Coronary heart disease is one of the most important causes of death in human, and consumes vast medical resources. Percutaneous coronary intervention (PCI) has been a significant breakthrough for its treatment. However, clinical application has been hampered by in-stent restenosis (ISR). Although drug eluting stent (DES) has reduced the occurrence of restenosis, incidence of ISR is still about 5% to 10%. The main reasons for restenosis after PCI are hyperplasia of vascular endothelial cells and smooth muscle cell migration. The exact mechanism of personalized differences in restenosis is not clear yet, but there may be a variety of risk factors. In addition to aging, smoking and diabetes, an increasing number of studies have found that genetic and epigenetic factors play an important role in ISR. In this article, authors have reviewed genetic and epigenetic factors on the progression of ISR, which may help to determine the genetic risk factors in patients with ISR after PCI.
Angioplasty, Balloon, Coronary ; methods ; Coronary Restenosis ; etiology ; genetics ; Disease Progression ; Epigenomics ; methods ; Humans ; Stents ; Treatment Outcome

Matrix metalloproteinases contribute to vascular remodeling by breaking down extracellular-matrix while new matrix is synthesized. Of the variety of MMPs, stromelysin-1 and gelatinase B may have key roles in coronary artery atherosclerosis. Moreover, The 5A/6A polymorphism in the promoter region of the stromelysin-1 gene may be a pathogenetic risk factor for acute myocardial infarction. Gelatinase B (92-kDa type IV collagenase and MMP-9) is one of the MMPs found to be highly expressed in the disruption-prone regions of atherosclerotic plaques. C- to T substitution at the promoter site (-1562) resulted in the higher promoter activity of the T-allelic promoter. The R279Q polymorphism in exon 6 led to the substitution of adenosine by guanine, and was a common polymorphism in the general population. We evaluated the relation between these polymorphisms and stable angina, the severity of atherosclerosis in coronary artery disease, and instent restenosis after percutaneous coronary angioplasty. The study population was composed of 131 patients with stable angina (mean age 61.3 years, 89 males) and 117 control subjects (mean age 59.3 years, 59 males). Coronary angiographies were performed in all cases at Yonsei University Cardiovascular Hospital from February 1998 to June 2000. The genotype for each polymorphism was determined using a SNaPshotTM kit and by restriction fragment length polymorphism (RFLP). The prevalence of 5A containing a polymorphism of the stromelysin-1 gene was higher in the stable angina group than in control patients, but no difference in the two polymorphisms of the gelatinase B gene was found between the two groups. By multiple logistic analysis, the 5A-allele of the stromelysin-1 gene was found to be an independent risk factor of stable angina with an odds ratio of 2.29 (95% CI; 1.19-4.38). However, the severity of atherosclerosis in coronary artery or in stent restenosis was not related to any polymorphism of stromelysin-1 or gelatinase B. Our results show that functional genetic variation of stromelysin-1 could be a significant risk factor for stable angina, and might play an important role in coronary atherosclerosis involving vascular remodeling.
Aged ; Angina Pectoris/*etiology/genetics ; Coronary Restenosis/etiology/genetics ; Female ; Gelatinase B/*genetics ; Genotype ; Human ; Male ; Middle Age ; *Polymorphism (Genetics) ; Promoter Regions (Genetics) ; Stromelysin 1/*genetics

Intimal proliferation is a main cause of in-stent restenosis. Over-excretion of angiotensin I converting enzyme (ACE) and aldosterone is reported to stimulate intimal hyperplasia and the genetic effect of these molecules may alter the process of in-stent restenosis. We hypothesized that the genetic polymorphisms that alter the expression of genes such as ACE I/D, CYP11B2-344C/T, and AGT M235T can affect in-stent restenosis. We analyzed the angiographic and clinical data of 238 patients (272 stents) who underwent coronary stenting and follow-up angiography, and analyzed the genotypes of ACE I/D, CYP11B2-344T/C, and AGT M235T. There was no significant difference in age, sex, or lipid profiles between the patent and restenosis groups. Diabetes mellitus was more frequent in the binary restenosis group. Quantitative computer-assisted angiographic (QCA) analysis revealed that the risk of in-stent restenosis increased with lesion length and was inversely proportional to post- stenting minimal luminal diameter (MLD) and reference diameter. There was no difference in the frequency of binary restenosis between genotypes in each of the three genes. However, follow-up MLD was significantly smaller in the ACE DD genotype than in the ACE II or ID genotypes. Defining restenosis as MLD 2 mm, the restenosis rate was significantly higher in the ACE DD genotype than in the ACE II or ID genotypes. There was no significant synergistic effect between the three gene polymorphisms. In conclusion, while the ACE I/D polymor phism promoted the progress of in-stent restenosis and was of clinical significance, the other potential variables examined did not correlate with in-stent restenosis.
Adult ; Aged ; Aldosterone Synthase/*genetics ; Angiotensinogen/*genetics ; Coronary Restenosis/*etiology/genetics ; Female ; Genotype ; Human ; Logistic Models ; Male ; Middle Age ; Peptidyl-Dipeptidase A/*genetics ; *Polymorphism (Genetics) ; Risk Factors ; *Stents

OBJECTIVETo investigate the effect of phVEGF165 transfer on vascular remodelling after balloon injury and its possible mechanisms.

METHODS90 New Zealand white rabbits were divided randomly into 3 groups: group I (balloon injury group), group II (pAdtrackCMV group) and group III (pAdtrackCMV-VEGF165 group). All animals were given hypercholesterol diet for 7 days before experiment and continued to receive hypercholesterol diet until being killed. Each group was further divided into five subgroups according to the sacrifice time (3 days, 1, 2, 4 and 8 weeks after transfection). Blood samples and arteries were harvested for further analysis.

RESULTSAt the end of 2 weeks, areas of neointima plus media of group III were smaller than those of group I and II (P < 0.05). The areas under external elastic membrane were larger in group III at 4 weeks and lumen stenosis rates were significantly lower than group I and II (P < 0.05 or 0.01). In group III, VEGF165, metalloproteinases (MMPs) -1, -2, -9 and their tissue inhibitors (TIMPs) 1, 2 could be detected from 3 days after gene transfer and reached the highest level at 2 weeks time and could not be detected by 8 weeks time. In groups I and II, MMP-2 and TIMP-1, -2 could be detected during the whole procedure and the value of TIMP1/MMP1 was significantly higher than in group III (P < 0.01).

CONCLUSIONRemodelling is the main reason for restenosis (RS) after vascular balloon injury. Local pAdtrackCMV-VEGF165 transfer can specifically change the expression of MMPs and facilitate the positive remodelling process, hence, inhibiting restenosis.

Angioplasty, Balloon ; adverse effects ; Animals ; Coronary Restenosis ; etiology ; pathology ; Endothelial Growth Factors ; genetics ; physiology ; Intercellular Signaling Peptides and Proteins ; genetics ; physiology ; Lymphokines ; genetics ; physiology ; Male ; Matrix Metalloproteinases ; metabolism ; Rabbits ; Vascular Endothelial Growth Factor A ; Vascular Endothelial Growth Factors