Impaired Cholesterol-Uptake Capacity of HDL Might Promote Target-Lesion Revascularization by Inducing Neoatherosclerosis After Stent Implantation

Impaired Cholesterol Uptake Capacity in Patients with Hypertriglyceridemia and Diabetes Mellitus

BACKGROUND

Although low high-density lipoprotein cholesterol (HDL-C) levels are a common metabolic abnormality associated with insulin resistance, their role in cardiovascular risk stratification remains controversial. Recently, we developed a simple, high-throughput, cell-free assay system to evaluate the "cholesterol uptake capacity (CUC)" as a novel concept for HDL functionality. In this study, we assessed the CUC in patients with hypertriglyceridemia and diabetes mellitus.

METHODS

The CUC was measured using cryopreserved serum samples from 285 patients who underwent coronary angiography or percutaneous coronary intervention between December 2014 and May 2019 at Kobe University Hospital.

RESULTS

The CUC was significantly lower in diabetic patients (n = 125) than in nondiabetic patients (93.0 vs 100.7 arbitrary units (A.U.), P = 0.002). Patients with serum triglyceride (TG) levels >150 mg/dL (n = 94) also had a significantly lower CUC (91.8 vs 100.0 A.U., P = 0.004). Furthermore, the CUC showed a significant inverse correlation with TG, hemoglobin A1c (Hb A1c), homeostasis model assessment of insulin resistance (HOMA-IR), and body mass index (BMI). Finally, the HDL-C/Apolipoprotein A1 (ApoA1) ratio, calculated as a surrogate index of HDL particle size, was significantly positively correlated with the CUC (r2 = 0.49, P < 0.001), but inversely correlated with TG levels (r2 = -0.30, P < 0.001).

CONCLUSIONS

The CUC decreased in patients with hypertriglyceridemia and diabetes mellitus, and HDL particle size was a factor defining the CUC and inversely correlated with TG levels, suggesting that impaired CUC in insulin-resistant states was partially due to the shift in HDL towards smaller particles. These findings provide a better understanding of the mechanisms underlying impaired HDL functionality.

Fully automated immunoassay for cholesterol uptake capacity to assess high-density lipoprotein function and cardiovascular disease risk

High-density lipoprotein (HDL) cholesterol efflux capacity (CEC), which is a conventional metric of HDL function, has been associated with coronary heart disease risk. However, the CEC assay requires cultured cells and takes several days to perform. We previously established a cell-free assay to evaluate cholesterol uptake capacity (CUC) as a novel measure of HDL functionality and demonstrated its utility in coronary risk stratification. To apply this concept clinically, we developed a rapid and sensitive assay system based on a chemiluminescent magnetic particle immunoassay. The system is fully automated, providing high reproducibility. Measurement of CUC in serum is completed within 20 min per sample without HDL isolation, a notably higher throughput than that of the conventional CEC assay. CUC decreased with myeloperoxidase-mediated oxidation of HDL or in the presence of N-ethylmaleimide, an inhibitor of lecithin: cholesterol acyltransferase (LCAT), whereas CUC was enhanced by the addition of recombinant LCAT. Furthermore, CUC correlated with CEC even after being normalized by ApoA1 concentration and was significantly associated with the requirement for revascularization due to the recurrence of coronary lesions. Therefore, our new assay system shows potential for the accurate measurement of CUC in serum and permits assessing cardiovascular health.

Prevalence and Impact of Neoatherosclerosis on Clinical Outcomes After Percutaneous Treatment of Second-Generation Drug-Eluting Stent Restenosis

BACKGROUND

Clinical and morphological factors associated with lipidic versus calcified neoatherosclerosis within second-generation drug-eluting stents and the impact of lipidic versus calcified neoatherosclerosis on long-term outcomes after repeat intervention have not been well studied.

METHODS

A total of 512 patients undergoing optical coherence tomography before percutaneous coronary intervention for second-generation drug-eluting stents in-stent restenosis were included. Neoatherosclerosis was defined as lipidic or calcified neointimal hyperplasia in ≥3 consecutive frames or ruptured lipidic neointimal hyperplasia. The primary outcome was target lesion failure (cardiac death, target vessel myocardial infarction, definite stent thrombosis, or clinically driven target lesion revascularization).

RESULTS

The overall prevalence of neoatherosclerosis was 28.5% (146/512): 56.8% lipidic, 30.8% calcified, and 12.3% both lipidic and calcific. The prevalence increased as a function of time from stent implantation: 20% at 1 to 3 years, 30% at 3 to 7 years, and 75% >7 years. Renal insufficiency, poor lipid profile, and time from stent implantation were associated with lipidic neoatherosclerosis, whereas severe renal insufficiency, female sex, and time from stent implantation were associated with calcified neoatherosclerosis. Multivariable Cox regression revealed that female sex and lipidic neoatherosclerosis were associated with more target lesion failure, whereas stent age and final minimum lumen diameter after reintervention were related to lower target lesion failure. Calcified neoatherosclerosis was not related to adverse events after reintervention for in-stent restenosis given a large enough minimum lumen diameter was achieved.

CONCLUSIONS

Lipidic but not calcified neoatherosclerosis was associated with poor subsequent outcomes after repeat revascularization if optimal stent expansion was achieved in lesions with calcified neoatherosclerosis.

Stent-based delivery of AAV2 vectors encoding oxidation-resistant apoA1

In-stent restenosis (ISR) complicates revascularization in the coronary and peripheral arteries. Apolipoprotein A1 (apoA1), the principal protein component of HDL possesses inherent anti-atherosclerotic and anti-restenotic properties. These beneficial traits are lost when wild type apoA1(WT) is subjected to oxidative modifications. We investigated whether local delivery of adeno-associated viral (AAV) vectors expressing oxidation-resistant apoA1(4WF) preserves apoA1 functionality. The efflux of 3H-cholesterol from macrophages to the media conditioned by endogenously produced apoA1(4WF) was 2.1-fold higher than for apoA1(WT) conditioned media in the presence of hypochlorous acid emulating conditions of oxidative stress. The proliferation of apoA1(WT)- and apoA1(4FW)-transduced rat aortic smooth muscle cells (SMC) was inhibited by 66% ± 10% and 65% ± 11%, respectively, in comparison with non-transduced SMC (p < 0.001). Conversely, the proliferation of apoA1(4FW)-transduced, but not apoA1(WT)-transduced rat blood outgrowth endothelial cells (BOEC) was increased 41% ± 5% (p < 0.001). Both apoA1 transduction conditions similarly inhibited basal and TNFα-induced reactive oxygen species in rat aortic endothelial cells (RAEC) and resulted in the reduced rat monocyte attachment to the TNFα-activated endothelium. AAV2-eGFP vectors immobilized reversibly on stainless steel mesh surfaces through the protein G/anti-AAV2 antibody coupling, efficiently transduced cells in culture modeling stent-based delivery. In vivo studies in normal pigs, deploying AAV2 gene delivery stents (GDS) preloaded with AAV2-eGFP in the coronary arteries demonstrated transduction of the stented arteries. However, implantation of GDS formulated with AAV2-apoA1(4WF) failed to prevent in-stent restenosis in the atherosclerotic vasculature of hypercholesterolemic diabetic pigs. It is concluded that stent delivery of AAV2-4WF while feasible, is not effective for mitigation of restenosis in the presence of severe atherosclerotic disease.

Healed neointima of in-stent restenosis lesions in patients with stable angina pectoris: an intracoronary optical coherence tomography study

The phenomenon to heal neointimal rupture or thrombus after coronary stenting occurs as well as in native coronary artery. We investigated clinical characteristics and neointimal vulnerability of healed neointima by optical coherence tomography (OCT). We treated 67 lesions by percutaneous coronary intervention for in-stent restenosis (ISR) and conducted OCT examinations. Healed neointima was defined as neointima having one or more layers with different optical densities and a clear demarcation from underlying components. ISR with healed neointima was found in 49% (33/67) of the lesions. Compared to ISR without healed neointima, ISR with healed neointima showed significantly longer stent age (102 ± 72 vs. 31 ± 39 months, P < 0.001), lower frequency of dual antiplatelet therapy [42% (14/33) vs. 74% (25/34), P = 0.017], lower use of angiotensin-converting enzyme inhibitor or angiotensin II receptor blocker (ACE-I or ARB) [61% (20/33) vs. 91% (31/34), P = 0.028], lower usage of second-generation drug-eluting stents (DESs) [36% (12/33) vs. 63% (22/34), P = 0.029], higher usage of thick-strut stents [42% (14/33) vs. 15% (5/34), P = 0.012], larger neointimal area (6.8 ± 2.6 vs. 5.2 ± 1.8 mm², P = 0.005), higher incidence of thin-cap fibroatheroma [58% (19/33) vs. 21% (7/34), P = 0.002], neointimal rupture [45% (15/33) vs. 9% (3/34), P = 0.001], and lower incidence of stent underexpansion [15% (5/33) vs. 44% (15/34), P = 0.010]. In conclusions, ISR with healed neointima was associated with neointimal vulnerability, stent age, stent type, stent strut thickness, stent expansion, antiplatelet therapy, and use of ACE-I or ARB.

Potential Mechanisms of In-stent Neointimal Atherosclerotic Plaque Formation

ABSTRACT

Percutaneous coronary intervention has become the main revascularization strategy for coronary artery disease. Compared with early percutaneous coronary angioplasty and the extensive clinical application of bare metal stents, drug-eluting stents can significantly reduce the stenosis caused by the elastic retraction of plaque and neoatherosclerosis (NA), but there is still a high incidence of in-stent restenosis (ISR), which restricts the clinical efficacy of stent implantation. In-stent neoatherosclerosis (ISNA), defined as atherosclerotic lesions in the neointima, is one of the main causes of late stent failure. ISNA plays an important role in stent thrombosis and ISR. The rate of target lesion revascularization and in-stent thrombosis is high when NA arises. Therefore, it is of great clinical significance to explore the occurrence of NA and its development mechanism after stent implantation to prevent ISR and improve stent implantation efficacy and associated clinical prognosis. In this article, we systematically reviewed the existing clinical research on ISNA and the role of optical coherence tomography in its evaluation.

Association of stent diameter and target vessel revascularization in patients undergoing percutaneous coronary intervention: a secondary retrospective analysis based on a Chinese cohort study

Background

In the treatment of coronary heart disease, target vessel revascularization (TVR) has attracted increasing attention as an efficient means of percutaneous coronary intervention (PCI). The purpose of this study was to explore the association between stent diameter and TVR in patients undergoing PCI.

Methods

This was a secondary retrospective analysis involving patients with PCI with at least one stent implanted. Information was obtained from the Dryad Digital Repository. Multivariable logistic regression models, interaction analyses, subgroup analyses and piecewise linear regression models were used to evaluate the association between stent diameter and TVR.

Results

A total of 2522 patients were eventually enrolled in this study, of which 122 (4.8%) had undergone TVR. Significant positive associations were observed between stent diameter and TVR (continuous: odds ratio [OR] 0.485, 95% confidence interval [CI] 0.305–0.773, P = 0.002; categorical variable: T2 vs. T1, OR 0.541, 95% CI 0.348–0.843; T3 vs. T1, OR 0.520, 95% CI 0.334–0.809; P for trend = 0.005). The association remained stable in the fully adjusted model (continuous: OR 0.526, 95% CI 0.306–0.902, P = 0.020; categorical variable: T2 vs. T1, OR 0.510, 95% CI 0.310–0.839; T3 vs. T1, OR 0.585, 95% CI 0.352–0.973; P for trend = 0.042). Among the subgroups of differing clinical presentations, stent diameter was a powerful protective factor for TVR, especially in the delayed PCI group (P for interaction = 0.002). The association was highly consistent across all the other subgroups studied (all P for interaction > 0.05). In the piecewise linear regression model, the need for TVR decreased with an increase in stent diameter when this ranged between 2.5 and 2.9 mm (OR 0.01, 95% CI: 0.01–0.13, P < 0.001).

Conclusions

A large stent diameter is a powerful protective factor for TVR in PCI patients, especially in the delayed PCI group. This “bigger-is-better” protective effect is remarkable in stents with diameter 2.5–2.9 mm.

Serum HDL cholesterol uptake capacity in subjects from the MASHAD cohort study: Its value in determining the risk of cardiovascular endpoints

BACKGROUND

The efficiency of high-density lipoprotein (HDL) to efflux cholesterol contributes to the reverse cholesterol transport (RCT) pathway as one of HDL's proposed functions and depends on the ability of HDL to uptake cholesterol. We aimed to investigate cholesterol uptake capacity (CUC) by a newly developed assay in samples from the MASHAD (Mashhad Stroke and Heart Atherosclerotic Disorders) cohort study.

METHOD

The study population comprised 153 individuals developed CVD diagnosed by a specialist cardiologist, over 6 years of follow-up, and 350 subjects without CVD. We used a modified CUC method to evaluate the functionality of HDL in serum samples.

RESULT

The CUC assay was highly reproducible with values for inter- and intra-assay variation of 13.07 and 6.65, respectively. The mean serum CUC was significantly lower in the CVD group compared to control (p = 0.01). Although, there were no significant differences in serum HDL-C between the groups and there was no significantly association with risk of progressive CVD. Multivariate logistic regression analysis showed that there was a significantly negative association between CUC and risk of CVD after adjustment for confounding parameters (OR = 0.57, 95% CI = 0.38-0.87, p = 0.009). The CUC was also inversely and independently associated with the risk of CVD event using Cox proportional hazards models analysis (HR = 0.62; 95% CI = 0.41-0.94, p = 0.02). We determined the optimum cutoff value of 1.7 a.u for CUC in the population. Furthermore, the CUC value was important in determining the CVD risk stratification derived from data mining analysis.

CONCLUSIONS

Reduced HDL functionality, as measured by CUC, appears to predict CVD in population sample from north-eastern Iran.

Relationship among clinical characteristics, morphological culprit plaque features, and long-term prognosis in patients with acute coronary syndrome

Culprit lesions of acute coronary syndrome (ACS) could be classified as plaque rupture (PR), erosion, or calcified nodule (CN). We aimed to determine the relationship among clinical characteristics, morphological plaque features, and long-term prognosis in ACS. Patients with ACS, who underwent pre-intervention optical coherence tomography between April 2013 and July 2018 were retrospectively enrolled, and classified into the three groups based on the culprit lesion morphology. In the 436 patients enrolled, incidences of PR, erosion, and CN in ACS culprit lesions were 46.1, 39.9, and 14.0%, respectively. Plaque erosion was more frequent in men aged < 60 years and CN was more frequent in older adults in both sexes (≥ 80 years) (P < 0.001). Patients with CN had a higher incidence of hemodialysis treatment (P < 0.001) and diabetes (P = 0.003). Multivariate analysis revealed that ST elevation myocardial infarction (STEMI) (P = 0.049) and presence of thin-cap fibroatheroma (TCFA) at the culprit lesion were independently associated with PR; in younger patients (< 60 year), preserved left ventricular ejection fraction and lower incidence of TCFA were correlated with plaque erosion; and older age, non-STEMI, or unstable angina pectoris, higher serum brain natriuretic peptide levels, and lower incidence of TCFA were independently associated with CN. Multivariable analysis revealed that CN (odds ratio [OR] 1.990, P = 0.005), male sex (OR 2.012, P = 0.004), and older age (OR 1.036, P < 0.001) were independently associated with future adverse events during a median follow-up of 757 days. Different patient characteristics and morphological features were associated with the type of culprit lesion in patients with ACS.

Incidence and Predictors of Neoatherosclerosis in Patients with Early In-Stent Restenosis Determined Using Optical Coherence Tomography

In-stent restenosis (ISR) still exists after drug-eluting stent (DES) implantation, even up to one year. The incidence and risk factors for neoatherosclerosis in patients with early ISR have not yet been elucidated. Here, we used optical coherence tomography (OCT) to evaluate the incidence and predictors of neoatherosclerosis in patients with early ISRs.OCT was performed on ISR lesions in 185 patients in order to detect neoatherosclerosis. The median follow-up was 180 days, and neoatherosclerosis was detected in 37% of early ISR lesions. According to the presence of neoatherosclerosis, patients with ISR were divided into two groups: neoatherosclerosis (group A, n = 69) and non-neoatherosclerosis (group B, n = 116) groups.The risk factors were similar, except for hypercholesterolemia. Moreover, the tissue characteristics were not significantly different between patients with and without neoatherosclerosis. Follow-up low-density lipoprotein-cholesterol (LDL-C) levels were divided into three grades (LDL < 70 mg/dL, 70 mg/dL≤ LDL < 100 mg/dL, and LDL ≥ 100 mg/dL). The incidence of neoatherosclerosis was significantly lower (23% versus 57%, P < 0.0001) in the LDL < 70 mg/dL group. There was no significant difference in the incidence of neoatherosclerosis in patients with lipid levels between 70 and 100 mg/dL (P = 0.53). However, neoatherosclerosis was significantly more common in patients with a follow-up LDL-C level > 100 mg/dL (45% versus 15%, P < 0.0001).In patients with early ISR lesions, the LDL-C levels may be related to the formation and progression of early neoatherosclerosis, and poor LDL-C control may be a risk factor for the occurrence of early-stage neoatherosclerosis following DES implantation.

Impaired Cholesterol-Uptake Capacity of HDL Might Promote Target-Lesion Revascularization by Inducing Neoatherosclerosis After Stent Implantation

Background We evaluated the importance of high-density lipoprotein (HDL) functionality for target-lesion revascularization in patients treated with coronary stents using a rapid cell-free assay system to evaluate the functional capacity of HDL to accept additional cholesterol (cholesterol-uptake capacity; CUC). Methods and Results From an optical coherence tomography (OCT) registry of patients treated with coronary stents, 207 patients were enrolled and their HDL was functionally evaluated by measuring the CUC. Follow-up OCT was performed (median duration, 24.5 months after stenting) to evaluate the presence of neoatherosclerosis. Clinical follow-up was performed to assess target-lesion revascularization for a median duration of 42.3 months after stent implantation. Neoatherosclerosis was identified in 37 patients (17.9%). Multivariate logistic regression analysis revealed that a decreased CUC was independently associated with neoatherosclerosis (odds ratio, 0.799; P<0.001). The CUC showed a significant inverse correlation with incidence of target-lesion revascularization (odds ratio, 0.887; P=0.003) and with lipid accumulation inside stents, suggesting that neoatherosclerosis contributes to the association between CUC and target-lesion revascularization. Conclusions Impaired HDL functionality, detected as decreased CUC, might lead to future stent failure by provoking atherogenic changes of the neointima within stents. Both quantitative and qualitative assessments of HDL might enable the improved prediction of clinical outcomes after stent implantation.