Determinants and long-term outcomes of largely uncovered struts in thin-struts drug-eluting stents assessed by optical coherence tomography

BACKGROUND

Uncovered struts are a determinant of stent failure. The impact of plaque composition and procedural factors on the occurrence, evolution, and outcomes of uncovered struts in a high-risk setting has not been investigated.

OBJECTIVE

To investigate the determinants and long-term clinical impact of largely uncovered struts (LUS) in thin-struts drug-eluting stents (DES) implanted in complex lesions by intracoronary optical coherence tomography (OCT).

METHODS

Ninety patients with multivessel disease undergoing staged complete revascularization were randomly assigned to bioabsorbable or durable polymer DES. OCT were serially performed during the index procedure, at 3- and 18-month follow-up, and analyzed by an independent core lab. Struts were defined uncovered by OCT if no tissue was visible above the struts. LUS were defined as ≥30% of uncovered struts at 3-month follow-up. Clinical outcomes were the occurrence of target vessel failure (TVF) and major adverse cardiac and cerebrovascular events (MACCE) at 5-year follow-up.

RESULTS

LUS occurred in 31 patients (34.4%) regardless of stent platform. At 5 years, no differences were observed in the rate of TVF (12.7% vs. 13.4%; p = 0.91) and MACCE (23.9% vs. 24.9%; p = 0.88) between the two groups. At multivariate logistic regression, plaque rupture, mean lumen diameter, proximal reference vessel area, and maximum stent deployment pressure were independent predictors of LUS.

CONCLUSIONS

LUS are a frequent finding in complex coronary lesions treated with thin-struts DES, especially in the presence of plaque rupture. However, in this study, no significant safety signal related to LUS emerged in long-term follow-up.

Optical Coherence Tomography to Assess Proximal Side Optimization Technique in Crush Stenting

Aim

The aim of this study was to explore the potential intraprocedural benefits of the Proximal Side Optimization (PSO) technique by Optical Coherence Tomography (OCT).

Methods

A case series of 10 consecutive true bifurcation lesions, with severe long pathology of long side branch (SB), were randomly assigned to be treated by standard DK Crush procedure (non-PSO group) as compared to DK Crush in PSO modification (PSO group). The data from OCT investigation before crushing of the SB Drug-Eluting Stent (DES), after crushing, after first kissing balloon inflation (KBI), and after final angiography were compared between the two groups (Public trials registry ISRCTN23355755).

Results

All 10 cases were successfully treated by the assigned technique. The two groups were similar in terms of indications for the procedure, bifurcation angle, and stent dimensions. As compared to the non-PSO, the PSO group showed larger proximal SB stent areas (5.8 ± 1.8 vs. 4.5 ± 0.5 mm²; p = 0.02), the larger delta between distal and proximal stent areas before crush (1.5 ± 0.7 vs. 0.6 ± 0.5 mm²; p = 0.004), and the larger Space of Optimal Wiring (SOW) after Crush (5.3 ± 1.8 vs. 2.5 ± 1.1 mm²; p = 0.02). The gaps in scaffolding within the ostial segment of the Side Branch DES were found in two patients from the non-PSO group.

Conclusion

The DK Crush in PSO modification results in larger SB DES and SOW areas with better apposition to the vessel wall. As result, the SB DES acquires a funnel shape, which reduces the risk of passage outside the SB stent struts during re-wiring, thus, allowing predictable and secure results.

Coronary Artery Perforation, Subepicardial Hematoma, and Cardiac Tamponade After Complex Percutaneous Coronary Intervention

This report presents the case of fissured subepicardial hematoma and cardiac tamponade after coronary artery perforation during a complex percutaneous intervention. Surgical therapy was required to achieve hemostasis because a percutaneous sealing result was insufficient. Prompt recognition and cardiac surgery availability are essential for patient survival in such situations. (Level of Difficulty: Beginner.).

Incidence, mechanisms and clinical impact of largely uncovered struts in current generation drug-eluting-stents: insight from the TRANSFORM-OCT Study

Background

Thin-strut drug-eluting stents (DES) and optimal implantation technique reduce the rate of stent failure significantly. Nevertheless, uncovered struts (US) have been observed as a key factor for stent thrombosis regardless of stent generation and time of follow-up. Associated factors and temporal evolution are currently unknown.

Purpose

To evaluate the prevalence, mechanisms and long-term clinical impact of largely-US after state-of-the-art DES implantation in complex coronary clinical/lesion cohorts

Methods

The study was a pre-specified analysis of TRASFORM-OCT, a randomized controlled trial comparing bioabsorbable or durable polymer DES by serial optical coherence tomography (OCT), obtained at baseline, immediately after procedure, at 3 and 18 months follow-up. Methods and results were published previously. For the current analysis enrolled patients (n=90) were divided in 2 groups according to the amount of US identified by OCT at 3 months: a largely US (LUS ≥30%) group and the control group (<30% US), to evaluate factors associated to LUS, and the clinical impact at follow-up.

Results

Out of 90 patients, 31 (34.4%) were assigned to the LUS group, and 59 (65.6%) to the control group. At baseline, LUS patients had larger vessels (reference area 5.51±1.1 vs. 4.27±1.5 mm2, p=0.001), a higher rate of plaque rupture (41.9 vs. 18.6%, p=0.02), thin-cap fibroatheroma (58.1% vs. 51.7% p=0.03) and thrombus (58.1% vs. 35.6%, p=0.001) as detected by OCT. 98% patients continued dual antiplatelet therapy up to 12 months, and 24% of them up to 18 months.

At stent implant, performed with high pressure dilation (21.18±3.8 vs 20.54±3.6 atm in LUS vs control group, p 0.48), the rate of apposed and embedded struts was high in both groups, although higher in controls (93.92±5.30% vs 96.46±3.68%, p 0.03 and 16.8±11.5% vs 21.7±15.8%, p=0.12, respectively for controls and LUS). At 3 months, US rate was 48.4±12% in the LUS group, and 13.3±7% in the control group (p<0.001). Global malapposition rate was 7.95±7.5% and 1.69±1.6% (p<0.001), respectively. 84.52±12.41% of the US in the LUS group and 86.49±19.98% in controls group were apposed to the wall (p 0.07). At 18 months, the rate of US dropped significantly to 8.4±10% in LUS group and 1.8±3% in control group (p<0.001), with malapposition rate being 1.4±3.3 and 0.16±0.43% (p 0.006). Of the US, 81.6±25.15 and 91.11±21.76% were apposed to the wall, respectively. At 5 years clinical follow-up, no differences were observed at the composite endpoint of major adverse cardiovascular events (detailed data will be presented).

Conclusions

In a setting of optimal PCI with modern DES and high-pressure inflation, LUS occur in 30% of patients at early follow-up, more frequently in large vessels with lipid-rich, complex plaques. The vast majority of US is apposed to the wall and near-complete coverage is observed at long-term follow-up, with no clinical impact compared to subjects with a low rate of US.

Funding Acknowledgement

Type of funding source: None

Analysis of the Amount of Polyphenols, Flavonoids and Assessment of the Antioxidant Capacity of Frozen Fruits

The data from literature shows that frozen vegetal products preserve their nutritional qualities for a long time. Fruits have a high content of substances with antioxidant capacity in the body. There are many recent studies demonstrating the importance of antioxidant substances in neutralizing free radicals in the human body. In this study there were analysed phenolic compounds and flavonoids in eight different species of fruits, belonging to three families. The antioxidant capacity of the extracts was evaluated by: CUPRAC assay, ABTS method and FRAP method. Our results show that the studied fruits represent rich sources of compounds with antioxidant capacity.

Correlations Between Oxidative Stress and Apoptosis During Anuran Metamorphosis

The living organisms can trigger the defense mechanisms against free radicals, by synthesizing different antioxidant enzymes. The present study is focused on establishing some correlation between oxidative stress and the structural changes in cell death at the intestinal larval epithelium level during anuran metamorphosis. Cell death in such conditions may be regarded as the result of an interaction activity in which takes place apoptosis, autophagy, and necrosis, the cell choosing one or more. The amphibian metamorphosis is a complex process, divided into three major periods: prometamorphosis, premetamorphosis and climax. The process ensures the passage of the organism from aquatic to terrestrial life, with dramatic changes in the morphology and structure of some organs. In the climax stages of metamorphosis, a variety of free radicals are produced, starting a numerous cellular oxidation reactions.

Perioperative management of oral antiplatelet therapy and clinical outcomes in coronary stent patients undergoing surgery

The aim was to investigate the perioperative risk of ischaemic and bleeding events in patients with coronary stents undergoing cardiac and non-cardiac surgery and how these outcomes are affected by the perioperative use of oral antiplatelet therapy. This was a multicentre, retrospective, observational study conducted in patients with coronary stent(s) undergoing cardiac or non-cardiac surgery. The primary efficacy endpoint was the 30-day incidence of major adverse cardiac events (MACE), defined as the composite of cardiac death, myocardial infarction (MI) or stroke. The primary safety endpoint was the 30-day incidence of Bleeding Academic Research Consortium (BARC) bleeding ≥ 2. A total of 666 patients were included. Of these, 371 (55.7 %) discontinued their antiplatelet medication(s) (all or partly) before undergoing surgery. At 30 days, patients with perioperative discontinuation of antiplatelet therapy experienced a significantly higher incidence of MACE (7.5 % vs 0.3 %, p < 0.001), cardiac death (2.7 % vs 0.3 %, p=0.027), and MI (4.0 % vs 0 %, p < 0.001). After adjustment, peri-operative antiplatelet discontinuation was the strongest independent predictor of 30-day MACE (odds ratio [OR]=25.8, confidence interval [CI]=3.37–198, p=0.002). Perioperative aspirin (adjusted OR 0.27, 95 % CI 0.11–0.71, p=0.008) was significantly associated with a lower risk of MACE. The overall incidence of BARC ≥ 2 bleeding events at 30-days was significantly higher in patients who discontinued oral antiplatelet therapy (25.6 % vs 13.9 %, p < 0.001). However, after adjustment, antiplatelet discontinuation was not independently associated with BARC ≥ 2 bleeding. In conclusion antiplatelet discontinuation increases the 30-day risk of MACE, in patients with coronary stents undergoing cardiac and non-cardiac surgery, while not offering significant protection from BARC≥ 2 bleeding.

Optical Coherence Tomography Findings in Patients With Coronary Stent Thrombosis: A Report of the PRESTIGE Consortium (Prevention of Late Stent Thrombosis by an Interdisciplinary Global European Effort)

BACKGROUND

Stent thrombosis (ST) is a serious complication following coronary stenting. Intravascular optical coherence tomography (OCT) may provide insights into mechanistic processes leading to ST. We performed a prospective, multicenter study to evaluate OCT findings in patients with ST.

METHODS

Consecutive patients presenting with ST were prospectively enrolled in a registry by using a centralized telephone registration system. After angiographic confirmation of ST, OCT imaging of the culprit vessel was performed with frequency domain OCT. Clinical data were collected according to a standardized protocol. OCT acquisitions were analyzed at a core laboratory. Dominant and contributing findings were adjudicated by an imaging adjudication committee.

RESULTS

Two hundred thirty-one patients presenting with ST underwent OCT imaging; 14 (6.1%) had image quality precluding further analysis. Of the remaining patients, 62 (28.6%) and 155 (71.4%) presented with early and late/very late ST, respectively. The underlying stent type was a new-generation drug-eluting stent in 50.3%. Mean reference vessel diameter was 2.9±0.6 mm and mean reference vessel area was 6.8±2.6 mm². Stent underexpansion (stent expansion index <0.8) was observed in 44.4% of patients. The predicted average probability (95% confidence interval) that any frame had uncovered (or thrombus-covered) struts was 99.3% (96.1-99.9), 96.6% (92.4-98.5), 34.3% (15.0-60.7), and 9.6% (6.2-14.5) and malapposed struts was 21.8% (8.4-45.6), 8.5% (4.6-15.3), 6.7% (2.5-16.3), and 2.0% (1.2-3.3) for acute, subacute, late, and very late ST, respectively. The most common dominant finding adjudicated for acute ST was uncovered struts (66.7% of cases); for subacute ST, the most common dominant finding was uncovered struts (61.7%) and underexpansion (25.5%); for late ST, the most common dominant finding was uncovered struts (33.3%) and severe restenosis (19.1%); and for very late ST, the most common dominant finding was neoatherosclerosis (31.3%) and uncovered struts (20.2%). In patients presenting very late ST, uncovered stent struts were a common dominant finding in drug-eluting stents, and neoatherosclerosis was a common dominant finding in bare metal stents.

CONCLUSIONS

In patients with ST, uncovered and malapposed struts were frequently observed with the incidence of both decreasing with longer time intervals between stent implantation and presentation. The most frequent dominant observation varied according to time intervals from index stenting: uncovered struts and underexpansion in acute/subacute ST and neoatherosclerosis and uncovered struts in late/very late ST.

Study of the Plasmatic Oxidative Stress Markers in Temporomandibular Joint Disorders

Oxidative stress is considered to have an important role in the pathogenesis of many inflammatory diseases. This investigation sought to determine whether the appliance of etiologic factors for temporomandibular joint disorder is associated with modified values of oxidative stress as measured by biomarkers in plasma. A case-control study design was used to compare oxidative stress biomarkers (malondialdehyde and glutathione) in plasma from Wistar rats with different etiologic factors (biomechanical stress, estrogen hormones and emotional stress), compared to non-temporomandibular joint controls. Etiologic factors were applied in five groups (n=10) of mature female Wistar rats, individually (biomechanical stress, estrogen hormones and emotional stress) in three groups or in combination for two groups (biomechanical stress-emotional stress and biomechanical stress-emotional stress). No factor applied for the control group. Blood samples were taken after 30 and 60 days of experiment. Malondialdehyde and glutathione levels in plasma were evaluated. The most important modifications in malondialdehyde levels were recorded for the fifth group (biomechanical stress-emotional stress) where values increased significantly from 30 to 60 days plasma analysis (p = 0.003). No statistical differences were recorded in glutathione plasmatic levels between control and experimental groups at 30 days analysis. At 60 days, glutathione plasmatic evaluation recorded higher values than control for all experimental groups. Our findings in this rat experimental model, clearly indicate that biomechanical stress, estrogen hormones and emotional stress, have an impact on oxidative stress development and consequently on the functionality of the temporomandibular joint in rats. Moreover combined actions of these factors, increase the oxidative stress phenomena on temporomandibular joint in rats.

Comparative Analysis upon Action of Aqueous and Alcoholic Trigonella sp. Extracts on Fibroblasts Culture

Flow cytometry with its numerous advantages, has become indispensable for modern biochemistry research, being a highly efficient and sensitive in many areas, particularly in the fundamental or applied cellular biology. Flow cytometry has greatly contributed to the exploration of the cellular structure and functions, combining analytical and preparative aspects. In combination with the use of the probes (fluorochromes, fluorogenic substrates, monoclonal antibodies and lectins), the FCM enables multiple investigations for the characterization of cellular populations, the analysis of the cellular components (nucleic acids, proteins, intercellular and surface antigens, enzyme activities, membrane potential, mitochondrial activity, intracellular pH, ion flux and membrane fluidity). We chose to study the behavior of fibroblasts using flow cytometry, in terms of effects induced by the presence of extracts from Trigonella foenum graecum L.

Malondialdehyde and Lipofuscin Biomarkers of Oxidative Stress in Rana temporaria temporaria During Metamorphosis

Anuran amphibians metamorphosis represents a model for the study of different processes, including tissue remodeling. One of the body�s systems whose morphological and structural properties are deeply transformed during metamorphosis is the digestive tract. The only structure in the digestive tract which is destroyed and then replaced with a new tissue (histolysis and histogenesis) under the action of oxidative stress and hormones, is the intestinal epithelium. Oxidative stress may be related to the production of malondialdehyde and the accumulation of lipofuscin. The two substances can be considered biomarkers of this process.

Relationship between Serum Inflammatory Biomarkers and Thrombus Characteristics in Patients with ST Segment Elevation Myocardial Infarction

Objectives: To compare angiographic and optical coherence tomography (OCT) data pertinent to thrombi, along with the histologic characteristics of aspirated thrombi in patients presenting with ST elevation myocardial infarction (STEMI) with or without inflammation, as assessed by C-reactive protein (CRP) and myeloperoxidase (MPO). Methods: In the OCTAVIA (Optical Coherence Tomography Assessment of Gender Diversity in Primary Angioplasty) study, 140 patients with STEMI referred for primary percutaneous intervention were enrolled. The patients underwent OCT assessment of the culprit vessel, along with blood sampling of CRP and MPO, and histologic analysis of the thrombus. Results: Biomarkers were available for 129 patients, and histology and immunohistochemistry of the thrombi were available for 78 patients. Comparisons were made using the median thresholds of CRP and MPO (2.08 mg/L and 604.124 ng/mL, respectively). There was no correlation between CRP and MPO levels in the whole population (p = 0.685). Patients with high CRP levels had higher thrombus grades and more frequent TIMI flow 0/1 compared with those with low CRP levels (5 [1st quartile 3; 3rd quartile 5] vs. 3.5 mg/L [1; 5], p = 0.007, and 69.3 vs. 48.5%, p = 0.04, respectively). Patients with high MPO levels more commonly had early thrombi than had those with low MPO levels (42.5 vs. 20.0%, p = 0.04). Conclusions: CRP and MPO were not correlated in STEMI patients, possibly reflecting different pathogenic mechanisms, with CRP more related to thrombus burden and MPO to thrombus age.

Percutaneous Coronary Intervention Planning and Optimization with Optical Coherence Tomography

Coronary angiography confirms or excludes coronary artery disease, assesses lesions severity, and helps to decide percutaneous coronary interventions (PCI). Coronary angiography has clear limitations. Intravascular imaging guides PCI. Frequency domain optical coherence tomography (OCT) gained attention for accurate planning and guidance of complex PCI. High-speed OCT image acquisition enables prompt vessel assessment in stable and unstable patients. The high-resolution images provide precise tissue characterization and a reliable quantitative assessment of the coronary pathology. Immediately after stent implantation, OCT allows accurate evaluation of stent expansion and symmetry. Real-time angio-OCT co-registration integrates OCT into the PCI workflow for accurate decision making.

Eroded Versus Ruptured Plaques at the Culprit Site of STEMI: In Vivo Pathophysiological Features and Response to Primary PCI

OBJECTIVES

The aim of this study was to evaluate the pathophysiological features and response to primary percutaneous coronary intervention (PCI) of nonruptured/eroded plaque versus ruptured plaque as a cause of ST-segment elevation myocardial infarction (STEMI).

BACKGROUND

Autopsy series identified nonruptured/eroded plaque and ruptured plaque as the principal pathological substrates underlying coronary thrombosis in STEMI. The real incidence of different plaque morphologies, associated biological factors, superimposed thrombus, and their interaction with primary PCI remain largely unknown.

METHODS

In a prospective study, 140 patients with STEMI underwent optical coherence tomography of the infarct-related artery (IRA) before PCI, after everolimus-eluting stent implantation and at 9-month follow-up. Histopathology and immunohistochemistry of thrombus aspirates and serum biomarkers were assessed at baseline.

RESULTS

Culprit plaque morphology was adjudicated in 97 patients: 32 plaques (33.0%) with an intact fibrous cap (IFC), 63 (64.9%) plaques with a ruptured fibrous cap (RFC), and 2 (2.1%) spontaneous dissections. Patients with an IFC and RFC had similar clinical characteristics, and serum inflammatory and platelets biomarkers. An IFC presented more frequently with a patent IRA (56.2% vs. 34.9%; p = 0.047), and had fewer lipid areas (lipid-rich areas: 75.0% vs. 100.0%; p < 0.001) and less residual thrombus before stenting (white thrombus: 0.41 mm(3) vs. 1.52 mm(3); p = 0.001; red thrombus: 0 mm(3) vs. 0.29 mm(3); p = 0.001) with a lower peak of creatine kinase-myocardial band (66.6 IU/l vs. 149.8 IU/l; p = 0.025). At the 9-month optical coherence tomography, IFC and RFC had similar high rates of stent strut coverage (92.5% vs. 91.2%; p = 0.15) and similar percentage of volume obstruction (12.6% vs. 10.2%; p = 0.27). No significant differences in clinical outcomes were observed up to 2 years.

CONCLUSIONS

In the present study, an IFC was observed at the culprit lesion site of one-third of STEMIs. IFC, compared with RFC, was associated with higher rates of patent IRA at first angiography, fewer lipid areas, and residual endoluminal thrombus. However, no difference in vascular response to everolimus-eluting stent was observed. (Optical Coherence Tomography Assessment of Gender Diversity in Primary Angioplasty [OCTAVIA]; NCT01377207).