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

Coronary Artery Stenosis, Fractional Flow Reserve

This is a randomized, non-inferiority, crossover investigation comparing the Direct Wire Pacing (DWP) versus standard method to measure Fractional Flow Reserve (FFR) in subjects with FFR indications. All subjects requiring on a clinical basis a pressure wire assessment of coronary artery stenosis(es) will be eligible to take part in the study.

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.

France