Predictors and Outcomes of Side-Branch Occlusion in Coronary Chronic Total Occlusion Interventions

Objectives: We investigated whether side-branch loss during chronic total occlusion (CTO) percutaneous coronary intervention (PCI) could adversely impact clinical outcomes. Background: Side-branch occlusion during PCI has been associated with periprocedural myocardial infarction and higher incidence of major adverse cardiac event (MACE), but has received limited study in CTO-PCI. METHODS: We retrospectively reviewed the medical records and coronary angiograms for 109 consecutive CTOPCI cases performed at our institution during 2012 and 2013. Post-PCI patency of ≥1 mm diameter side branches and associated clinical outcomes were assessed. RESULTS: Mean age was 65 ± 8 years and 99.1% of the patients were men. The CTO target vessel was the right coronary artery (54%), circumflex (26%), and left anterior descending artery (20%). Side-branch loss occurred in 28 cases (25.7%) due to antegrade dissection/reentry (n ≤ 9), retrograde dissection/reentry (n ≤ 5), stenting over the branch (n ≤ 12), and dissection during antegrade crossing attempts (n ≤ 2). Recanalization of the occluded side branch was pursued in 8 cases (28.6%) and was successful in 4 patients. Patients with side-branch loss had higher post-PCI increase in CK-MB levels (8.4 ng/mL [interquartile range, 2.7-33.5 ng/mL] vs 1.8 ng/mL [interquartile range, 0.025-6.775 ng/mL]; P<.001) and higher 12-month incidence of all-cause death (17.3% vs 2.8%; P≤.02) and cardiovascular death (7.4% vs 0.0%; P≤.02). CONCLUSIONS: Side-branch loss occurs in approximately 1 in 4 CTO-PCIs and is associated with higher risk for periprocedural myocardial infarction and higher mortality.