Background: The early use of aggressive antiplatelet and anticoagulation therapies during and after stent implantation with the consequent hemorrhagic complications motivated the need to develop stents with a non-thrombogenic. Amorphous silicon carbide (a-SiC:H) has been reported to reduce fibrin deposition, which may result in reduced platelet and leucocyte adherence as well. In-stent restenosis is a consequence of tissue hyperplasia, occurring principally around the points where the stent struts impinge upon the artery wall. Whilst the struts may create the problem, they may also present the solution, by carrying a coating targeted at the thrombotic or hyperplastic responses occurring locally.Objectives: To compare the rates of acute occlusion of stent and subacute stent thrombosis (AOS\SAT) in silicon-carbide coated tantalum stents (Tensum III, Biotronik, Germany) vs. different non-coated stents and to assess the long-term follow-up with respect to stent restenosis. Patients and Methods: An open, single center, non-randomized, prospective, observational study. The study population included all consecutive patients in the period between August 97- January 2000 requiring stent implantation for their native vessels as far as written and oral informed consent was given. They were divided into groupA who received the coated stent and groupB who received different brands of non-coated stents.Results: The study comprised 447 patients (675 stents), Group A (125 patients) and group B (322 patients). Both groups were comparable regarding the demographic and risk profile criteria (age, sex, hypertension, diabetes mellitus, smoking and hyperlipidemia). The two groups were also comparable regarding the distribution of the stented vessel, severity of CAD as well as the ACC/AHA classification of lesion morphology. Group A patients had significantly more unstable angina and acute myocardial infarction as their initial presentation 54.4 vs. 33.5% p= 0.001 and 25 vs. 9% p= 0.032 respectively. Ejection fraction was also significantly lower in group A patients 54+12.7 vs. 57+13.4% p= 0.007. Reference vessel diameter and severity of diameter stenosis were significantly higher in group A patients 3.18+0.52mm vs. 3.06+0.40mm p= 0.015 and 88.04+10.1% vs. 82.98+10.2% p= 0.001 respectively. They also had significantly longer periods of follow-up 222+87 vs. 202+ 84 days p= 0.026. The success rate for stent implantation and availability of follow up data was 100% and there was no in-hospital mortality. Group A patients had significantly lower rates of AOS\SAT (0 vs. 2% p= 0.05). However, no significant differences were observed regarding total mortality (cardiac and non-cardiac), re-infarction and the need for bypass of the stented vessels. Stent restenosis rate showed a strong trend in favor the coated Tensum stent 28.8% in group A vs. 36% in group B p=0.09.Conclusion: Silicon-carbide coating could significantly affect the AOS\SAT rates and has a strong favorable trend toward reduced long-term restenosis. Large randomized trials are needed for further evaluation of these findings.