Patients with rheumatoid arthritis are at increased risk for myocardial infarction. It has been hypothesized that mental stress-induced cardiovascular reactions may play a role in the triggering of myocardial infarction. Cardiovascular activity was measured during rest, stress, and recovery in rheumatoid arthritis patients with high systemic inflammation (C-reactive protein >8 mg/l), rheumatoid arthritis patients with low systemic inflammation (C-reactive protein <or= 8 mg/l), and osteoarthritis patients. Systemic vascular resistance increased only in rheumatoid arthritis patients with high systemic inflammation. Heart rate and mean arterial pressure increased during the stress task in all groups. Thus, acute cardiovascular events in rheumatoid arthritis patients may be related to stress-induced increases in systemic vascular resistance, particularly in patients with high levels of systemic inflammation.