This study examines the cardiovascular performance in relation to age in 61 patients with moderate or severe chronic mitral regurgitation (MR). Coronary artery disease (CAD) (50% or more diameter narrowing of one or more major coronary arteries) was present in 20 patients (33%). Patients <60 years (n = 33) had lower pulmonary artery pressure, systolic arterial pressure, left ventricular (LV) end-diastolic pressure, and pulmonary artery wedge pressure than the patients ≥ 60 years (n = 28) (p < 0.05). In the 41 patients without associated CAD, the LV end-diastolic pressure and systemic arterial pressure were higher in patients ≥60 years (n = 14) than patients <60 years (n = 27) (p < 0.05). The LV end-diastolic pressure showed an age-related increase in the presence or absence of CAD. Thus, older patients with MR have higher LV end-diastolic pressure, probably because of an increase in myocardial stiffness. © 1985.