Neoatherosclerosis after Drug-Eluting Stent Implantation: Roles and Mechanisms

A historical view of estrogen effect on arterial endothelial healing: From animal models to medical implication

Endothelial barrier integrity is required for maintaining vascular homeostasis and fluid balance between the circulation and surrounding tissues. In contrast, abnormalities of endothelial cell function and loss of the integrity of the endothelial monolayer constitute a key step in the onset of atherosclerosis. Endothelial erosion is directly responsible for thrombus formation and cardiovascular events in about one-third of the cases of acute coronary syndromes. Thus, after endothelial injury, the vascular repair process is crucial to restore endothelial junctions and rehabilitate a semipermeable barrier, preventing the development of vascular diseases. Endothelial healing can be modulated by several factors. In particular, 17β-estradiol (E2), the main estrogen, improves endothelial healing, reduces neointimal accumulation of smooth muscle cells and atherosclerosis in several animal models. The aim of this review is to highlight how various experimental models enabled the progress in the cellular and molecular mechanisms underlying the accelerative E2 effect on arterial endothelial healing through the estrogen receptor (ER) α, the main receptor mediating the physiological effects of estrogens. We first summarize the different experimental procedures used to reproduce vascular injury. We then provide an overview of how the combination of transgenic mouse models impacting ERα signalling with pharmacological tools demonstrated the pivotal role of non-genomic actions of ERα in E2-induced endothelial repair. Finally, we describe recent advances in the action of selective estrogen receptor modulators (SERMs) on this beneficial vascular effect, which surprisingly involves different cell types and activates different ERα subfunctions compared to E2.

Vascular Wall Reactions to Coronary Stents-Clinical Implications for Stent Failure

Coronary stents belong to the most commonly implanted devices worldwide. A number of different types of stent exist, with very different mechanical and biochemical characteristics that influence their interactions with vascular tissues. Inappropriate inflammatory reactions are the major cause of the two major complications that follow implantation of stents in a percentage as high as 5-20%. It is therefore important to understand these reactions and how different they are among different generations of stents.

<p>The Predictive Value of Monocyte Count to High-Density Lipoprotein Cholesterol Ratio in Restenosis After Drug-Eluting Stent Implantation</p>

Background

The clinical value of monocyte count to high-density lipoprotein cholesterol ratio (MHR) in in-stent restenosis (ISR) of patients who have undergone bare metal stent implantation has been studied. However, the predictive value of MHR in ISR for patients who have undergone drug-eluting stent (DES) implantation has not been explored.

Methods

Non-ST segment elevation acute coronary syndrome (NSTE-ACS) patients who had undergone DES implantation and coronary angiography follow-up at the Beijing Shijitan Hospital, Capital Medical University, between January 1, 2008, and December 31, 2018, were retrospectively enrolled. Patients were divided into ISR and non-ISR groups depending on the follow-up coronary angiography results. Relative clinical information was recorded and analyzed. The receiver operating characteristic curve analysis was used to determine the optimum cut-off pre-procedural MHR to predict ISR.

Results

A total of 214 patients were enrolled in our study. The mean period between two coronary angiography procedures was 25.4±9.8 months. Percutaneous coronary intervention due to NSTE myocardial infarction, a bifurcation lesion, increased platelet count, and a high MHR were the independent risk factors in multivariate logistic regression analyses.

Conclusion

Our results indicated that elevated MHR is an independent and useful predictor of ISR in NSTE-ACS patients who have undergone DES implantation.

Comparison of drug-eluting stents vs. drug-coated balloon after rotational atherectomy for severely calcified lesions of nonsmall vessels

Calcified lesion is a risk factor for adverse events, even in the drug-eluting stent (DES) era. Recently, drug-coated balloon (DCB) has been shown to have favourable results for in-stent restenosis and small vessels, but its results for calcified lesions are unknown. This study aimed to clarify the rotational atherectomy (RA) and DCB results for calcified lesions of nonsmall vessels. A total of 194 consecutive de novo lesions from 165 cases underwent RA for calcified lesions of nonsmall vessels between January 2016 and August 2018 in a single centre. Overall, 8 cases/10 lesions were excluded because of RA followed plain old balloon angioplasty (POBA). Remaining lesions were grouped into the DES (88 cases/104 lesions) and DCB (69 cases/80 lesions) groups and then compared retrospectively. The primary endpoint was post-discharge major adverse cardiovascular events (MACE) at 1 year, and it was defined as cardiac death, noncardiac death, target-vessel-related myocardial infarction, target lesion revascularization (TLR), and major bleeding (BARC ≥ type 3). There was no difference in the clinical follow-up rate between RA + DES (96/104 lesions) and RA + DCB (78/80 lesions). The post-discharge MACE values after 1 year of RA + DES and RA + DCB were 8% and 11% (P = 0.30), respectively, in terms of cardiac death (0% vs. 0%, respectively), noncardiac death (4% vs. 3%, respectively, P = 0.36), target-vessel-related myocardial infarction (0% vs. 0%, respectively), TLR (4% vs. 8%, respectively, P = 0.30), and major bleeding (1% vs. 0%, respectively). For calcified lesions of nonsmall vessels, RA + DCB showed good results as well as RA + DES. RA + DCB is a potential new strategy for these lesions.