Abstract: Objective To analyze the clinical application effect of intravascular ultrasound (IVUS)-guided drug-coated balloons (DCB) in the treatment of small-vessel coronary artery disease (SVD). 
Methods A retrospective analysis was conducted on 284 patients with unstable angina hospitalized at the Second Hospital of Hebei Medical University from June 2020 to June 2022. Patients were divided into two groups: the IVUS-guided group (IVUS group, n=142) and the coronary angiography (CAG)-guided group (CAG group, n=142). Immediate and long-term imaging outcomes and clinical events of DCB treatment for SVD between IVUS and simple CAG evaluation were compared. 
Results IVUS, as a high-resolution imaging technique, provided more detailed vascular structural information than CAG. The IVUS group demonstrated larger pre-treatment balloon diameter ［(2.38±0.25) mm vs. (2.25±0.34) mm, P＜0.05］, more sufficient pre-dilation, including lower immediate residual stenosis ［(13.18±6.40)% vs. (16.74±6.55)%, P＜0.05］, larger DCB diameter ［(2.46±0.25) mm vs. (2.24±0.33) mm, P＜0.05］, longer DCB length ［(24.09±4.84) mm vs. (21.67±4.08) mm, P＜0.05］, and reduced long-term residual stenosis ［(8.22±10.66)% vs. (16.39±13.66)%, P＜0.05］. 
Conclusion IVUS-guided DCB for the treatment of SVD yields superior imaging and clinical outcomes compared with CAG guidance alone. 

Key words: angina, unstable, coronary vessels, ultrasonography, drug-coated balloons