Prospective evaluation of myocardial ischemia related to post-procedural side-branch stenosis in bifurcated lesions treated by provisional approach with drug-eluting stents.

OBJECTIVES: To prospectively assess the impact of post-procedural side-branch (SB) stenosis on inducible myocardial ischemia in patients with bifurcated lesions undergoing percutaneous interventions. BACKGROUND: Provisional-stenting with drug-eluting stents (DES) is the recommended strategy to treat percutaneously bifurcated lesions but is associated to variable degrees of residual SB stenosis. The role of SB residual stenosis on post-procedural myocardial ischemia is uncertain. METHODS: Patients with bifurcations treated by DES according to provisional-stenting technique were enrolled in the study if they had no other untreated lesion. Patients were divided into two groups according to post-procedural 3D-quantitative coronary analysis (3DQCA): group OR (optimal result: stenosis < 50% of SB lumen area at 3DQCA) and group SR, suboptimal result: (stenosis ≥ 50% of SB lumen area at 3DQCA). Treadmill exercise stress test (EST) was performed within 1 week from PCI. The primary study endpoint was myocardial ischemia (≥1 mm ST-segment depression at EST). RESULTS: Sixty patients were enrolled: 49 (81.7%) comprised group OR and 11 (18.3%) group SR. Post-PCI myocardial ischemia at EST was inducible in 17 (34.7%) patients of group OR versus 10 (90.9%) patients of group SR (P = 0.0007). During the follow-up, patients of Group SR (vs. Group OR) had a significantly higher occurrence of inducible myocardial ischemia during late (>8 weeks) stress tests (P < 0.001). CONCLUSIONS: In patients with bifurcated lesions treated by a provisional-stenting technique, residual SB stenosis ≥ 50% at 3DQCA is associated with post-procedural inducible myocardial ischemia at EST.