Usefulness of the intracardiac electrocardiogram recorded using central venous catheters on P-wave magnification.

BACKGROUND: The detection of atrial electrical activity is extremely valuable in recognizing complex cardiac arrhythmias. However, P-wave detection on a surface electrocardiogram (S-ECG) can sometimes be challenging. The intracardiac electrocardiogram (IC-ECG), recorded by a central venous catheter loaded with saline solution, has proven to be a safe and effective method for amplifying atrial electrical activity. We aim to compare the P-wave amplitude recorded in the S-ECG and the IC-ECG in different venous accesses, catheters, heart rhythms, and atrial dimensions. METHODS: We compared the P wave amplitude obtained by the IC-ECG and the S-ECG recordings from cardiac intensive care unit patients. RESULTS: In 109 nonconsecutive patients, a total of 166 IC-ECG were collected. The median amplitude of the P wave was 0.1 (0.083-0.3) mV in the S-ECG and 0.4 (0.25-2.4) mV in the IC-ECG; p < 0.001. This difference remained significant regardless of the patient's heart rhythm, left atrial dimension, and catheter or vascular access used. CONCLUSION: The IC-ECG acquired using central venous catheters significantly increases atrial electrical activity signals. This technique might help identify complex cardiac arrhythmias.

Differences in pacemaker programming between electrophysiology specialists and other physicians.

BACKGROUND: Appropriate programming of cardiovascular implantable electronic devices (CIED) is essential to ensure adequate function and avoid harmful effects. In underdeveloped countries, CIED monitoring and programming are often performed by physicians involved in their implantation. However, many of them often do not have sufficient training in CIED programming. OBJECTIVE: We aimed to assess the differences in pacemaker programming between electrophysiology (EP) specialists and other physicians. METHODS: We retrospectively reviewed changes in pacemaker programming performed by an EP specialist in patients who attended for pacemaker evaluation and reported previous follow-ups by a non-EP specialist. RESULTS: Among 58 patients (26 males), 41 patients (71%) had programming errors and required setting modifications. The rate adaptative pacing function (R-mode) was incorrectly deactivated in 9 patients (15%) and improperly activated in 2 patients (3%). Unnecessary ventricular stimulation was detected in 23 patients (40%) with a pacing burden of 60% (32-95%). The lower rate limit was unnecessarily high in 12 patients (21%). Atrial or ventricular pacing output was inappropriate in 15 patients (26%) and was consequently modified (4 patients unnecessarily high, 9 patients below requirements). The auto-adapted pacing output was switched off in 17 of 18 patients (16 due to physician's preference, and 1 due to algorithm inaccuracy). The programmed sensitivity was inaccurate in 2 patients (3%). In 2 patients (3%) switching from DDDR to VVIR mode was required. CONCLUSION: We found a high prevalence of errors in pacemaker programming by non-EP specialists. An EP specialist should always be responsible for CIED follow-up.

StarPep Toolbox: an open-source software to assist chemical space analysis of bioactive peptides and their functions using complex networks.

MOTIVATION: Antimicrobial peptides (AMPs) are promising molecules to treat infectious diseases caused by multi-drug resistance pathogens, some types of cancer, and other conditions. Computer-aided strategies are efficient tools for the high-throughput screening of AMPs. RESULTS: This report highlights StarPep Toolbox, an open-source and user-friendly software to study the bioactive chemical space of AMPs using complex network-based representations, clustering, and similarity-searching models. The novelty of this research lies in the combination of network science and similarity-searching techniques, distinguishing it from conventional methods based on machine learning and other computational approaches. The network-based representation of the AMP chemical space presents promising opportunities for peptide drug repurposing, development, and optimization. This approach could serve as a baseline for the discovery of a new generation of therapeutics peptides. AVAILABILITY AND IMPLEMENTATION: All underlying code and installation files are accessible through GitHub (https://github.com/Grupo-Medicina-Molecular-y-Traslacional/StarPep) under the Apache 2.0 license.

Comportamiento del tiempo de conducción retrógrada al momento de la inducción de las taquicardias supraventriculares y su rol en el diagnóstico diferencial / Behavior of Retrograde Conduction Time at Supraventricular Tachycardia Induction and its Role in Differential Diagnosis

RESUMEN Antecedentes : El diagnóstico diferencial entre la taquicardia reentrante ortodrómica (TRO) y la taquicardia por reentrada nodal atípica (TRNa) puede ser dificultoso. Nuestra hipótesis es que las TRNa tienen más variabilidad en el tiempo de con ducción retrógrada al comienzo de la taquicardia que las TRO. Nuestros objetivos fueron evaluar la variabilidad en el tiempo de conducción retrógrada al inicio de la taquicardia en TRNa y TRO, y proponer una nueva herramienta diagnóstica para diferenciar estas dos arritmias. Métodos : Se midió el intervalo ventrículo-auricular (VA) de los primeros latidos tras la inducción de la taquicardia, hasta su estabilización. La diferencia entre el intervalo VA máximo y el mínimo se definió como delta VA (ΔVA). También contamos el número de latidos necesarios para que se estabilice el intervalo VA. Se excluyeron las taquicardias auriculares. Resultados : Se incluyeron 101 pacientes. Se diagnosticó TRO en 64 pacientes y TRNa en 37. El ΔVA fue 0 (rango intercuartílico, RIC, 0-5) milisegundos (ms) en la TRO frente a 40 (21-55) ms en la TRNa (p < 0,001). El intervalo VA se estabilizó significativamente antes en la TRO (1,5 [1-3] latidos) que en la TRNa (5 [4-7] latidos; p < 0,001). Un ΔVA < 10 ms diagnosticó TRO con 100% de sensibilidad, especificidad y valores predictivos positivo y negativo. La estabilización del intervalo VA en menos de 3 latidos predijo TRO con buena precisión diagnóstica. Los resultados fueron similares considerando sólo vías accesorias septales. Las TRN típicas tuvieron una variación intermedia. Conclusión : Un ΔVA < 10 ms es un criterio simple, que distingue con precisión la TRO de la TRNa, independientemente de la localización de la vía accesoria.

ABSTRACT Background : Differential diagnosis between orthodromic reentrant tachycardia (ORT) and atypical nodal reentrant tachy cardia (ANRT) can be challenging. Our hypothesis was that ANRT presents more variability in retrograde conduction time at tachycardia onset than ORT. Objectives : The objectives of this study were to assess retrograde conduction time variability at the start of tachycardia in ANRT and ORT, and postulate a new diagnostic tool to differentiate these two types of arrhythmias. Methods : The ventriculoatrial (VA) interval of the first beats after tachycardia induction was measured until stabilization. The difference between the maximum and minimum VA interval was defined as delta VA (ΔVA), and the number of beats needed for VA interval stabilization was also assessed. Atrial tachycardias were excluded. Results : In a total of 101 patients included in the study, ORT was diagnosed in 64 patients and ANRT in 37. ΔVA interval was 0 (interquartile range [IQR] 0-5) milliseconds (ms) in ORT vs. 40 (21-55) ms in ANRT (p <0.001). The VA interval significantly stabilized earlier in ORT (1.5 [1-3] beats) than in ANRT (5 [4-7] beats) (p<0.001). A ΔVA <10 ms diagnosed ORT with 100% sensitivity, specificity, and positive and negative predictive values. Ventriculoatrial interval stabilization in less than 3 beats predicted ORT with good diagnostic accuracy. The results were similar considering only accessory septal pathways. Typical NRTs presented an intermediate variation. Conclusion : Presence of DVA <10 ms is a simple criterion that accurately differentiates ORT from ANRT, independently of the accessory pathway localization.

Magnetization transfer saturation reveals subclinical optic nerve injury in pediatric-onset multiple sclerosis.

BACKGROUND: The presence of subclinical optic nerve (ON) injury in youth living with pediatric-onset MS has not been fully elucidated. Magnetization transfer saturation (MTsat) is an advanced magnetic resonance imaging (MRI) parameter sensitive to myelin density and microstructural integrity, which can be applied to the study of the ON. OBJECTIVE: The objective of this study was to investigate the presence of subclinical ON abnormalities in pediatric-onset MS by means of magnetization transfer saturation and evaluate their association with other structural and functional parameters of visual pathway integrity. METHODS: Eleven youth living with pediatric-onset MS (ylPOMS) and no previous history of optic neuritis and 18 controls underwent standardized brain MRI, optical coherence tomography (OCT), Magnetoencephalography (MEG)-Visual Evoked Potentials (VEPs), and visual battery. Data were analyzed with mixed effect models. RESULTS: While ON volume, OCT parameters, occipital MEG-VEPs outcomes, and visual function did not differ significantly between ylPOMS and controls, ylPOMS had lower MTsat in the supratentorial normal appearing white matter (-0.26 nU, p = 0.0023), and in both in the ON (-0.62 nU, p < 0.001) and in the normal appearing white matter of the optic radiation (-0.56 nU, p = 0.00071), with these being positively correlated (+0.57 nU, p = 0.00037). CONCLUSIONS: Subclinical microstructural injury affects the ON of ylPOMS. This may appear as MTsat changes before being detectable by other currently available testing.

Variability of the VA interval at tachycardia induction: a simple method to differentiate orthodromic reciprocating tachycardia from atypical atrioventricular nodal reentrant tachycardia.

BACKGROUND: The differential diagnosis between orthodromic atrioventricular reentry tachycardia (AVRT) and atypical AV nodal reentrant tachycardia (aAVNRT) is sometimes challenging. We hypothesize that aAVNRTs have more variability in the retrograde conduction time at tachycardia onset than AVRTs. METHODS: We aimed to assess the variability in retrograde conduction time at tachycardia onset in AVRT and aAVNRT and to propose a new diagnostic tool to differentiate these two arrhythmia mechanisms. We measured the VA interval of the first beats after tachycardia induction until it stabilized. The difference between the maximum and minimum VA intervals (∆VA) and the number of beats needed for the VA interval to stabilize was analyzed. Atrial tachycardias were excluded. RESULTS: A total of 107 patients with aAVNRT (n = 37) or AVRT (n = 64) were included. Six additional patients with decremental accessory pathway-mediated tachycardia (DAPT) were analyzed separately. All aAVNRTs had VA interval variability. The median ∆VA was 0 (0 - 5) ms in AVRTs vs 40 (21 - 55) ms in aAVNRTs (p < 0.001). The VA interval stabilized significantly earlier in AVRTs (median 1.5 [1 - 3] beats) than in aAVNRTs (5 [4 - 7] beats; p < 0.001). A ∆VA < 10 ms accurately differentiated AVRT from aAVNRT with 100% of sensitivity, specificity, and positive and negative predictive values. The stabilization of the VA interval at < 3 beats of the tachycardia onset identified AVRT with sensitivity, specificity, and positive and negative predictive values of 64.1%, 94.6%, 95.3%, and 60.3%, respectively. A ∆VA < 20 ms yielded good diagnostic accuracy for DAPT. CONCLUSIONS: A ∆VA < 10 ms is a simple and useful criterion that accurately distinguished AVRT from atypical AVNRT. Central panel: Scatter plot showing individual values of ∆VA in atypical AVNRT and AVRT. Left panel: induction of atypical AVNRT. The VA interval stabilizes at the 5th beat and the ∆VA is 62 ms (maximum VA interval: 172 ms - minimum VA interval: 110 ms). Right panel: induction of AVRT. The tachycardia has a fixed VA interval from the first beat. ∆VA is 0 ms.

Value of Electrocardiography to Distinguish Fabry Disease from Sarcomeric Hypertrophic Cardiomyopathy.

Fabry disease (FD) is a rare genetic disorder that leads to left ventricular hypertrophy (LVH), frequently misdiagnosed as hypertrophic cardiomyopathy (HCM). We sought to assess the value of electrocardiography for distinguishing FD from HCM. We retrospectively reviewed and compared standard electrocardiograms and echocardiograms from 26 patients with FD and LVH and 33 sarcomeric patients with HCM, matched for gender, age, and degree of LVH. The mean age of patients with FD was 46 years (interquartile range) (28 to 53) and of HCM 50 (30 to 61) years (p = 0.27). Of them, 16 (61%) and 25 (76%) were male, respectively (p = 0.26). Indexed left ventricular mass was 166 g/m2 in FD versus 181 g/m2 in HCM (p = 0.88). All patients with FD and 30 (91%) with HCM were in sinus rhythm (p = 0.25). A higher prevalence of right bundle branch block (RBBB) was observed in FD (27%) versus HCM (6%) (p = 0.03). The PR interval was shorter in FD, 140 ms (120-160) versus 160 ms (140 to 180) (p = 0.004). P-wave duration was longer in patients with FD, 100 ms (80 to 120) versus 80 ms (80 to 100) (p = 0.01). The PQ interval (PR interval minus P-wave duration) was shorter in patients with FD, 40 ms (20 to 45) versus 80 ms (40 to 80) (p = 0.001). There were no differences regarding P-wave amplitude, QRS complex duration, corrected QT length, conduction or repolarization abnormalities, Sokolow-Lyon index, and Cornell index. After multivariate adjustments for RBBB, PR interval, P-wave duration, and PQ interval, a PQ interval ≤40 ms and RBBB were significantly associated with FD. In conclusion, there are electrocardiogram characteristics, such as the presence of RBBB or a PQ interval ≤40 ms, that may be helpful for screening and reducing the delay in FD diagnosis.

Corrigendum to "Best match graphs".

Two errors in the article Best Match Graphs (Geiß et al. in JMB 78: 2015-2057, 2019) are corrected. One concerns the tacit assumption that digraphs are sink-free, which has to be added as an additional precondition in Lemma 9, Lemma 11, Theorem 4. Correspondingly, Algorithm 2 requires that its input is sink-free. The second correction concerns an additional necessary condition in Theorem 9 required to characterize best match graphs. The amended results simplify the construction of least resolved trees for n-cBMGs, i.e., Algorithm 1. All other results remain unchanged and are correct as stated.

Alteraciones hematológicas en gestantes con covid-19 residentes en la altura / Hematological alterations in covid-19 pregnant women living at high altitude

Introducción. La pandemia por COVID-19 también ha afectado a mujeres embarazadas. Aunque en menor porcentaje, reportes de eventos graves maternos y compromiso fetal generan preocupación. Igualmente, alteraciones como linfopenia y eosinopenia en gestantes con COVID-19, infrecuentes aun en gestantes normales, han sido reportadas. Objetivo. Caracterizar las alteraciones hematológicas en mujeres gestantes a término con COVID-19 residentes en la altura. Métodos. Se realizó un estudio longitudinal descriptivo de tipo retrospectivo que incluyó 295 mujeres embarazadas a termino con positividad para SARS-COV-2, internadas para fines de parto y alumbramiento en el Hospital de la Mujer de la ciudad de La Paz-Bolivia situada a 3640 m.s.n.m. Se analizó resultados de hemogramas, glucemia, creatinina, proteínas totales y coagulograma. Resultados. El promedio de edad fue 28,5 años, la edad gestacional correspondió a 37,4 semanas. Todas las gestantes fueron clasificadas con COVID-19 de presentación leve (Etapa I). Estudios laboratoriales reflejaron promedios de hemoglobina 13,0 g/dl, leucocitos 9825/ul y plaquetas 266 10³/ul; el coagulograma y las concentraciones de glucemia, creatinina, proteínas totales y albúmina estuvieron dentro de parámetros normales. Un 39 % de las gestantes presentaron leucocitosis asociada a neutrofilia y un 1.4 % linfopenia. Conclusiones. Las gestantes a término con COVID-19 leve en nuestro entorno generalmente no presentan linfopenia; sin embargo, su presencia sirve de alerta para tomar medidas de acción temprana en caso de complicación por COVID-19 en mujeres gestantes. Probablemente, los embarazos en edades tempranas y sin patología base están relacionados con cuadros clínicos menos graves de covid.

Introduction. COVID-19 pandemic has also affected pregnant women. Although at lower percentage, reports of serious maternal events as well as fetal compromise raise concern. Likewise, hematological conditions such as lymphopenia and eosinopenia in pregnant women with COVID-19, uncommon even in normal pregnant, have been reported. Objective. To characterize hematological alterations in full-term pregnant women with COVID-19, living at high altitude. Methods. It was conducted a retrospective descriptive longitudinal study that included 295 full-term pregnant women SARS-Cov-2 positives, hospitalized because of labor and delivery at Hospital de la Mujer in La Paz city (Bolivia) located at 3640 masl. Complete blood count, blood glucose, creatinine, total protein and clottin screening results were analyzed. Results. Average age was 28.5 years, and gestational age corresponded to 37.4 weeks. All pregnant women were classified with COVID-19 at Stage I. Laboratory studies showed averages of hemoglobin 13.0 g/dl, leukocytes 9825/ul and platelets 266 103 / ul; the clotting screening and the concentrations of glycemia, creatinine, total proteins and albumin were within normal parameters. 39% of the pregnant women had leukocytosis associated with neutrophilia and 1.4% had lymphopenia. Conclusions. Full-term pregnant women with COVID-19 at stage I in our context generally do not have lymphopenia; however, the presence ofsuch condition serves as a warning to take early action measures in case of COVID-19 complications in pregnant women. Probably, pregnancies at an early age and without underlying pathology are related to a less severe COVID-19.

Automatic construction of molecular similarity networks for visual graph mining in chemical space of bioactive peptides: an unsupervised learning approach.

The increasing interest in bioactive peptides with therapeutic potentials has been reflected in a large variety of biological databases published over the last years. However, the knowledge discovery process from these heterogeneous data sources is a nontrivial task, becoming the essence of our research endeavor. Therefore, we devise a unified data model based on molecular similarity networks for representing a chemical reference space of bioactive peptides, having an implicit knowledge that is currently not explicitly accessed in existing biological databases. Indeed, our main contribution is a novel workflow for the automatic construction of such similarity networks, enabling visual graph mining techniques to uncover new insights from the "ocean" of known bioactive peptides. The workflow presented here relies on the following sequential steps: (i) calculation of molecular descriptors by applying statistical and aggregation operators on amino acid property vectors; (ii) a two-stage unsupervised feature selection method to identify an optimized subset of descriptors using the concepts of entropy and mutual information; (iii) generation of sparse networks where nodes represent bioactive peptides, and edges between two nodes denote their pairwise similarity/distance relationships in the defined descriptor space; and (iv) exploratory analysis using visual inspection in combination with clustering and network science techniques. For practical purposes, the proposed workflow has been implemented in our visual analytics software tool ( http://mobiosd-hub.com/starpep/ ), to assist researchers in extracting useful information from an integrated collection of 45120 bioactive peptides, which is one of the largest and most diverse data in its field. Finally, we illustrate the applicability of the proposed workflow for discovering central nodes in molecular similarity networks that may represent a biologically relevant chemical space known to date.

[Cilostazol and sick sinus syndrome]. / Efecto del cilostazol en la enfermedad del nodo sinusal.

Here we present the case of a 60-year-old patient with sinus node disease (NSS), symptomatic with dizziness and angor. The electrocardiogram showed episodes of sinus pauses with nodal escapes. During hospitalization, pending the placement of a definitive pacemaker, cilostazol (100 mg every 12 hours orally) was indicated, observing an increase in heart rate 48 hours after starting the medication, and the disappearance of sinus pauses in the 24 hours Holter. Our objective has been to show that cilostazol can be useful in patients with SNN, although long-term chronotropic effects of this treatment has yet to be evaluated.

Se presenta el caso de una paciente de 60 años con enfermedad del nodo sinusal (ENS), sintomática con mareos y ángor, con electrocardiograma que evidenciaba episodios de pausas sinusales con escapes nodales. Durante la internación, a la espera de colocación de marcapaso definitivo, se indicó cilostazol (100 mg cada 12 h vía oral), observando a las 48 horas del inicio un incremento en la frecuencia cardíaca y la desaparición de las pausas sinusales en Holter de 24 horas. Nue stro objetivo ha sido demostrar que el cilostazol puede ser útil en pacientes con ENS, aunque es necesario evaluar los efectos cronotrópicos a largo plazo de este tratamiento.

Efecto del cilostazol en la enfermedad del nodo sinusal / Cilostazol and sick sinus syndrome

Resumen Se presenta el caso de una paciente de 60 años con enfermedad del nodo sinusal (ENS), sintomática con mareos y ángor, con electrocardiograma que evidenciaba episodios de pausas sinusales con escapes nodales. Durante la internación, a la espera de colocación de marcapaso definitivo, se indicó cilostazol (100 mg cada 12 h vía oral), observando a las 48 horas del inicio un incremento en la frecuencia cardíaca y la desaparición de las pausas sinusales en Holter de 24 horas. Nuestro objetivo ha sido demostrar que el cilostazol puede ser útil en pacientes con ENS, aunque es necesario evaluar los efectos cronotrópicos a largo plazo de este tratamiento.

Abstract Here we present the case of a 60-year-old patient with sinus node disease (NSS), symptomatic with dizziness and angor. The electrocardiogram showed episodes of sinus pauses with nodal escapes. During hospitalization, pending the placement of a definitive pacemaker, cilostazol (100 mg every 12 hours orally) was indicated, observing an increase in heart rate 48 hours after starting the medication, and the disappearance of sinus pauses in the 24 hours Holter. Our objective has been to show that cilostazol can be useful in patients with SNN, although long-term chronotropic effects of this treatment has yet to be evaluated.

Best match graphs.

Best match graphs arise naturally as the first processing intermediate in algorithms for orthology detection. Let T be a phylogenetic (gene) tree T and [Formula: see text] an assignment of leaves of T to species. The best match graph [Formula: see text] is a digraph that contains an arc from x to y if the genes x and y reside in different species and y is one of possibly many (evolutionary) closest relatives of x compared to all other genes contained in the species [Formula: see text]. Here, we characterize best match graphs and show that it can be decided in cubic time and quadratic space whether [Formula: see text] derived from a tree in this manner. If the answer is affirmative, there is a unique least resolved tree that explains [Formula: see text], which can also be constructed in cubic time.

Iron deficiency in chronic kidney disease patients with diabetes mellitus.

BACKGROUNDS: Iron deficiency has been studied extensively in patients with chronic kidney disease on hemodialysis therapy. However, few studies looked at iron treatment in the non-dialysis chronic kidney disease population. METHODS: Five hundred and eighty patients were studied (247 were diabetic persons). Patients were divided into 4 groups: non-diabetic subjects without CKD, non-diabetic ones with GFR < 60 mL/min, diabetic persons without CKD and diabetic ones with GFR < 60 mL/min). Iron deficiency was diagnosed when serum ferritin level was <100 mg/dl. It was defined as diminished iron availability when ferritin was above 100 mg/dl and serum transferrin saturation (TSAT) was <20%. RESULTS: Anemia was more frequent in the diabetic CKD patients group (52.4%, p < 0.001). Anemia prevalence was also higher in all CKD patients as well as in diabetic patients compared with non-diabetic ones. Iron deficiency was more frequent in diabetic patients. Among CKD diabetic patients the prevalence of iron deficiency was higher than in non-diabetic CKD ones. Diminished iron availability prevalence was higher in non-diabetic patients. Logistic regression analysis showed that only sex and diabetes mellitus were independently associated with iron deficiency. CONCLUSIONS: Anemia was more common in diabetic CKD patients. Diabetes mellitus was independently associated with iron deficiency. Surprisingly, diminished iron availability was not more frequent in diabetic patients. The physio-pathological mechanisms that could explain these findings remain to be elucidated.

A comparison of cystatin C concentrations between patients with chronic interstitial nephritis and glomerular diseases.

AIMS: Cystatin C have shown to be a renal function parameter with higher sensitivity and specificity than serum creatinine. In tubular diseases, cystatin C degradation and an increase in its urinary elimination would be observed. We have tried to define if different kinds of kidney diseases may significantly affect the serum levels of cystatin C. DESIGN AND METHODS: Four hundred and four patients were studied: 249 men and 155 women, mean age was 64.3±10.1 years. Patients were classified into three groups: (1) Chronic interstitial nephropathy (CIN), (2) Glomerular nephropathy (GN), and (3) Non- CKD patients (control). GFR was estimated though the CKD-EPI equation and the Hoek formula. RESULTS: Median of serum creatinine levels was higher in CIN group than in GN and control groups. Median cystatin C levels were lower in control group compared with CIN and GN groups. No significant differences were found between CIN group and GN group. Nevertheless, the cystatin/creatinine rate was lower in the CIN group patients (0.94, 0.81-1.11) than in the GN group (1.02,I 0.85-1.25) as well as the control group (1.02, I 0.88-1.20). The cystatin C-estimated GFR/creatinine-estimated GFR rate was higher in the CIN group (1.18, 1.03-1.36) than in the GN patients (1.03, 0.88-1.21) and control ones (1.07, 0.88-1.20). CONCLUSIONS: Patients with CIN had lower serum levels of cystatin C defined as cystatin C/creatinine rate when they were compared with GN subject and control ones. In the same way, the index between cystatin C-estimated GFR and creatinine-estimated GFR was higher in CIN patients.

Muerte súbita en pacientes con enfermedad renal crónica avanzada / Sudden cardiac death in non-dialysis chronic kidney disease patients

Antecedentes: Una alta proporción de fallecimientos en pacientes tratados mediante diálisis ocurre de forma súbita e inesperada. La incidencia de muerte súbita (MS) en pacientes con enfermedad renal crónica (ERC) en estadios prediálisis es menos conocida. Objetivos: Determinar la incidencia y factores asociados a la MS en una cohorte de 1.078 pacientes con ERC avanzada. Métodos: Estudio de cohortes prospectivo y de observación, que incluyó a pacientes con ERC estadio 4-5 prediálisis. La asociación entre las variables basales y la MS fue analizada mediante modelos de regresión de Cox y de competencia de riesgo (Fine y Gray). Los datos demográficos, clínicos, la medicación y los parámetros bioquímicos basales de potencial interés fueron incluidos como covariables en el análisis predictivo. Resultados: Durante el periodo de estudio (mediana de seguimiento 12 meses), fallecieron 210 pacientes (19%) y de forma súbita 34 casos (16% total de muertes). Las tasas de incidencia de muerte por cualquier causa y de MS fueron: 113 (IC 95%: 99-128) y 18 (IC 95%: 13-26) eventos por 1.000 pacientes/año, respectivamente. Mediante análisis de regresión de Cox, la edad, el índice de comorbilidad y el tratamiento con antiagregantes plaquetarios fueron las covariables que se asociaron significativamente con MS. Esta última covariable mostró un efecto beneficioso sobre el desarrollo de MS. En los modelos de regresión por competencia de riesgo, en los que el evento competidor fue la muerte no súbita por cualquier causa, solo la edad y el índice de comorbilidad se asociaron significativamente con la MS. Conclusiones: La MS es relativamente frecuente en pacientes con ERC prediálisis. La MS se asoció significativamente con la edad y la comorbilidad, y varios datos indirectos de este estudio muestran que un infradiagnóstico o infratratamiento de la enfermedad cardiovascular podría predisponer a un mayor riesgo de MS (AU)

BACKGROUND: A relatively high proportion of deaths in dialysis patients occur suddenly and unexpectedly. The incidence of sudden cardiac death (SCD) in non-dialysis advanced chronic kidney disease (CKD) stages has been less well investigated. OBJECTIVE: This study aims to determine the incidence and predictors of SCD in a cohort of 1078 patients with CKD not yet on dialysis. METHODS: Prospective observational cohort study, which included patients with advanced CKD not yet on dialysis (stage 4-5). The association between baseline variables and SCD was assessed using Cox and competing-risk (Fine and Grey) regression models. Demographic, clinical information, medication use, and baseline biochemical parameters of potential interest were included as covariates. RESULTS: During the study period (median follow-up time 12 months), 210 patients died (19%), and SCD occurred in 34 cases (16% of total deaths). All-cause mortality and SCD incidence rates were 113 (95% CI: 99-128), and 18 (95% CI: 13-26) events per 1000 patients/year, respectively. By Cox regression analysis, covariates significantly associated with SCD were: Age, comorbidity index, and treatment with antiplatelet drugs. This latter covariate showed a beneficial effect over the development of SCD. By competing-risk regression, in which the competing event was non-sudden death from any cause, only age and comorbidity index remained significantly associated with SCD. CONCLUSIONS: SCD is relatively common in non-dialysis advanced CKD PATIENTS: SCD was closely related to age and comorbidity, and some indirect data from this study suggest that unrecognised or undertreated cardiovascular disease may predispose to a higher risk of SCD (AU)

Sudden cardiac death in non-dialysis chronic kidney disease patients. / Muerte súbita en pacientes con enfermedad renal crónica avanzada.

BACKGROUND: A relatively high proportion of deaths in dialysis patients occur suddenly and unexpectedly. The incidence of sudden cardiac death (SCD) in non-dialysis advanced chronic kidney disease (CKD) stages has been less well investigated. OBJECTIVE: This study aims to determine the incidence and predictors of SCD in a cohort of 1078 patients with CKD not yet on dialysis. METHODS: Prospective observational cohort study, which included patients with advanced CKD not yet on dialysis (stage 4-5). The association between baseline variables and SCD was assessed using Cox and competing-risk (Fine and Grey) regression models. Demographic, clinical information, medication use, and baseline biochemical parameters of potential interest were included as covariates. RESULTS: During the study period (median follow-up time 12 months), 210 patients died (19%), and SCD occurred in 34 cases (16% of total deaths). All-cause mortality and SCD incidence rates were 113 (95% CI: 99-128), and 18 (95% CI: 13-26) events per 1000 patients/year, respectively. By Cox regression analysis, covariates significantly associated with SCD were: Age, comorbidity index, and treatment with antiplatelet drugs. This latter covariate showed a beneficial effect over the development of SCD. By competing-risk regression, in which the competing event was non-sudden death from any cause, only age and comorbidity index remained significantly associated with SCD. CONCLUSIONS: SCD is relatively common in non-dialysis advanced CKD patients. SCD was closely related to age and comorbidity, and some indirect data from this study suggest that unrecognised or undertreated cardiovascular disease may predispose to a higher risk of SCD.

Machine Learnable Fold Space Representation based on Residue Cluster Classes.

MOTIVATION: Protein fold space is a conceptual framework where all possible protein folds exist and ideas about protein structure, function and evolution may be analyzed. Classification of protein folds in this space is commonly achieved by using similarity indexes and/or machine learning approaches, each with different limitations. RESULTS: We propose a method for constructing a compact vector space model of protein fold space by representing each protein structure by its residues local contacts. We developed an efficient method to statistically test for the separability of points in a space and showed that our protein fold space representation is learnable by any machine-learning algorithm. AVAILABILITY: An API is freely available at https://code.google.com/p/pyrcc/.