Association of Iliofemoral Calcium Score and Major Vascular Complications within the First Year after Lower Limb Endovascular Revascularization

Background

The accumulation of calcium load in peripheral lower extremity arteries has been associated with increased severity of peripheral artery disease (PAD) and mortality. While calcium scores are commonly calculated from non-contrast computed tomography (CT) scans, patients with PAD often undergo contrast-enhanced CT scans. This study aims to explore the association between a length-adjusted calcium score (LACS) of the iliofemoral arteries, determined through pre-intervention contrast-enhanced CT, and major adverse events in patients with chronic limb-threatening ischemia (CLTI).

Methods

A cohort of CLTI patients subjected to endovascular revascularization between 2005 and 2017 at a tertiary referral center were categorized into 2 groups. The complication group experienced one of the composite outcomes (reintervention, above-the-ankle amputation, and/or all-cause mortality within 1 year of the primary endovascular procedure), while control patients did not encounter this composite endpoint. Patients from the complication group were matched one-to-one with controls based on sex and Fontaine classification. LACS was calculated (Ca volume[mm³]/length[cm]) at 3 arterial segments; 1. the common iliac artery (CIA), 2. the external iliac artery and common femoral artery (EIA + CFA), and 3. the superficial femoral artery plus the popliteal artery (SFA + PA). Binary logistic regression analysis was conducted to investigate the association between LACS in the different arterial segments and the occurrence of the composite binary outcome (complication and control) and LACS of the different segments, adjusting influences of age, sex, BMI >25, Fontaine classification, diabetes mellitus type 1 & 2, chronic kidney disease stage, and hemodialysis treatment.

Results

Sixty-four CLTI patients were included in this study (complication group [n = 32], and control group [n = 32]). A significant difference (higher LACS was found for the complication group in the CIA, the SFA + PA, as well as the total trajectory. CLTI patients with high LACS in the SFA + PA or the total trajectory were more likely to suffer adverse events (SFA + PA: OR: 1.010, 95% CI: 1.000–1.020, P = 0.04; Total LACS: OR: 1.008, 95% CI: 1.000–1.017, P = 0.05).

Conclusions

Patients with a high calcium load in the ilio-femoral arteries are at increased risk of major adverse events during 1 year after endovascular revascularization. The calcium score, derived from contrast-enhanced CT scans, holds potential utility in decision making for CLTI patients.