Association Between Coronary Flow Reserve and BH4 Levels in High CV Risk

Primary parameter :

relationship between coronary flow reserve (CFR) and platelet/plasma BH2 and BH4 levels in patients with hypertension and concomitant cardiovascular risk factors.

Secondary parameter:

Levels of cGMP in platelets.

• Study design

Three parallel groups of patients (n=15 per group):

• Group 1 with normal coronary flow reserve (CFR ≥2.5)
• Group 2 with reduced coronary flow reserve (CFR≤2.0)

o Group 3 control subjects (without a high risk profile according to ESC score chart http://www.heartscore.org. ) matched for age (between 40 and 80 years of age)

• and gender. 1/3 enrolled patients must be diabetic (Type2 diabetes)

Inclusion criteria

• o men and women (females of childbearing potential must be using highly effective contraceptive precautions such as implants, injectables, combined oral contraceptives, intrauterine devices, sexual abstinence or vasectomised partner)

• Females of childbearing potential or within two years from the menopause must have a negative urine pregnancy test
• between 40 and 80 years of age
• documented history of hypertension
• smokers/non smokers R
• type 2 diabetes R
• Moderate to severe kidney disease (GFR >30 and <60 ml/min/1.73m2 (estimated MDRD) R
• Hypercholesterolemia R
• Receiving an optimal standard antihypertensive treatment for at least 6 months, stable for at least 15 days
• All other concomitant treatments stabilized at least for the preceding 15 days
• Able to give written informed consent

Exclusion criteria

• o Females of childbearing potential not using highly effective contraceptive precautions

• Patients with obstructive (>50% diameter reduction) CAD on the LAD (based on invasive angiography or coronary CTA) or with evidence of previous myocardial infarction or history of revascularization in the LAD territory.
• CAD on the RCA or CX with diameter reduction > 50% (based on invasive angiography or coronary CTA) , either native or revascularized (stent)
• Patients with infectious disease and/or chronic inflammatory diseases
• Epicardial coronary arteries spasm
• Patients with severe valve disease and/or significant left ventricular wall motion abnormalities
• Patients under treatment with non-selective beta blockers including propranolol, nadolol, pindolol, labetalol, penbutolol, sotalol, carvedilol, and timolol.
• Contraindications to dipyridamole infusion: asthma, bronchospasm, previous < 24 hours ingestion of phylline derivatives (tea, coffee, cola, xanthines and chocolate) sick sinus syndrome, advanced AV block (second and third degree), systolic blood pressure < 90 mmHg, cerebral ischemia, severe sinus bradycardia (heart rate <40/min), use of dipyridamole during the last 24 h, severe atherosclerotic lesions of extracranial artery >75%.
• Acute treatment or treatment for acute diseases
• Patients receiving steroidal anti-inflammatory drugs, dietary supplements of folic acid, or antioxidant vitamins.
• Any condition that may prevent the pt to give informed consent , enter the study or bias the results.
• Participating into other studies