Brain Natriuretic Peptide: Structure, Action and Role in the Diagnosis and Prognosis of Heart Failure

Brain natriuretic peptide (BNP) is a peptide hormone secreted by cardiomyocytes in response to atrial or ventricular wall stretch. It promotes a number of systemic effects, including vasodilatation, increase in urinary output and sodium excretion as well as inhibition of the sympathetic nervous system and the renin–angiotensin–aldosterone system. Plasma BNP levels have been reported to be elevated in patients with left ventricular hypertrophy, congestive heart failure, acute coronary syndromes, atrial fibrillation and impaired renal function. Moreover, elevated BNP levels have been shown to be a strong predictor of morbidity and mortality in patients with heart failure. Interestingly, it has also been found that the N-terminal peptide of BNP is slightly superior to BNP for predicting death or re-hospitalization for heart failure. Presumably, it is the longer half-life of NT-pro-BNP that may promote it as a more accurate index of ventricular stress and therefore a better predictor of prognosis

Unobserved automated office BP is similar to other clinic BP measurements: A prospective randomized study

Results of the SPRINT study have been disputed, based on the assumption that unattended BP measurements do not correlate with usual BP measurements. In this study, the authors investigated the correlation of unattended SPRINT-like measurements with other conventional measurements. All BP measurements were taken with the patient seated in a comfortable chair with the legs uncrossed and not speaking during the procedure. For the purpose of this study, sixty-five patients, mostly male (93%), were recruited from our hypertension clinic and all were on antihypertensive medication (av 3.0 ± 1.1). Patients were at high cardiovascular risk with high rates of comorbidities, av age 68 ± 12 years, 49% with diabetes, 34% with mild CKD (CKD 1-3, average eGFR 55.0 ± 13 mL/min/1.73 m2), and 20% with history of stable coronary artery disease. All BP measurements were similar with no statistically significant difference (one-way ANOVA, P = 0.621). Compared to unattended SPRINT BP values (139.77 ± 19.22/75.42 ± 11.72 mm Hg), the clinic BP measurements were numerically slightly higher but with a NS P value (P = 0.163). Similarly, unattended BP measurements were similar to values taken by the clinic physician. In a smaller cohort of 11 patients, the authors compared unobserved vs observed SPRINT-like BP measurements, and in 13 patients, the authors compared unobserved SPRINT-like BP measurements to average home BP measurements (Table 3). There were no significant differences between any of the subgroups (one-way ANOVA, P = 0.816 for systolic and P = 0.803 for diastolic). The authors conclude that unattended BP measurements taken (the SPRINT way) are similar to other conventional office blood pressure measurements. ©2018 Wiley Periodicals, Inc

Diabetes mellitus in the era of climate change

Worldwide, diabetes mellitus (DM) represents a major public-health problem due to its increasing prevalence in tandem with the rising trend of obesity. However, climate change, with its associated negative health effects, also constitutes a worrisome problem. Patients with DM are experiencing more visits to emergency departments, hospitalizations, morbidity and mortality during heat waves at ever-increasing numbers. Such patients are particularly vulnerable to heat waves due to impaired thermoregulatory mechanisms in conjunction with impaired autonomous nervous system responses at high temperatures, electrolyte imbalances and rapid deterioration of kidney function, particularly among those aged > 80 years and with preexisting chronic kidney disease (CKD). Moreover, exposure to cold temperatures is associated with increased rates of acute myocardial infarction as well as poor glycaemic control, although results are conflicting regarding cold-related mortality among patients with DM. In addition to extremes of temperature, air pollution as a consequence of the climate crisis may also be implicated in the increased prevalence and incidence of DM, particularly gestational DM (GDM), and lead to deleterious effects in patients with DM. Thus, more large-scale studies are now required to elucidate the association between specific air pollutants and risk of DM. This review presents the currently available evidence for the detrimental effects of climate change, particularly those related to weather variables, on patients with DM (both type 1 and type 2) and GDM. Specifically, the effects of heat waves and extreme cold, and pharmaceutical and therapeutic issues and their implications, as well as the impact of air pollution on the risk for DM are synthesized and discussed here. (C) 2020 Elsevier Masson SAS. All rights reserved

Cluster-distinguishing genotypic and phenotypic diversity of carbapenem-resistant gram-negative bacteria in solid-organ transplantation patients: A comparative study

Purpose. Solid-organ transplant recipients may display high rates of colonization and/or infection by multidrug-resistant bacteria. We analysed and compared the phenotypic and genotypic diversity of carbapenem-resistant (CR) strains of Klebsiella pneumoniae, Pseudomonas aeruginosa and Acinetobacter baumannii isolated from patients in the Solid Organ Transplantation department of our hospital. Methodology. Between March 2012 and August 2013, 56 CR strains from various biological fluids underwent antimicrobial susceptibility testing with VITEK 2, molecular analysis by PCR amplification and genotypic analysis with pulsed-field gel electrophoresis (PFGE). They were clustered according to antimicrobial drug susceptibility and genotypic profiles. Diversity analyses were performed by calculating Simpson’s diversity index and applying computed rarefaction curves. Results/Key findings. Among K. pneumoniae, KP-producers predominated (57.1%). VIM and OXA-23 carbapenemases prevailed among P. aeruginosa and A. baumannii (89.4 and 88.9%, respectively). KPC-producing K. pneumoniae and OXA-23 A. baumannii were assigned in single PFGE pulsotypes. VIM-producing P. aeruginosa generated multiple pulsotypes. CR K. pneumoniae strains displayed phenotypic diversity in tigecycline, colistin (CS), amikacin (AMK), gentamicin (GEN) and cotrimoxazole (SXT) (16 clusters); P. aeruginosa displayed phenotypic diversity in cefepime (FEP), ceftazidime, aztreonam, piperacillin, piperacillin–tazobactam, AMK, GEN and CS (9 clusters); and A. baumannii displayed phenotypic diversity in AMK, GEN, SXT, FEP, tobramycin and rifampicin (8 clusters). The Simpson diversity indices for the interpretative phenotype and PFGE analysis were 0.89 and 0.6, respectively, for K. pneumoniae strains (P < 0.001); 0.77 and 0.6 for P. aeruginosa (P=0.22); and 0.86 and 0.19 for A. baumannii (P=0.004). Conclusion. The presence of different antimicrobial susceptibility profiles does not preclude the possibility that two CR K. Pneumoniae or A. baumannii isolates are clonally related. © 2017 The Authors

Epidemiological surveillance of multidrug-resistant gram-negative bacteria in a solid organ transplantation department

Background: We assessed the impact of intensified infection control measures (ICM) on colonization and infection caused by carbapenem-resistant (CR) Klebsiella pneumoniae, Pseudomonas aeruginosa, and Acinetobacter baumannii in a solid organ transplantation (SOT) department. Methods: A quasi-experimental methodology was followed. The study was divided into three periods: pre-intervention, intervention with implementation of an ICM bundle including active surveillance program (ASP) and gradually enhanced measures, and post-ASP without ASP. The bundle included active surveillance cultures, contact precautions, hand hygiene, education of health care workers (HCWs), monitoring of compliance, and environmental cleaning. Incidence of colonization and infection caused by CR gram-negative bacteria was recorded. Molecular analysis of CR bacteria was performed for a certain period. Results: During the intervention, incidence of colonization reduced from 19% to 9% (P<.001). The compliance of HCWs with contact precautions and hand hygiene also improved. Monthly incidence of infections caused by these CR bacteria increased from 2.8 to 6.9/1000 bed-days (P<.001). However, this increase did not have such a strong trend after the intervention. Most K. pneumoniae isolates, the commonest pathogen, carried the blaKPC gene. Colonization and infection rates by CR K. pneumoniae, P. aeruginosa, and A. baumannii were high among SOT recipients. Conclusion: In settings where CR gram-negative bacteria are endemic, colonization and infection rates by these bacteria are high among SOT recipients. Implementation of enhanced ICM in all related units of a hospital, although challenging, reduces colonization rates by CR gram-negative bacteria. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Lt

Cluster-distinguishing genotypic and phenotypic diversity of carbapenem-resistant gram-negative bacteria in solid-organ transplantation patients: A comparative study

Purpose. Solid-organ transplant recipients may display high rates of colonization and/or infection by multidrug-resistant bacteria. We analysed and compared the phenotypic and genotypic diversity of carbapenem-resistant (CR) strains of Klebsiella pneumoniae, Pseudomonas aeruginosa and Acinetobacter baumannii isolated from patients in the Solid Organ Transplantation department of our hospital. Methodology. Between March 2012 and August 2013, 56 CR strains from various biological fluids underwent antimicrobial susceptibility testing with VITEK 2, molecular analysis by PCR amplification and genotypic analysis with pulsed-field gel electrophoresis (PFGE). They were clustered according to antimicrobial drug susceptibility and genotypic profiles. Diversity analyses were performed by calculating Simpson’s diversity index and applying computed rarefaction curves. Results/Key findings. Among K. pneumoniae, KP-producers predominated (57.1%). VIM and OXA-23 carbapenemases prevailed among P. aeruginosa and A. baumannii (89.4 and 88.9%, respectively). KPC-producing K. pneumoniae and OXA-23 A. baumannii were assigned in single PFGE pulsotypes. VIM-producing P. aeruginosa generated multiple pulsotypes. CR K. pneumoniae strains displayed phenotypic diversity in tigecycline, colistin (CS), amikacin (AMK), gentamicin (GEN) and cotrimoxazole (SXT) (16 clusters); P. aeruginosa displayed phenotypic diversity in cefepime (FEP), ceftazidime, aztreonam, piperacillin, piperacillin–tazobactam, AMK, GEN and CS (9 clusters); and A. baumannii displayed phenotypic diversity in AMK, GEN, SXT, FEP, tobramycin and rifampicin (8 clusters). The Simpson diversity indices for the interpretative phenotype and PFGE analysis were 0.89 and 0.6, respectively, for K. pneumoniae strains (P < 0.001); 0.77 and 0.6 for P. aeruginosa (P=0.22); and 0.86 and 0.19 for A. baumannii (P=0.004). Conclusion. The presence of different antimicrobial susceptibility profiles does not preclude the possibility that two CR K. Pneumoniae or A. baumannii isolates are clonally related. © 2017 The Authors

Adenosine-Guided Pulmonary Vein Antral Isolation for Paroxysmal Atrial Fibrillation: A Randomized Study

Objectives: The prognostic significance of adenosine-mediated pulmonary vein (PV) dormant conduction and whether such conduction should be eliminated still remain controversial. This randomized study aimed to investigate whether adenosine-guided ablation of the reconnection gaps improves the long-term outcomes of pulmonary vein antral isolation (PVAI) for paroxysmal atrial fibrillation (AF). Methods and Results: Consecutive patients with paroxysmal AF were randomly assigned to undergo (n = 80, group 1) or not (n = 81, group 2) adenosine testing following PVAI. Adenosine-mediated PV dormant conduction was unmasked in 26 patients (32.5%) of group 1. Successful elimination of the reconnection gaps was subsequently performed in all patients. During a mean follow-up period of 11.39 ± 5.10 months, 30 patients of group 1 (37.5%), and 27 patients of group 2 (33.3%) experienced arrhythmia recurrence. The Kaplan–Meier arrhythmia free survival curves failed to demonstrate any significant differences between study groups (log rank 0.217, P = 0.642). Fourteen of 26 (53.8%) patients with adenosine-mediated dormant conduction and subsequent elimination of reconnection gaps experienced AF recurrence during follow-up. On the contrary, only 16 of 54 patients without dormant conduction (29.6%) displayed arrhythmia recurrence (P = 0.049). Logistic regression analysis showed that adenosine-mediated PV reconnection (hazard ratio 0.292, 95% confidence interval 0.122–0.483; P = 0.01) was an independent predictor of AF recurrence. Conclusion: In this patients’ cohort, adenosine-mediated PV reconnection is predictive of future arrhythmic events. Elimination of dormant conduction with additional ablation lesions does not improve the long-term outcome of the procedure compared to the standard PVAI. © 2016 Wiley Periodicals, Inc