ObjectivesIntravascular ultrasound (IVUS) facilitates detailed visualization of endoluminal anatomy not adequately appreciated on conventional angiography. However, it is unclear if IVUS use improves clinical outcomes of peripheral vascular interventions (PVI) for peripheral arterial disease (PAD). This study aimed to evaluate the impact of IVUS on 1-year outcomes of PVI in the vascular quality initiative (VQI). MethodsThe VQI-PVI modules were reviewed (2016-2020). All patients with available one-year follow up after lower extremity PVI were included and grouped as IVUS-PVI or non-IVUS PVI based on use of IVUS. Propensity matching (1:1) was performed using demographics and comorbidities. One-year major amputation and patency rates were compared. A generalized estimating equation (GEE) model was used to identify predictors of 1-year outcomes. Subgroup analysis based on Trans-Atlantic Inter-Society Consensus (TASC) classification, treatment length and treatment modalities were performed using same modeling approaches. ResultsThere were 56,633 procedures (non-IVUS PVI=55,302 vs IVUS-PVI=1,331) in 44,042 patients. Propensity matching yielded a total cohort of 1,854 patients matched (1:1), with no baseline differences. LER for claudication was performed in 60.4%, while one-third (33.9%) had chronic limb threatening ischemia (CLTI). IVUS was more commonly used for lesions >15cm in length (46.6% vs 43.3%) and for aortoiliac disease (31.8% vs 27.2%). Rates of atherectomy and stenting were significantly higher with IVUS-PVI (21.1% vs 16.8%), while balloon angioplasty was less common (13.5% vs 24.4%). One-year patency was better with IVUS-PVI (97.7% vs 95.2%, p=0.004). On subgroup analysis, IVUS (OR 2.20, 95% CI 1.29- 3.75) was associated with improved patency in CLTI patients, TASC C or D lesions, and treatment length >15cm. Adjunctive IVUS use during PVI did not significantly impact 1-year amputation (OR 1.7, 95%CI 0.78-3.91). On multivariable regression, adjunctive use of IVUS (OR 2.46 95%CI 1.43-4.25) and aortoiliac interventions (OR 2.91, 95%CI 1.09-7.75) were independent predictors of patency. Treatment modalities such as atherectomy, stenting or balloon angioplasty did not significantly impact patency at 1-year. ConclusionIVUS during lower extremity PVI is associated with improved 1-year patency, when compared to angiography alone. Certain subgroups, such as CLTI patients, lesions>15cm, and TASC C or D lesions might benefit from adjunctive use of IVUS.