OBJECTIVE: To investigate the ultrasound criterion of minimum luminal area (MLA) with a cutoff value of 4.0 mm² in an attempt to differentiate the lesions that should be treated from those that should not. METHODS: The study comprised 173 consecutive patients with moderate angiographic lesions (percentage of stenosis between 40 and 70) who underwent ultrasound imaging. They were divided into 2 groups as follows: group 1 or clinical group (MLA > 4.0 mm²); and group 2 or revascularization group (MLA < 4.0 mm²). The patients were followed up to determine the rate of major cardiac events (MCE) in 2 years, the need for revascularization of the target lesion, and to identify the clinical, angiographic, and ultrasound predictors of events. RESULTS: Seventy-five (43%) patients had MLA > 4.0 mm² and were clinically treated; 98 (57%) patients had MLA < 4.0 mm² and were treated with coronary stents. On quantitative coronary angiography, no significant difference was observed between the percentage of vessel stenosis [group 1: 48% vs group 2: 53%; P=0.06]. By the other hard ultrasound measurements, as MLA was significantly greater in group 1 compared with that in group 2 [4.54 mm² vs 2.45 mm²; P < 0.001)]. The clinical impact of the decision was favorable, and no difference was observed in regard to the occurrence of major cardiac events: [group 1: 5 (7%) vs group 2: 14 (15%); P = 0.09]. The need for revascularization of the target lesion also did not differ (group 1: 3 (4%) vs group 2: 11 (12%); P = 0.07). The predictive variables for MCE were diabetes, functional class III (FC III) angina before hospitalization, and MLA assessed on ultrasound. CONCLUSION: This strategy for deciding on appropriate treatment guarantees low rates of MCE in both groups in the 24-month follow-up, with reduced revascularization rates. The predictive variables of major cardiac events were as follows: diabetes mellitus, FC III angina, and MLA on intravascular ultrasound.
intravascular ultrasound; moderate coronary lesion; coronary artery disease
