El peligro de los metanálisis Hernández-Vaquero, Daniel; Díaz, Rocío; Avanzas, Pablo ...
Revista española de cardiologia,
September 2021, 2021-09-00, Letnik:
74, Številka:
9
Journal Article
: Diurnal rhythms influence cardiovascular physiology, i.e. heart rate and blood pressure, and they appear to also modulate the incidence of serious adverse cardiac events. Diurnal variations occur ...also at the molecular level including changes in gene expression in the heart and blood vessels. Moreover, the risk/benefit ratio of some therapeutic strategies and the concentration of circulating cardiovascular system biomarkers may also vary across the 24‐hr light/dark cycle. Synchrony between external and internal diurnal rhythms and harmony among molecular rhythms within the cell are essential for normal organ biology. Diurnal variations in the responsiveness of the cardiovascular system to environmental stimuli are mediated by a complex interplay between extracellular (i.e. neurohumoral factors) and intracellular (i.e. specific genes that are differentially light/dark regulated) mechanisms. Neurohormones, which are particularly relevant to the cardiovascular system, such as melatonin, exhibit a diurnal variation and may play a role in the synchronization of molecular circadian clocks in the peripheral tissue and the suprachiasmatic nucleus. Moreover, mounting evidence reveals that the blood melatonin rhythm has a crucial role in several cardiovascular functions, including daily variations in blood pressure. Melatonin has antioxidant, anti‐inflammatory, chronobiotic and, possibly, epigenetic regulatory functions. This article reviews current knowledge related to the biological role of melatonin and its circadian rhythm in cardiovascular disease.
To explore whether episodes of exposure to atmospheric Saharan dust is a risk factor for hospitalization in patients with acute heart failure (AHF) attended in a hospital emergency department (ED).
...Single-center retrospective study of patients with AHF. The cohort was analyzed in 2 groups: ED patients hospitalized with AHF and patients discharged home from the ED. Air pollution on the 5 days leading to ED admission for AHF was recorded as the average concentration of breathable particulate matter with an aerodynamic diameter of no more than 10 µm (PM10) in the following ranges: fine PM (diameter less than 2.5 µm) or coarse PM (diameters between 2.5 and 10 µm). High Saharan dust pollution exposure was defined by mean daily PM10 concentrations between 50 and 200 µg/m3. Multivariable analysis was used to estimate risk for AHF in relation to PM10 exposure in the 5 days before the ED visit.
A total of 1097 patients with AHF were treated in the ED; 318 of them (29%) were hospitalized and 779 (71%) were discharged home. Hospitalized patients were older, had more concomitant illnesses, and more episodes of exposure to Saharan dust (P < .0001). Multivariable analysis confirmed the association between Saharan dust exposure and hospital admission in these patients (odds ratio, 2.36; 95% CI, 1.21-4.58; P = .01).
In the absence of prospective studies, the results of this series suggest that exposure to high levels of Saharan dust (PM10 concentrations between 50 and 200 µg/m3) may be a precipitating factor for hospitalization in AHF episodes.
The treatment of heart failure continues to pose a real challenge for clinicians. This condition is sometimes reversible and therapy should therefore pursue this outcome. In the context of coronary ...ischemic syndromes, myocardial stunning can cause heart failure and even cardiogenic shock, with important prognostic repercussions. Myocardial stunning is mainly due to calcium overload in the cytosol of myocardial cells, the loss of myofilaments and their reduced sensitivity to calcium. Enhanced immune activation with inflammatory phenomena also plays an important role in the pathophysiology of cardiac dysfunction. Increasing evidence has shown that the myocardial ATP-dependent potassium channel (K(ATP)) plays an important role in many myocardial cell functions and that it is involved in ischemia-reperfusion injury and myocardial stunning. K(ATP) is thus considered a therapeutic target in this setting. Currently used inotropic drugs improve contractility by increasing intracellular concentrations of free calcium, but they increase myocardial consumption of energy and even produce arrhythmia; therefore, in this clinical context, they do not seem to be 'pathophysiologically correct' drugs. Levosimendan, a new calcium-sensitizing agent, increases contractility by enhancing the sensitivity of myofilaments to calcium by binding to the C cardiac troponin in cardiac muscle in a calcium-dependent way. Levosimendan also exerts a coronary and systemic vasodilatory effect through its K(ATP) channel-opening properties and may exert other cardioprotective actions through this mechanism. Levosimendan produces positive hemodynamic effects without increasing myocardial oxygen demand or causing arrhythmias. Intravenous levosimendan is generally well tolerated and has been approved by several European countries, and recently recommended in European Society of Cardiology guidelines, as inotropic therapy for the short-term treatment of acute severe decompensated heart failure in adults. Randomized, double-blind trials have shown that levosimendan is not only more clinically and hemodynamically effective but also that it significantly reduces morbidity and mortality when compared with dobutamine or placebo. Clinical trials addressing the use and efficacy of intravenous levosimendan in acute heart failure in patients with systolic dysfunction or cardiogenic shock due to myocardial stunning are scarce. Beneficial effects on myocardial contractility in patients with myocardial stunning have only been shown in small clinical trials. A positive experience with levosimendan in a small series of patients with cardiogenic shock complicating ST-elevation myocardial infarction suggests that the use of this drug in cardiogenic shock should be further evaluated.
There is a lack of knowledge about the real incidence of acute coronary syndrome (ACS) in patients with COVID-19, their clinical characteristics, and their prognoses.
We investigated the incidence, ...clinical characteristics, risk factors, and outcomes of ACS in patients with COVID-19 in the emergency department.
We retrospectively reviewed all COVID-19 patients diagnosed with ACS in 62 Spanish emergency departments between March and April 2020 (the first wave of COVID-19). We formed 2 control groups: COVID-19 patients without ACS (control A) and non–COVID-19 patients with ACS (control B). Unadjusted comparisons between cases and control subjects were performed regarding 58 characteristics and outcomes.
We identified 110 patients with ACS in 74,814 patients with COVID-19 attending the ED (1.48% 95% confidence interval {CI} 1.21–1.78%). This incidence was lower than that observed in non–COVID-19 patients (3.64% 95% CI 3.54–3.74%; odds ratio OR 0.40 95% CI 0.33–0.49). The clinical characteristics of patients with COVID-19 associated with a higher risk of presenting ACS were: previous coronary artery disease, age ≥60 years, hypertension, chest pain, raised troponin, and hypoxemia. The need for hospitalization and admission to intensive care and in-hospital mortality were higher in cases than in control group A (adjusted OR aOR 6.36 95% CI 1.84–22.1, aOR 4.63 95% CI 1.88–11.4, and aOR 2.46 95% CI 1.15–5.25). When comparing cases with control group B, the aOR of admission to intensive care was 0.41 (95% CI 0.21–0.80), while the aOR for in-hospital mortality was 5.94 (95% CI 2.84–12.4).
The incidence of ACS in patients with COVID-19 attending the emergency department was low, around 1.48%, but could be increased in some circumstances. Patients with COVID-19 with ACS had a worse prognosis than control subjects with higher in-hospital mortality.
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