Chief of Vascular Surgery Yale University School of Medicine New Haven, Connecticut
Objectives: We have recently developed a simple scoring system for femoral artery calcification based on arterial duplex ultrasound (DUS) of the lower extremities. We now aim to determine whether these scores are predictive of outcomes for patients with PAD.
Methods: Under an IRB approved protocol, patients with PAD who underwent arterial duplex US imaging of the lower extremity were identified. Five femoral artery segments were assessed for the presence or absence of calcification using a scale from 0-2. A score of 0 signified a completely normal vessel, 1 signified intimal heterogeneity, and 2 signified anechoic shadowing in the arterial wall. Scores were then averaged for the index extremity, and then further dichotomized into those less than or equal to 1.4 versus greater than 1.4, based on receiver operator curve analysis. Medical records were reviewed for major adverse limb events including amputation, femoral artery occlusion, and re-intervention at 6 months. Logistic regression was then performed using cardiovascular and demographic risk factors as covariates.
Results: At total of 94 patients were included in the present study. In unadjusted analyses, the US femoral calcification score over 1.4 was significantly associated with increased major adverse limb events as were DM, tobacco use, HTN, and age. In a multiple logistic regression, a duplex US femoral calcification score over 1.4 remained significantly associated with MALE. (odds ratio: 1.899, 95% CI [0.53 to 7.43].
Conclusions: Arterial DUS based scoring of femoral artery calcification can identify patients at increased risk of major adverse limb events. Because it is non-invasive and widely used to assess patients with PAD, it may provide useful information for predicting limb outcomes. Further refinements of US-based calcification scoring algorithms are needed as are studies aimed at identifying the role of calcification in lower extremity ischemia.