Gender differences in response to cold pressor test assessed with velocity-encoded cine-MR imaging of the coronary sinus

Methods Twenty-four healthy volunteers (12 men, 12 women) underwent MRI in a 3 Tesla scanner (Verio, Siemens, Erlangen, Germany). CPT was performed by immersing the right ankle in ice-water during 4 min. Heart rate and blood pressure were monitored throught the protocol. Coronary sinus flow was measured at rest and during CPT using a non breath-hold velocity encoded phase contrast cine MRI (TR/TE: 45 ms / 2 ms, slice thickness:5.5mm, FOV: 250, averages:11, matrix:256, flow encoding 70cm/s, flip angle: 25°, acquisition time: 4 min, GRAPPA k-space reduction factor:4). Left ventricular volumes, function and morphology were evaluated using SSFP sequence. MBF was calculated combining coronary sinus flow quantification and morphologic data using Argus work station (Siemens, Erlangen, Germany). Coronary endothelial function was assessed by comparing MBF at rest and during CPT. Coronary vascular resistance (CVR), rate pressure product and endothelium-dependent vasodilatation index (EDVI) were calculated. Results At baseline, MBF was 0.63 ± 0.23 mL.g.min in men and 0.79 ± 0.21 mL ·g ·min in women (P=ns) (figure 1). During CPT, the rate pressure product in men significantly increased by 49 ± 36 % (p<0.0001) and in women by 52 ± 22 % (p<0.0001). MBF increased significantly in both men and women by 0.22 ± 0.19 mL·g·min (p=0.0022) and by 0.73 ± 0.43 mL·g·min (p=0.0001), respectively. The increase in MBF was significantly higher in women than in men (p = 0.0012)