la mayoría de los enfermos, pero se debe ajustar en cada caso. Las terapias como la ablación con catéter focal o lineal, así como la estimulación auricular o biauricular y los desfibriladores implantables requieren de un seguimiento a mayor plazo y también necesitan de tratamiento antiarrítmico agregado. La cirugía tiene una morbi-mortalidad alta, por lo que el riesgo supera al beneficio.

Cardiac conduction distrurbances in mixed connective tissue disease

Objetivo: Determinar la prevalencia de trastornos de conducción cardiaca en pacientes con enfermedad mixta de tejido conectivo, atendidos en un instituto de la Ciudad de México y su relación con otras manifestaciones de la enfermedad. Método: Ciento trece pacientes admitidos en el Instituto con diagnóstico de enfermedad mixta de tejido conectivo fueron divididos en aquellos con alteraciones de conducción (n=23) y sin estos (n=90). Durante un período de seguimiento de 10.2 ñ 7.8 años, se examinaron, el curso clínico, duración de la enfermedad, tratamiento, tipos de trastornos de conducción y alteraciones sistémicas. Resultados: Observamos un marcado predominio de mujeres en ambos grupos. Las alteraciones de conducción ocurrieron en cerca de 20 por ciento de los pacientes con enfermedad mixta de tejido conectivo y no encontramos diferencias significativas entre los grupos durante el seguimiento. Como era de esperarse, una diferencia significativa entre ambos fue la desviación del aQRS, relacionado a la presencia del bloqueo de fascículo anterior de la rama izquierda del HH, la más frecuente de las alteraciones de conducción observadas. Durante el seguimiento un paciente del grupo A murió, pero ninguno en el grupo B. Conclusión: Las alteraciones de conducción estuvieron presentes en 20 por ciento, en concordancia con lo referido por otros autores en la literatura. Sin embargo, no participaron en la evolución de la enfermedad.