[1] Wake Forest Univ, Bowman Gray Sch Med, Div Vasc Ultrasound Res, Winston Salem, NC 27157 USA
[2] A Cardarelli Hosp, Div Cardiol, Naples, Italy
[3] A Cardarelli Hosp, Clin Anal Lab, Naples, Italy
[4] Univ Naples Federico II, Dept Clin & Expt Med, Naples, Italy
[5] S Maria di Lorcto Hosp, Div Cardiol, Naples, Italy
[6] SUNY Buffalo, Dept Social & Prevent Med, Buffalo, NY 14260 USA