Combined Use of Multiple Intravascular Imaging Techniques in Acute Coronary Syndrome

Recent advances in intravascular imaging techniques have made it possible to assess the culprit lesions of acute coronary syndrome (ACS) in the clinical setting. Intravascular ultrasound (IVUS) is the most commonly used intravascular imaging technique that provides cross-sectional images of coronary arteries. IVUS can assess plaque burden and vessel remodeling. Optical coherence tomography (OCT) is a high-resolution (10 μm) intravascular imaging technique that uses near-infrared light. OCT can identify key features of atheroma, such as lipid core and thin fibrous cap. Near-infrared spectroscopy (NIRS) can detect lipid composition by analyzing the near-infrared absorption properties of coronary plaques. NIRS provides a chemogram of the coronary artery wall, which allows for specific quantification of lipid accumulation. These intravascular imaging techniques can depict histological features of plaque rupture, plaque erosion, and calcified nodule in ACS culprit lesions. However, no single imaging technique is perfect and each has its respective strengths and limitations. In this review, we summarize the implications of combined use of multiple intravascular imaging techniques to assess the pathology of ACS and guide lesion-specific treatment.

The role of intravascular methods of examination of coronary arteries in the selection of patients with diffuse and multivessel lesions for myocardial revascularization

Objective Assessment of the role of intravascular imaging methods in choosing the surgical strategy of myocardial revascularization.Material and Methods The study included 62 patients with diffuse and multivessel coronary artery disease, who underwent percutaneous coronary infervention (PCI) using intravascular imaging methods. Measurement of fractional flow reserve (FFR) in diffusely altered arteries was performed under conditions of maximum hyperemia, sequentially between stenoses, using the sensor, starting from the distal segment. Initially, the most distal hemodynamically significant stenosis was stented. Then, a repeated measurement of FFR was performed, and the issue of the need for stenting of other stenoses was solved. The results of stenting, as well as determination of the area of stent implantation were carried out by the method of optical coherence tomography (OCT).Results After FFR measurement the number of arteries with hemodynamically significant stenoses decreased by 24.7% (from 93 to 70). It was also noted that in patients with two-vessel lesions, the average number of such stenoses decreased from 2.95 ± 0.65 to 1.82 ± 0.88, and in patients with three-vessel lesions – from 2.96 ± 0.6 to 2.24 ± 0.76 respectively (p = 0.0024). Complete (functionally adequate according to FFR measurements) myocardial revascularization was achieved in 88.7% of patients. The second-generation drug eluting stents were implanted in 82 (47.1%) patients, and the third generation stents – in 92 (52.9%) patients. At the same time, the success rate of recanalization of occlusions was 100%. Overall, optimal stent implantation was achieved in all patients. Major cardiovascular complications were observed in 1 (1.6%) patient, which required additional interventions.Conclusion Complex use of intravascular imaging methods (OCT and FFR measurements) allows a differentiated approach to the assessment of each stenosis of the affected artery in patients with diffuse and multivessel coronary lesions, to achieve a high frequency of complete myocardial revascularization, as well as to reduce the number of unnecessary interventions and intraoperative complications.

499 What light through yonder window breaks? Benefits of optical coherence tomography (OCT) in a case of spontaneous coronary artery dissection

Aims Spontaneous coronary artery dissection (SCAD) is a non-traumatic and non-iatrogenic separation of the coronary arterial walls, creating a false lumen. SCAD is an infrequent and often missed diagnosis especially in women presenting with acute coronary syndrome and in the majority of cases angiography alone could be insufficient for identification. Methods and results A 43-year-old woman presented to the Emergency Department of Fondazione Policlinico Universitario A. Gemelli IRCCS (Rome, Italy) for oppressive acute chest pain radiated to the right jaw, resolved spontaneously within a few minutes. Physical examination, including cardiovascular evaluation, was normal. High-sensitivity troponin was 152 ng/l and 250 ng/l in two serial determination (reference range, 0.0–37 ng/l). EKG showed sinus rhythm with no significant ST-segment alterations. Echocardiography revealed preserved biventricular systolic function with mild hypokinesia of the apical segments of the left ventricle. A diagnosis of NSTEMI was made based on clinical and laboratory parameters. Thus, urgent coronary angiography was performed, which demonstrated a single vessel disease with an eccentric, and angiographically complex stenosis of the proximal left anterior descending (LAD) artery with an image of plus compatible with a plaque ulceration. In order to define the extension of the disease and ostium involvement for a better procedural planning, OCT imaging was performed. Surprisingly, OCT showed a intramural haematoma extending from the ADA ostium to the proximal tract (approximately 22 mm) with ulceration in the body, minimal lumen area (MLA) 2.0 mm2 and evidence of normal trilaminar structure of the vessel both on downstream and upstream of the lesion. The angiographic features were compatible with type 2A SCAD. The therapeutic management was conservative with continuation of the double antiplatelet therapy and remote CT monitoring. Three days later, because of a new onset of chest pain and slight elevation of the ST segment on EKG, was performed a coronarographic control: the angiographic appearance of the lesion was substantially unchanged; OCT showed unmodified longitudinal extension of the lesion (about 22 mm) and relative increase in the endoluminal caliber compared to the previous examination (MLA 4.0 mm2).After 2 weeks, coronary CTA control was carried out, which documented the stability of the intramural hematoma in the proximal LAD, extended for 22 mm and with a maximum thickness of 2 mm, determining lumen narrowing of 40–45% The patient was discharged on medical therapy and no events occurred during the follow-up. Six month later, repeat CTA showed a complete resorption of the intramural haematoma. Conclusions In this case we highlight the utility of intravascular imaging, in particular OCT, in the evaluation of angiographic lesions of non-univocal interpretation and how its use can change the management and prognosis of ACS patients. Furthermore, the spontaneous resolution of the clinical and anatomical scenario through conservative treatment additionally confirms spontaneous healing as the natural history of SCAD and foreground the role of precise diagnosis (and intravascular imaging showed to improve it) for therapy shift and calibration.

Cardiovascular Imaging and Intervention Through the Lens of Artificial Intelligence

Artificial Intelligence (AI) is the simulation of human intelligence in machines so they can perform various actions and execute decision-making. Machine learning (ML), a branch of AI, can analyse information from data and discover novel patterns. AI and ML are rapidly gaining prominence in healthcare as data become increasingly complex. These algorithms can enhance the role of cardiovascular imaging by automating many tasks or calculations, find new patterns or phenotypes in data and provide alternative diagnoses. In interventional cardiology, AI can assist in intraprocedural guidance, intravascular imaging and provide additional information to the operator. AI is slowly expanding its boundaries into interventional cardiology and can fundamentally alter the field. In this review, the authors discuss how AI can enhance the role of cardiovascular imaging and imaging in interventional cardiology.