Prospective Application of Pre-Defined Intravascular Ultrasound Criteria for Assessment of Intermediate Left Main Coronary Artery Lesions: Results From the Multicenter LITRO Study

Objectives tudy is a prospective validation of 6 mm2 as a minimum lumen area (MLA) cutoff value for revascularization of left main coronary artery (LMCA) lesions. ound s involving the LMCA are prognostically relevant. Angiography has important limitations in the evaluation of LMCA lesions with intermediate severity. An MLA of 6 mm2 assessed by intravascular ultrasound has been proposed as a cutoff value to determine lesion severity, but there are no large studies evaluating the prospective application and safety of this approach. s e designed a multicenter, prospective study. Consecutive patients with intermediate lesions in unprotected LMCA were evaluated with intravascular ultrasound. An MLA <6 mm2 was used as criterion for revascularization. s l of 354 patients were included in 22 centers. LMCA revascularization was performed in 90.5% (152 of 168) of patients with an MLA <6 mm2 and was deferred in 96% (179 of 186) of patients with an MLA of 6 mm2 or more. A large scatter was observed between both groups regarding angiographic parameters. In a 2-year follow-up period, cardiac death-free survival was 97.7% in the deferred group versus 94.5% in the revascularized group (p = 0.5), and event-free survival was 87.3% versus 80.6%, respectively (p = 0.3). In the 2-year period, only 8 (4.4%) patients in the deferred group required subsequent LMCA revascularization, none with an infarction. sions raphic measurements are not reliable in the assessment of intermediate LMCA lesions. An MLA of 6 mm2 or more is a safe value for deferring revascularization of the LMCA, given the application of the clinical and angiographic inclusion criteria used in this study.