The radial approach for a coronary angiography is currently adopted by several centers because of its simplicity. The radial artery spasm is the main inconvenient. Nitrates in intra-arterial have been widely studied in prevention of this spasm. No studies have compared the different routes of administration of nitrates as a patch and a continuous intravenous injection.

The radial approach is favored for coronary angiography due of several advantages: reduction of local bleeding risk, even in the most hemorragiparic situations, decreased downtime and time reduction of hospitalization, improved patient ulterior comfort. However, this approach is subject to an immediate major complication that is the radial artery spasm (RAS) which, according to the criteria used, has an average incidence of 30%. The administration of a vasodilator just before coronary angiography procedure enables an increase of the radial artery diameter and thus a decrease of friction probes. Theoretically this prevents the occurrence of the RAS.

The literature re-counts several vasodilator product tests (DN calcic blocker, magnesium sulfate, alpha-adrenergic antagonist ...) and various routes of administration (direct intravenous route (IV), subcutaneous injected route, direct intra-arterial route (IA)). Overall intra-arterial DN appears to be more efficient. The downside is a brief, painful thermal sensation but intense and notably unpleasant. IV injection is better tolerated but it was a direct injection and without proof of its superiority over IA. The para-radial subcutaneous injection has only been studied to facilitate access to the radial artery. The investigators randomized study compares, for the first time, the effectiveness of the transdermal administration of trinitrine (D) and continuous intravenous of dinitrate isosorbide (V) to dinitrate isosorbide intraarterial (A) standard.

Inclusion Criteria:

• Patients > 18 ans.
• Patients with hemodynamic stability.
• Patients informed consent was signed by each individual. The study obtained approval from the local ethics committee.

Exclusion Criteria:

• 'Test d'Allen' negative
• Pregnancy.
• STEMI
• Hemodynamic Instability : PAS < 100 mmHg, FC > 100 bpm, tachycardia uncontrollable.
• Allergy of nitrates.