Relationship between coronary plaque morphology of the left anterior descending artery and 12 months clinical outcome: the CLIMA study.

AIMS: The CLIMA study, on the relationship between coronary plaque morphology of the left anterior descending artery and twelve months clinical outcome, was designed to explore the predictive value of multiple high-risk plaque features in the same coronary lesion [minimum lumen area (MLA), fibrous cap thickness (FCT), lipid arc circumferential extension, and presence of optical coherence tomography (OCT)-defined macrophages] as detected by OCT. Composite of cardiac death and target segment myocardial infarction was the primary clinical endpoint. METHODS AND RESULTS: From January 2013 to December 2016, 1003 patients undergoing OCT evaluation of the untreated proximal left anterior descending coronary artery in the context of clinically indicated coronary angiogram were prospectively enrolled at 11 independent centres (clinicaltrial.gov identifier NCT02883088). At 1-year, the primary clinical endpoint was observed in 37 patients (3.7%). In a total of 1776 lipid plaques, presence of MLA <3.5 mm2 [hazard ratio (HR) 2.1, 95% confidence interval (CI) 1.1-4.0], FCT <75 µm (HR 4.7, 95% CI 2.4-9.0), lipid arc circumferential extension >180° (HR 2.4, 95% CI 1.2-4.8), and OCT-defined macrophages (HR 2.7, 95% CI 1.2-6.1) were all associated with increased risk of the primary endpoint. The pre-specified combination of plaque features (simultaneous presence of the four OCT criteria in the same plaque) was observed in 18.9% of patients experiencing the primary endpoint and was an independent predictor of events (HR 7.54, 95% CI 3.1-18.6). CONCLUSION: The simultaneous presence of four high-risk OCT plaque features was found to be associated with a higher risk of major coronary events.

Role of residual acute stent malapposition in percutaneous coronary interventions.

OBJECTIVES: Assess clinical consequences of acute stent malapposition (ASM) in the context of the multicenter Centro per la Lotta Contro l'Infarto-Optimization of Percutaneous Coronary Intervention (CLI-OPCI) registry. BACKGROUND: ASM as important determinant of stent thrombosis (ST) risk remains controversial. METHODS: From 2009 to 2013, we retrospectively analyzed postprocedural optical coherence tomography (OCT) findings in 864 patients undergoing percutaneous coronary intervention, assessing prevalence and magnitude of ASM and exploring correlation with outcome, especially ST. RESULTS: Postprocedural OCT revealed a variable grade of ASM in 72.3% of stents without correlation between maximal strut-vessel distance and longitudinal extension (R = 0.164, P < 0.01). At a median follow up of 302 (IQ 127-567) days, ASM did not affect risk of following major cardiac adverse events (MACE); residual ASM was comparable in terms of thickness (median [quartiles] 0.21[IQ 0.1-0.4] vs. 0.20[IQ 0.0-0.3], P = 0.397) and length (2.0[IQ 0.5-4.1] vs. 2.2[IQ 0.0-5.2], P = 0.640) in patients with versus without MACE. The predictive accuracy for outcome was low (C-statistic 0.52, CI 95% 0.47-0.58, P = 0.394) as well for target lesion revascularization (HR 0.80, CI 95% 0.5-1.4) and ST (HR 0.71, CI 95% 0.3-1.5). Likewise, timing to MACE was not influenced by presence of such an ASM with similar rate of acute-subacute (HR 1.09, CI 95% 0.6-1.9), late (HR 0.91, CI 95% 0.5-1.8), and very late (HR 1.23, CI 95% 0.5-2.9) events. CONCLUSIONS: Limited ASM was a common finding after stent implantation, but was not associated to increased risk of stent failure or ST during mid-term follow-up. © 2017 Wiley Periodicals, Inc.

CADUCEO: A Platform to Support Federated Healthcare Facilities through Artificial Intelligence.

Data-driven algorithms have proven to be effective for a variety of medical tasks, including disease categorization and prediction, personalized medicine design, and imaging diagnostics. Although their performance is frequently on par with that of clinicians, their widespread use is constrained by a number of obstacles, including the requirement for high-quality data that are typical of the population, the difficulty of explaining how they operate, and ethical and regulatory concerns. The use of data augmentation and synthetic data generation methodologies, such as federated learning and explainable artificial intelligence ones, could provide a viable solution to the current issues, facilitating the widespread application of artificial intelligence algorithms in the clinical application domain and reducing the time needed for prevention, diagnosis, and prognosis by up to 70%. To this end, a novel AI-based functional framework is conceived and presented in this paper.

Prevalence and quantitative assessment of macrophages in coronary plaques.

Although optical coherence tomography (OCT) proved to be able to identify macrophage clusters, there are no available data on the possibility to obtain reproducible measurements of their circumferential extension and location. The purpose of the present post-hoc analysis of the CLIMA study was to revise the clinical and demographic variables of patients having coronary plaques with macrophages and to investigate the reproducibility of their quantitative assessment. A total of 577 patients out of 1003 undergoing OCT showed macrophage accumulation. Three groups were identified; group 1 (426 patients) without macrophages, group 2 (296) patients with low macrophage content (less than median value [67°] of circumferential arc) and group 3 (281) with high macrophage content arc [> 67°]. Patients with macrophages (groups 2 and 3) showed a higher prevalence of family history for coronary artery disease and hypercholesterolemia and had a significantly larger body mass index. Furthermore, group 3 had more commonly triple vessel disease and higher value of LDL cholesterol levels compared to the two other groups. The inter-observer agreement for macrophage interpretation was good: R values were 0.97 for the circumferential arc extension, 0.95 for the minimum distance and 0.98 for the mean distance. A non-significant correlation between circumferential extension of macrophages and hsCRP values was found (R = 0.013). Quantitative assessment of macrophage accumulations can be obtained with high reproducibility by OCT. The presence and amount of macrophages are poorly correlated with hsCRP and identify patients with more advanced atherosclerosis and higher LDL cholesterol levels.

Role of optical coherence tomography in identifying sub-optimal stent positioning and predicting major adverse cardiac events in a comparative study with angiography: a CLIO-OPCI II sub-study.

BACKGROUND: Quantitative coronary angiography (QCA) is the gold standard for evaluating correct stenting, despite its limitation in recognizing features indicative of suboptimal deployment. This subanalysis of the CLI-OPCI II registry addressed the role of optical coherence tomography (OCT) to verify whether suboptimal OCT deployment occurs in the presence of an optimal angiographic result. PATIENTS AND METHODS: We retrospectively analyzed 125 lesions in the 105 patients with major adverse cardiac events of the CLI-OPCI II. Every lesion was evaluated with OCT and angiography, including visual and QCA assessment. Optimal angiographic result was defined as residual stenosis of less than 30% at QCA and absence of haziness at visual angiography. The following OCT features of suboptimal stenting were considered: edge dissection (linear rim of tissue with a width >200 µm), reference lumen narrowing (lumen area <4.5 mm in the presence of significant residual plaque adjacent to stent endings), and in-stent narrowing (minimum lumen area<4.5 mm). RESULTS: Among the 125 lesions, 105 showed an optimal angiographic result. At OCT, a suboptimal positioning was common (56%). In the group of optimal angiographic results, OCT showed a suboptimal deployment in 54% of cases. Minimum lumen area of less than 4.5 mm, distal and proximal reference narrowing, and distal edge dissections were found in 30, 25, 15, and 7% of cases, respectively. CONCLUSION: This substudy of the CLI-OPCI II showed that in patients with major adverse cardiac events, the presence of an optimal postintervention angiographic appearance with suboptimal OCT metrics is a frequent finding. Our data further support the effectiveness of OCT, which provide valuable information even in the presence of optimal poststenting angiographic results.

Clinical Impact of Suboptimal Stenting and Residual Intrastent Plaque/Thrombus Protrusion in Patients With Acute Coronary Syndrome: The CLI-OPCI ACS Substudy (Centro per la Lotta Contro L'Infarto-Optimization of Percutaneous Coronary Intervention in Acute Coronary Syndrome).

BACKGROUND: Clinical consequences of optical coherence tomographic (OCT) high-definition visualization of plaque/stent structures in acute patients remain undefined. In this retrospective substudy, we assessed the prognostic impact of postprocedural culprit lesion OCT findings in patients with acute coronary syndrome undergoing percutaneous coronary intervention. METHODS AND RESULTS: In the CLI-OPCI (Centro per la Lotta Contro L'Infarto-Optimization of Percutaneous Coronary Intervention) database collecting cases from 5 independent OCT-experienced centers, we retrospectively analyzed postprocedural OCT findings in acute coronary syndrome patients and explored its possible impact (specifically that of residual intrastent plaque/thrombus protrusion) on outcome. From 2009 to 2013, 507 patients (588 lesions) were evaluated. Patients experiencing device-oriented cardiovascular events showed more frequently the features of suboptimal stent implantation defined as the presence of significant residual intrastent plaque/thrombus protrusion (hazard ratio [HR], 2.35; P<0.01), in-stent minimum lumen area (MLA) <4.5 mm2 (HR, 2.72; P<0.01), dissection >200 µm at distal stent edge (HR, 3.84; P<0.01), and reference lumen area <4.5 mm2 at either distal (HR, 6.07; P<0.001) or proximal (HR, 8.50; P<0.001) stent edges. Postprocedural OCT assessment of treated culprit lesion revealed at least one of these parameters in 55.2% of cases, with an associated increased risk of device-oriented cardiovascular events during follow-up (17.9% versus 4.8%; P<0.001). Both the presence of at least one of these parameters (HR, 3.69; P=0.002) and the residual intrastent plaque/thrombus protrusion (HR, 2.83; P=0.008) were confirmed as independent predictors of device-oriented cardiovascular events. CONCLUSIONS: In this retrospective study of acute coronary syndrome patients undergoing percutaneous coronary intervention, a composite of OCT-defined suboptimal stent implantation characteristics at the culprit lesion and residual intrastent plaque/thrombus protrusion was associated with adverse outcome.

Optical coherence tomography guided in-stent thrombus removal in patients with acute coronary syndromes.

The persistence of thrombus inside stent struts is a frequent event in patients with acute coronary syndromes (ACS) undergoing percutaneous coronary intervention (PCI), and this phenomenon might be associated with an increased risk of stent thrombosis. We sought to quantify by means of optical coherence tomography (OCT) the presence of in-stent thrombus after achievement of an optimal angiographic result in patients with ACS undergoing PCI. In addition, we evaluated the feasibility and safety of an OCT-guided strategy of in-stent thrombus removal. Eighty consecutive patients with ACS undergoing PCI were treated with two different strategies equally divided into two groups: angio-guided PCI, and OCT-guided PCI, in which additional OCT-driven in-stent balloon dilatation was adopted to reduce thrombus encroachment of the lumen. Overall in-stent thrombus area was 4.3 % with a maximal thrombus encroachment of 16.7 %. In the OCT-guided group, use of high pressure intra-stent dilatation led to a significant increase in stented area (9.6 ± 2.4 vs. 9.1 ± 2.49 mm(2), p = 0.002) and lumen area (9.2 ± 2.4 vs. 8.7 ± 2.3 mm(2), p < 0.001) and also significantly decreased in-stent thrombus area in absolute (0.35 ± 0.29 vs. 0.42 ± 0.30 mm(2), p = 0.001) and relative terms (3.58 ± 3.25 vs. 4.53 ± 3.01 %, p = 0.001). Values of TIMI flow, frame count and blush grade, as well as clinical outcomes were not detrimentally affected by such additional dilatations. The use of additional OCT-driven in-stent balloon dilatations is feasible, safe and might be effective in the treatment of in-stent thrombus for patients with ACS.

Early vessel healing of the Avantgarde cobalt-chromium coronary stent: the ON-GARDE OCT study.

INTRODUCTION: Uncoverage and malapposition of stent struts at optical coherence tomography (OCT) have been associated with stent thrombosis. Stent uncoverage by OCT is being used as a surrogate to address the propensity of a stent to develop thrombosis. We aimed to appraise early vessel healing in patients with ST-elevation myocardial infarction (STEMI) treated with the novel Avantgarde stent. METHODS: Patients with STEMI and multivessel disease were enrolled. The stent deployed on the infarct-related artery was imaged by frequency domain-OCT during deferred intervention (4-7 days apart). The primary end-point was the percentage of uncovered struts. Secondary end-points were the percentage of malapposed struts and struts covered with thrombus. RESULTS: Twenty patients (20 lesions) were enrolled, with 18 (18 stents) achieving a complete OCT pull-back and thus entering the final analysis (1497 cross-sections, 11 446 struts). Uncovered struts were 3.9%, whilst 8.0% of struts were malapposed and 2.6% were covered by thrombus. At per-stent analysis, all stents but two had a homogeneous distribution of strut coverage (i.e. % of uncovered struts ≥10). CONCLUSIONS: This study, originally exploiting OCT data early after stenting in STEMI patients, shows that the Avantgarde stent is associated with favourable vessel healing features.

Detection of very early stent healing after primary angioplasty: an optical coherence tomographic observational study of chromium cobaltum and first-generation drug-eluting stents. The DETECTIVE study.

BACKGROUND: Lack of stent coverage appears to be associated with stent thrombosis, a problem of particular concern in patients with ST elevation myocardial infarction (STEMI). METHODS: The DETECTIVE European Multicenter Registry was set up to address the early modality of stent healing in the setting of STEMI. The Registry compared, with an early optical coherence tomography (OCT) evaluation performed at 3-7 days, the patterns of coverage and apposition of the first generation of drug-eluting stents (DESs) and cobalt chromium non-drug-eluting stents (CCSs) that were deployed in culprit lesions and in non-culprit segments. The Registry included only patients with a multi-vessel disease to allow, at 3-7 days from the first angioplasty, a deferred OCT examination and a staged intervention in another vessel. RESULTS: 28 stented lesions (15 patients) eventually entered the final OCT assessment. 13 stents were first-generation DESs, while the remaining 15 were CCSs. 18 stents (64%) were deployed at culprit STEMI lesions, and the remaining 10 (36%) were deployed at non-culprit sites. The distribution of clinical and procedural variables in DES and CCS as well as in culprit and non-culprit sites was not different. In total, 27,019 struts were analysed in 28 stents. The percentage of stent uncoverage in the overall analysis was 11.7%, while the percentage of malapposition and that of struts covered with thrombus were 4.8% and 2.2%, respectively. A low percentage of strut uncoverage was found in all the four studied subgroups: DES 12.8%, CCS 10.9%, stents deployed in culprit lesions 13.2% and stents deployed in non-culprit lesions 8.7%. CONCLUSIONS: In conclusion, our data show that in patients with STEMI, a very high percentage of stent struts is covered by an early thin rim of tissue within 7 days after stent positioning. The present data bring new insights in the mechanism and timing of strut coverage.

Safety and feasibility of frequency domain optical coherence tomography to guide decision making in percutaneous coronary intervention.

AIMS: The purpose of this single centre registry is to assess safety and feasibility of the frequency domain optical coherence tomography (FD-OCT) system during coronary interventions. METHODS AND RESULTS: Ninety patients with unstable or stable coronary artery disease were included in this study. OCT imaging was performed in a first group of 40 patients (group 1), to evaluate ambiguous/intermediate lesions (24 patients in group 1 had OCT also done post-PCI, for assessment of stent deployment); and in a second group of 50 patients (group 2), to address the adequacy of stent deployment. Therefore, 74 patients underwent FD-OCT after stent implantation. A complex-lesion population was studied (B2 type lesion=72.2% and C type lesion=20.3%). The mean time of a FD-OCT pull-back (from the set up to the completion of the pull back) was 2.1 min and in all but one (99.1%) the procedure was successful. No patients experienced major complications in terms of death, myocardial infarction, emergency revascularisation, embolisation, life-threatening arrhythmia, coronary dissection, prolonged and severe vessel spasm and contrast induced nephropathy. In the ambiguous lesion group, 60% of patients were treated with PCI, whilst in the others, PCI were deferred. In total, 113 deployed stents (33,6% chromium cobalt stent, 66,4% drug eluting stent) were imaged with OCT. OCT findings led to additional interventions in 24 out of 74 patients (32%): 15 had further balloon inflations, nine had additional stent deployment whilst two had both treatments. At clinical follow-up, (4.6 ± 3.,2 months), there were no death, acute myocardial infarctions and cases of stent thrombosis, whilst two patients underwent revascularisation for recurrence of angina. CONCLUSIONS: The present registry shows that FD-OCT is a feasible and safe technique for guidance of coronary interventions. Randomised studies will confirm whether the use of FD-OCT will improve the clinical outcome.