The comparison between self-expanding and balloon expandable stent results in left anterior descending artery

Abstract

The first Wallstent results had high thrombosis and death. It was reported that the left anterior descending (LAD) artery was the vessel implicated in major complications that occurred in patients who received a Wallstent. Subsequently, Wallstent applications were refrained from with LAD lesions. However, the promising results of second-generation self-expanding Magic Wallstent implantation have been reported recently. The purpose of this study is to assess the immediate and intermediate clinical outcomes of patients undergoing self-expanding Magic Wallstent implantation at the LAD site and to compare those outcomes with those of a similar group of patients undergoing balloon expandable stenting at the same site. Between 1995 and 1999, 255 consecutive patients underwent LAD stenting at our center. The study population was divided into two groups based on the mode of delivery (self-expanding versus balloon-expandable) of stent design. Group I included 97 patients in whom self-expanding Magic Wallstents were implanted. Group II included 158 patients in whom various types of balloon-expandable stents were implanted. Procedural success was defined as successful deployment of the stent in the absence of adverse cardiac events (death, acute myocardial infarction, emergency coronary bypass surgery). Clinical success was defined as the absence of adverse cardiac events (death, acute myocardial infarction, emergency coronary bypass surgery, repeat balloon angioplasty) within the first two weeks. The mean follow-up period was 8 ± 5.3 months for Group I and 9.8 ± 7.5 months for Group II. There was no difference in baseline characteristics between the two groups. Fourteen patients in Group I and 22 patients in Group II had bailout procedures. The number of patients with reference vessel diameter less than 3 mm was 37 in Group I and 60 in Group II. The stent length was greater in Group I than in Group II (p=0.0003). In Group I, stenting improved minimal lumen diameter (MLD) from 0.65 ± 0.4 mm to 2.35 ± 0.4 and percent diameter stenosis (PDS) from 76.24 ± 17.3 to 22.78 ± 13.6. In Group II, stenting improved MLD from 0.73 ± 0.4 mm to 2.49 ± 0.5 and PDS from 76.71 ± 15.5 to 18.99 ± 9.6. Final MLD and final PDS improved more in Group II than Group I. Stent could not be delivered in three patients in Group I and nine in Group II. In Group II, six stents were dislocated from its delivery system. Procedural and clinical success and subacute stent thrombosis rates were 93.8%, 85.6%, and 7.2% in Group I, and 93%, 86.7%, and 5.1% in Group II, respectively. Within the first two weeks, death occurred in one patient in each group, acute myocardial infarction in four (Group I) and two (Group II) patients; coronary bypass surgery in three (Group I) and five (Group II) patients, and balloon angioplasty in two (Group I) and four (Group II) patients, respectively. In Group I, following the first two weeks, no patients died, two patients had nonfatal myocardial infarction, and coronary bypass surgery and target vessel repeat balloon angioplasty was required in five and ten patients, respectively. In Group II, one patient died in the follow-up period, there was no nonfatal myocardial infarction, and bypass surgery and target vessel repeat balloon angioplasties were required in three and eleven patients, respectively. None of these differences in clinical events was statically significant. We found that self-expanding Magic Wallstent implantation can be performed in LAD lesions and was associated with a rate of early clinical results and intermediate term clinical results similar to that of balloon-expandable stents in LAD arteries. In conclusion, the Magic Wallstent may confidently be used for LAD lesions.