Spyridon Papaioannou

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It is well known that the endothelium maintains the vascular homeostasis. Importantly, endothelial dysfunction is regarded as a key early step in the development of atherosclerosis. Back in the early 1990s, it was found that asymmetric dimethylarginine (ADMA), an arginine metabolite derived from l-arginine (Arg) residues in proteins by asymmetric(More)
Atherosclerotic lesions initiate in regions characterized by low shear stress and reduced activity of endothelial atheroprotective molecules such as nitric oxide, which is the key molecule managing vascular homeostasis. The generation of reactive oxygen species from the vascular endothelium is strongly related to various enzymes, such as xanthine oxidase,(More)
Asymmetric dimethylarginine (ADMA) is a competitive endogenous inhibitor of nitric oxide synthase with a key role in the pathophysiology of endothelial dysfunction, in the progression of atherosclerosis and in cardiovascular diseases. Statins, renin-angiotensin-aldosterone system inhibitors, blood glucose lowering agents, insulin sensitizers, beta-blockers,(More)
BACKGROUND Although the use of myocardial perfusion imaging (MPI) for prognostic purposes in general population is well understood, its role in very elderly patients is not extensively studied. METHODS 247 octgogenarians (79% male, 56% previous myocardial infarction-MI or revascularization) who underwent treadmill exercise testing (TET) with MPI were(More)
BACKGROUND In the present study, we evaluated the association of platelet reactivity with vascular function in patients after percutaneous coronary intervention receiving clopidogrel treatment. METHODS We enrolled 150 patients with stable CAD receiving clopidogrel regimen (75 mg/d), 1 month after percutaneous coronary intervention. Carotid-femoral pulse(More)
BACKGROUND Evaluation of tolerability, safety, and prognostic implications of adenosine stress myocardial perfusion imaging (MPI) in octogenarians. METHODS 370 octogenarians (49% known coronary artery disease) were studied. Hemodynamic response, MPI-related data, and rest-left ventricular ejection fraction (LVEF) based on echocardiography were registered(More)
Evaluation of the long-term prognostic value of myocardial perfusion imaging (MPI) in octogenarians. Six hundred and twenty-nine octogenarians [51% previous myocardial infarction (MI) or revascularization] who underwent single-isotope MPI (78% 201Tl, 22% 99mTc-tetrofosmin) with exercise (38% Bruce, 2% leg ergometry) or pharmacologic (58% adenosine, 2%(More)