Troglitazone reduces neointimal tissue proliferation after coronary stent implantation in patients with non-insulin dependent diabetes mellitus - A serial intravascular ultrasound study

OBJECTIVES The aim of the present study was to determine whether troglitazo ne reduces neointimal tissue proliferation after coronary stent implantatio n in patients with non-insulin dependent diabetes mellitus (NIDDM). BACKGROUNND Increased in-stent restenosis in patients with diabetes mellitu s is due to accelerated neointimal tissue proliferation after coronary sten t implantation. Troglitazone inhibits intimal hyperplasia in experimental a nimal models. METHODS We studied 62 stented lesions in 52 patients with plasma glucose le vels (PG) greater than or equal to 11.1 mmol/liter at 2 h after 75 g oral g lucose load. The study patients were randomized into two groups: the trogli tazone group of 25 patients with 29 stents, who were treated with 400 mg of troglitazone, and the control group of 27 patients with 33 stents. All pat ients underwent oral glucose tolerance tests before and after their six-mon th treatment period. The sum of PG (Sigma PG) and the sum of insulin levels (Sigma IRI) were measured. Serial (postintervention and at six-month follo w-up) intravascular ultrasound studies were performed. Cross-sectional imag es within stents were taken at every 1 mm, using an automatic pullback. Ste nt areas (SA), lumen areas (LA), and intimal areas (IA = SA - LA) were meas ured and averaged over a number of selected image slices. The intimal index was calculated as intimal index = averaged IA/averaged SA x 100%. RESULTS There were no differences between the two groups before treatment i n Sigma PG (31.35 +/- 3.07 mmol/liter vs. 32.89 +/- 4.87 mmol/liter, respec tively, p = 0.2998) and Sigma IRI (219.6 +/- 106.2 mU/liter vs. 209.2 +/- 9 1.6 mU/liter, respectively, p = 0.8934). However, reductions in Sigma PG at the six-month follow-up in the troglitazone group were significantly great er than those in the control group (-21.4 +/- 8.846 vs. -4.5 +/- 7.4%, resp ectively, p < 0.0001). Likewise, decreases in <Sigma>IRI were greater in th e troglitazone-treated group (-31.4 +/- 17.9% vs. -1.9 +/- 15.1%, respectiv ely, p < 0.0001). Although, there were no differences between the two group s in SA at postintervention (7.4 +/- 2.2 mm(2) vs. 7.3 +/- 1.7 mm(2), respe ctively, p = 0.9382) and at follow-up (7.3 +/- 2.3 mm(2) vs. 7.3 +/- 1.8 mm (2), respectively, p = 0.2307), the LA at follow-up in the troglitazone gro up was significantly greater than that in the control group (5.3 +/- 1.7 mm (2) vs. 3.7 +/- 1.7 mm, respectively, p = 0.0002). The IA at follow-up in t he troglitazone group was significantly smaller than that in the control gr oup (2.0 +/- 0.9 mm vs. 3.5 +/- 1.8 mm2, respectively, p < 0.0001). This wa s also true for intimal index (27.1 +/- 11.5% vs. 49.0 +/- 14.4%, respectiv ely, p < 0.0001). CONCLUSIONS Serial intravascular ultrasound assessment shows that administr ation of troglitazone reduces neointimal tissue proliferation after coronar y stent implantation in patients with NIDDM. (C) 2000 by the American Colle ge of Cardiology.