Hohneck AL, et al. - Since a relevant link between heart rate and cardiovascular mortality has been reported in epidemiological and clinical studies, researchers investigated how endothelial function and indices of arterial stiffness in patients with stable coronary artery disease were affected by heart rate reduction. In this prospective, placebo-controlled clinical crossover study, they included 23 patients (18 men and 5 women) with a resting heart rate (HR) of at least 70 beats per minute (bpm) and stable coronary artery disease. Ivabradine (Iva, 7.5 mg b.i.d.) and placebo were administered, for 6 months each, in a cross-over design to all patients. Among the participants, increased endothelium-dependent vasodilation and reduced arterial stiffness were observed in relation to heart rate reduction with Iva. The findings in experimental studies are confirmed and expanded by the findings in this study. Heart rate was suggested to be significant as a determinant of vascular function.