Objective: The behavior of cardiovascular parameters during exercise remains unsettled. Our aim was to evaluate carotid elasticity during graded bicycle semi-supine exercise test, in patients with known or suspected coronary artery disease (CAD) and to compare it with a control group.

Methods: 36 consecutive patients (20 men, 61±8years), and 18 healthy volunteers (9 men, 34±3 years) were recruited. Right carotid diameter (D) and distension (ΔD) were estimated by ultrasound B-mode image processing, and central pulse pressure (PPa) by radial tonometry; then, carotid cross-sectional distensibility coefficient (DC) was obtained. All measurements were performed at rest and peak of age-dependent maximal heart rate.

Results: At rest, D and PPa were higher in patients than in controls (7.8±1.1 vs 6.2±0.6mm and 49±11 vs 27±5mmHg, p<0.05), whereas no significant differences were observed in ΔD and mean blood pressure (0.50±0.21 vs 0.54±0.24mm and 98±7 vs 97±5mmHg, p=ns); DC was lower in patients than in healthy volunteers (22.1±8.5 vs 59.7±20.6 10-3/KPa, p<0.05). At peak, D (8.1±1.3 and 6.4±0.7mm) and ΔD (0.65±0.31 and 0.79±0.24mm) were similar to rest in both groups; PPa (67±17 and 45±12mmHg) and mean blood pressure (128±9 and 123±13mmHg) increased both in patients and controls (p<0.05 vs rest); DC significantly decreased in healthy subjects (39.7±14.5 10-3/KPa, p<0.05 vs rest), but not in patients (21.2±7.9 10-3/KPa, p=ns vs rest).

Conclusions: In patients with known or suspected CAD, carotid distensibility, which at rest is lower than in healthy controls, remains unchanged during maximal exercise, despite a similar increase in mean blood pressure in the two populations.