Inflammation and restenosis: is there a link?

The utility of high-sensitivity C-reactive protein levels in patients with moderate coronary lesions and gray-zone fractional flow reserve

OBJECTIVE

It remains controversial whether patients with fractional flow reserve (FFR) values of 0.75-0.80 (gray-zone) should be treated with percutaneous coronary intervention (PCI). This study aimed to evaluate the prediction of high-sensitivity C-reactive protein (hs-CRP) levels to guide treatment selection in gray-zone patients.

METHODS

This prospective interventional trial was conducted between January 2015 and March 2016. A total of 785 patients with stable angina and single-vessel stenosis with moderate coronary lesions were admitted to hospital in this period. After measurement of hs-CRP levels, coronary angiography, and FFR, gray-zone patients (n=308) were included in the study and were divided into four groups on the basis of a cutoff hs-CRP level of 3 mg/L and then on the basis of whether they underwent PCI or not. Patients in groups I (≥3 mg/L, n=70) and III (<3 mg/L, n=84) underwent PCI, whereas those in groups II (≥3 mg/L, n=70) and IV (<3 mg/L, n=84) were administered only drugs. Major adverse clinical events (MACEs) included cardiac death, nonfatal myocardial infarction (MI), target vessel revascularization (TVR), and PCI or coronary artery bypass grafting (CABG). These parameters were also evaluated during follow-up.

RESULTS

The total Kaplan-Meier curves showed macrodistribution differences among the four groups (p<0.05). There was a significantly increased MACE incidence in group II compared with group I or IV (p=0.039 or 0.006, respectively), and an increased incidence in group I compared with group III (p=0.028). However, there were no differences in MACE incidence between groups III and IV (p=0.095) despite the fact that these patients received different treatments.

CONCLUSION

Among FFR gray-zone patients, hs-CRP level was a predictor of MACE and risk stratification could guide treatment selection. Increased hs-CRP levels (≥3 mg/L) are an indication for urgent PCI whereas normal levels (<3 mg/L) are an indication for delayed PCI treatment. Patients with identical FFR values could require different treatment.

Anti-inflammatory agents and antioxidants as a possible "third great wave" in cardiovascular secondary prevention

There are 3 important factors that predispose patients to plaque rupture or recurrent events: plaque burden or multiple arterial plaques, the presence of persistent hyperreactive platelets, and ongoing vascular arterial inflammation. Successful therapeutic strategies focus on these predisposing factors, and the use of low-density lipoprotein-lowering medications (principally statins) and antiplatelet agents (principally aspirin) has had a major impact on the occurrence of cardiovascular outcomes and overall mortality over the last 2 decades. However, despite these interventions, a significant number of patients experience recurrent events or progression of disease. Novel compounds are being studied to determine, for example, whether an increase in high-density lipoprotein will provide additional risk reduction; to date, this has not proved to be sufficiently effective. Although early invasive management has been proved to be superior to medical therapy in patients with plaque rupture producing acute coronary syndromes, its superiority in patients with clinically stable obstructive disease has been questioned. Thus, the search for additional agents to improve the outcomes of patients with atherothrombotic disease continues. The importance of inflammation, a potentially critical element in the initiation, progression, and rupture of plaque, has become increasingly evident. In this supplement, the role of inflammation and its principal cause, oxidative stress, are analyzed as potential targets of pharmacologic therapy. The history of anti-inflammatory and antioxidant therapy in cardiovascular disease is critically examined. Finally, the whole process of contemporary drug discovery and development from lead rationale and identification through biologic screening and testing in animals and then humans is explored, using as an example the xanthophyll carotenoids, a class of potent antioxidants currently under investigation.

Inflammatory events in a vascular remodeling model induced by surgical injury to the rat carotid artery

1.--The aim of our study was to gain insight into the molecular and cellular mechanisms of the inflammatory response to arterial injury in a rat experimental model. 2.--Rats (five for each experimental time) were subjected to brief clamping and longitudinal incision of a carotid artery and monitored for 30 days. Subsequently, Nuclear Factor-kappaB (NF-kappaB) expression was measured by electrophoretic mobility shift assay. Heat shock protein (HSP) 27, HSP47 and HSP70 were evaluated by Western blot. Morphological changes of the vessel wall were investigated by light and electron microscopy. 3.--In injured rat carotid artery NF-kappaB activity started immediately upon injury, and peaked between 2 and 3 weeks later. Western blot showed a significant increase of HSP47 and HSP70 7 days after injury. At 2 weeks postinjury, HSP27 expression peaked. Light microscopy showed a neointima formation, discontinuity of the media layer and a rich infiltrate. Among infiltrating cells electron microscopy identified dendritic-like cells in contact with lymphocytes. 4.--Our model of surgical injury induces a significant inflammatory process characterized by enhanced NF-kappaB activity and HSPs hyperexpression. Dendritic-like cells were for the first time identified as a novel component of tissue repair consequent to acute arterial injury.

Coronary Stenting and Inflammation: Implications for Further Surgical and Medical Treatment

The introduction of percutaneous coronary interventions (PCI) with stent implant has substantially shifted the treatment of coronary artery disease. The current approach to coronary artery disease treatment includes first-choice PCI in selected subgroups; and once this therapy fails, frequently the patient is referred for coronary artery bypass graft surgery. However, evidence of chronic inflammatory reaction and endothelial dysfunction after PCI has been emerging and that might be interfering with patient outcome when surgical or medical treatments are subsequently required. The clinical significance of these complications after PCI, herein examined, has been less studied and needs better assessment. Also, the premise that coronary artery bypass graft surgery can safely be performed in patients with coronary stenting failure may not hold true, as graft patency might be adversely affected. Furthermore, the superimposed inflammatory reaction may blunt the efficacy of medical treatment.

Comparison of C-reactive protein levels before and after coronary stenting and restenosis among patients treated with sirolimus-eluting versus bare metal stents

We prospectively studied the inflammatory response to coronary stenting (calculated as the difference between the highest postprocedural C-reactive protein [CRP] and baseline CRP levels [DeltaCRP]) and restenosis in 301 patients who received a sirolimus-eluting stent (n = 149) or a bare stent (n = 152) in the setting of a randomized trial. Median values of DeltaCRP were 3.1 mg/L in the sirolimus-eluting stent group and 3.0 mg/L in the bare stent group (p = 0.71). In the sirolimus-eluting group, restenotic rates were 9.7% in the subgroup with DeltaCRP higher than the median and 11.5% in the subgroup with DeltaCRP no higher than the median (p = 0.37). In the bare stent group, restenotic rates were 28.6% in the subgroup with DeltaCRP higher than the median and 15.4% in the subgroup with DeltaCRP no higher than the median (p = 0.04).