Introduction: Femoral and carotid atherosclerotic plaques can both accurately predict the presence of coronary artery disease. The correlation, however, of femoral artery inflammation with coronary artery disease (CAD) is an under-investigated area. Microwave radiometry (MWR) can noninvasively evaluate the inflammatory status of peripheral superficial vessels, indirectly, by measuring their temperatures.
Hypothesis: Femoral plaque temperatures, as evaluated by MWR, are associated with the extent of coronary artery disease.
Methods: Consecutive patients with significant CAD as documented by coronary angiography by radial approach were included in the study. All patients underwent evaluation of both carotid and femoral arteries by 1) ultrasound and 2) microwave radiometry (MWR). During ultrasound study intima-media thickness and the presence of atherosclerotic plaques were evaluated in both carotid and femoral arteries. Temperature difference (ΔT) by MWR was defined as maximal temperature along the carotid or femoral artery minus minimum.
Results: In total 50 patients with significant CAD were included in the study (44 male, 6 female). No correlation was documented between carotid and femoral temperature values (R=0.03, p=0.87). Patients with femoral plaques bilaterally showed higher ΔT values, compared to patients with unilateral or no plaques (0.79 ±0.16 vs 0.66±0.18 °C, p=0.007). Similarly, patients with atherosclerotic plaques in at least one femoral artery (n=38, 76%) exhibited higher ΔT values compared to patients with no subclinical femoral atherosclerosis (0.75±0.16 vs 0.59±0.14°C, p=0.005). Interestingly, patients with 3 vessel CAD had higher femoral temperatures compared to patients with two or one vessel CAD (0.82±0.15 vs 0.71±0.17 vs 0.67±0.17 °C, p=0.05). In contrast, no difference was noticed in carotid Δτ values between patients with one-, two- or three-vessel disease (0.77±0.25 vs 0.75±0.27 vs 0.83±0.29 °C, p=0.73).
Conclusions: Femoral atherosclerosis is highly prevalent in patients with CAD. In this patient group, femoral artery temperatures are associated with the extent of CAD.