Distinctive Morphological Patterns of Complicated Coronary Plaques in Acute Coronary Syndromes: Insights from an Optical Coherence Tomography Study

Abstract

Optical coherence tomography (OCT) is an ideal imaging technique for assessing culprit coronary plaque anatomy. We investigated the morphological features and mechanisms leading to plaque complication in a single-center observational retrospective study on 70 consecutive patients with an established diagnosis of acute coronary syndrome (ACS) who underwent OCT imaging after coronary angiography. Three prominent morphological entities were identified. Type I or intimal discontinuity, which was found to be the most common mechanism leading to ACS and was seen in 35 patients (50%), was associated with thrombus (68.6%; p = 0.001), mostly affected the proximal plaque segment (60%; p = 0.009), and had no distinctive underlying plaque features. Type II, a significant stenosis with vulnerability features (inflammation in 16 patients, 84.2%; thin-cap fibroatheroma (TCFA) in 10 patients, 52.6%) and a strong association with lipid-rich plaques (94.7%; p = 0.002), was observed in 19 patients (27.1%). Type III, a protrusive calcified nodule, which was found to be the dominant morphological pattern in 16 patients (22.9%), was found in longer plaques (20.8 mm vs. 16.8 mm ID vs. 12.4 mm SS; p = 0.04) and correlated well with TCFA (93.8%; p = 0.02) and inflammation (81.3%). These results emphasize the existence of a wide spectrum of coronary morphological patterns related to ACS.

Pathophysiology of Acute Coronary Syndromes—Diagnostic and Treatment Considerations

“…The latter is an important feature of culprit lesions in ACS, which are also characterized by a large plaque burden [12]. We should also state that OCT and IVUS may additionally identify healed plaque ruptures that were asymptomatic, indicating that plaque rupture is a phenomenon occurring more frequently than clinically expected [12,13].…”

Diagnosis and treatment of angiographically unclear coronary lesions

“…Additionally, non-atherosclerotic lesions are often unclear, which makes decisions regarding further treatment difficult. 2,5,6 Identifying non-atherosclerotic lesions in the pathogenesis of ischemic heart disease is important. It enables early risk assessment of complications and acute coronary events, determination of the constituent components of the lesions, elucidation of the pathophysiological mechanism of their origin, and administration of adequate treatment.…”

“…Additionally, non-atherosclerotic lesions are often unclear, which makes decisions regarding further treatment difficult. 2,5,6…”

Superficial Calcified Plates Associated to Plaque Erosions in Acute Coronary Syndromes

“…Intravascular imaging, mainly through optical coherence tomography (OCT), represents a useful diagnostic tool in the setting of ACS, providing good analytical capacity for culprit plaque morphology and can even detect non-atherosclerotic lesions. Equally as important, this technique can help guide percutaneous coronary interventions (PCI) from procedure indication, choice of adequate treatment strategy and advanced stent optimization and complication management [ 2 , 3 , 4 , 5 , 6 , 7 , 8 ].…”