Anatomic runoff score predicts cardiovascular outcomes in patients with lower extremity peripheral artery disease undergoing revascularization.

BACKGROUND

Although the presence, extent, and severity of obstruction in patients with lower extremity peripheral artery disease (LE PAD) affect their functional status, quality of life, and treatment, it is not known if these factors are associated with future cardiovascular events. We empirically created an anatomic runoff score (ARS) to approximate the burden of LE PAD and determined its association with clinical outcomes.

METHODS

We evaluated all patients with LE PAD and bilateral angiography undergoing revascularization in a community-based clinical study. Primary clinical outcomes of interest were (1) a composite of all-cause death, myocardial infarction (MI), and stroke and (2) amputation-free survival. Cox proportional hazards models were created to identify predictors of clinical outcomes.

RESULTS

We evaluated 908 patients undergoing angiography, and a total of 260 (28.0%) patients reached the composite end point (45 MI, 63 stroke, and 152 death) during the study period. Anatomic runoff score ranged from 0 to 15 (mean 4.7; SD 2.5) with higher scores indicating a higher burden of disease, and an optimal cutpoint analysis classified patients into low ARS (<5) and high ARS (≥5). The unadjusted rates of the primary composite end point and amputation-free survival were nearly 2-fold higher in patients with a high ARS when compared with patients with a low ARS. The most significant predictors of the composite end point (death/MI/stroke) were age (δ 10 years; hazard ratio [HR] 1.53; CI 1.32-1.78; P < .001), diabetes mellitus (HR 1.65; CI 1.26-2.18; P < .001), glomerular filtration rate <30 (HR 2.23; CI 1.44-3.44; P < .001), statin use (HR 0.66; CI 0.48-0.88; P < .001), and ARS (δ 2 points; HR 1.21; CI 1.08-1.35; P < .001).

CONCLUSIONS

After adjustment for clinical factors, the LE PAD ARS was an independent predictor of future cardiovascular morbidity and mortality in a broadly representative patient population undergoing revascularization for symptomatic PAD. A clinically useful anatomic scoring system, if validated, may assist clinicians in risk stratification during the course of clinical decision making.