BACKGROUND: The effect of telmisartan, which has selective PPAR- 款 activity, in reducing late lumen loss has not been verified. We compared the effect of telmisartan and valsartan on the late lumen loss and inflammatory markers after sirolimus-eluting stent (SES) implantation in hypertensive diabetic patients. METHODS: This was a prospective, randomized, single-blinded 8 months follow-up study including hypertensive diabetic patients with significant coronary artery stenosis (previously untreated de novo lesions with > 70% diameter stenosis) assigned to the Telmisartan Group (30 patients, 56 lesions) and the Valsartan Group (27 patients, 40 lesions). RESULTS: Risk factors such as hyperlipidemia, smoking, and obesity were similar in both groups. At 8 months follow-up, only the Telmisartan Group showed significant decreases in IL-6 (1.31 짹 1.48 at baseline vs. 0.76 짹 0.50 pg/ml at follow-up, p<0.05) and TNF-慣 (12.7 짹 2.3 at baseline vs. 10.8 짹 1.8 pg/ml at follow-up, p<0.05). The changes from baseline in total cholesterol, LDL-cholesterol, and triglyceride concentrations revealed no significant differences between the 2 groups. The increase in adiponectin concentrations from baseline was significantly greater in the Telmisartan Group compared with the Valsartan Group (2.08 짹 2.55 vs. 0.76 짹 1.94 關g/ml, p<0.05, respectively). Moreover, the late lumen loss was significantly lower in the Telmisartan Group compared with the Valsartan Group (0.15 짹 0.39 vs. 0.40 짹 0.56 mm, p<0.05, respectively). Major adverse cardiac events (death, myocardial infarction, the need for repeated target vessel revascularization) were similar between the 2 groups [10.0% (n=3) in the Telmisartan Group and 11.1% (n=3) in the Valsartan Group (p=1.000)]. CONCLUSION: Telmisartan compared with valsartan was associated with significant decrease in the late lumen loss and inflammatory markers after SES implantation in hypertensive diabetic patients with significant coronary lesions.