Percutaneous coronary intervention for chronic total occlusions: The role of side-branch obstruction

Aims: The aim of this study was to review all percutaneous coronary interventions (PCI) performed in our department for chronic total occlusions (CTO) over the last three years, and analyse the success rate and complications. Methods and results: We retrospectively studied all PCIs for total occlusions of more than four weeks duration, performed between 2004 and 2006, after excluding multivessel PCI, venous grafts and in-stent restenosis (n=106 cases). The in-hospital complications were recorded; periprocedural myocardial infarction (MI) was defined as elevation of troponin I more than 3 times the upper reference limit. Procedural success was defined as angiographic success and absence of major adverse cardiac events (MACE: death, large MI, emergency bypass). Logistic regression analysis was used to determine predictors of success and complications. The procedural success was 77%, and was mainly associated with duration of occlusion less than three months (OR 4.17, 95% CI 1.23-14.28, p=0.02), preprocedural TIMI 1 coronary flow (OR 3.29, 95% CI 1.00-10.82, p=0.05) and absence of ipsilateral collaterals (OR 4.54, 95% CI 1.35-16.67, p=0.01). Periprocedural MI occurred in 12 cases (12%), while MACE occurred in 3 (3%). The only parameter significantly associated with periprocedural MI was the obstruction of side-branches (with diameter >1 mm) within 5 mm of the CTO (OR 10.00, 95% CI 1.76-56.67, p<0.01). Conclusions: In our CTO cohort the success rate was 77%, with a low complication rate. Periprocedural MI was mainly due to obstruction of side-branches.