A Study to Evaluate Direct Wire Pacing (DWP) for Measuring Fractional Flow Reserve (FFR)

Pressure wire-based Fractional Flow Reserve (FFR) has become the reference standard index of haemodynamic significance to guide revascularisation of intermediate coronary artery lesions.

The FFR measurement determines the ratio of the maximum blood flow that can be achieved in a diseased or narrowed coronary artery to the maximum blood flow in a normal coronary artery. This ratio represents the potential decrease in distal coronary flow relative to coronary stenosis.

FFR is easily measured during routine coronary angiography using a pressure wire to calculate the ratio of coronary pressure distal to a stenosis or diseased segment to aortic pressure under conditions of maximum myocardial hyperemia. An FFR of 1.0 is widely accepted as normal. An FFR of less than 0.80 is generally considered to be associated with coronary ischemia and widely accepted in favor of revascularization rather than conservative management.

The current standard method of measuring FFR is to insert a pressure wire into the coronary artery while the hyperaemic agent, usually adenosine, is delivered by intracoronary bolus or continuous intravenous injection.

Administration of adenosine may cause bradycardia and thus cause patient vagal discomfort. Direct Wire Pacing (DWP) can potentially overcome the drawbacks of the standard method when measuring FFR. Indeed, DWP allows to transmit an electrical current from the external pacemaker to the heart thanks to metallic FFR guidewire already used, and thus prevent bradycardia.

In addition, there are some absolute contraindications to the use of Adenosine such as 2nd or 3rd degree atrioventricular block, untreated sinus dysfunction or long QT syndrome ...DWP could allow this highly recommended diagnostic tool (1A) to be used in this patient population.

The investigators would therefore like to determine if the measurement of FFR by DWP would be non-inferior to the standard method to obtain precise FFR values and maximize patient's comfort.

Eligible patient for coronary angiography.

Inclusion criteria

The patients included in the study must meet the following inclusion criteria :

• Patients ≥ 18 years old
• Patients with FFR indications
• Has given consent to undergo diagnostic coronary procedure
• Patients able to understand and provide informed consent
• Patients with Social Security coverage

Prior to randomisation: Angiography demonstrates at least one coronary stenosis in an artery, requiring FFR measurement for physiological assessment.

Exclusion criteria

The patients included in the study should not meet the following inclusion criteria :

• Contraindications to use sensitivity to Adenosine or any of its excipients
• Technically inaccessible stenosis(es)
• Pregnant or breastfeeding woman
• Patients under judicial protection, tutorship or curatorship
• Patient participating in another interventional clinical trial