Intracoronary Imaging Modalities for Vulnerable Plaques

Pannus-related prosthetic valve dysfunction. Case report

Pannus-related prosthetic valve dysfunction, a complication of mechanical prosthetic valve replacement, is rare, with a slowly progressive evolution, but it can be acute, severe, requiring surgical reintervention. We present the case of a patient with a mechanical single disc aortic prosthesis, with moderate prosthesis-patient mismatch, minor pannus found on previous ultrasound examinations, who presented to our service with angina pain with a duration of 1 hour, subsequently interpreted as non-ST segment elevation myocardial infarction (NSTEMI) syndrome. Coronarography showed normal epicardial coronary arteries, an ample movement of the prosthetic disc, without evidence of coronary thromboembolism, and Gated Single-Photon Emission Computerized Tomography (SPECT) with Technetium (Tc)-99m detected no perfusion defects. Transthoracic echocardiography (TTE) evidenced a dysfunctional prosthesis due to a subvalvular mass; transesophageal echocardiography (TOE) showed the interference of this mass, with a pannus appearance, with the closure of the prosthetic disc. Under conditions of repeated angina episodes, under anticoagulant treatment, surgery was performed, with the intraoperative confirmation of pannus and its removal. Postoperative evolution was favorable. This case reflects the diagnostic and therapeutic management problems of pannus-related prosthetic valve dysfunction.

Fundamentals of Optical Coherence Tomography: Image Acquisition and Interpretation

Optical coherence tomography (OCT) is an intravascular imaging modality that enables high-resolution cross-sectional imaging of coronary arteries in vivo. With resolution that is a 10-fold improvement compared with intravascular ultrasonography, OCT can facilitate detailed plaque characterization. This article introduces the basic principles of OCT image acquisition and interpretation. Qualitative analysis entails the evaluation of plaque morphology, including features associated with plaque vulnerability to rupture. Quantitative analysis and recognition of OCT image artifacts are also discussed.

Intracoronary optical coherence tomography: a review of clinical applications

Optical coherence tomography (OCT) is a light-based technology that provides very high spatial resolution images. OCT has been initially employed as a research tool to investigate plaque morphology and stent strut coverage. The introduction of frequency domain OCT allowing fast image acquisition during a prolonged contrast injection via the guiding catheter has made OCT applicable for guidance of coronary interventions. In this manuscript, the various applications of OCT are reviewed, from assessment of plaque vulnerability and severity to characteristics of unstable lesions and thrombus burden to stent optimization and evaluation of late results.

Observation of vertebral artery damage using angioscopy in autopsy cases

The vertebral arteries are important blood vessels that supply the cerebral circulation in conjunction with the internal carotid arteries. In cases of subarachnoid hemorrhage, it is necessary to examine the vertebral arteries as potential sources of bleeding due to blunt trauma (head and neck) or of cerebral embolism that originated on the surface of the damaged intima as a result of hyperflexion or hyperextension. However, a considerable part of the vertebral arterial surface is surrounded by bone, resulting in challenges during examination in a routine autopsy. In this study, angioscopy was used to inspect the vertebral artery intima for damage in cases of neck injury, head injury, or neck strangulation. Intimal damage was detected in 34 out of the total 75 cases. Of the 28 cases with cervical discopathy or fracture, 61% had intimal damage. In addition, postmortem application of computed tomography angiography was performed to identify the injured vessel in a case with traumatic subarachnoid hemorrhage, and a perforated hole was detected using angioscopy, which did not introduce autopsy-related artifacts. Therefore, angioscopy may be a useful and nondestructive method to identify intimal damage in the vertebral arteries during an autopsy.

Multi-modal imaging technologies in cardiovascular risk assessment

Atherosclerotic plaques can be responsible for life-threatening cardiovascular and cerebrovascular events. Some features of the plaque, such as a thin fibrous cap, large necrotic core, macrophage infiltration, neovascularization, and intraplaque hemorrhage, are associated with a major risk of such events and so their assessment is fundamental. Novel imaging techniques, each one with its own strength and drawbacks, can help in the evaluation and quantification of atherosclerosis. An analysis of the recent literature was carried out. The different techniques were compared by evaluating the accuracy of each one in the detection and assessment of the atherosclerotic plaque's features named above.

Plaque stability and the southern European paradox

Differences between European countries in coronary heart disease mortality were initially described in the 20th century, and albeit less dramatic than first reported, these differences remain substantial. Three main hypotheses have been proposed to explain the so-called "Mediterranean paradox": a) underestimation of coronary heart disease mortality due to methodological flaws; b) the "lag time" hypothesis, and c) the traditional Mediterranean diet and lifestyle. In this manuscript we present and discuss another possible explanation for the Mediterranean paradox related to the higher prevalence and and incidence of stable atheromatous plaques in this area.