Elevation of the sensitive acute-phase proteins C-reactive protein and serum amyloid A protein at the time of hospital admission predicts a poor outcome in patients with unstable angina and may reflect an important inflammatory component in the pathogenesis of this condition.
The widespread activation of neutrophils across the coronary vascular bed in patients with unstable angina, regardless of the location of the culprit stenosis, challenges the concept of a single vulnerable plaque in unstable coronary syndromes.
Background-Experimental interleukin-1 receptor antagonist gene overexpression has shown that interleukin-1 receptor antagonist is cardioprotective during global cardiac ischemia. The aim of the present study was to test the impact of an exogenous recombinant human interleukin-1 receptor antagonist (anakinra) in experimental acute myocardial infarction. Methods and Results-Two animal studies were conducted: one of immediate anakinra administration during ischemia in the mouse and one of delayed anakinra administration 24 hours after ischemia in the rat. Seventy-eight Institute of Cancer Research mice and 20 Wistar rats underwent surgical coronary artery ligation (or sham operation) and were treated with either anakinra 1 mg/kg or NaCl 0.9% (saline). Treatment was administered during surgery and then daily for 6 doses in the mice and starting on day 2 daily for 5 doses in the rats. Twenty-eight mice underwent infarct size assessment 24 hours after surgery, 6 saline-treated mice and 22 mice treated with increasing doses of anakinra (1 mg/kg [nϭ6], 10 mg/kg [nϭ6], and 100 mg/kg [nϭ10]); 6 mice were euthanized at 7 days for protein expression analysis. The remaining animals underwent transthoracic echocardiography before surgery and 7 days later just before death. Cardiomyocyte apoptosis was measured in the peri-infarct regions. The antiapoptotic effect of anakinra was tested in a primary rat cardiomyocyte culture during simulated ischemia and in vitro on caspase-1 and -9 activities. At 7 days, 15 of the 16 mice (94%) treated with anakinra were alive versus 11 of the 20 mice (55%) treated with saline (Pϭ0.013).No differences in infarct size at 24 hours compared with saline were observed with the 1-and 10-mg/kg doses, whereas a 13% reduction in infarct size was found with the 100-mg/kg dose (Pϭ0.015). Treatment with anakinra was associated with a significant reduction in cardiomyocyte apoptosis in both the immediate and delayed treatment groups (3.1Ϯ0.2% versus 0.5Ϯ0.3% [PϽ0.001] and 4.2Ϯ0.4% versus 1.1Ϯ0.2% [PϽ0.001], respectively). Compared with saline-treated animals, anakinra-treated mice and rats showed signs of more favorable ventricular remodeling. In vitro, anakinra significantly prevented apoptosis induced by simulated ischemia and inhibited caspase-1 and -9 activities. Conclusions-Administration of anakinra within 24 hours of acute myocardial infarction significantly ameliorates the remodeling process by inhibiting cardiomyocyte apoptosis in 2 different experimental animal models of AMI. This may open the door for using anakinra to prevent postischemic cardiac remodeling and heart failure.
Preprocedural CRP level, an easily measurable marker of acute phase response, is a powerful predictor of both early and late outcome in patients undergoing single vessel PTCA, suggesting that early complications and clinical restenosis are markedly influenced by the preprocedural degree of inflammatory cell activation.
Myeloperoxidase (MPO) is an enzyme stored in azurophilic granules of polymorphonuclear neutrophils and macrophages and released into extracellular fluid in the setting of inflammatory process. The observation that myeloperoxidase is involved in oxidative stress and inflammation has been a leading factor to study myeloperoxidase as a possible marker of plaque instability and a useful clinical tool in the evaluation of patients with coronary heart disease. The purpose of this review is to provide an overview of the pathophysiological, analytical, and clinical characteristics of MPO and to summarize the state of art about the possible clinical use of MPO as a marker for diagnosis and risk stratification of patients with acute coronary syndrome (ACS).
Sex has a profound impact on myocardial remodeling, which is defined as the molecular and cellular events after an injury to the myocardium (i.e., necrosis, pressure overload, volume overload, and aging) leading to a change in shape, dimension, and function of cardiac chambers. Indeed, experimental studies and post-mortem and observational clinical studies suggest the presence of important differences in myocardial remodeling between females and males in response to different types of injures including aging, pressure and volume overload, and myocardial infarction. Interestingly, the remodeling process appears to be more favorable in women versus men; women are more likely to present heart failure with preserved systolic function and are at greater risk for low output syndrome acutely. These differences between men and women are widely held to be related to sex hormones such as estrogen, although the molecular effects of estrogen on ventricular cardiomyocytes are incompletely understood. In this review, we summarize the evidence supporting these notions and discuss the underlying mechanisms and the clinical implications.
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