Hybrid imaging represents a combination of two different imaging techniques resulting in a single image that contains all the information provided by the two investigations. Hybrid imaging tends to improve the accuracy of the diagnosis in many diseases. Coronary computed tomography angiography (CCTA) has unquestionable abilities in highlighting coronary artery diseases (CAD). Cardiac magnetic resonance imaging (MRI) also has a powerful predictive role in assessing the functionality of the myocardial tissue.
The aim of the study is to develop new imaging markers for a complex evaluation of myocardial viability (MV) after an acute myocardial infarction (AMI), using hybrid technology.
Material and methods: This study will enroll 100 patients at one month after an AMI. CCTA, MRI, 3D echocardiography, and blood tests will be performed in all patients. All the acquisitions will be processed using a supercomputer, and MV and other parameters will be assessed on hybrid images. A secondary objective will be to correlate the level of inflammatory markers with the outcome of patients, left ventricular function, ischemic time, and the rate of major adverse cardiovascular events.
Myocardial viability plays an important role in preventing the development of left ventricular remodeling following an acute myocardial infarction. A preserved viability in the infarcted area has been demonstrated to be associated with a lower amplitude of the remodeling process, while the extent of the non-viable myocardium is directly correlated with the amplitude of the remodeling process. A number of methods are currently in use for the quantification of the viable myocardium, and some of them are based on the estimation of myocardial perfusion during pharmacologic stress. 64-slice Multi-detector Computed Tomography (MDCT) during vasodilator stress test, associated with CT Coronary Angiography (CCTA) has a high diagnostic accuracy in evaluating myocardial perfusion. In this article, we present a sequence of 3 clinical cases that presented with symptoms of myocardial ischemia, who underwent 64-slice MDCT imaging at rest and during adenosine stress test, in order to assess the extent of the hypoperfused myocardial areas. Coronary artery anatomy and the Coronary Calcium Score was assessed for all 3 patients by performing CT Coronary Angiography. The combination of CT Angiography and adenosine stress CT myocardial perfusion imaging can accurately detect atherosclerosic lesions that cause perfusion abnormalities, compared with the combination of invasive angiography and single-photon emission computed tomography (SPECT).
Stem cell-based therapy is a new therapeutic option that can be used in patients with cardiac diseases caused by myocardial injury. Cardiac magnetic resonance imaging (MRI) is a new noninvasive imaging method with an increasingly widespread indication. The aim of this review was to evaluate the role of cardiac MRI in patients with myocardial infarction undergoing stem cell therapy. We studied the role of MRI in the assessment of myocardial viability, stem cell tracking, assessment of cell survival rate, and monitoring of the long-term effects of stem cell therapy. Based on the current knowledge in this field, this noninvasive, in vivo cardiac imaging technique has a large indication in this group of patients and plays an important role in all stages of stem cell therapy, from the indication to the long-term follow-up of patients.
Introduction: The term “myocardial bridging” is used to describe an anatomic variant where a band of cardiac muscle overlies a segment of an epicardial coronary artery. It is a highly debated topic, because it can cause conditions such as acute coronary syndrome. Myocardial bridging (MB) can be diagnosed using invasive procedures, but also non-invasive ones, such as Multislice Computed Tomography Angiography (MSCTA).
Objectives: A comparative analysis was performed on the patients who were admitted to the clinic with typical angina, ischemic ECG changes and muscular bridging shown on MSCTA, and patients with the same symptoms, but without MB. A sub-study was also undertaken in which the MB site and ischemia revealed by thickening of the myocardial muscle, using 3D Polar Mapping, were compared.
Materials and methods: A retrospective study assessed 59 patients with typical angina pectoris, shortness of breath and clinical appearance of an acute coronary syndrome, and for whom MSCTA was carried out. Patients were divided into two groups: Group 1 — patients with MB, and Group 2 — patients without MB. Thirty patients in Group 1 had 3D polar mapping to evaluate the thickness of the myocardial muscle.
Results: The mean age of our patients with muscular bridging was 55.51 ± 11.4 years, CI 51.57–59.45 years. Patients without MB had a mean age of 59.17 ± 9.6 years, CI 54.98–63.6 years, p = 0.211. 24.32% of the patients with MB were females and 60.86% from the patients without MB were males, p = 0.040. 40.54% of patients presented with MB in the first segment of the LAD and 15.62% had an MB in the second segment of LAD. In patients with an ischemic site smaller than 2 cm of the MB, the ischemic myocardial area was more pronounced compared to the patients with higher length MB (21.85 ± 6.123% vs. 17.62 ± 5.856%).
Conclusions: MSCTA is an important procedure that contributes to the clinical investigations of patients with typical angina and suspected acute coronary syndrome. There is a good positive correlation between the location of the MB and the ischemic segments as shown on 3D CT-based polar maps.
Pulmonary embolism (PE) remains a common and potentially life-threatening cardiovascular emergency. Systemic thrombolysis with intravenous infusion of a thrombolytic agent is generally recommended for treatment of high risk PE. However, this method has known limitations in the presence of high bleeding risk. Catheter-directed thrombolysis has the potential to achieve the same benefits as systemic thrombolysis, with a lower risk of haemorrhage. The case presented is of a 67-year-old male patient with a high risk of pulmonary embolism and contraindications for systemic thrombolysis, in whom the presence of severe comorbidities presented an increased risk of surgical embolectomy, who was successfully treated by catheter-directed thrombolysis.
Myocardial ischemia results from a reduction in blood flow as a consequence of a coronary stenosis, which produces ischemia in the myocardial territories irrigated by the stenotic artery. Myocardial viability is a concept that derived from several studies in which it was observed that, even if revascularization occurred, an irreversible left ventricular contractile dysfunction remained. The terms “stunned” and “hibernating” myocardium have been traditionally associated with the viable myocardium, and many controversies still exist on the most appropriate method to assess the presence and extent of viable myocardium. During the last decades, many efforts have been made to identify the best method to determine the viability of the myocardial tissue. Due to the fact that none of the stand-alone imaging methods provide sufficient data about myocardial viability, new methods for the investigation of myocardial viability became necessary. Thus, the concept of hybrid imaging was developed, consisting in the association of different imaging techniques, finally resulting in a single image that offers all the details provided by the two isolated methods of diagnosis, therefore being more precise in regards to the identification of viable myocardium territory. This review aims to appraise the recent studies related to myocardial viability investigated with hybrid imaging.
Introduction: In-stent restenosis (ISR) is traditionally associated with neointimal hyperplasia. However, recent studies have suggested that an underlying progression of the atherosclerotic process called neoatherosclerosis, different from intimal proliferation, could be involved in ISR development. In this study the aim was to compare the characteristics of the neoatheromatous plaque evidenced by Multislice Angio Computed Tomography, Optical Coherence Tomography (OCT) and Virtual Histology Intravascular Ultrasound (VH-IVUS) with the characteristics of de-novo lesions in native coronary vessels of patients with ISR. Material and methods: This is a prospective single-center pilot study in which patients presenting with acute chest pain and having at least one symptomatic bare-metal stent (BMS) restenosis at six months to one year after BMS implantation, were enrolled. The characteristics of the neointimal tissue developed within the implanted stents using Acio CT, OCT and VH-IVUS were studied. Results: In total, 27 patients with 38 coronary BMS were included in the study, in whom 27 ISR lesions and 43 lesions in native coronary vessels were identified. Angio CT examination revealed that atheromatous plaques responsible for ISR tend to have a larger volume compared with native lesions located in the same coronary vessel (plaque volume 91.2 mm3 for ISR vs. 60.4 mm3 for native vessels, p <0.0001). Additionally, they show more low density plaques compared to native coronary lesions located in the same coronary vessel (33.9 mm3 vs. 18.2 mm3 for the volume of the plaque with density <30 HU, p <0.0001). Plaques responsible for ISR exhibit a higher lipid content than native ones (41.1% vs. 22.9%, p = 0.05). OCT analysis indicated an irregular shaped vascular lumen in 44.4% of ISR lesions compared to 25.6% of de-novo lesions (p = 0.1). Conclusions: Neoatherosclerosis within the implanted coronary stents is associated with signs of plaque vulnerability to a significantly higher extent than the atheromatous plaques in native coronary arteries in patients with ISR presenting with an acute coronary syndrome.
Radiofrequency catheter ablation of parahisian accessory pathways in pre-excitation syndrome is a challenging task, due to the extremely high risk of complete atrioventricular block. In this brief report we describe the case of a 32 year-old man presenting a parahisian accessory pathway, who has been successfully treated by radiofrequency ablation. Radiofrequency catheter ablation using low-power radiofrequency current is considered to be the most appropiate method of ablation in adult patients.
Myocardial ischemia caused by coronary atherosclerosis is the main cause of cardiovascular mortality, which is the first cause of death in developed countries. Inducible myocardial ischemia is a negative prognostic factor for coronary artery disease patients, and it represents a major risk stratification marker for predicting mortality. The evolution of these patients depends largely on the extension of the ischemic myocardial mass and the severity of the inducible ischemia. Most patients do not show angiographically significant coronary stenosis. Therefore, such patients do not undergo coronary revascularization therapies, even though they present functional stenoses that trigger myocardial ischemia under stress conditions, which subsequently lead to a high risk for major adverse cardiovascular events. We performed a review that aims to pinpoint invasive techniques used for evaluating the functional impact of a coronary lesion that is considered non-significant upon angiographic examination, but which triggers episodes of myocardial ischemia under stress conditions, and to describe the functional markers that show the highest specificity for predicting ischemic risk, in order to recommend invasive coronary revascularization.