Toru Misawa

Relationship between quantities of tissue prolapse after percutaneous coronary intervention and neointimal hyperplasia at follow-up on serial optical coherence tomography examination

BACKGROUND The clinical significance of the extent of tissue prolapse (TP) after percutaneous coronary intervention (PCI) for long-term outcomes remains undetermined. This study investigated the relationship between the quantities of TP immediately after PCI and neointimal hyperplasia (NIH) at follow-up on serial optical coherence tomography (OCT) examination. METHODS We evaluated 145 native coronary lesions (89 lesions with stable angina pectoris [SAP] and 56 with acute coronary syndrome [ACS]). OCT was performed to examine pre-PCI plaque morphologies at the narrowest culprit sites, post-PCI TP area in each cross-sectional area (CSA) and TP volume throughout the stented segments, 9-month follow-up NIH area in each CSA and NIH volume throughout the stented segments. We investigated the relationships between the quantities of TP and NIH and their differences according to clinical presentation. RESULTS ACS lesions had a larger TP area at the narrowest culprit sites (0.39 [0.14-0.85] vs. 0.11 [0.00-0.32] mm2, P<0.001) and at the most protruding sites (0.51 [0.24-1.08] vs. 0.21 [0.10-0.52] mm2, P<0.001) compared with SAP lesions. In ACS lesions, TP area was correlated with NIH area at the culprit sites (r=0.283, P=0.042) and at the most protruding sites (r=0.288, P=0.038). In SAP lesions, TP area was correlated with NIH area at the most protruding sites (r=0.244, P=0.030), but not at the culprit sites. CONCLUSIONS The extent of TP immediately after PCI was quantitatively related to the degree of NIH at 9-month follow-up on serial OCT examination. The quantities of TP might influence long-term stent outcomes.

Comparison of vascular responses after different types of second-generation drug-eluting stents implantation detected by optical coherence tomography

Few studies have directly compared vascular responses to second-generation drug-eluting stents (DESs). We performed optical coherence tomography examinations in 56 consecutive patients with implanted single stent [19 cobalt-chromium everolimus-eluting stents (CoCr-EES), 22 platinum-chromium EES (PtCr-EES), and 15 resolute zotarolimus-eluting stents (R-ZES)] for de novo lesions, and who did not have restenosis at their 9-month follow-up. Neointimal thickness (NIT), stent apposition, and neointimal coverage were assessed in every strut. A neointimal unevenness score [(NUS), maximum NIT/average NIT in the same cross-section] was determined for every 1-mm cross-section (CS). A total of 8350 struts and 1159 CSs were analyzed. The CoCr- and PtCr-EES had significantly fewer malapposed struts compared to the R-ZES (CoCr-EES: 0.19 % vs. PtCr-EES: 0.19 % vs. R-ZES: 0.61 %, p = 0.007). Furthermore, the PtCr-EES had a lower frequency of uncovered struts compared to the others (CoCr-EES: 2.0 % vs. PtCr-EES: 1.4 % vs. R-ZES: 2.3 %, p = 0.047). The NUS correlated with the frequency of uncovered struts (p < 0.001, r = 0.54). The EESs demonstrated more homogenous neointimal growth, as shown in the NUS, compared to the R-ZES [CoCr-EES: 1.66 (1.38–1.97) vs. PtCr-EES: 1.67 (1.41–2.00) vs. R-ZES: 1.94 (1.56–2.28), p < 0.001]. Our results demonstrate that unevenness neointimal growth may relate with strut coverage after second-generation DES implantation. The PtCr-EES had a high frequency of strut coverage with a homogeneous neointima, suggesting fewer risks for stent thrombosis.

Impact of optical coherence tomography- and coronary angioscopy-assessed neointimal tissue characteristics on occurrence of periprocedural myonecrosis in patients with in-stent restenosis.

Several characteristics of neointimal tissues, including neoatherosclerotic progression, have been reported in lesions with in-stent restenosis (ISR). However, the effects of these characteristics on outcomes after percutaneous coronary intervention (PCI) for ISR lesions remain unclear. We assessed the relationships between neointimal tissue characteristics and the occurrence of periprocedural myonecrosis (PMN) after PCI in ISR lesions. We investigated 72 ISR lesions in 72 patients with stable angina pectoris (SAP) who underwent pre- and post-revascularization optical coherence tomography (OCT) and coronary angioscopy (CAS). All lesions were classified as with PMN, defined by an elevated peak high-sensitivity cardiac troponin-T level during the 24-h post-PCI period, and without PMN. PMN was observed in 23 (31.9 %) lesions. PMN lesions had higher frequencies of OCT-derived thin-cap fibroatheroma (26.1 vs. 6.1 %, P = 0.03), CAS-derived intensive yellow neointima (30.4 vs. 10.2 %, P = 0.04), neointima with complex surface (60.9 vs. 28.6 %, P = 0.01), and CAS-derived atheromatous appearance (CAS-AAP), defined as yellow plaque including complex thrombi underneath disrupted neointimal coverage after ballooning (47.8 vs. 16.3 %, P = 0.008) at the most stenotic sites inside stents, compared to lesions without PMN. Multivariate logistic regression analysis identified CAS-AAP (odds ratio: 3.568, 95 % confidence interval: 1.109–11.475, P = 0.033) as an independent predictor of PMN. For ISR lesions in SAP patients, an OCT- and CAS-based assessment of neointimal tissue characteristics might help to predict the occurrence of PMN.

The clinical significance of echo-attenuated plaque in stable angina pectoris compared with acute coronary syndromes: A combined intravascular ultrasound and optical coherence tomography study

BACKGROUND Echo-attenuated plaque (EA) on intravascular ultrasound (IVUS) is related to poor outcomes after percutaneous coronary intervention (PCI) in acute coronary syndrome (ACS) patients. However, the clinical significance of EA in stable angina pectoris (SAP) patients compared with that in ACS patients remains unclear. We assessed the relationships between EA and unstable plaque characteristics in patients with ACS and SAP. METHODS We investigated 609 coronary lesions in 609 patients (234 with ACS; 375 with SAP) undergoing pre-intervention IVUS and optical coherence tomography (OCT). The differences in plaque morphology and post-PCI outcomes were assessed according to the clinical status of ACS or SAP and the presence or absence of EA. RESULTS EA was more frequent in patients with ACS than in those with SAP (44.0% vs. 25.1%, p < 0.001). SAP-EA lesions showed thicker fibrous cap (157 ± 97 μm vs. 100 ± 58 μm, p < 0.001), smaller lipid arc (208 ± 76° vs. 266 ± 99°, p < 0.001), smaller plaque burden (83.0 ± 6.1% vs. 86.5 ± 4.1%, p < 0.001), and lower frequency of transient slow-reflow phenomenon during PCI (21.3% vs. 51.5%, p < 0.001) than ACS-EA lesions, but similar plaque vulnerability compared with ACS-non-EA lesions. SAP-EA lesions had less frequent OCT-thrombus than ACS-non-EA lesions (20.2% vs. 71.2%, p < 0.001). CONCLUSIONS SAP-EA lesions had less plaque vulnerability than ACS-EA lesions, but were comparable to ACS-non-EA lesions. Less frequent thrombus formation might differentiate SAP-EA lesions from ACS-non-EA lesions. A combined IVUS and OCT approach might be useful to assess plaque vulnerability in SAP-EA lesions compared with ACS lesions.

Observation of an Asymptomatic Dissecting Aortic Aneurysm Using Non-Obstructive Angioscopy: A Novel Method

Non-obstructive angioscopy has become a novel method of evaluating atheromatous plaques of the aortic intimal wall. A 77-year-old man with coronary artery disease underwent percutaneous coronary intervention in the left descending artery. We subsequently used non-obstructive angioscopy to identify aortic atheromatous plaques and incidentally diagnosed an aortic dissecting aneurysm. Non-obstructive angioscopy demonstrated a great fissure in severe atheromatous plaques at the entry site of the aortic dissection identified by enhanced computed tomography. This is the first report to describe the aortic intimal findings of an aortic dissecting aneurysm in vivo by using trans-catheter angioscopy.

Intravascular Ultrasound and Angioscopy Assessment of Coronary Plaque Components in Chronic Totally Occluded Lesions

BACKGROUND The in vivo lesion morphologies and plaque components of coronary chronic total occlusion (CTO) lesions remain unclear.Methods and Results:We investigated 57 consecutive CTO lesions in 57 patients with stable angina pectoris undergoing elective percutaneous coronary intervention with intravascular ultrasound (IVUS) and coronary angioscopy (CAS) examination. All CTO lesions were classified according to the proximal angiographic lumen pattern; tapered-type (T-CTO) and abrupt-type (A-CTO). The differences in the intracoronary images of these lesion types were evaluated according to the location within the CTO segment. A total of 35 lesions (61.4%) were T-CTO. T-CTO lesions had higher frequencies of red thrombi (proximal 71.4%; middle 74.3%; distal 31.4%; P<0.001) and bright-yellow plaques (yellow-grade 2-3) (48.6%; 74.3%; 2.9%; P<0.001) at the proximal or middle than at the distal subsegment; A-CTO lesions showed no significant differences among the 3 sub-segments. At the middle subsegment, T-CTO lesions showed higher frequencies of positive remodeling (51.4% vs. 18.2%, P=0.01) and bright-yellow plaques (74.3% vs. 13.6%, P<0.001) compared with A-CTO lesions. Multivariate analysis identified bright-yellow plaque as an independent predictor (odds ratio, 7.25; 95% confidence interval, 1.25-42.04; P=0.03) of the occurrence of periprocedural myocardial necrosis. CONCLUSIONS The combination of IVUS and CAS analysis may be useful for identifying lesion morphology and plaque components, which may help clarify the pathogenetic mechanism of CTO lesions.