
18F-fluorocholine PET-MR Imaging of Coronary Plaque Vulnerability
Myocardial InfarctionMyocardial Ischemia5 moreThis study is designed as a prospective observational feasibility study. The investigators will study whether vulnerable plaques on OCT (fibrous cap ≤ 70 μm) show a locally increased uptake of 18F-choline on PET-MRI compared to stable plaques and whether the culprit plaque shows a locally increased uptake of 18F-choline on PET-MRI compared to non-culprit plaques. First, 15 NSTEMI or STEMI patients who underwent urgent percutaneous coronary intervention (PCI) of the culprit vessel, who are diagnosed with multivessel coronary disease and are currently scheduled for a second PCI at the VieCuri hospital will be included. These patients will be subjected to an additional 18F-choline PET-MRI examination at the MUMC+ and an additional optical coherence tomography (OCT) examination (during the PCI procedure at the Viecuri hospital). OCT will be performed as a reference standard to validate 18F-choline PET-MRI for detection of vulnerable plaques in the coronary arteries. In addition, 15 NSTEMI patients, who are scheduled for PCI of the culprit lesion at the MUMC+, will be subjected to an additional 18F-choline PET-MRI examination at the MUMC+. Hereby, the culprit coronary vessel and thereby the culprit plaque can be identified by the location of the myocardial infarct, as identified by late enhanced MRI. The investigators will study whether the culprit plaque shows an increased 18F-choline uptake on 18F-choline PET-MRI compared to non-culprit plaques in the other coronary arteries. All patients will receive standard, guideline-based clinical care, while PET-MRI and OCT will be performed as additional measurements. Before the start of the study, 5 stable angina pectoris patients that are scheduled for a PCI procedure at the MUMC+ will be included at the MUMC+ for a single PET-MRI scan to optimize the parameters of the coronary PET-MRI scan.

Interaction Between NGF and Acute Exercise-induced Ischemia
HyperalgesiaPain Response1 moreThe purpose of this study is to investigate pain evoked responses and facilitation of NGF-induced mechanical muscle hyperalgesia over time following an acute exercised-induced ischemic condition in a NGF-sensitized muscle.

Danish Study of Non-Invasive Diagnostic Testing in Coronary Artery Disease 2
Angina PectorisAtherosclerosis2 moreIn a cohort of symptomatic patients referred to coronary computed tomography angiography (CCTA), the investigators aim: To investigate and compare the diagnostic precision of Rubidium Positron Emission Tomography (Rb PET) and 3 Tesla Cardiac Magnetic Resonance imaging (3T CMRI) in patients where CCTA does not exclude significant coronary artery disease (CAD) using invasive coronary angiography with fractional flow reserve (ICA-FFR) as reference standard. To evaluate the diagnostic precision of quantitative flow ratio (QFR) and ICA-FFR in patients where CCTA does not exclude significant CAD using Rb PET and 3T CMRI as reference standard. To show superiority for the CADScor®System compared to the Diamond-Forrester score in detection of CAD with CCTA and ICA quantitative coronary angiography (ICA-QCA) as reference standard. To study the diagnostic accuracy of computed tomography fractional flow reserve (CT-FFR) in patients where CCTA does not exclude significant CAD with ICA-FFR as reference standard. To identify and characterize genetic risk variants´ and circulating biomarkers´ importance in developing CAD. To evaluate the bone mineral density in the hip and spine and correlate this to the degree of vascular calcification.

Mild Acute Ischemic Stroke With Large Vessel Occlusion (MISTWAVE)
Acute Ischemic StrokeStroke remains the leading cause of disability in the United States. An estimated 40-50% of all ischemic strokes are caused by large-vessel occlusion of a major cerebral artery (LVO). However, in some cases, the occlusion results in mild symptoms, at least initially, and these patients frequently do not receive any treatment. These strokes, however, may result in unfavorable long-term outcomes despite relatively benign initial course. Recent large randomized studies in patients with severe stroke symptoms and associated LVO showed efficacy and safety of endovascular mechanical thrombectomy, but patients with mild symptoms were not specifically addressed. Based on the investigators' own data and limited evidence in the literature, the investigators propose that early mechanical thrombectomy in patients with LVO associated with mild stroke symptoms (defined as NIHSS ≤ 5) is safe, and results in favorable long-term patient outcomes. The objective of this prospective pilot study is to assess the safety and outcomes of mechanical thrombectomy in patients presenting with acute ischemic stroke due to a large vessel occlusion in the anterior or posterior circulation under 24 hours with mild symptoms (NIHSS ≤ 5).

Cerebral Perfusion Associated With Postural Changes: an ASL MR Perfusion Study
Brain IschemiaPostural changes are commonly used as therapeutic maneuver to enhance or reduce cerebral perfusion. For instance, in acute stroke, the patient can be positioned in head down tilt position so as to increase perfusion of cerebral tissues perfusion. In During stroke and in hypertensive patients and during stroke, varying degrees a various loss of cerebral autoregulation is loss are usually observed. The aim of this study is to assess cerebral perfusion with ASL perfusion in human subjects in different conditions: healthy, hypertensive and stroke.

PROspective Study to OPTimize thE HEALTH of Patients With TIAs (Transient Ischemic Attacks) and...
StrokeTransient Ischemic Attack (TIA)This will be a prospective randomized 2 year study of patients admitted to the Hamad General Hospital (HGH) and the Stroke Prevention Clinic with a diagnosis of ischemic stroke (IS) and Transit ischemic attacks (TIAs). After signing of the informed consent forms and initial evaluation and investigations, all patients enrolled in the two arms ( study arm and control arm) of the study will be followed for one year (monthly visits for the first three months followed by visits three months until completion of study: total of 6 follow up visits) and the pre-specified investigations repeated at the one year follow up. In one arm (the control group), the patients will be offered best risk factor management strategies as currently being practiced by stroke specialists at HGH in Qatar. And in the second ( the subject group) arm, with assistance of a nurse-practitioner and pharmacist, the investigators will make aggressive attempts to meet "to target" defined risk factors and have the evaluations and investigations completed as in the initial year cohort. All patients will have risk factor stratification according the Framingham Risk Score (FRS) and the change in score measured over time.The primary objective will be to determine if an approach that utilizes a comprehensive strategy results in a significantly outcome. A clinically 'meaningful' difference in the blood pressure (BP) and lipid control of 10% between the aggressively managed versus patients treated with the standard of care will require minimum of 200 patients in each group (alpha error set at 0.05 and beta error at 0.20, power 80%) to be recruited over 1 year and followed for one year (total study duration 2 years). All patients will have screening magnetic resonance imaging (MRI) (including gradient echo (GRE) sequence), carotid 3D Doppler measurement of plaque volume, and PAD assessments, C-reactive protein (CRP) and evaluation for protein urea at baseline. These studies will be repeated in 1 year at the time of exit from the study. The co-primary objective would be to monitor progression (or regression) of plaque build-up on 3D Doppler imaging of the carotid arteries between the two cohorts. The investigators hypothesize that aggressive management of vascular risk factors to "recommended target levels" will lead to better vascular health. Compared to current practice, comprehensive and coordinated approach at preventive measures will lead to more patients with better control of blood pressure and lipid levels. Improved risk factor management will result in slowing of atherosclerosis and its downstream effects which will be measurable on sophisticated blood and imaging testing. Clinically this will translate into fewer hospital re-admissions.

Digital Variance Angiography in Diagnostic Angiographies for Effective Radiation Dose Reduction...
Peripheral Arterial DiseasePeripheral Artery Disease6 moreDigital Variance Angiography (DVA) is a new tool in medical imaging with proven image quality reserve. The previously observed quality reserve of Digital Variance Angiography (DVA) in lower extremity angiographies, allowed to lower radiation exposure by 70 % during DSA in lower extremity diagnostic angiographies with non-inferior image quality. The aim of this study is to apply this non-inferior image quality and use it for radiation exposure reduction in diagnostic lower limb angiography. The project would prospectively block-randomise (50:50) patients, who undergo elective diagnostic angiography into two groups: a comparator group examined by means of conventional DSA using a standard care protocol (Siemens Artis Zee, Extremities Care setting, 1.2 µGy/frame) (Group B) and a study group examined by means of DVA using a low-dose protocol (0.36 µGy/frame corresponding to 70% decrease of radiation dose) (Group A). During each procedure the investigators record radiation exposure (cumulative dosage, dose area product) and contrast media usage and procedural time then compare the results of the groups. Qualitative image review is done to compare conventional DSA and reduced radiation exposure DVA images after image acquisition. Our hypothesis is that with the previously proven non-inferior image quality, the investigators will be able to reduce radiation exposure of the participants and also staff members in everyday clinical practice.

Hormone Therapy on Serum Ischemia Modified Albumin in Menopausal Women
Hormone Therapy Induced Morphologic ChangeSurgical MenopauseWomen suffer from cardiovascular diseases 10 years later than men, therefore female sex has been considered as a 'protective factor'. However, the risk of cardiovascular disease in women increases rapidly after menopause and the declining levels of endogenous estrogen is thought to be the causative factor. Furthermore, Postmenopausal hormone therapy (HT) decreases the severity and intensity of menopausal symptoms and improves women's quality of life. Until the last 10 years, based on the results of observational studies, postmenopausal HT may protect women against cardiovascular events and decrease the risk of coronary artery disease by 35-50%. However, recent randomized primary and secondary prevention trials did not support the cardioprotective effect of HT. The aim of this study is to assess the effect of hormone therapy on serum ischemia modified albumin (IMA) levels. Thirty surgical menopausal women who admitted to Karadeniz Technical University, Faculty of Medicine, Department of Obstetrics and Gynecology during 1-year period and diagnosed as menopause and planned to have hormone therapy for menopausal symptoms were enrolled for this prospective study. The serum İMA levels were recorded before and after (3 months, 6 months, 12 months later) hormone treatment (2 mg Estradiol Hemihidrat).

The Impact of COVID-19 Pandemic on Critical Limb Threatening Ischemia and Emergency Vascular Practice...
COVIDCritical Limb IschemiaThis is a retrospective analytical study conducted at Vascular and Endovascular surgery Department, Mansoura University Hospital, including all patients admitted at the two periods first six months of 2019 and 2020.To demonstrate the effect of COVID-19 pandemic on the practice of emergency vascular surgery and critical limb threatening ischemia interventions by comparison two periods first six months of 2019 and 2020.

Serum Lactate in Acute Mesenteric Ischemia
Mesenteric IschemiaBackground: Acute mesenteric ischemia is a vascular emergency with high mortality because of ambiguous symptomatology and a lack of early diagnostic markers. Lactate dehydrogenase has been described as a mortality biomarker and bowel necrosis length too. Nevertheless, the association between them has been mildly studied. Our objective was to evaluate the association between serum lactate admission levels, bowel necrosis extension, and mortality. Additionally, we performed a mortality characterization. Materials and Methods: A retrospective cross-sectional study was designed. We reviewed patients' clinical records with acute mesenteric ischemia that attended a hospital between 2012 and 2018. We compared serum lactate admission levels with bowel necrosis length and mortality. A receiver operating characteristic curve was performed on the last association. As post hoc analysis, a classification and regression tree on mortality was fitted.