Objectives To investigate the characteristics of intravascular ultrasound (IVUS) image of target borderline lesion in the proximal anterior descending artery (LAD) for finding the basement to treating these patients with the lesions.

Methods The borderline lesions with 30%-70% dimension stenosis in the proximal LAD were found in 10 patients from June, 2010 to October, 2011. All the 10 patients had some discomfort in the precordium, including 7 males, 1 with diabetes, 3 with hypertension, 2 smokers and 2 with infarct history. The intervention was done in the patient with the typical syndrome after IVUS. For the atypical patients, the exercise test was done. The intervention was done in the positive patient after IVUS.

Results The discomfort in the precordium disappeared in all the 10 patients. The minimal lumen area (MLA) of them in the proximal LAD was 4.85 ± 1.49 mm². MLA in the 7 patients was more than 4 mm². The area stenosis (AS) of them in the proximal LAD was 69.99% ± 7.07%. AS in the 4 patients was less than 70%.

Conclusions It is questionable that the 4 mm² of MLA or 70% of AS was considered to be the cut-off value for the intervention therapy. The suitable strategy to the patients with borderline lesion in the proximal LAD should come from the combination of IVUS and clinical condition.