Prediction of coronary artery disease severity in lower extremity artery disease patients: A correlation study of TASC II classification, syntax and syntax II scores

Abstract

Background: Lower extremity arterial disease (LEAD) is a well-established risk factor for concomitant coronary artery disease (CAD). There are no published data combining all three lower limb arterial segments (aortoiliac, femoropopliteal and below the knee vessels) in order to estimate CAD severity in LEAD patients. Herein has been derived a new scoring system for this purpose, which uses the well-known TASC II classification, Syntax score and, for the first time in medical literature, a Syntax II score. Methods: The study population consisted of 178 patients who underwent lower limb and coronary diagnostic angiography for assessment of LEAD and CAD at the same session. Syntax and Syntax II scores were calculated. TASC II classifications of the lower limb arteries were done. A new scoring system, called “Total Peripheral Score” (TPS), for lower limbs was also calculated. Results: A positive correlation was found between TPS and Syntax score and a less prominent positive correlation between TPS and Syntax II score (p < 0.001). A cut-off value of ‘6’ for the new score was found for estimating high risk subgorup of CAD (Syntax score > 32; p < 0.001). Critical femoropopliteal arterial segment stenosis was the most predictive lower limb arterial zone for presence of severe CAD (Syntax score > 32; p = 0.011). Conclusions: Taking into account all lower limb arterial segments for predicting CAD during lower limb arterial angiography was recommended. A TPS of more than ‘6’ is the practical cut-off value for estimating severe CAD. Femoropopliteal arterial critical stenosis is the most predictive arterial zone for estimating severe CAD.