Sidebranch occlusion in direct intracoronary stenting: predictors and results.

We assessed the angiographic predictors and results of major (> 1 mm) sidebranch occlusion (SBO) following direct intracoronary stenting (DS) in 86 patients. The occlusion of a sidebranch is a well-defined risk after balloon angioplasty and stenting. However, the impact of direct stenting without predilatation on the coronary flow of sidebranches emerging within the stented segment has not been studied solely. A total of 111 sidebranches were analyzed. Sidebranch type, take-off angle, ostial involvement and procedural characteristics were evaluated. Nine out of 111 (8%) stent-covered sidebranches were occluded. Sidebranches with > 50% stenosis that take off within or just beyond the diseased portion of the lesion (unfavorable morphology) were the most powerful morphologic predictor of SBO (odds ratio: 8.0; 95% confidence interval: 1.5--40.8; p = 0.007). Take-off angle of the sidebranch was not found to have any effect on SBO. Post-stent dilation using high-pressure inflation (15.0 +/- 2.1 atmospheres), inflation (odds ratio: 1.1; 95% CI: 1.0--1.2; p = 0.038), and 3 times inflation (odds ratio: 4.5; 95% CI: 1.1--18.3; p = 0.023) were the procedural predictor of SBO. Of those 40 unfavorable morphologies, seven (17.5%) were occluded compared to 2.8% (2/71) of the favorable morphologies. Nine out of 9 (100%) occluded after high-pressure inflation. Three patients complained of chest pain and 1 had non-Q wave myocardial infarction attributed to SBO. These findings indicate that the incidence of SBO and complications are less than expected and has a favorable outcome in direct intracoronary stenting.