Different patterns of vascular response between patients with or without diabetes mellitus after drug-eluting stent implantation: optical coherence tomographic analysis

Beneficial effects of high-density lipoprotein (HDL) on stent biocompatibility and the potential value of HDL infusion therapy following percutaneous coronary intervention

Several epidemiological studies have shown a clear inverse relationship between serum levels of high-density lipoprotein cholesterol (HDL-C) and the risk of atherosclerotic cardiovascular disease (ASCVD), even at low-density lipoprotein cholesterol levels below 70 mg/dL. There is much evidence from basic and clinical studies that higher HDL-C levels are beneficial, whereas lower HDL-C levels are detrimental. Thus, HDL is widely recognized as an essential anti-atherogenic factor that plays a protective role against the development of ASCVD. Percutaneous coronary intervention is an increasingly common treatment choice to improve myocardial perfusion in patients with ASCVD. Although drug-eluting stents have substantially overcome the limitations of conventional bare-metal stents, there are still problems with stent biocompatibility, including delayed re-endothelialization and neoatherosclerosis, which cause stent thrombosis and in-stent restenosis. According to numerous studies, HDL not only protects against the development of atherosclerosis, but also has many anti-inflammatory and vasoprotective properties. Therefore, the use of HDL as a therapeutic target has been met with great interest. Although oral medications have not shown promise, the developed HDL infusions have been tested in clinical trials and have demonstrated viability and reproducibility in increasing the cholesterol efflux capacity and decreasing plasma markers of inflammation. The aim of the present study was to review the effect of HDL on stent biocompatibility in ASCVD patients following implantation and discuss a novel therapeutic direction of HDL infusion therapy that may be a promising candidate as an adjunctive therapy to improve stent biocompatibility following percutaneous coronary intervention.

A novel 6-metabolite signature for prediction of clinical outcomes in type 2 diabetic patients undergoing percutaneous coronary intervention

Background

Outcome prediction tools for patients with type 2 diabetes mellitus (T2DM) undergoing percutaneous coronary intervention (PCI) are lacking. Here, we developed a machine learning-based metabolite classifier for predicting 1-year major adverse cardiovascular events (MACEs) after PCI among patients with T2DM.

Methods

Serum metabolomic profiling was performed in a nested case–control study of 108 matched pairs of patients with T2DM occurring and not occurring MACEs at 1 year after PCI, then the matched pairs were 1:1 assigned into the discovery and internal validation sets. External validation was conducted using targeted metabolite analyses in an independent prospective cohort of 301 patients with T2DM receiving PCI. The function of candidate metabolites was explored in high glucose-cultured human aortic smooth muscle cells (HASMCs).

Results

Overall, serum metabolome profiles differed between diabetic patients with and without 1-year MACEs after PCI. Through VSURF, a machine learning approach for feature selection, we identified the 6 most important metabolic predictors, which mainly targeted the nicotinamide adenine dinucleotide (NAD⁺) metabolism. The 6-metabolite model based on random forest and XGBoost algorithms yielded an area under the curve (AUC) of ≥ 0.90 for predicting MACEs in both discovery and internal validation sets. External validation of the 6-metabolite classifier also showed good accuracy in predicting MACEs (AUC 0.94, 95% CI 0.91–0.97) and target lesion failure (AUC 0.89, 95% CI 0.83–0.95). In vitro, there were significant impacts of altering NAD⁺ biosynthesis on bioenergetic profiles, inflammation and proliferation of HASMCs.

Conclusion

The 6-metabolite model may help for noninvasive prediction of 1-year MACEs following PCI among patients with T2DM.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12933-022-01561-1.

Left Main Coronary Artery Disease in Diabetics: Percutaneous Coronary Intervention or Coronary Artery Bypass Grafting?

The choice between coronary artery bypass grafting (CABG) and percutaneous coronary intervention (PCI) for myocardial revascularization in patients with left main disease (LMD) is controversial. There is general agreement that CABG is appropriate for all patients, and PCI is acceptable for those with low-to-intermediate anatomic complexity. However, there is uncertainty about the relative safety and efficacy of PCI in patients with more complex LMD and with comorbidities such as diabetes. No direct comparison trial has focused on revascularization in diabetic patients with LMD, and thus conclusions on the topic are subject to the limitations of subgroup analysis, as well as the heterogeneous exclusion criteria, and methodologies of individual trials. The available evidence suggests that among diabetics, CABG is superior in patients with LMD with SYNTAX (SYNergy between percutaneous coronary intervention with TAXus and dardiac surgery) score greater than 33, distal bifurcation disease, or multivessel disease. PCI may be appropriate in those with less-extensive disease or those with limited life expectancy or high surgical risk.

Glycemic Control Status and Long-Term Clinical Outcomes in Diabetic Chronic Total Occlusion Patients: An Observational Study

Background

Whether good glycemic control can result in clinical benefits for diabetic chronic total occlusion (CTO) patients is still a matter of debate.

Methods

We studied 1029 diabetic CTO patients. Based on one-year glycosylated hemoglobin A (HbA1c) levels, we assigned the patients into 2 groups: HbA1c<7% group (n = 448) and HbA1c ≥ 7% group (n = 581). We further subdivided the patients into the successful CTO revascularization (CTO-SR) and nonsuccessful CTO revascularization (CTO-NSR) groups. Kaplan-Meier analysis and Cox regression before and after propensity score matching were used to compare major adverse cardiovascular events (MACE) and other endpoints.

Results

There were no significant differences between the groups in terms of most endpoints in the overall patients. After propensity score-matched analysis, patients with HbA1c < 7.0 tended to be superior in terms of MACE, which was mainly attributed to repeat revascularization but the other endpoints. Furthermore, the benefit of the HbA1c < 7 group was more prominent among patients with CTO-NSR in terms of MACE, repeat revascularization, and target vessel revascularization (TVR); and the improvement of the HbAc1 < 7 group was more prominent among patients without chronic heart failure (CHF) (P=0.027).

Conclusions

HbA1c < 7.0 was associated with a reduced incidence of MACE, which was mainly attributed to a reduction in repeat revascularization. Good glycemic control can improve diabetic CTO patients' clinical prognosis, especially in CTO-NSR patients.

Impact of diabetes mellitus on vascular healing process after everolimus-eluting stent implantation: An optical coherence tomography study

BACKGROUND/PURPOSE

To study the impact of diabetes mellitus (DM) on vascular healing process after implantation of everolimus-eluting stent (EES).

METHODS/MATERIALS

Data from 3 prospective studies (HEAL-EES, REVER, and RESERVOIR), including patients with EES implantation and OCT follow-up, were merged. Differences in vascular healing process assessed by OCT were compared between DM and non-DM using generalized estimating equations. Neointimal proliferation, neointimal signal pattern (high, low, and layered), and uncovered/malapposed struts were evaluated.

RESULTS

A total of 96 lesions (61 DM lesions and 35 non-DM lesions) were included. Mean OCT follow-up time was 8.9 ± 1.5 months and comparable between groups. DM were older, high frequently female and acute coronary syndrome, and received smaller stent than non-DM. No differences were observed in quantitative vascular healing process between groups. However, DM exhibited higher low and layered signal pattern neointima compared to non-DM at lesion level (p = 0.030) and cross-section level (p < 0.001). Uncovered/malapposed struts were comparable between groups.

CONCLUSIONS

Quantitative vascular healing process was comparable between groups. However, DM was significantly associated with low signal pattern, which is characteristic of focal inflammation, after EES implantation. Further study might be required to study relationship between neointimal signal pattern and clinical events.

The association of diabetes mellitus with neointimal formation following deployment of second-generation drug-eluting stents: an optical coherence tomographic study

OBJECTIVES

The purpose of this study was to evaluate the association of diabetes mellitus (DM) with neointimal formation after implantation of second-generation drug-eluting stent (DES) visualized by optical coherence tomography (OCT).

METHODS

Patients with single de novo coronary artery disease treated with second-generation DES between June 2014 and June 2017 in our department underwent OCT examination at 1-year follow-up and were enrolled in this retrospective study. The primary end point was in-stent mean neointimal thickness (MNT), and secondary end points included uncovered stent strut, minimal lumen area (MLA), neointimal burden, neointimal hyperplasia (NIH) patterns and stent thrombosis (ST) after 1 year of OCT follow-up.

RESULTS

A total of 68 patents with DM (DM group) and 216 patients without DM (non-DM group) were enrolled. At 1-year follow-up, the DM group compared with the non-DM group, showed: MNT [160 (85-245) μm vs. 120 (60-220) μm, P = 0.038] and neointimal burden [21.4 (8.3-30.1)% vs. 14.0 (5.7-26.1)%, P = 0.023] to be significantly increased. Concurrently, MLA [4.60 (3.53-6.06) mm vs. 5.76 (4.28-7.20) mm2, P = 0. 0.002] was significantly reduced. Interestingly, the degree of uncovered struts (7.3 ± 7.1% vs. 7.7 ± 6.7%, P = 0.704), NIH patterns (P = 0.984), and ST (7.9% vs. 7.4%, P = 0.88) were comparable between the two groups. After propensity score matching, the MNT [160 (90-240) μm vs. 110 (60-220) μm, P = 0.048] and neointimal burden [21.4 (8.3-30.1)% vs. 15.4 (5.6-26.3)%, P = 0.044] remained significantly different in the DM compared to the non-DM group.

CONCLUSION

DM leads to significant increase in MNT and neointimal burden even with second-generation DES, nevertheless stent strut coverage, ST and NIH characteristics remained comparable among the cohorts at 1-year.

Efficacy of Zotarolimus-Eluting Stents in Treating Diabetic Coronary Lesions: An Optical Coherence Tomography Study

BACKGROUND

Diabetes mellitus (DM) plays an important role in restenosis and late in-stent thrombosis (ST). The current study using optical coherence tomography (OCT) aims to compare target lesion neointima in patients with or without diabetes after zotarolimus-eluting stent (ZES) treatment.

METHODS

OCT images of 90,212 struts and quantitative coronary angiography (QCA) in 62 patients (32 with DM and 30 without DM) with 69 de novo coronary lesions (34 DM and 35 non-DM) both after ZES implantation and 12 ± 1 month angiographic follow-up were recorded. Patient characteristics, lesion characteristics, clinical outcomes, and OCT findings including neointimal thickness, coverage, malapposition, and intimal morphology were analyzed.

RESULTS

Baseline patient characteristics and lesion characteristics data were similar between the two groups. Higher neointimal thickness (0.14 ± 0.09 mm vs. 0.09 ± 0.04 mm, p = 0.021), more neovascularization (3.03 ± 6.24 vs. 0.52 ± 1.87, p = 0.017) and higher incidence of layered signal pattern (12.19 ± 19.91% vs. 4.28 ± 9.02%, p = 0.049) were observed in diabetic lesions comparing with non-diabetic lesions. No differences were found in malapposition, uncovered percentage, and thrombus between the two groups (all p > 0.05). Occurrence of clinical adverse events was also similar during the follow-up period (p > 0.05).

CONCLUSION

Although more neointimal proliferation and more neovascularization were found in diabetic coronary lesions when compared with non-diabetic lesions, treatment with ZES showed similar stent malapposition rate at 1-year follow-up. The data indicated that ZES treatment could possibly be effective in treating diabetic coronary lesions.

TRIAL REGISTRATION

ClinicalTrials.gov identifier, NCT01747356.

Safety and efficacy of zotarolimus-eluting stents in the treatment of diabetic coronary lesions in Chinese patients: The RESOLUTE-DIABETES CHINA Study

BACKGROUND

The RESOLUTE-DIABETES CHINA study was specifically designed to investigate the safety and efficacy of Resolute zotarolimus-eluting stents (ZES; Medtronic, Santa Rosa, CA, USA) in the treatment of diabetic coronary lesions in the Chinese population.

METHODS

In all, 945 patients with de novo native coronary lesions and type 2 diabetes mellitus were recruited at 32 cardiac centers across the Chinese mainland and were implanted with Resolute ZES. The primary endpoint was target vessel failure (TVF); secondary endpoints were clinical outcomes, namely all-cause death, stroke, bleeding, target lesion revascularization (TLR), target vessel revascularization (TVR), non-TVR, and stent thrombosis (ST). The follow-up period for all endpoints was 12 months after the procedure.

RESULTS

In all, 933 patients (98.73%) had clinical follow-up at 12 months. The rate of TVF was 11.60%, whereas the rate of occurrence of secondary endpoints was 5.47%, with four patients (0.43%) having subacute or late ST. There were no significant differences in TVF rates comparing patients with different HbA1c levels or receiving different glucose control treatments (all P > 0.05). Patients with multivessel lesions had higher TVF rates (95% confidence intervals) than those with single-vessel lesions (16.76% [12.10%-22.97%) vs 9.72% [7.79%-12.11%], respectively; P = 0.006). There were no significant differences in TVF rates in patients with or without small vessels, bifurcated lesions, or chronic total occlusions (all P > 0.05). [Correction added on 17 January 2019, after first online publication: in the second sentence of Results section, "TLF" was changed to "TVF".].

CONCLUSIONS

Resolute ZES may perform well in the Chinese diabetic population, especially in those with poor glucose control, complex lesions, and certain unfavorable clinical features. Further studies are needed to determine why ZES perform well in this population.

Lipoxins Protect Against Inflammation in Diabetes-Associated Atherosclerosis

Increasing evidence points to the fact that defects in the resolution of inflammatory pathways predisposes individuals to the development of chronic inflammatory diseases, including diabetic complications such as accelerated atherosclerosis. The resolution of inflammation is dynamically regulated by the production of endogenous modulators of inflammation, including lipoxin A4 (LXA₄). Here, we explored the therapeutic potential of LXA₄ and a synthetic LX analog (Benzo-LXA₄) to modulate diabetic complications in the streptozotocin-induced diabetic ApoE^-/- mouse and in human carotid plaque tissue ex vivo. The development of diabetes-induced aortic plaques and inflammatory responses of aortic tissue, including the expression of vcam-1, mcp-1, il-6, and il-1β, was significantly attenuated by both LXA₄ and Benzo-LXA₄ in diabetic ApoE^-/- mice. Importantly, in mice with established atherosclerosis, treatment with LXs for a 6-week period, initiated 10 weeks after diabetes onset, led to a significant reduction in aortic arch plaque development (19.22 ± 2.01% [diabetic]; 12.67 ± 1.68% [diabetic + LXA₄]; 13.19 ± 1.97% [diabetic + Benzo-LXA₄]). Secretome profiling of human carotid plaque explants treated with LXs indicated changes to proinflammatory cytokine release, including tumor necrosis factor-α and interleukin-1β. LXs also inhibited platelet-derived growth factor-stimulated vascular smooth muscle cell proliferation and transmigration and endothelial cell inflammation. These data suggest that LXs may have therapeutic potential in the context of diabetes-associated vascular complications.

Glucose Variability and Coronary Artery Disease

Fasting blood glucose, postprandial blood glucose and glycated haemoglobin are considered three important indicators for diabetes treatment. There is increasing evidence that glucose variability has more detrimental effects on the coronary arteries than does chronic sustained hyperglycaemia. This overview summarises recent findings in the field of glucose variability and its possible relationship with coronary artery disease. Glucose variability may be a marker of increased progression of coronary disease and plaque vulnerability. It might be a potential new therapeutic target for secondary prevention of coronary artery disease. Future studies will focus on the early detection and control of glucose variability to improve the clinical outcomes in patients with coronary artery disease.

Comparison of the vessel healing process after everolimus-eluting stent and bare metal stent implantations in patients with ST-elevation myocardial infarction

Cobalt-chromium everolimus-eluting stent (CoCr EES) is associated with a lower rate of stent thrombosis even in patients with ST-elevation myocardial infarction (STEMI). However, the time-serial changes of endothelial coverage of the stent struts in the extremely early period have never been reported, especially in patients with STEMI. The aim of this study was to compare the vessel healing process between CoCr EES and cobalt-chromium bare metal stent (CoCr BMS) implantations using optical coherence tomography (OCT) in patients with STEMI. Sixty-three patients who had primary emergent percutaneous coronary intervention (PCI) with CoCr EES (42 patients) or CoCr BMS (21 patients) were enrolled in this study for 3 years. OCT was performed just after, 2 and 12 weeks after EES or BMS implantations. Time-serial changes in the neointimal coverage (NIC), the neointimal thickness, and malapposition of stent struts were evaluated. NIC of stent struts did not differ between CoCr EES (23.2%, 99.4%) and CoCr BMS (24.0%, 97.8%) at 2 weeks and 12 weeks after PCI, respectively. Thicknesses of the neointima on the stent strut was significantly thinner in CoCr EES (34.0 ± 13.8, 107.0 ± 32.4 µm) than in CoCr BMS (40.0 ± 14.6, 115.7 ± 33.8 µm) at 2 weeks and 12 weeks after PCI (p = 0.011, p = 0.008), respectively. The malapposition did not differ just after PCI, and was completely resolved at 12 weeks after PCI in both groups. Thrombus was significantly less in CoCr EES than in CoCr BMS at 2 weeks (19.0% vs 42.9%, p < 0.01), and decreased over time in both groups, but at 12 weeks, disappeared only in CoCr EES (CoCr EES: 0% vs. CoCr BMS: 4.8%, p = 0.56). This study demonstrated that NIC and apposition of the stent struts almost completed at 12 weeks after EES and BMS implantations, while the neointimal thickness on the stent struts were thinner in EES than in BMS. Moreover, thrombus was significantly less in EES than in BMS implantations 2 weeks after PCI, which may explain the lower rate of acute and subacute stent thrombosis of EES compared with BMS.

Impact of low tissue backscattering by optical coherence tomography on endothelial function after drug-eluting stent implantation

This study evaluated the impact of optical coherence tomography (OCT)-derived low-backscattered tissue on mid-term coronary endothelial function after drug-eluting stent (DES) implantation. Although OCT enables detailed in vivo evaluation of neointimal tissue characterization after DES implantation, its association with physiological vascular healing response is unclear. Thirty-three stable angina pectoris patients underwent OCT examination and endothelial function testing with intracoronary infusion of incremental doses of acetylcholine 8-month after DES implantation in a single lesion of the left anterior descending artery. Neointimal tissue was classified into two patterns based on the predominant OCT light backscatter: high backscatter and low backscatter. Although the presence of uncovered or malapposed stent strut was not associated with the degree of vasoconstriction, the degree of vasoconstriction was significantly greater in the DES with low-backscattered neointima than in the DES without low-backscattered neointima (- 32.1 ± 25.7 vs. - 4.1 ± 20.1%, p = 0.003). Moreover, there was an inverse linear relationship between low backscatter tissue index and degree of vasoconstriction after acetylcholine infusion (r = 0.50 and p = 0.003). The endothelium-dependent vasomotor response after 8-month of DES was impaired in patients with low neointimal tissue backscatter on OCT imaging. OCT assessment of low-backscattered tissue may be used as surrogate markers for impairment of endothelial function after DES.

Randomised trial of the comparison of drug-eluting stents in patients with diabetes: OCT DES trial

Background

To date, there have been limited comparisons performed between everolimus-eluting stents (EES) and zotarolimus-eluting stents (ZES) in patients with diabetes mellitus (DM). The objectives of this study was to assess the use of second-generation drug-eluting stents in patients with DM, using optical coherence tomography (OCT) to compare the level of stent coverage of Boston Scientific Promus Element EES compared with Medtronic Resolute Integrity ZES.(Clinicaltrials.gov number NCT02060357).

Methods

This is a single-centre randomised blinded trials assessing two commercially available stents in 60 patients with diabetes (ZES: n=30, EES: n=30). Patients underwent intracoronary assessment at 6 months with OCT assessing stent coverage, malapposition, neointimal thickness and percentage of in-stent restenosis (ISR).

Results

Of the 60 patients randomised, 46 patients underwent OCT analysis. There was no difference in baseline characteristics between the two groups. Both Promus Element and Resolute Integrity had low rates of uncovered struts at 6 months with no significant difference between the two groups (2.44% vs 1.24%, respectively; P=0.17). Rates of malapposition struts (3.9% vs 2.5%, P=0.25) and percentage of luminal loss did not differ between stent types. In addition, there was no significant difference in major adverse cardiovascular events (P=0.24) between the stent types.

Conclusions

This study is the first randomised trial to evaluate OCT at 6 months for ZES and EES in patients with diabetes. Both stents showed comparable strut coverage at 6 months, with no difference in ISR rates at 6 months.

Protective Effect of let-7 miRNA Family in Regulating Inflammation in Diabetes-Associated Atherosclerosis

The let-7 miRNA family plays a key role in modulating inflammatory responses. Vascular smooth muscle cell (SMC) proliferation and endothelial cell (EC) dysfunction are critical in the pathogenesis of atherosclerosis, including in the setting of diabetes. Here we report that let-7 levels are decreased in diabetic human carotid plaques and in a model of diabetes-associated atherosclerosis, the diabetic ApoE^-/- mouse. In vitro platelet-derived growth factor (PDGF)- and tumor necrosis factor-α (TNF-α)-induced vascular SMC and EC activation was associated with reduced let-7 miRNA expression via Lin28b, a negative regulator of let-7 biogenesis. Ectopic overexpression of let-7 in SMCs inhibited inflammatory responses including proliferation, migration, monocyte adhesion, and nuclear factor-κB activation. The therapeutic potential of restoring let-7 levels using a let-7 mimic was tested: in vitro in SMCs using an endogenous anti-inflammatory lipid (lipoxin A₄), ex vivo in murine aortas, and in vivo via tail vein injection in a 24-h murine model. Furthermore, we delivered let-7 mimic to human carotid plaque ex vivo and observed significant changes to the secretome in response to let-7 therapy. Restoration of let-7 expression could provide a new target for an anti-inflammatory approach in diabetic vascular disease.

Effects of daily glucose fluctuations on the healing response to everolimus-eluting stent implantation as assessed using continuous glucose monitoring and optical coherence tomography

Background

Several studies have revealed that glucose fluctuations provoke oxidative stress that leads to endothelial cell dysfunction, progression of coronary atherosclerosis, and plaque vulnerability. However, little is known regarding their effect on neointimal growth after stenting in patients with coronary artery disease (CAD). We aimed to investigate the effects of glucose fluctuations on neointimal growth after everolimus-eluting stent (EES) implantation.

Methods

This study examined 50 patients who underwent a 9-month follow-up using optical coherence tomography (OCT) after EES implantation. Glucose fluctuation was expressed as the mean amplitude of glycemic excursion (MAGE), and was determined via continuous glucose monitoring before stenting. At the OCT follow-up, we evaluated the percentage of uncovered struts and three-dimensional uniformity of neointimal distribution by calculating the mean neointimal thickness (NIT) within 360 equally-spaced radial sectors for every 1-mm cross-sectional OCT analysis, and assessed the incidence of major adverse cardiovascular events (MACE).

Results

We evaluated 60 lesions in 50 patients. Linear mixed effect models were used to explore the influence of different variables on variability in NIT and the percentage of uncovered struts and to adjust for covariates. Univariate analysis showed that MAGE was most strongly correlated with the previously mentioned OCT measurements (coefficient β ± standard error = 0.267 ± 0.073 and 0.016 ± 0.003, t = 3.668 and 6.092, both P < 0.001, respectively). In multivariate analysis, MAGE had the strongest effect on variability in NIT (coefficient β ± standard error = 0.239 ± 0.093, P = 0.014) and the percentage of uncovered struts (coefficient β ± standard error = 0.019 ± 0.004, P < 0.001). Five lesions in four patients required target lesion revascularization (10.0 %) at a mean duration of 9 months after EES implantation. Compared to non-MACE cases, cases of MACE exhibited a significantly higher MAGE (99 vs. 68; P = 0.004), maximum NIT (580 vs. 330 µm; P = 0.002), and variability in NIT (100 vs. 65; P = 0.007), although there was no significant difference in these groups’ HbA1c levels.

Conclusions

Glucose fluctuation may affect vessel healing after EES implantation in patients with CAD who are receiving lipid-lowering therapy. Therefore, glucose fluctuations may be an important target for secondary prevention after coronary stenting, which is independent of dyslipidemia control.

Comparison of long-term clinical outcomes after the second-generation cobalt-chromium sirolimus-eluting stents implantation in diabetic versus non-diabetic patients: a subgroup analysis from the prospective FOCUS registry

BACKGROUND

Diabetes mellitus (DM) was broadly acknowledged as a risk factor for adverse events after coronary stent implantation. However, the role of DM in patients treated with second-generation cobalt-chromium sirolimus-eluting stents (CoCr-SES) was less known.

METHODS

A total of 4720 patients available for 3-year follow-up in the prospective FOCUS registry were subdivided into the DM group and the non-DM group to assess the effect of DM on the clinical outcomes after CoCr-SES implantation both before and after propensity score matching.

RESULTS

The rates of major adverse cardiovascular event was low (<10%) in both DM and non-DM groups but significantly greater in the DM group after matching (9.6% versus 6.1%; p = 0.005). Although the soft endpoints including target vessel revascularization (2.3% versus 2.3%; p = 0.938) and target lesion revascularization (1.2% versus 1.1%; p = 0.828) was not significantly different between two groups, the hard endpoints represented by cardiovascular death or myocardial infarction (7.3% versus 5.3%; p = 0.012) demonstrated a significant increase in the DM group.

CONCLUSIONS

This subgroup analysis demonstrated that DM significantly increased the risk of adverse events after implantation of CoCr-SES, but the general safety and efficacy performance of CoCr-SES in both diabetic and non-diabetic patients was satisfying and comparable with other types of new-generation drug-eluting stents.

Treatment of in-stent restenosis with bioresorbable vascular scaffolds: optical coherence tomography insights

The role of the bioresorbable vascular scaffold (BVS) in patients with in-stent restenosis (ISR) remains unsettled. We present optical coherence tomography (OCT) findings in a series of 15 consecutive patients undergoing treatment of ISR with a BVS under systematic OCT guidance. OCT disclosed severe ISR in all patients (minimal lumen area [MLA], 1.3 ± 0.6 mm(2); stent obstruction 80% ± 10%). After the procedure, OCT MLA was 6.4 ± 2 mm(2) with a final BVS expansion of 79% ± 19%. "Angiographically silent" edge dissections (n = 6), intradevice dissections (n = 3), tissue prolapse (n = 3), and malapposition (n = 3) were also readily visualized. These findings underscore the diagnostic value of OCT in patients undergoing BVS implantation for ISR.

Optical coherence tomography and histopathology assessment after implantation of first- and second-generation drug-eluting stents in a porcine coronary model

BACKGROUND

This study directly compared optical coherence tomography (OCT) and histopathology for the assessment of vascular response to first- and second-generation drug-eluting stents. METHODS AND RESULTS: Sirolimus-, everolimus-, and biolimus-eluting stents (SES, EES, and BES, respectively) were randomly implanted into the coronary arteries of 12 porcine. OCT was conducted after implantation: at 1, 3, and 6 months; histopathology was assessed at 3 and 6 months. At 1-month OCT, EES had the highest neointimal area (NA) and lowest neointimal unevenness score (NUS). At 6 months, NA and NUS were equivalent among the stent types. ∆NA from 1 to 6 months was lowest for EES, and ∆NA correlated with the histopathological inflammation score at 6 months, which was highest for SES (P<0.001). The mean signal intensity (MSI) and the attenuation were different for the stent types at 3 months, and were associated with inflammation score. Moderate diagnostic efficiency for measuring MSI was found, with an optimal cut-off of 6.88 predicting a high (≥grade 3) inflammation score.

CONCLUSIONS

EES had the greatest uniformity and the least neointimal proliferation and were associated with less persistent inflammation. OCT provides accurate morphometric data; furthermore, quantitative measurement of the optical properties may help assess histological inflammation, which was more predominantly associated with SES than with EES and BES.

Percutaneous coronary intervention in patients with diabetes: current concepts and future directions

Patients with diabetes and coronary artery disease represent a challenging and growing subset of the population. Although surgical revascularization is the preferred treatment for patients with diabetes and multivessel coronary artery disease with stable angina, a significant proportion of diabetic patients undergo percutaneous revascularization due to comorbidities, presence of single-vessel disease, or presentation with myocardial infarction. The development of drug-eluting stents has significantly improved the results of percutaneous revascularization among diabetic patients, but a number of challenges remain, including higher rates of restenosis and stent thrombosis among diabetic patients. With current technologies, the outcomes of diabetic patients treated with noninsulin agents have approached that of nondiabetic patients. In comparison, patients with diabetes who require insulin therapy represent a high-risk cohort with increased rates of target vessel failure after coronary revascularization. The development of bioresorbable stents and new drug elution systems may provide additional future benefit among patients with diabetes undergoing percutaneous coronary artery revascularization.

Evolving management of patients treated by drug-eluting stent: prevention of late events

SUMMARY

Drug eluting stents (DES) were introduced in clinical practice to overcome the problem of in-stent restenosis (ISR) that limited the overall efficacy of percutaneous coronary revascularization with bare metal stent (BMS). Long-term outcome data confirm a sustained benefit of DES as compared with BMS. However, this benefit is mainly evident in the first year of follow-up. Indeed, DES-related events may extend over this time, due to late events (late ISR and/or very late stent thrombosis). Prevention of late failure of DES may become a specific therapeutic target.

Very late stent thrombosis related to incomplete neointimal coverage or neoatherosclerotic plaque rupture identified by optical coherence tomography imaging

AIMS

Recent data have reported that neoatherosclerosis could develop long after stent implantation and lead to subsequent rupture and acute coronary syndrome (ACS). We sought to identify the presence of in-stent neoatheroma (ISNA) in patients with very late stent thrombosis (VLST) using optical coherence tomography (OCT).

METHODS AND RESULTS

All patients from two catheterization centres who presented with ACS related to VLST underwent a standard coronary angiography and intra-coronary OCT. ISNA was defined as the combination of diffuse neointimal proliferation, lipid-laden intima with plaque organization, and fibrous cap rupture with no evidence of an uncovered strut. Out of 2139 ACS patients, 20 presented with definite VLST, including 10 with evidence of ISNA lesions, detected using OCT. The mean delay between initial percutaneous coronary intervention and VLST was longer in the ISNA patients compared with non-ISNA patients (10.5 ± 1.6 vs. 4.0 ± 0.6 years, P = 0.003). The mean LDL-cholesterol tended to be higher in ISNA patients compared with non-ISNA patients. OCT analysis revealed significantly thicker neointimal coverage as well as a lower number of uncovered struts in ISNA lesions compared with the other patients. LDL-cholesterol levels were correlated with the average neointima thickness (Spearman's rho = 0.46, P = 0.04). All the ISNA lesions were treated through initial thrombectomy followed by redo stenting in nine patients.

CONCLUSION

Our data show that ISNA is frequent in patients with VLST. These results suggest that OCT imaging is helpful in identifying the underlying mechanisms of VLST and, therefore, in the clinical decision-making process.

Optical coherence tomography evaluation of drug-eluting stents: a systematic review

AIMS

We performed a systematic review of studies reporting stent strut coverage and malapposition post implantation of different drug-eluting stent (DES), as assessed by optical coherence tomography (OCT).

METHODS

A review of publications and online databases in May 2011 retrieved 33 published studies reporting stent strut coverage and malapposition post-DES implantation using OCT: 24 for sirolimus-eluting stents (SES), 13 for paclitaxel-eluting stents (PES), 10 for zotarolimus-eluting stents (ZES), and two for everolimus-eluting stents (EES). The follow-up duration ranged from 3 months to 4 years. Stent strut coverage and malapposition were compared between DES at various time intervals post implantation.

RESULTS

Significant differences in stent strut coverage and malapposition exist between various DES. The SES had the highest frequency of uncovered struts at 3, 6, 9, and 12 months (13.1%, 10.9%, 8.1%, and 7.5%, respectively), followed by PES (5.5%, 4.4%, and 5.7% at 6, 9, and 12 months, respectively) and ZES (0.7%, 0%, and 0.5% at 3, 6, and 9 months, respectively) (P < 0.001 for all comparisons between stents). Only two studies reported 3.1% uncovered struts at 9 months with the EES. Stent strut malapposition at 6, 9, and 12 months was highest with SES (3.2%, 2.2%, and 1.2%, respectively) followed by PES (1.6%, 1.3%, and 0.9%, respectively), EES (0.46% at 9 months), and ZES (0.7% and 0.1% at 6 and 9 months, respectively).

CONCLUSIONS

SES had the highest rates of uncovered struts and malapposition, followed by PES and ZES. Such differences may explain the different clinical outcomes between various DES. © 2012 Wiley Periodicals, Inc.

The role of optical coherence tomography in coronary intervention

Optical coherence tomography (OCT) is an optical analog of intravascular ultrasound (IVUS) that can be used to examine the coronary arteries and has 10-fold higher resolution than IVUS. Based on polarization properties, OCT can differentiate tissue characteristics (fibrous, calcified, or lipid-rich plaque) and identify thin-cap fibroatheroma. Because of the strong attenuation of light by blood, OCT systems required the removal of blood during OCT examinations. A recently developed frequency-domain OCT system has a faster frame rate and pullback speed, making the OCT procedure more user-friendly and not requiring proximal balloon occlusion. During percutaneous coronary intervention (PCI), OCT can provide detailed information (dissection, tissue prolapse, thrombi, and incomplete stent apposition [ISA]). At follow-up examinations after stent implantation, stent strut coverage and ISA can be assessed. Several OCT studies have demonstrated delayed neointimal coverage following drug-eluting stent (DES) implantation vs. bare metal stent (BMS) placement. While newer DESs promote more favorable vascular healing, the clinical implications remain unknown. Recent OCT studies have provided insights into restenotic tissue characteristics; DES restenotic morphologies differ from those with BMSs. OCT is a novel, promising imaging modality; with more in-depth assessments of its use, it may impact clinical outcomes in patients with symptomatic coronary artery disease.

Tissue coverage of a hydrophilic polymer-coated zotarolimus-eluting stent vs. a fluoropolymer-coated everolimus-eluting stent at 13-month follow-up: an optical coherence tomography substudy from the RESOLUTE All Comers trial

Aims

To compare the tissue coverage of a hydrophilic polymer-coated zotarolimus-eluting stent (ZES) vs. a fluoropolymer-coated everolimus-eluting stent (EES) at 13 months, using optical coherence tomography (OCT) in an ‘all-comers' population of patients, in order to clarify the mechanism of eventual differences in the biocompatibility and thrombogenicity of the devices.

Methods and results

Patients randomized to angiographic follow-up in the RESOLUTE All Comers trial (NCT00617084) at pre-specified OCT sites underwent OCT follow-up at 13 months. Tissue coverage and apposition were assessed strut by strut, and the results in both treatment groups were compared using multilevel logistic or linear regression, as appropriate, with clustering at three different levels: patient, lesion, and stent. Fifty-eight patients (30 ZES and 28 EES), 72 lesions, 107 stents, and 23 197 struts were analysed. Eight hundred and eighty-seven and 654 uncovered struts (7.4 and 5.8%, P= 0.378), and 216 and 161 malapposed struts (1.8 and 1.4%, P= 0.569) were found in the ZES and EES groups, respectively. The mean thickness of coverage was 116 ± 99 µm in ZES and 142 ± 113 µm in EES (P= 0.466). No differences in per cent neointimal volume obstruction (12.5 ± 7.9 vs. 15.0 ± 10.7%) or other areas–volumetric parameters were found between ZES and EES, respectively.

Conclusion

No significant differences in tissue coverage, malapposition, or lumen/stent areas and volumes were detected by OCT between the hydrophilic polymer-coated ZES and the fluoropolymer-coated EES at 13-month follow-up.