"Acute takeoff" of the circumflex artery: a newly recognized coronary anatomic variant with potential clinical consequences.

Human coronary anatomy allows for a wide range of anatomic variants while maintaining certain consistent features. The use of specific descriptions and names is helpful in talking about variants that have an implicit potential for clinical consequences. In reviewing the angiograms of 813 patients, we newly identified a coronary pattern that we propose to name "acute takeoff of the circumflex artery" in 16 patients (2%). This previously unreported pattern angiographically features a <or=45 degrees angle between the mainstem of the left main stem and the circumflex coronary artery in 2 orthogonal, caudal projections. The acute angle is associated with a substantially longer left main trunk than that seen in the general population (24.9 vs 9.8 mm, respectively). This anomaly increases the technical difficulty and failure rate of percutaneous coronary intervention unless the operator makes specific adaptations, some of which we describe herein.