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Background Diagnostic strategies depend on non-standardized workup, and the causes of myocardial infarction with non-obstructive coronary arteries remain unclear for some patients. Intracoronary imaging is recommended for detecting the missed causes by coronary angiography. Myocardial infarction with non-obstructive coronary arteries is a heterogeneous entity; a meta-analysis of myocardial infarction with non-obstructive coronary artery studies demonstrated that all-cause mortality rate at 1 year is 4.7%, and its prognosis is not so favourable. Case summary A 62-year-old man without remarkable medical history complained of acute chest pain at rest, which resolved at his arrival. Although echocardiography and electrocardiogram exhibited normal findings, the concentration of high-sensitive cardiac troponin T increased up to 0.384 from 0.04 ng/mL. Coronary angiography was performed, and mild stenosis of the proximal right coronary artery was detected. He was discharged without catheter intervention and medications as he reported no symptoms. He returned 8 days later because of inferoposterior ST-segment elevation myocardial infarction with ventricular fibrillation. Emergent coronary angiography showed that the mild stenosis of the proximal right coronary artery had progressed to total occlusion. Optical coherence tomography after thrombectomy revealed rupture of the thin-cap fibroatheroma and protruding thrombus. Discussion Patients presenting with myocardial infarction with non-obstructive coronary arteries and plaque disruption and/or thrombus detected by optical coherence tomography do not show normal coronaries on coronary angiography. Aggressive investigation into plaque disruption using intracoronary imaging is recommended even if coronary angiography demonstrates mild stenosis to prevent a fatal attack for suspicious cases of myocardial infarction with non-obstructive coronary arteries. [ABSTRACT FROM AUTHOR]

Recent retrospective investigations have suggested that optical coherence tomography (OCT) enables the diagnosis of underlying acute coronary syndrome (ACS) causes such as plaque rupture, plaque erosion, and calcified nodule. The relationships of these etiologies with clinical outcomes, and the clinical utility of OCT-guided primary percutaneous coronary intervention (PCI) are not systematically studied in real-world ACS treatment settings. The TACTICS registry is an investigator-initiated, prospective, multicenter, observational study to be conducted at 21 hospitals in Japan. A total of 700 patients with ACS (symptom onset within 24 h) undergoing OCT-guided primary PCI will be enrolled. The primary endpoint of the study is to identify the underlying causes of ACS using OCT-defined morphological assessment of the culprit lesion. The key secondary clinical endpoints are hazard ratios of the composite of cardiovascular death, non-fatal myocardial infarction, heart failure, or ischemia-driven revascularization in patients with underlying etiologies at the 12- and 24-month follow-ups. The feasibility of OCT-guided primary PCI for ACS will be assessed by the achievement rates of optimal post-procedural results and safety endpoints. The TACTICS registry will provide an overview of the underlying causes of ACS using OCT, and will reveal any difference in clinical outcomes depending on the underlying causes. The registry will also inform on the feasibility of OCT-guided primary PCI for patients with ACS. The TACTICS (Tokyo, Kanagawa, Chiba, Shizuoka, and Ibaraki active OCT applications for ACS) registry. ACS, acute coronary syndrome; OCT, optical coherence tomography; PCI, percutaneous coronary intervention. [Display omitted] • TACTICS is an investigator-initiated prospective multicenter observational study. • Optical coherence tomography (OCT)-guided primary percutaneous coronary intervention (PCI) will be performed. • The primary endpoint is to identify the underlying causes of acute coronary syndrome (ACS). • Clinical outcomes and feasibility of OCT-guided PCI will be clarified. [ABSTRACT FROM AUTHOR]

Objectives: We aimed to examine the relations of very high levels of serum uric acid (sUA) with features of culprit lesion plaque morphology determined by optical coherence tomography (OCT) and adverse clinical outcomes in patients with acute coronary syndrome (ACS). Methods: We retrospectively compared ACS patients according to sUA levels of > 8.0 mg/dL (n = 169), 7.1–8.0 mg/dL (n = 163), 6.1–7.0 mg/dL (n = 259), and ≤6.0 mg/dL (n = 717). Angiography and OCT findings were analyzed in patients with preintervention OCT and the 4 sUA groups (> 8.0 mg/dL, n = 61; 7.1–8.0 mg/dL, n = 72; 6.1–7.0 mg/dL, n = 131; and ≤6.0 mg/dL, n = 348) were compared. Results: Cardiogenic shock was more prevalent in ACS patients with sUA > 8.0 mg/dL (22% vs. 19% vs. 10% vs. 6%, p < 0.001). Plaque rupture was observed more prevalently by OCT in patients with sUA > 8.0 mg/dL (67% vs. 47% vs. 56% vs. 45%, p = 0.027). At the 2-year follow-up, Kaplan-Meier estimates showed higher cardiac mortality in patients with sUA > 8.0 mg/dL (25% vs. 12% vs. 5% vs. 5%, p < 0.001). After adjusting for traditional cardiovascular risk factors and creatinine levels, patients with sUA > 8.0 mg/dL showed a 4.5-fold increased risk in 2-year cardiac death by multivariate Cox proportional hazard analysis (hazard ratio 4.54, 95% confidence interval 2.98–6.91; p < 0.001). Conclusions: Very high sUA levels like > 8.0 mg/dL are the primary predictor of 2-year cardiac mortality and could partly be caused by adverse effects of accumulated sUA on plaque morphology in patients with ACS. [ABSTRACT FROM AUTHOR]

Objectives: We sought to clarify clinical features and outcomes related to calcified nodules (CN) compared with plaque rupture (PR) and plaque erosion (PE) detected by optical coherence tomography (OCT) at the culprit lesions in patients with acute coronary syndrome (ACS). Methods: Based on OCT findings for culprit lesion plaque morphologies, ACS patients with analyzable OCT images (n = 362) were classified as CN, PR, PE, and other. Results: The prevalence of CN, PR, and PE was 6% (n = 21), 45% (n = 163), and 41% (n = 149), respectively. Patients with CN were older (median 71 vs. 65 years, p = 0.03) and more diabetic (71 vs. 35%, p = 0.002) than those without CN. In OCT findings, the distal reference lumen cross-sectional area (median 4.2 vs. 5.2 mm2, p = 0.048) and the postintervention minimum lumen cross-sectional area (median 4.5 vs. 5.3 mm2, p = 0.04) were smaller in lesions with CN than in those without. Kaplan-Meier estimate survival curves showed that the 500-day survival without target lesion revascularization (TLR) was lower (p = 0.011) for patients with CN (72.9%) than for those with PR (89.3%) or PE (94.8%). Conclusions: ACS patients with CN at the culprit lesion had more TLR compared to those with PR or PE. [ABSTRACT FROM AUTHOR]

Objectives: The present study sought to clarify the relationship between matrix metalloproteinase-9 (MMP-9) levels and plaque morphology demonstrated by optical coherence tomography (OCT), and to examine their prognostic impacts in patients with acute coronary syndrome (ACS). Methods: MMP-9 levels were measured for patients with ACS (n = 249). Among 249 patients, 120 with evaluable OCT images were categorized into patients with ruptured plaques (n = 65) and those with nonruptured plaques (n = 55) on the basis of culprit lesion plaque morphology demonstrated by OCT. Results: MMP-9 levels on admission were significantly higher in the rupture group than in the nonrupture group (p = 0.029). Although creatine kinase-MB (CK-MB) on admission was comparable between the groups, peak CK-MB was higher in the rupture group than in the nonrupture group (p < 0.001). By receiver operating characteristic curve analysis, the optimal cut-off value of MMP-9 to detect ruptured plaques was 65.5 ng/ml (p = 0.029). There was a nonstatistically significant trend toward increased cardiac death at 2 years (5.9 vs. 1.0%, p = 0.059) in patients with high MMP-9 ( ≥ 65.5 ng/ml) compared to those with low MMP-9 (<65.5 ng/ ml). Conclusions: MMP-9 can differentiate ACS with ruptured plaques from nonruptured plaques, and MMP-9 may be a valuable predictor of long-term cardiac mortality in patients with ACS reflecting plaque rupture. [ABSTRACT FROM AUTHOR]

Abstract: Background: Relationships between plaque morphology on optical coherence tomography (OCT) and biomarker levels in the patients with acute coronary syndrome (ACS) have not been fully investigated. Methods: ACS patients (n=128) were prospectively enrolled and their plasma levels of soluble lectin-like oxidized LDL receptor-1 (sLOX-1), high-sensitivity C-reactive protein (hs-CRP), and high-sensitivity troponin T (hs-TnT) were measured. Another set of 20 patients with stable angina pectoris (SAP) without plaque rupture or erosion served as controls. Among 128 ACS patients, 75 patients underwent OCT procedure to evaluate culprit plaque morphology, and were categorized into two groups; ACS with plaque rupture (ruptured ACS; R-ACS, n=54) and ACS without plaque rupture (non-ruptured ACS; N-ACS, n=21). Results: Levels of sLOX-1 (p<0.001), hs-CRP (p=0.048) and hs-TnT (p<0.001) were significantly higher in R-ACS than SAP. Levels of sLOX-1 were also significantly higher in R-ACS than in N-ACS (p<0.001); whereas levels of hs-CRP (p=0.675), as well as those of hs-TnT (p=0.055), were comparable between R-ACS and N-ACS. Comparison of receiver operating characteristic (ROC) curves among sLOX-1, hs-CRP and hs-TnT to differentiate R-ACS from N-ACS revealed that the area under the curve (AUC) values of sLOX-1, hs-CRP and hs-TnT were 0.782, 0.531 and 0.643, respectively. ROC curves, generated for these biomarkers, to differentiate ACS with thin-cap fibroatheroma (TCFA) from those without demonstrated that the AUC values of sLOX-1, hs-CRP and hs-TnT were 0.718, 0.506 and 0.524, respectively. Conclusion: sLOX-1, but not hs-CRP or hs-TnT, can differentiate ACS with plaque rupture from those without, and ACS with TCFA from those without. [Copyright &y& Elsevier]

Abstract: Background: Although several clinical trials have shown the superior efficacy and safety of second-generation everolimus-eluting stents (EES) in comparison with first-generation paclitaxel-eluting stents (PES), the differences in the vascular healing process between EES and PES in a human coronary artery during an early stage are unknown. Methods: A prospective optical coherence tomography (OCT) observation was performed for 25 EES in 21 patients and 27 PES in 21 patients at 6months after implantation. Cross-sections within single-stent segments were analyzed at intervals of 1mm. The neointimal (NI) thickness on each strut was measured. Uncovered struts (NI thickness=0μm), malapposed struts, NI area (%), uncovered strut ratio >0.3 (UCSR; number of uncovered struts/number of total struts) per cross-section, and in-stent thrombus were evaluated. Results: A total of 5198 EES struts in 514 cross-sections and 4243 PES struts in 469 cross-sections were identified. NI thickness and its area were smaller for EES than PES (80.0±84.8μm vs. 117.9±140.0μm and 19.1±8.9% vs. 23.7±11.5%, respectively; P<0.001). The frequencies of uncovered struts and malapposed struts were lower in EES compared to PES (2.3% vs. 5.2% and 2.1% vs. 5.7%, respectively; P<0.001). Patients who had cross-sections of UCSR >0.3 and thrombi were identified less frequently in EES than in PES group (5% vs. 57%; P<0.001, and 19% vs. 48%; P=0.05, respectively). Conclusions: Six-month OCT examination showed a favorable vessel healing response after the implantation of EES, demonstrating less in-stent late loss as well as fewer uncovered struts and better stent apposition to the vessel wall in comparison with PES. [Copyright &y& Elsevier]

Abstract: Background: Although in-stent restenosis (ISR) after bare-metal stent (BMS) implantation is considered to be clinically benign, ISR is often associated with adverse complications, such as acute coronary syndrome (ACS). The frequency, type, and location of thrombi in ISR lesions and their clinical presentation have not yet been precisely validated. Methods: Thirty angiographic ISR lesions occurring within 3 to 8months after stenting were evaluated by optical coherence tomography (OCT). A thrombus was defined as a mass protruding into the lumen with an irregular surface, and its type was divided into red or white. The maximum size of a thrombus and the longitudinal distance from the thrombus to the narrowest lumen were measured. Results: A thrombus was identified in 2 patients by angiography and in 10 patients by OCT (7% vs. 33%; P =0.01). OCT showed that 9 patients had white thrombus and another patient had both types of thrombi. ACS relevant to ISR was seen in 6 patients, and the frequency of ACS was significantly higher in patients with thrombus than in those without thrombus [50% (5/10) vs. 5% (1/20); P =0.003]. The maximum size of the thrombus was 412±220µm in height, 424±251µm in width, and the longitudinal distance between the thrombus and the minimum lumen area was 0.3±0.7mm. Conclusions: One third of ISR lesions following BMS deployment dominantly contained a white thrombus, and half of them were associated with ACS. A small thrombus formation adjacent to the narrowest lumen in an ISR lesion may therefore contribute to the clinical presentation of ACS. [Copyright &y& Elsevier]

Objectives: We examined the neointimal characteristics of bare-metal stents (BMS) in extended late phase by the use of optical coherence tomography (OCT). Background: The long-term neointimal features after BMS implantation have not yet been fully characterized. Methods: Intracoronary OCT observation of BMS segments was performed during the early phase (<6 months, n = 20) and late phase (≥5 years, n = 21) after implantation. Internal tissue of the BMS was categorized into normal neointima, characterized by a signal-rich band without signal attenuation, or lipid-leaden intima, with marked signal attenuation and a diffuse border. In addition, the presence of disrupted intima and thrombus was evaluated. Neovascularization was defined as small vesicular or tubular structures, and the location of the microvessels was classified into peristent or intraintima. Results: Normal neointima proliferated homogeneously, and lipid-laden intima was not observed in the early phase. In the late phase, lipid-laden intima, intimal disruption, and thrombus frequently were found in comparison with the early phase (67% vs. 0%, 38% vs. 0%, and 52% vs. 5%, respectively; p < 0.05). Peristent neovascularization demonstrated a similar incidence between the 2 phases. The appearance of intraintima neovascularization was more prevalent in the late phase than the early phase (62% vs. 0%, respectively; p < 0.01) and in segments with lipid-laden intima than in nonlipidic segments (79% vs. 29%, respectively; p = 0.026). Conclusions: This OCT study suggests that neointima within the BMS often transforms into lipid-laden tissue during an extended period of time and that expansion of neovascularization from peristent to intraintima contributes to atherosclerotic progression of neointima. [Copyright &y& Elsevier]

Atherosclerotic yellow plaques identified by coronary angioscopy are considered as vulnerable plaques. However, characteristics of yellow plaques are not well understood. Optical coherence tomography (OCT) provides accurate tissue characterization in vivo and has the capability to measure fibrous cap thickness covering a lipid plaque. Characteristics of yellow plaques identified by angioscopy were evaluated by OCT. We examined 205 plaques of 41 coronary arteries in 26 patients. In OCT analysis, plaques were classified as fibrous or lipid. Minimal lumen area of the plaque, arch of the lipid, and fibrous cap thickness on the lipid plaque were measured. Yellow grade of the plaque was defined as 0 (white), 1 (light yellow), 2 (medium yellow), or 3 (dark yellow) based on the angioscopy. A total of 149 plaques were diagnosed as lipid plaques. Neither the minimal lumen area nor the arch of the lipid was related to the yellow grade. There was an inverse relationship between color grade and the fibrous cap thickness (grade 0 [n = 45] 218 ± 89 μm, grade 1 [n = 40] 101 ± 8 μm, grade 2 [n = 46] 72 ± 10 μm, and grade 3 [n = 18] 40 ± 14 μm; p <0.05). Sensitivity and specificity of the angioscopy-identified yellow plaque for having a thin fibrous cap (thickness ≤110 μm) were 98% and 96%, respectively. In conclusion, angioscopy-identified yellow plaques frequently were lipid tissue with an overlying thin fibrous cap. Fibrous caps of the intense yellow plaques were very thin, and these plaques might be structurally vulnerable. [Copyright &y& Elsevier]

Abstract: In-stent restenosis (ISR) after sirolimus-eluting stent (SES) implantation rarely occurs, and these lesions are commonly recognized as focal restenosis on angiograms. Optical coherence tomography (OCT) is able to distinguish from several components of intracoronary structures by different signal patterns. We herein report three cases of various OCT images from ISR lesions in spite of similar angiographic findings. Our OCT findings suggested that ISR lesions that develop after SES implantation might be composed of not uniform but various tissues. [Copyright &y& Elsevier]

Summary: Neointimal proliferation after sirolimus-eluting stent (SES) implantation is generally inhibited by the pharmacological effects of sirolimus in comparison to bare metal stent (BMS). Neointimal hyperplasia after BMS implantation is mainly composed of vascular smooth muscle cells, and is usually observed as a white mass by angioscopy and as a layer of uniform signal intensity without attenuation on optical coherence tomography (OCT). In this case, angioscopic color of the neointima covering the SES was obviously yellow and OCT signal patterns of the neointima showed rapid attenuation similar to lipid tissues in atherosclerotic lesions. These findings suggest that neointima within the SES is quite different from that of the BMS and may contain atherosclerotic components. [Copyright &y& Elsevier]

The article provides information on a study which examined the history of thin-cap fibroatheromas (TCFA). A small lumen area and presence of TCFA at a nonculprit lesion are associated with future major adverse cardiovascular events, based on an investigation made. It also features the case of a 69-year-old man with stable angina who underwent successful drug-eluting stent implantation in the left anterior descending coronary artery.

Abstract: Background: Although measurement of stent strut by optical coherence tomography (OCT) is important as an index for evaluating incomplete stent apposition, the effects of drug-eluting stents (DES) polymer on it are unknown. Methods and results: DES and bare-metal stents (BMS) as platforms of DES were implanted in an artificial artery. Thickness of stent strut, defined as a distance from inner surface of the strut to the adjacent surface of the tube, and thickness of high-signal band were measured by OCT. Each measurement of DES was significantly larger comparing with BMS. Conclusion: This in-vitro study demonstrates that DES polymer may influence OCT measurement for the stent strut. [ABSTRACT FROM AUTHOR]

Abstract: A 67-year-old male was admitted because of acute myocardial infarction (AMI). An emergent coronary angiography showed a total occlusion in the left anterior descending artery, and a stent was deployed. Moderate lesion stenosis was found in the right coronary artery (RCA). Fractional flow reserve indicated 0.96, and percutaneous coronary intervention was not performed. Six months later, the patient visited an emergency room due to AMI. Angiograms showed a patency of the previous stent and progressed stenosis with filling delay of the RCA. Protruding red thrombi and plaque disruption of thin-cap fibroatheroma (TCFA) were identified by optical coherence tomography. Mild to moderate lesions are physiologically benign but morphologically malignant in cases of TCFA. [Copyright &y& Elsevier]

Summary: Very late stent thrombosis (VLST) after implantation of a drug-eluting stent (DES) is a rare but catastrophic complication and the mechanisms are not completely understood. We describe a 76-year-old patient with recurrent VLST of DES that developed at 13 and 23 months after the initial catheter procedure of DES implantation under the cessation of dual antiplatelet therapy. Optical coherence tomography (OCT) observation revealed small stent area of a DES. Based on the OCT findings, balloon angioplasty for expansion of the DES was performed and angiographic Thrombolysis In Myocardial Infarction grade 3 flow was subsequently obtained. Small stent area is considered a significant factor in acute or subacute stent thrombosis according to previous reports. The present report shows that small stent area of DES may be regarded as a key factor in recurrent VLST as well as cessation of dual antiplatelet therapy. [ABSTRACT FROM AUTHOR]

Abstract: The AngioSculpt™ scoring balloon catheter (AngioScore, Inc., Fremont, California) has recently been developed for percutaneous intervention in coronary and peripheral arteries. This device is composed of two major components, a minimally compliant balloon and three nitinol wore. The three wires encapsulate the low-compliant balloon in a spiral configuration. The concept is for the spiral wires to score the lumen surface during balloon expansion. However, the precise mechanisms and efficacy of this scoring technology in humans had not yet to be determined. In this case, both a de novo coronary lesion and an in-stent restenosis lesion were treated with the scoring balloon and were subsequently observed via optical coherence tomography (OCT) with high-resolution images (≈15 μm). OCT clearly demonstrated the effects of this device on plaque and neointimal hyperplasia scoring, as well as its ability to achieve sufficient lumen sizes after coronary artery dilatation. [Copyright &y& Elsevier]

Abstract: Aims: Postmortem series have reported that subjects with diabetes mellitus have coronary plaques with larger necrotic cores and increased macrophage infiltration. Optical coherence tomography (OCT) is a high-resolution imaging modality that allows in vivo characterization of atherosclerotic plaques. Using OCT imaging, we compared in vivo plaque characteristics between diabetic and non-diabetic subjects. Methods: Sixty-three patients undergoing cardiac catheterization were enrolled. OCT imaging was performed in culprit coronary arteries. Assessment of plaque lipid content, fibrous cap thickness and frequency of thin-cap fibroatheroma were made independently. Macrophage density was determined from the optical signal within fibrous cap. Results: Eighty-two plaques in total were imaged (19 diabetic vs. 63 non-diabetic). There were no significant differences in frequency of lipid-rich plaques (68% vs. 71%; P =0.78), thin-cap fibroatheroma (29% vs. 36%; P =0.76) or minimum fibrous cap thickness (66.6μm vs. 62.9μm; P =0.87) between diabetic and non-diabetic patients. Fibrous cap macrophage density was higher in lipid-rich plaques (P =0.01) but showed no difference between diabetic and non-diabetic patients (5.94% vs. 5.94%; P =0.37). Conclusions: There were no significant differences in culprit vessel plaque characteristics between diabetic and non-diabetic patients presenting with coronary artery disease. This represents the first study to characterize coronary plaques in diabetic patients using OCT. [Copyright &y& Elsevier]

South Asians, and Indians in particular, are known to have a higher incidence of premature atherosclerosis and acute coronary syndromes (ACS) with worse clinical outcomes, compared to populations with different ethnic backgrounds. However, the underlying pathobiology accounting for these differences has not been fully elucidated. ACS patients who had culprit lesion optical coherence tomography (OCT) imaging were enrolled. Culprit plaque characteristics were evaluated using OCT. Among 1315 patients, 100 were South Asian, 1009 were East Asian, and 206 were White. South Asian patients were younger (South Asians vs. East Asians vs. Whites: 51.6 ± 13.4 vs. 65.4 ± 11.9 vs. 62.7 ± 11.7; p < 0.001) and more frequently presented with ST-segment elevation myocardial infarction (STEMI) (77.0% vs. 56.4% vs. 35.4%; p < 0.001). On OCT analysis after propensity group matching, plaque erosion was more frequent (57.0% vs. 38.0% vs. 50.0%; p = 0.003), the lipid index was significantly greater (2281.6 [1570.8–3160.6] vs. 1624.3 [940.9–2352.4] vs. 1303.8 [1090.0–1757.7]; p < 0.001), and the prevalence of layered plaque was significantly higher in the South Asian group than in the other two groups (52.0% vs. 30.0% vs. 34.0%; p = 0.003). Compared to East Asians and Whites, South Asians with ACS were younger and more frequently presented with STEMI. Plaque erosion was the predominant pathology for ACS in South Asians and their culprit lesions had more features of plaque vulnerability. Clinical Trial Registration: http://www.clinicaltrials.gov , NCT03479723 [Display omitted] • South Asians with ACS were younger and more frequently presented with STEMI. • Plaque erosion was the predominant pathology for ACS in South Asians. • South Asian patients had more features of plaque vulnerability in culprit lesions. [ABSTRACT FROM AUTHOR]

The development of optical coherence tomography (OCT) has revolutionized our understanding of coronary artery disease. In vivo OCT research has paralleled with advances in computational fluid dynamics, providing additional insights in the various hemodynamic factors influencing plaque growth and stability. Recent OCT studies introduced a new concept of plaque healing in relation to clinical presentation. In addition to known mechanisms of acute coronary syndromes such as plaque rupture and plaque erosion, a new classification of calcified plaque was recently reported. This review will focus on important new insights that OCT has provided in recent years into coronary plaque development, progression, and destabilization, with a focus on the role of local hemodynamics and endothelial shear stress, the layered plaque (signature of previous subclinical plaque destabilization and healing), and the calcified culprit plaque. [ABSTRACT FROM AUTHOR]

Abstract Background While preinfarction angina pectoris (pre-IA) is recognized as favorable effects on acute myocardial infarction (AMI), the detail has not been fully investigated. The aims of the current study were to clarify patient characteristics, lesion morphologies determined by optical coherence tomography (OCT), and cardiac outcomes related to pre-IA in patients with AMI. Methods Clinical data and outcomes were compared between AMI patients with pre-IA (pre-IA group, n = 507) and without pre-IA (non-pre-IA group, n = 653). Angiography and OCT findings were analyzed in patients with pre-intervention OCT and compared between groups of pre-IA (n = 219) and non-pre-IA (n = 269). Results ST-segment elevation myocardial infarction (61% vs. 75%, p < 0.001) and cardiogenic shock (8% vs. 14%, p = 0.001) were less prevalent in pre-IA group. Peak creatine kinase-MB levels were lower in pre-IA group (median 83 IU/mL vs. 126 IU/mL, p < 0.001). In pre-intervention coronary angiography findings, initial TIMI flow grade 0/1 (43% vs. 56%, p = 0.019) and Rentrop collateral circulation 0/1 (69% vs. 79%, p = 0.018) were less frequently observed in pre-IA than in non-pre-IA patients. In post-thrombectomy OCT images, plaque rupture (39% vs. 56%, p = 0.003) and red thrombi (42% vs. 54%, p = 0.027) were also less frequently observed in pre-IA group. Kaplan–Meier estimate survival curves showed that cardiac death at 12-months was lower in pre-IA group than in non-pre-IA group (6.9% vs. 10.1%, p = 0.036). Conclusions Patients with pre-IA had less severe AMI on admission, smaller infarction size, and more favorable long-term survival, which may be caused by difference of lesion morphology between patients with and without pre-IA. Highlights • Features of AMI with preinfarction angina (pre-IA) have not been fully examined. • Clinical presentation on admission was less severe in patients with pre-IA. • Initial TIMI flow grade and Rentrop collateral grade were more favorable in pre-IA. • Plaque rupture and red thrombi determined by OCT were less prevalent in pre-IA. • Cardiac mortality at 12 months was more favorable in patients with pre-IA. [ABSTRACT FROM AUTHOR]

Background: Lipid-rich plaque (LRP) is thought to be a precursor to cardiac events. However, its clinical significance in coronary arteries has never been systematically investigated.Objectives: This study investigated the prevalence and clinical significance of LRP in the nonculprit region of the target vessel in patients undergoing percutaneous coronary intervention (PCI).Methods: The study included 1,474 patients from 20 sites across 6 countries undergoing PCI, who had optical coherence tomography (OCT) imaging of the target vessel. Major adverse cardiac events (MACE) were defined as a composite of cardiac death, acute myocardial infarction, and ischemia-driven revascularization. Patients were followed for up to 4 years (median of 2 years).Results: Lipid-rich plaque was detected in nonculprit regions of the target vessel in 33.6% of patients. The cumulative rate of nonculprit lesion-related MACE (NC-MACE) over 48 months in patients with LRP was higher than in those without LRP (7.2% vs. 2.6%, respectively; p = 0.033). Acute coronary syndrome at index presentation (risk ratio: 2.538; 95% confidence interval [CI]: 1.246 to 5.173; p = 0.010), interruption of statin use ≥1 year (risk ratio: 4.517; 95% CI: 1.923 to 10.610; p = 0.001), and LRP in nonculprit regions (risk ratio: 2.061; 95% CI: 1.050 to 4.044; p = 0.036) were independently associated with increased NC-MACE. Optical coherence tomography findings revealed that LRP in patients with NC-MACE had longer lipid lengths (p < 0.001), wider maximal lipid arcs (p = 0.023), and smaller minimal lumen areas (p = 0.003) than LRPs in patients without MACE.Conclusions: Presence of LRP in the nonculprit regions of the target vessel by OCT predicts increased risk for future NC-MACE, which is primarily driven by revascularization for recurrent ischemia. Lipid-rich plaque with longer lipid length, wider lipid arc, and higher degree of stenosis identified patients at higher risk of future cardiac events. (The Massachusetts General Hospital Optical Coherence Tomography Registry; NCT01110538). [ABSTRACT FROM AUTHOR]

The concept of vulnerable plaque (VP) has been widely accepted as the primary cause of acute coronary syndrome (ACS) and sudden cardiac death. ACS is thought to result from sudden disruption of a VP with subsequent occlusive thrombosis. VP typically consists of several components; a large necrotic core, thin fibrous cap, increase in macrophage activity, increase in vaso vasorum, and positive remodeling. In recent years, invasive or non-invasive diagnostic imaging modalities have been developed for indentifying VP. VP has been recognized in various modalities not only by visualization of cross sectional images by high-resolution imaging modalities, such as virtual histology intravascular ultrasound (VH-IVUS), integrated backscatter (IB) IVUS, and optical coherence tomography (OCT), but also by direct visualization by intracoronary angioscopy. VH-IVUS uses advanced radiofrequency signal analysis of ultrasound signals and allows detailed qualitative and quantitative assessment of plaque composition, while IB-IVUS analyzes the radiofrequency signal by applying a fast Fourier transformation of the component of the backscattered signals. Different tissue components reflect the radiofrequency signaling at different power levels, which could be used to differentiate various tissue components. Angioscopy allows direct visualization of internal surface of the lumen, providing the detailed information of characteristics of plaque and thrombus. Optical coherence tomography (OCT) is an analog of IVUS, but uses light instead of sound. OCT has a 10-fold higher image resolution (10-15 &microlam) compared to conventional IVUS, therefore it is able to provide superior image quality. The commercially available versions of the technology used time-domain (TD) OCT (M2, M3, Lightlab, Westford, MA, USA) and fourier-domain (FD) OCT (C7XR, Lightlab, Westford, MA, USA). OCT is the only imaging modality with high enough resolution to measure fibrous cap thickness and neovascularization. Moreover OCT has a unique ability of detecting macrophages. In this review, we attempted to summarize the advantages and limitations of the currently available intravascular modalities. [ABSTRACT FROM AUTHOR]