Pietro Sedati

In Situ Electrostimulation Drives a Regenerative Shift in the Zone of Infarcted Myocardium

Electrostimulation represents a well-known trophic factor for different tissues. In vitro electrostimulation of non-stem and stem cells induces myogenic predifferentiation and may be a powerful tool to generate cells with the capacity to respond to local areas of injury. We evaluated the effects of in vivo electrostimulation on infarcted myocardium using a miniaturized multiparameter implantable stimulator in rats. Parameters of electrostimulation were organized to avoid a direct driving or pacing of native heart rhythm. Electrical stimuli were delivered for 14 days across the scar site. In situ electrostimulation used as a cell-free, cytokine-free stimulation system, improved myocardial function, and increased angiogenesis through endothelial progenitor cell migration and production of vascular endothelial growth factor (VEGF). In situ electrostimulation represents a novel means to stimulate repair of the heart and other organs, as well as to precondition tissues for treatment with cell-based therapies.

Preliminary in vivo evaluation of a hybrid armored vascular graft combining electrospinning and additive manufacturing techniques

In this study, we tested in vivo effectiveness of a previously developed poly-L-lactide/poly-8-caprolactone armored vascular graft releasing heparin. This bioprosthesis was designed in order to overcome the main drawbacks of tissue-engineered vascular grafts, mainly concerning poor mechanical properties, thrombogenicity, and endothelialization. The bioprosthesis was successfully implanted in an aortic vascular reconstruction model in rabbits. All grafts implanted were patent at four weeks postoperatively and have been adequately populated by endogenous cells without signs of thrombosis or structural failure and with no need of antiplatelet therapy. The results of this preliminary study might warrant for further larger controlled in vivo studies to further confirm these findings.

Implantation of a Poly-L-Lactide GCSF-Functionalized Scaffold in a Model of Chronic Myocardial Infarction.

A previously developed poly-l-lactide scaffold releasing granulocyte colony-stimulating factor (PLLA/GCSF) was tested in a rabbit chronic model of myocardial infarction (MI) as a ventricular patch. Control groups were constituted by healthy, chronic MI and nonfunctionalized PLLA scaffold. PLLA-based electrospun scaffold efficiently integrated into a chronic infarcted myocardium. Functionalization of the biopolymer with GCSF led to increased fibroblast-like vimentin-positive cellular colonization and reduced inflammatory cell infiltration within the micrometric fiber mesh in comparison to nonfunctionalized scaffold; PLLA/GCSF polymer induced an angiogenetic process with a statistically significant increase in the number of neovessels compared to the nonfunctionalized scaffold; PLLA/GCSF implanted at the infarcted zone induced a reorganization of the ECM architecture leading to connective tissue deposition and scar remodeling. These findings were coupled with a reduction in end-systolic and end-diastolic volumes, indicating a preventive effect of the scaffold on ventricular dilation, and an improvement in cardiac performance.

CT angiography and magnetic resonance angiography findings after surgical and interventional radiology treatment of peripheral arterial obstructive disease

In the last years, technical innovations in the field of CT angiography (CTA) and magnetic resonance angiography (MRA) have allowed accurate and highly detailed evaluation of peripheral vascular pathologies. This has dramatically changed the diagnostic approach in treatment planning of peripheral arterial obstructive disease and also enabling early identification of treatment failure or treatment-related complications after surgical or endovascular procedures. Although Doppler Ultrasound is the first-line imaging modality during follow-up after treatment, its role is currently diminishing in importance mostly because of the proliferation of high-end CT and MR scanners capable of fast, reproducible, and highly reliable vascular imaging. The aim of this study is to review the various surgical and endovascular procedures for peripheral arterial obstructive disease and to provide CTA and MRA samples of common and uncommon complications related to treatment.

A rare, life-threatening effort angina and anomalous origin of the left circumflex coronary artery: CT and SPECT findings

In July 2012, a 63-year-old man presented with effort angina occurring in a predictable fashion. He worked as a porter and when carrying heavy loads, angina with palpitations and feeling loss of consciousness, suggested prodromal symptoms of syncope owing to arrhythmia. Stress/rest thallium-201 single-photon emission cardiac tomography (SPECT) revealed inferior and septal wall reversible defects (ischaemia) without ST-depression at peak during a bicycle maximal exercise test. Cardiac CT documented an anomalous origin of the left circumflex coronary artery (ACXCA) arising from the right sinus of Valsalva with an extramural course between the …

Inducible myocardial ischaemia and anomalous origin of the right coronary artery coursing between the aorta and pulmonary artery: a rare, sinister entity

The authors report the case of a 49-year-old man with episodes of chest discomfort. Exercise/rest single-photon emission tomography (SPECT) with technetium-99m sestamibi (MIBI) revealed inferior and septal myocardial ischaemia, and MIBI anterior reverse redistribution, representing damaged myocardium. Cardiac tomography documented anomalous origin of the right coronary artery (ARCA) arising from the left sinus of valsalva coursing between the aorta and pulmonary artery. Myocardial ischaemia and myocardial damage revealed by SPECT are related to the transient coronary flow reduction elicited by the compression of the ARCA that is produced by the great arteries during exercise. The ARCA is a rare condition, but may cause myocardial infarction and sudden death. β-blockers and dihydropyridine calcium-channel blockers may provide cardioprotection from inducible myocardial ischaemia. However, in case of failure of medical cardioprotection, relocation of the ARCA to the appropriate aortic sinus and coronary bypass grafting could be considered as the best options.

Exercise-induced myocardial ischaemia on scintigraphy despite β-blocker therapy in patients with an anomalous origin of the right coronary artery coursing between the aorta and pulmonary artery

In February 2012, a 60-year-old man presented to us with a positive exercise test for ST-depression, which was performed before beginning sports activity. Rest/stress thallium-201 single-photon emission cardiac tomography (SPECT) revealed inferior and lateral wall reversible defects (ischaemia) and a painless ST-depression at peak during a bicycle maximal exercise test. Cardiac tomography (CT) documented an anomalous origin of the right coronary artery (ARCA) arising from the left sinus of Valsalva with an extramural …

Transapical closure of paraprosthetic mitral leak in a patient with inferior vena cava interruption and azygos continuation.

Para-valvular leaks represent a relevant post-operative complication of cardiac valve replacement, often causing heart failure or severe hemolysis. We report a case of a 72 year-old woman with aortic and mitral mechanical prostheses who developed hemolytic anemia because of a para-prosthetic mitral leak. Chest tomography in such patient unexpectedly documented inferior vena cava interruption with azygos continuation into superior vena cava. Given the high surgical risk, the venous anomaly and the presence of the aortic valve prosthesis, transcatheter leak closure via antero-lateral mini-thoracotomy and transapical approach was performed.

Pitfalls and bugs of nuclear and CT cardiac scans in an extremely obese patient: reasons for using conventional coronary angiography as first-line test

In October 2012, an asymptomatic 54-year-old man, with a body mass index (BMI) of 50 kg/m2, smoking habits, hypertension, dyslipidaemia and family history of coronary artery disease (CAD) presented to us for a clinical work out. Since these conditions indicate high risk of CAD,1 he underwent exercise/rest sestamibi gated single-photon-emission cardiac tomography (G-SPECT). This procedure documented submaximal exercise test and inconclusive anterior wall perfusion defect. A reduced exercise capacity and tissue attenuation characterise obesity and determine doubtful SPECT results (figure 1). A 64-slice cardiac tomography (CT) detected calcium deposits over the anterior descending (LAD) and first diagonal (D1) coronary …

Ventricular ectopy after exercise and occult ischaemia in a patient with multiple risk factors for ischaemic heart disease and defective anginal warning system

In May 2012, a 73-year-old man presented with effort dyspnoea and chest discomfort, negative exercise test for ST depression and ventricular ectopy after exercise. He had a history of Sjogrens syndrome, diabetes, dyslipidemia, hypertension, chronic obstructive pulmonary disease and was under methotrexate treatment for rheumatoid arthritis. Such diseases imply a severe dysfunctional burden, tend to develop accelerated atherosclerosis, endothelial dysfunction and ischaemic heart disease (IHD).1 ,2 A functional assessment was thus provided with an exercise/rest technetium-99 m tetrofosmin-gated …