Stress-induced hyperviscosity in the pathophysiology of takotsubo cardiomyopathy.

Takotsubo cardiomyopathy (TC) is characterized by transient hypokinesis of the left ventricular apex or midventricular segments with coronary arteries without significant stenosis. It is often associated with emotional or physical stress; however, its pathophysiology is still unclear. In the present study, we analyzed the alterations in blood viscosity and markers of endothelial damage induced by sympathetic stimulation in patients with previous TC.

Microvascular dysfunction, myocardial ischemia, and progression to heart failure in patients with hypertrophic cardiomyopathy.

Microvascular dysfunction can be demonstrated in most patients with hypertrophic cardiomyopathy (HCM), both in the hypertrophied and nonhypertrophied myocardial walls, mostly due to intimal and medial hyperplasia of the intramural coronary arteries and subsequent lumen reduction. As a consequence, regional myocardial ischemia may be triggered by exercise, increased heart rate, or arrhythmias, in areas which are unable to increase myocardial blood flow. In patients with HCM, microvascular dysfunction leading to severe myocardial hypoperfusion during maximal hyperemia represents a strong predictor of unfavorable outcome, left ventricular remodeling with progressive wall thinning, left ventricular dysfunction, and heart failure.

Cytochrome P450 2C19 loss-of-function polymorphism, but not CYP3A4 IVS10 + 12G/A and P2Y12 T744C polymorphisms, is associated with response variability to dual antiplatelet treatment in high-risk vascular patients.

Objectives: The aim of this study was to evaluate the effect of polymorphisms affecting the clopidogrel metabolism (CYP3A4 IVS10+12G/A and CYP2C19*2) and the P2Y12 receptor (P2Y12 T744C) on modulating platelet function in acute coronary syndrome patients on dual antiplatelet treatment.

Background: Residual platelet reactivity (RPR) phenomenon on antiplatelet therapy requires clarification. P2Y12 T744C, CYP3A4 IVS10+12G/A and, in healthy individuals only, CYP2C19*2 polymorphisms have been investigated; however, the influence on platelet reactivity in a large population of high-risk vascular patients on dual antiplatelet treatment has not yet been elucidated.

Midventricular obstruction and clinical decision-making in obstructive hypertrophic cardiomyopathy.

The presence of intraventricular obstruction is a powerful predictor of outcome in patients with hypertrophic cardiomyopathy (HCM) and, when associated with severe, drug-refractory symptoms, should be managed aggressively. Resting left ventricular outflow obstruction is found in approximately 20% of the patients, classically occurs at the subaortic level, and is associated with mitral valve systolic anterior motion (SAM). In a minority of patients, however, the impedance to flow occurs at midventricular level, unrelated to SAM.

Use of the Parodi anti-embolism system in carotid stenting: Italian trial results.

Purpose: To investigate the safety and efficacy of the Parodi anti-embolism system (PAES) in establishing flow reversal in the internal carotid artery (ICA) as a means of protecting against embolic phenomena during carotid stenting.

Methods: Seven centers participated in a nonrandomized, prospective trial of carotid angioplasty and stenting under PAES protection in 30 patients (22 men; mean age 72 years, range 49-88) with 15 symptomatic (>70%) and 15 asymptomatic (>80%) stenotic ICAs. Safety was defined as achieving sufficient brain oxygenation during flow reversal as determined by level of awareness and motor control.