Longitudinal dynamics of circulating miRNAs in a swine model of familial hypercholesterolemia during early atherosclerosis.

Atherosclerosis is a complex progressive disease involving intertwined biological mechanisms. We aimed to identify miRNA expression dynamics at the early stages of atherosclerosis using a large swine model (Wisconsin Miniature Swine, WMS). A total of 18 female pigs; 9 familial hypercholesterolemic (WMS-FH) and 9 normal control swine (WMS-N) were studied.

Design and construction of three-dimensional physiologically-based vascular branching networks for respiratory assist devices.

Microfluidic lab-on-a-chip devices are changing the way that diagnostics and drug development are conducted, based on the increased precision, miniaturization and efficiency of these systems relative to prior methods. However, the full potential of microfluidics as a platform for therapeutic medical devices such as extracorporeal organ support has not been realized, in part due to limitations in the ability to scale current designs and fabrication techniques toward clinically relevant rates of blood flow. Here we report on a method for designing and fabricating microfluidic devices supporting blood flow rates per layer greater than 10 mL min for respiratory support applications, leveraging advances in precision machining to generate fully three-dimensional physiologically-based branching microchannel networks.

Preclinical in vivo long-term evaluation of the novel Mitra-Spacer technology: experimental validation in the ovine model.

Aims: The Mitra-Spacer (Cardiosolutions, Bridgewater, MA, USA) is designed to treat mitral regurgitation by introducing a dynamic spacer that constantly adapts to the changing haemodynamic conditions during the cardiac cycle. We aimed to evaluate the performance and safety of this device in the chronic ovine model.

Methods And Results: Eight sheep were enrolled in this study.

Stenting and Adjunctive Delivery of Paclitaxel Via Balloon Coating Versus Durable Polymeric Matrix for De Novo Coronary Lesions: Clinical and Angiographic Results from the Prospective Randomized Trial.

Background: There is limited comparative clinical data regarding the safety and efficacy profile of paclitaxel delivery via balloon versus stent-polymer matrix. In this study, we aimed to compare the clinical and angiographic results of two different methods of paclitaxel delivery among patients undergoing percutaneous coronary intervention (PCI) for single de novo coronary lesions.

Methods: A total of 202 patients undergoing PCI due to symptomatic heart disease and at least one significant coronary artery lesion were prospectively enrolled in a multicenter non-inferiority trial.

Early feasibility evaluation of thoracoscopically assisted transcatheter ventricular reconstruction in an experimental model of ischaemic heart failure with left anteroapical aneurysm.

Aims: To test the feasibility of a thoracoscopically assisted, off-pump, transcatheter ventricular reconstruction (TCVR) approach in an ovine model of left ventricular (LV) anteroapical aneurysm.

Methods And Results: Myocardial infarction (MI) was induced by coil occlusion of the middle left anterior descending artery and diagonals. Two months after MI creation, TCVR was performed via a minimal thoracotomy in eight sheep.

Tissue uptake, distribution, and healing response after delivery of paclitaxel via second-generation iopromide-based balloon coating: a comparison with the first-generation technology in the iliofemoral porcine model.

Objectives: This study sought to evaluate vascular drug uptake, distribution and response of second-generation paclitaxel coated balloon (PCB) (Cotavance, MEDRAD Interventional, Indianola, Pennsylvania) and compare it with first-generation technology, containing identical excipient and drug concentration.

Background: Original PCB technologies displayed a heterogeneous deposition of crystalline paclitaxel-iopromide inside the balloon folds, whereas second-generation PCBs consisted of more homogeneous, circumferential coatings.

Methods: Paclitaxel tissue uptake was assessed in 20 iliofemoral arteries of a domestic swine.

Experimental evaluation of pharmacokinetic profile and biological effect of a novel paclitaxel microcrystalline balloon coating in the iliofemoral territory of swine.

Background: New paclitaxel coated balloons (PCB) developments have been proposed to maintain therapeutic levels of drug in the tissue while decreasing particle release. In this series of studies, we evaluated the pharmacokinetic profile and biological effects after paclitaxel delivery via novel microcrystalline PCB coating (mcPCB, Pax®, Balton) in porcine iliofemoral arteries.

Methods: Ten domestic swine were enrolled yielding 24 iliofemoral segments for evaluation.

Comparable clinical safety and efficacy of biodegradable versus durable polymer paclitaxel eluting stents despite shorter dual antiplatelet therapy: insights from a multicenter, propensity score-matched registry.

Background: The biodegradable polymer drug-eluting stents have been proposed as an alternative to durable polymer DES, theoretically improving vessel healing and reducing the need for prolonged double anti platelet therapy (DAPT), however clinical significance of this technology is under debate. Therefore, we sought to compare the clinical outcomes of two Paclitaxel eluting stents (PES) containing different polymer-based eluting matrices.

Methods: In this multicenter registry of 392 consecutive patients who underwent PCI between June 2006 and September 2008, we included patients with stable angina or NSTE-ACS displaying at least one significant lesion (>50% diameter stenosis) in native coronary arteries.

Increased apoptosis and myocyte enlargement with decreased cardiac mass; distinctive features of the aging male, but not female, monkey heart.

We studied gender-specific changes in aging cardiomyopathy in a primate model, Macaca fascicularis, free of the major human diseases, complicating the interpretation of data specific to aging in humans. Left ventricular (LV) weight/body weight decreased, p<0.05, in old males but did not change in old females.

Mechanism of gender-specific differences in aortic stiffness with aging in nonhuman primates.

Background: Our hypothesis was that the changes in vascular properties responsible for aortic stiffness with aging would be greater in old male monkeys than old female monkeys.

Methods And Results: We analyzed the effects of gender differences in aging on in vivo measurements of aortic pressure and diameter and on extracellular matrix of the thoracic aorta in young adult (age, 6.6+/-0.

Sex-specific regulation of gene expression in the aging monkey aorta.

Although increased vascular stiffness is more prominent in aging males than females, and males are more prone to vascular disease with aging, no study has investigated the genes potentially responsible for sex differences in vascular aging. We tested the hypothesis that the transcriptional adaptation to aging differs in males and females using a monkey model, which is not only physiologically and phylogenetically closer to humans than the more commonly studied rodent models but also is not afflicted with the most common forms of vascular disease that accompany the aging process in humans, e.g.

Telomere dynamics in macaques and humans.

In humans, telomere length in proliferating tissues shortens with age--a process accelerated with age-related diseases. Thus, telomere length and attrition with age in the nonhuman primate may serve as a useful paradigm for understanding telomere biology in humans. We examined telomere parameters in tissues of young and old Macaca fascicularis and compared them with several tissues from humans.

Obligatory role of cardiac nerves and alpha1-adrenergic receptors for the second window of ischemic preconditioning in conscious pigs.

We tested the hypothesis that cardiac nerves may mediate ischemic preconditioning. Pigs were chronically instrumented to measure aortic, left atrial and left ventricular pressures, and regional myocardial function (wall thickening). Hemodynamic variables, area at risk, and tissue blood flows (radioactive microspheres) were similar among groups.

Cardiac nerves affect myocardial stunning through reactive oxygen and nitric oxide mechanisms.

The goal of this study was to investigate the role of cardiac nerves on the response to 90-minute coronary artery stenosis (CAS), which reduced coronary blood flow by 40% for 90 minutes, and subsequent myocardial stunning after reperfusion in chronically instrumented conscious pigs. In pigs with regional cardiac denervation (CD), myocardial stunning was intensified, ie, at 12 hours reperfusion wall thickening (WT) was depressed more, P<0.05, in CD (-46+/-5%) as compared with intact pigs (-31+/-3%) and remained depressed in CD at 24 hours reperfusion (-45+/-6%).

Gender differences on the effects of aging on cardiac and peripheral adrenergic stimulation in old conscious monkeys.

We examined the effects of gender and aging on cardiac and peripheral hemodynamic responses to beta-adrenergic receptor (beta-AR) stimulation in young (male = 5.9 +/- 0.4 yr old and female = 6.

Persistent stunning induces myocardial hibernation and protection: flow/function and metabolic mechanisms.

To test the hypothesis that persistent myocardial stunning can lead to hibernating myocardium, 13 pigs were chronically instrumented, and persistent stunning was induced regionally by 6 repetitive episodes of 90-minute coronary stenosis (CS) (30% reduction in baseline coronary blood flow [CBF]) followed by full reperfusion every 12 hours. During the 1st CS, CBF fell from 43+/-2 to 31+/-2 mL/min, and anterior wall thickening (AWT) fell by 54+/-8%, but posterior WT did not change. AWT never recovered fully and remained depressed by 31+/-7% before the 6th CS, reflecting persistent myocardial stunning, but baseline CBF was not changed.