Stenting of Nonacute Total Coronary Occlusions: Predictors of Late Angiographic Outcome

Objectives. This study was designed to determine and assess factors predictive of the intermediate-term outcome of stenting of nonacute total coronary occlusions. Background. Balloon angioplasty of recanalized coronary occlusions is associated with combined restenosis/reocclusion rate of up to 65%. Adjunctive stenting holds the potential to reduce this rate significantly. However, variables affecting the late angiographic outcome of coronary stenting in the setting of total occlusion have not been elucidated sufficiently. Methods. Coronary stenting was performed in 143 consecutive patients with nonacute total occlusion; 120 of these patients (84%), with total of 121 occlusions, underwent repeat angiography within 6 months and comprised the study group. High pressure stent implantation aimed to cover the site of the occlusion as well as adjacent diameter stenoses ≥70% and all possibly induced dissections. Pertinent angiographic and procedural variables obtained at the time of the intervention were entered into multivariate logistic regression analysis model to assess their influence on the angiographic outcome at follow-up. Results. Mean preinterventional reference lumen diameter for the 121 vessels was 2.99 ± 0.53 mm (mean ± SD); occlusion length ranged from 4 to 44 mm (median of 7.7). After balloon angioplasty, dissections were found in 80% of patients. Lesions were covered with stents median of 16 mm in length (range 8 to 53). The minimal lumen diameter (MLD) achieved after stenting was 2.89 ± 0.48 mm. After median follow-up period of 4.5 months, mean MLD was assessed at 1.91 ± 0.90 mm, corresponding to loss index of 0.34 ± 0.31. There were 27 vessels with nonocclusive restenosis ≥50% and 8 with reocclusion, for combined restenosis/reocclusion rate of 29%. Factors found to adversely influence angiographic outcome were post-stenting MLD ≤2.54 mm, stented vessel segment length >16 mm, balloon/vessel diameter ratio for final stent expansion ≤1.00 and the presence of dissection after balloon angioplasty. Conclusions. Compared with previous reports on stand-alone balloon angioplasty, stenting of nonacute total coronary occlusions lowers the 6-month restenosis/reocclusion rate to not, vert, similar30%. The late procedural outcome is independently and statistically significantly influenced by the MLD after stenting, the length of the stented vessel segment, the balloon/vessel diameter ratio for final stent expansion and the incidence of dissections after balloon angioplasty.