Cobalt chromium stents versus stainless steel stents in diabetic patients

Abstract

The clinical outcome in diabetic patients undergoing percutaneous coronary intervention (PCI) is inferior to that in non-diabetic patients. Several aspects of diabetic coronary artery disease appear to be responsible for this observation. In comparison with stainless steel stent, cobalt chromium stent has a higher radial strength and radio-opacity for similar electronegativity, this allow for the production of thinner struts with a similar radiological visibility. Therefore we studied and compared six-months prognosis of cobalt chromium stent versus stainless steel Bare metal stents in diabetic patients undergoing PCI. Our study included seventy diabetic patients with Ischemic heart disease amendable to percutaneous stenting with stents ⩾3 mm in diameter and ⩽25 mm length. They were randomly assigned to cobalt chromium stents (Group I) or stainless steel stents (Group II). PCI was done with initial success and we excluded patients with unsuccessful PCI or complications during intervention, using stainless steel stent and chromium stent in the same lesion, left main stem lesions, osteal and bifurcational lesions. Our primary end point was Major adverse cardiac events (death, Myocardial infarction, unstable angina, emergency CABG or target lesion revascularization); over period of 6 months and our secondary end point was in-stent restenosis assessed by coronary angiography at 6 months in the follow up period. Total MACE in group (I) was 9 patients, coronary angiography was done for those patients after the cardiac event, that showed 7 patients with ISR and 2 of them showed patent stents. Patients without MACE whom undergone follow up coronary angiography after 6 months, revealed 6 patients suffered ISR out of 23 patients. While total MACE in group (II) was 5 patients, coronary angiography for those patients showed 4 patients with ISR and 1 of them showed patent stent. Patients without MACE whom undergone follow up coronary angiography after 6 months revealed 10 patients suffered ISR out of 28 patients. So as a result for all patients included in our study, 13 patients from group (I) suffered ISR in the period of 6 months follow up period, they represented 40% of the group, while 14 patients in group (II) with a percentage of 42.4% of the group suffered ISR at 6 months. There was no statistically significant difference between the two groups as regard the incidence of ISR at follow up. ( P > 0.05). We concluded that no significant statistical difference was found between the two stents (cobalt-chromium alloy bare metal stent versus conventional bare metal stainless steel stent) in diabetic patients regarding (initial procedural success, in-hospital complications, the incidence of ISR at follow up, event-free survival at follow up).