Antiplatelet therapy in elderly patients with acute coronary syndrome: Between scientific evidence and future perspectives.

Dual antiplatelet therapy (DAPT) is an important strategy for reducing cardiovascular events (CV) after an acute coronary syndrome (ACS). Elderly patients undergoing DAPT have a higher risk of bleeding than younger patients for a variety of reasons. Stratification of thrombotic/hemorrhagic risk is mandatory in order to decide on the type and duration of DAPT. The percentage of patients ≥ 75 years represented in clinical trials is not large, so very often elderly people are prescribed treatment protocols only experimented on younger patients with a lower hemorrhagic risk. However, even in patients aged ≥ 75 treated with invasive or conservative therapy, after an ACS, a DAPT with aspirin 80-100 mg/day plus a P2Y12 receptor inhibitor for 12 months is recommended. In elderly patients, DAPT should be considered a dynamic process that can be modified over time based on the patient's clinical conditions, or any other necessities (non-procrastinating surgical interventions, comorbid-like effects that can increase hemorrhagic risk). In patients with moderate-high or very high hemorrhagic risk, DAPT treatment should last less than 12 months. A prolongation of DAPT beyond 12 months in this setting is limited to a very low percentage of patients, after careful assessment of ischemic/hemorrhagic profile

Local and Global Energies for Shape Analysis in Medical Imaging

In a previous contribution a new Riemannian shape space, named TPS space, was introduced to perform statistics on shape data. This space was endowed with a Rie-mannian metric and a flat connection, with torsion, compatible with the given metric. This connection allows the definition of a Parallel Transport of the deformation compatible with the threefold decomposition in spherical, deviatoric and non affine components. Such a Parallel Transport also conserves the-energy, strictly related to the total elastic strain energy stored by the body in the original deformation. New machinery is here presented in order to calculate the bending energy on the body only (body bending energy) in order to restrict it exclusively within physical boundaries of objects involved in the deformation analysis. The novelty of this new procedure resides in the fact that we propose a new metric to conserve during the TPS direct transport. This allows transporting the shape change more coherently with the mechanical meaning of the deformation. The geometry of the TPS Space is then further developed in order to better represent the relationship between the-energy, the strain energy and the so called bending-energy densities

Left atrial trajectory impairment in hypertrophic cardiomyopathy disclosed by geometric morphometrics and parallel transport

The analysis of full Left Atrium (LA) deformation and whole LA deformational trajectory in time has been poorly investigated and, to the best of our knowledge, seldom discussed in patients with Hypertrophic Cardiomyopathy. Therefore, we considered 22 patients with Hypertrophic Cardiomyopathy (HCM) and 46 healthy subjects, investigated them by three-dimensional Speckle Tracking Echocardiography, and studied the derived landmark clouds via Geometric Morphometrics with Parallel Transport. Trajectory shape and trajectory size were different in Controls versus HCM and their classification powers had high AUC (Area Under the Receiving Operator Characteristic Curve) and accuracy. The two trajectories were much different at the transition between LA conduit and booster pump functions. Full shape and deformation analyses with trajectory analysis enabled a straightforward perception of pathophysiological consequences of HCM condition on LA functioning. It might be worthwhile to apply these techniques to look for novel pathophysiological approaches that may better define atrio-ventricular interaction

The TPS Direct Transport: a new method for transporting deformations in the Size-and-shape Space

Modern shape analysis allows the fine comparison of shape changes occurring between different objects. Very often the classic machineries of Generalized Procrustes Analysis and Principal Component Analysis are used in order to contrast the shape change occurring among configurations represented by homologous landmarks. However, if size and shape data are structured in different groups thus constituting different morphological trajectories, a data centering is needed if one wants to compare solely the deformation representing the trajectories. To do that, inter-individual variation must be filtered out. This maneuver is rarely applied in studies using simulated or real data. A geometrical procedure named Parallel Transport, that can be based on various connection types, is necessary to perform such kind of data centering. Usually, the Levi Civita connection is used for interpolation of curves in a Riemannian space. It can also be used to transport a deformation. We demonstrate that this procedure does not preserve some important characters of the deformation, even in the affine case. We propose a novel procedure called `TPS Direct Transport' which is able to perfectly transport deformation in the affine case and to better approximate non affine deformation in comparison to existing tools. We recommend to center shape data using the methods described here when the differences in deformation rather than in shape are under study

Intravenous versus intracoronary bolus of glycoprotein IIb/IIIa inhibitor administration during primary percutaneous coronary intervention on long-term left ventricular systolic and diastolic function

Background: In primary percutaneous coronary intervention (PCI), glycoprotein (GP) IIb/IIIa inhibitors are often given in order to attain and maintain better myocardial perfusion. Wetested the hypothesis that intracoronary (IC) bolus of GP IIb/IIIa inhibitors might producea greater improvement in left ventricular (LV) systolic and diastolic function than an intravenous(IV) bolus.Methods and results: Seventy seven patients undergoing primary PCI for their firstST elevation myocardial infarction (STEMI) were randomly assigned to either an IC or IVbolus of GP IIb/IIIa inhibitor, followed by IV infusion. Compared with the echocardiographic findings within 3 days after PCI, LV ejection fraction was higher at 1 year, with no significant differences between the IV and IC groups (IV: 44% vs. 49%, p = 0.001; IC: 43% vs. 48%,p < 0.001). LV diastolic function (E/E’) did not significantly change at 1 year by either approach.Conclusions: LV systolic function improved by a similar magnitude following primary PCI, with either IC or IV bolus administration of GP IIb/IIIa inhibitor therapy. However, no significant changes were observed in LV diastolic function

intravenous versus intracoronary bolus of glycoprotein iib iiia inhibitor administration during primary percutaneous coronary intervention on long term left ventricular systolic and diastolic function

Background: In primary percutaneous coronary intervention (PCI), glycoprotein (GP) IIb/IIIa inhibitors are often given in order to attain and maintain better myocardial perfusion. Wetested the hypothesis that intracoronary (IC) bolus of GP IIb/IIIa inhibitors might producea greater improvement in left ventricular (LV) systolic and diastolic function than an intravenous(IV) bolus. Methods and results: Seventy seven patients undergoing primary PCI for their firstST elevation myocardial infarction (STEMI) were randomly assigned to either an IC or IVbolus of GP IIb/IIIa inhibitor, followed by IV infusion. Compared with the echocardiographic findings within 3 days after PCI, LV ejection fraction was higher at 1 year, with no significant differences between the IV and IC groups (IV: 44% vs. 49%, p = 0.001; IC: 43% vs. 48%,p < 0.001). LV diastolic function (E/E') did not significantly change at 1 year by either approach. Conclusions: LV systolic function improved by a similar magnitude following primary PCI, with either IC or IV bolus administration of GP IIb/IIIa inhibitor therapy. However, no significant changes were observed in LV diastolic function

The decomposition of deformation: new metrics to enhance shape analysis in medical imaging

In landmarks-based Shape Analysis size is measured, in most cases, with Centroid Size. Changes in shape are decomposed in affine and non affine components. Furthermore the non affine component can be in turn decomposed in a series of local deformations (partial warps). If the extent of deformation between two shapes is small, the difference between centroid size and m-Volume increment is barely appreciable. In medical imaging applied to soft tissues bodies can undergo very large deformations, involving large changes in size. The cardiac example, analyzed in the present paper, shows changes in m-Volume that can reach the 60%. We show here that standard Geometric Morphometrics tools (landmarks, Thin Plate Spline, and related decomposition of the deformation) can be generalized to better describe the very large deformations of biological tissues, without losing a synthetic description. In particular, the classical decomposition of the space tangent to the shape space in affine and non affine components is enriched to include also the change in size, in order to give a complete description of the tangent space to the size-and-shape space. The proposed generalization is formulated by means of a new Riemannian metric describing the change in size as change in m-Volume rather than change in Centroid Size. This leads to a redefinition of some aspects of the Kendall’s size-and-shape space without losing Kendall’s original formulation. This new formulation is discussed by means of simulated examples using 2D and 3D platonic shapes as well as a real example from clinical 3D echocardiographic data. We demonstrate that our decomposition based approaches discriminate very effectively healthy subjects from patients affected by Hypertrophic Cardiomyopathy