Objective: To quantify non-coronary vascular calcifications (VC) in asymptomatic patients at low-intermediate cardiovascular risk by a new color Doppler ultrasound (DUS)-based score (the carotid, aortic, lower limbs calcium score, CALCs), and to correlate this score with classical parameters associated with cardiovascular risk [carotid intima media thickness (IMT), and arterial stiffness (AS)].
Patients and methods: All consecutive asymptomatic patients who underwent a screening DUS of non-coronary circulation were evaluated and patients at low-intermediate cardiovascular risk were selected according to Framingham risk score (FRS). Among them, we enrolled 70 patients with US evidence of VC and 71 age, sex and FRS matched controls. The presence of VC was correlated with classical markers of cardiovascular risk, such as AS and intima-media thickness (IMT). AS, expressed as pulse wave velocity (PWV) and arterial distensibility, carotid IMT and CALCs were measured for both groups. AS and c-IMT were assessed by a new Radio-Frequency (RF) DUS-based method. CALCs was generated by our previously described B-mode DUS-based method according to number/size of VC in 11 non-coronary segments (range 0-33).
Results: Patients with VC presented higher AS and IMT values than controls (PWV 8.34±0.98 m/s vs. 6.74±0.68 m/s, p<0.0001; arterial distensibility 267±12 mm vs. 315±65 mm, p=0.001; IMT 687±132 mm vs. 572±91 mm, p<0.0001). Mean CALCs of patients with VC was 8.41±7.78. CALCs were significantly correlated with c-IMT (p<0.0001; r=0.3), PWV (p<0.0001; r=0.4) and arterial distensibility (p=0.002; r=-0.1).
Conclusions: DUS-based CALCs is highly correlated with other validated markers of subclinical atherosclerosis, such as c-IMT and AS. Our results demonstrated the ability of CALCs to identify individual predictive factors beyond the traditional risk factors by quantifying an interesting and novel step of the atherogenic process. Future studies on larger series and with adequate follow up are necessary to confirm these results and to evaluate the role of this new marker in monitoring calcific atherosclerosis progression.