Author + information
- Received July 8, 1992
- Revision received November 4, 1992
- Accepted November 19, 1992
- Published online June 1, 1993.
- Takeshi Kimura, MD∗,
- Hideyuki Nosaka, MD,
- Hiroyoshi Yokoi, MD,
- Masashi Iwabuchi, MD and
- Masakiyo Nobuyoshi, MD, FACC
- ↵∗Address for correspondence: Takeshi Kimura, MD, Department of Cardiology, Kokura Memorial Hospital, 1-1 Kokurakita-ku, Kitakyushu, 802, Japan.
Objectives. Serial angiographic follow-up study was designed to evaluate the temporal mode of lumen diameter changes after Palmaz-Schatz stent implantation, and the results were compared with those from a cohort of patients undergoing balloon angioplasty.
Background. Restenosis remains a major limitation of balloon angioplasty. The Palmaz-Schatz balloon expandable coronary stent is now under clinical investigation to evaluate its efficacy in preventing restenosis.
Methods. Serial angiographic follow-up study was performed the day after stent implantation and at 1, 3 and 6 months after the procedure. The stent group consisted of 96 patients who had 97 lesions with a single stent. A cohort of 179 patients with 192 lesions were selected as the balloon group by the criteria of final balloon size ≥3 mm and lesion length <20 mm.
Results. A significantly larger lumen diameter was obtained immediately after stent implantation (2.9 ± 0.4 mm [mean ± SD] in the stent group vs. 2.1 ± 0.5 mm in the balloon group, p < 0.001). At 3 to 6 months of follow-up, a significantly larger lumen diameter was maintained in the start group (2.2 ± 0.6 vs. 1.5 ± 9.7 mm, p < 0.001). The late restenosis rate according to a binary definition was significantly lower to the stent group (13% vs. 39%, p < 0.001). Stenosis exacerbation, frequently observed within 24 h after balloon angioplasty, was not found after stenting. Between the next day and 1 month, regression was dominant in the balloon group, whereas progression of stenosis was observed in the stent group. The greatest tendency to restenosis was observed in both groups between 1 and 3 months after the procedure. Between 3 and 6 months, significantly greater diameter loss was found in the stent group.
Conclusions. The Palmaz-Schatz stent was effective in reducing the restenosis rate in this highly selected cobort of patients. Reduction in restenosis rate was dependent on a larger lumen obtained immediately. Late loss of diameter was significantly greater after stenting. The restenosis rate after stenting should be evaluated by follw-up angiography at 6 months rather than at 3 months, which is adequate after conventional balloon angioplasty.
- Received July 8, 1992.
- Revision received November 4, 1992.
- Accepted November 19, 1992.