The present study is designed to evaluate the hypothesis that the Angiotensin-Converting Enzyme (ACE) inhibitor Ramipril improves vascular function and reduces markers of low-grade chronic inflammation and oxidative stress in patients with Rheumatoid Arthritis.

The effect of an 8-week treatment with either ramipril or placebo is studied using a randomized, double-blind, and crossover protocol. After given written informed consent, baseline characteristics including physical examination, ECG, blood sample and a noninvasive assessment of endothelial function are obtained. The patients are randomly assigned to receive either ramipril 10mg (up-titration-scheme: starting with 2.5mg in Week1, then 5mg in Week2 followed by 2-5mg for the final 6 weeks) followed by placebo or vice versa.The individual disease-modifying antirheumatic drug therapy is continued throughout the study. The examinations are repeated after 8 weeks treatment of the first and 8 weeks after the second study drug. At week 1 and 2 in each treatment period a safety visit is scheduled.

Inclusion Criteria:

• patients with rheumatoid arthritis (4 out of 7 ARA criteria must be fulfilled to establish diagnosis) on stable background therapy for the last three months
• endothelial dysfunction (FMD < 4%, FMD:Flow-Mediated-Dilatation)
• non-smokers

Exclusion Criteria:

• previous myocardial infarction, coronary intervention or coronary surgery
• previous treatment with statins in the last 6 months
• previous treatment with ACE-inhibitors in the last 6 months
• uncontrolled hypertension SAP/DAP > 160/90 mmHg (SAP:Systolic Arterial Pressure, DAP:Diastolic Arterial Pressure)
• dyslipidemia (LDL-cholesterol > 4.9 mmol)
• normal CRP < 3 mg/l
• overweight BMI > 35kg/m2
• anaemia (hemoglobin < 10g/dl)
• kidney disease (creatinine > 150 umol/l)
• insulin-dependent diabetes mellitus
• congestive heart failure (> NYHA I)
• AV-Block>I
• pregnancy
• angio-edema
• malignancy or chronic infection
• drug abuse