The Impact of Caffeine on Brachial Endothelial Function in Healthy Subjects and in Patients With Ischemic Heart Disease
Condition: Coronary Disease
MeSH terms: Heart Diseases; Coronary Disease; Coronary Artery Disease; Myocardial Ischemia
Study type: Interventional
Phase: Phase 3

Summary: 
      Prior work (Chris, M. et al, Clinical Science 2005; 109, 55-60) has demonstrated that
      drinking a cup of coffee (80-100 mg of caffeine) an hour before endothelium-dependent FMD
      (flow-mediated dilatation) of the brachial artery, effects endothelial function in healthy
      adults subjects.

      This effect might be attributed to caffeine, given that decaffeinated coffee (<2 mg of
      caffeine) was not associated with any change in endothelial performance.

      In the current study we intend to further examine the impact of caffeine on brachial
      endothelial function among healthy subjects & in patients with proven ischemic heart disease.
    

Detailed description: 
      Background:

      Prior work (Chris, M. et al, Clinical Science 2005; 109, 55-60) has demonstrated that
      drinking a cup of coffee (80-100 mg of caffeine) an hour before endothelium-dependent FMD
      (flow-mediated dilatation) of the brachial artery, effects endothelial function in healthy
      adults subjects.

      This effect might be attributed to caffeine, given that decaffeinated coffee (<2 mg of
      caffeine) was not associated with any change in endothelial performance.

      In the current study we intend to further examine the impact of caffeine on brachial
      endothelial function among healthy subjects & in patients with proven ischemic heart disease.

      Aim:

      To evaluate the impact of 200 mg caffeine tablet intake (equivalent to 2 cups of coffee),
      compared to placebo on brachial endothelial function in healthy subjects & in patients with
      proven ischemic heart disease.

      Methods:

        1. Patients will be invited for two endothelial function tests 1 week apart.

        2. ECG, heart rate & blood pressure will be recorded at rest prior to each test.

        3. Following overnight fasting and discontinuation of all medications for ≥ 12 hours and
           absence of > 48 hour caffeine consumption, patients will receive 200 mg of caffeine
           tablets or placebo, in a double-blind, cross-over study design. An hour later the
           patient will undergo endothelium-dependent flow-mediated dilation (FMD) and
           endothelium-independent, nitroglycerin (NTG)-mediated vasodilation will be assessed
           non-invasively in the brachial artery, using a high resolution (15 MHz) linear array
           ultrasound.

        4. Prior to and after the FMD, blood will be drawn to test caffeine levels, adiponectin,
           CBC, electrolytes, CRP and lipids.
    

Intervention name(s): Caffeine; Placebo
Intervention type(s): Drug; Drug
Intervention description(s): Caffeine 200 mg tablet; Placebo pills
Intervention MeSH terms: Caffeine
Allocation: Randomized
Intervention model: Crossover Assignment
Masking: Triple (Participant, Care Provider, Investigator)
Primary purpose: Prevention
Keywords: coronary disease; atherosclerosis; endothelial function; caffeine; cerebrovascular disease; prevention