The Carina Angle—New Geometrical Parameter Associated with Periprocedural Side Branch Compromise and the Long-Term Results in Coronary Bifurcation Lesions with Main Vessel Stenting Only

Background: The two main problems unresolved in coronary bifurcation stenting are periprocedural side branch compromise and higher restenosis at long term. The purpose of this study is to reveal the link between periprocedural side branch compromise and long-term results after main vessel stenting only in coronary bifurcations.

Methods: Eighty-four patients formed the study population. The inclusion criteria were good-quality angiograms, with maximal between-branch angle opening, no overlap, permitting accurate angiographic analysis. Carina angle (α)—the distal angle between main vessel (MV) before bifurcation and side branch (SB)—was measured pre- and poststenting. Clinical follow-up 9–12 months was obtained with coronary angiography if needed.

Results: The patient population was high-risk with 33% diabetics and 84% two- and three-vessel disease. Ninety-five stents were implanted in 92 lesions, with three T-stenting cases. Drug-eluting stents were implanted in 54%. Kissing-balloon (KBI) or sequential inflation was performed in 35%. SB functional closure occurred in 17.4%, with independent predictors α < 40° and diameter ratio MB/SB >1.22. After 12±4 months there were five myocardial infarctions (6%) and 13 (15%) target lesion revascularization procedures. Independent predictors of major cardiovascular events were carina angle <40°, MB lesion length >8 mm, negative change of between-branch angle, DES usage, and KBI.

Conclusions: Smaller carina angle with straightening of MV—main branch from stent implantation in coronary bifurcations predicted higher SB compromise, restenosis, and MACE rates during follow-up of 1 year.