Interventional therapy of the acute coronary syndromes

Rationale and study design of the OISTER trial: optical coherence tomography evaluation of stent struts re-endothelialization in patients with non-ST-elevation acute coronary syndromes--a comparison of the intrEpide tRapidil eluting stent vs. taxus drug-eluting stent implantation

BACKGROUND

Drug-eluting stents (DES) have been designed to prevent restenosis, but long-term clinical outcome may be offset by an increased risk of stent thrombosis, which is associated with suboptimal stent implantation or delayed re-endothelialization. DES implantation has also been associated with local persistent endothelial dysfunction. Conversely, Trapidil is a potent anti-inflammatory, vasodilatator and antiproliferative drug and several studies have shown anti-restenotic effects, suggesting substantial clinical benefits through the use of Trapidil-eluting DES.

STUDY DESIGN

This is a longitudinal, single-blind, double-arm, randomized multicenter study. Forty patients with non-ST-elevation acute coronary syndromes who present at the index procedure with multivessel coronary disease in the major epicardial coronary arteries will be enrolled. Patients should present a culprit lesion with stenosis 70% or more associated with another stenosis 70% or more in another coronary artery. Patients will be randomized in a 1: 1 fashion to receive either an Intrepide trapidil-eluting stent or a Taxus paclitaxel-eluting stent on the culprit lesion. After 90 days, the nonculprit lesion will be treated with the stent of the opposite randomization arm and optical coherence tomography (OCT) analysis of the index stented segment will be performed. Follow-up angiography, combined with vasomotor analysis of endothelial function by rapid atrial pacing, will be done at 12 months after the index procedure on both stents. To further characterize the status of the endothelium, serum measurement of vascular endothelial growth factor gradient between the aorta and 15 mm distal to the implanted stent will be performed at 12 months. The primary endpoint of the study is to compare stent struts re-endothelialization at 90 days by OCT. The secondary endpoint is to compare angiographic outcome and coronary endothelial function 12 months after the index procedure and to compare clinical outcome at 1 and 2 years between trapidil-eluting DES versus paclitaxel-eluting DES.

CONCLUSION

We hypothesize that the utilization of trapidil-eluting DES in the setting of acute coronary syndromes will be characterized by a greater early re-endothelialization associated with an antiproliferative effect offering a similar efficacy with a better safety profile compared with first-generation DES.

Usefulness of high-sensitivity IL-6 measurement for clinical characterization of patients with coronary artery disease

Interleukin 6 (IL-6) may represent an early marker of inflammatory activation and may be useful to ameliorate risk stratification in patients with ischemic heart disease. The aim of this study was to verify the performance characteristics of an ultrasensitive immunoassay (Biosource International, Camarillo, CA) for high-sensitivity (hs)-IL-6 measurement in comparison with hs-R&D Systems (Abingdon, United Kingdom) and Immulite System (Diagnostic Products Corporation [DPC], Los Angeles, CA) methods in patients with ischemic heart disease. In addition, hs-C-reactive protein (hs-CRP) concentrations were measured, to evaluate the correlation with hs-IL-6 levels. We measured IL-6 and CRP serum levels in 39 patients with ischemic heart disease and in 12 controls. Out of the 39 patients studied, 13 were affected by unstable angina, 13 by post-acute myocardial infarction (AMI) unstable angina, and 13 by stable angina. The imprecision profile and functional sensitivity were performed measuring 9 different serum pools in 10 runs. The Biosource method had the best performance characteristics as compared to the others. Mean IL-6 level was higher in patients with unstable and post-AMI unstable angina with respect to controls. CRP levels were elevated in patients with post-AMI. In the whole population a high significant linear regression was observed between Biosource hs-IL-6 and hs-CRP serum levels. The Biosource method for IL-6 measurement is characterized by a high functional sensitivity that allows a better stratification of patients with ischemic heart disease.

Modulation of tachykinin and cytokine release in patients with coronary disease undergoing percutaneous revascularization

Plasma levels of substance P (SP) and neurokinin A (NKA) tachykinin and of gamma interferon (IFN-gamma) and tumor necrosis factor alpha (TNF-alpha) cytokines were assayed in plasma obtained from peripheral blood of 19 patients presenting with stable chronic coronary stenosis and 12 patients with acute coronary syndrome (ACS). Plasma samples were obtained before, during, and after percutaneous coronary intervention (PCI) consisting of implantation of a metallic stent. Fourteen healthy subjects without any evident risk factors for coronary artery disease (CAD) were also included for comparison at basal time. We found that plasma levels of both IFN-gamma and TNF-alpha were significantly higher in patients with chronic or acute CAD than those in control subjects at the time of presentation. NKA and IFN-gamma levels were also significantly increased in ACS patients compared with those in patients with stable disease. The analysis performed during and after PCI revealed that IFN-gamma levels increased 15 min after stent implantation in both chronic and ACS patients and that TNF-alpha levels increased in chronic patients only compared to basal values. In addition, a significant decrease of both NKA and SPA levels 48 h after the end of the revascularization procedure was observed in ACS patients. These data suggest that modulation of tachykinin and/or cytokine release with proinflammatory activity in chronic or acute cardiac ischemia and during following coronary stenting might play an important role in heart tissue damage and in long-term inflammatory complications of PCI.