Microcatheter-versus wire-based measurement of the fractional flow reserve

Fractional flow reserve (FFR) guided-percutaneous interventions is nowadays the gold standard for optimal coronary artery revascularization. While multiple pressure guidewires have been validated, the use of microcatheter for FFR measurements is still a matter of debate.

The aim of this study was to investigate the crossing profile characteristics of the NAVVUS^® microcatheter as compared with the COMET^TM pressure wire. At the same time, we compared non-hyperaemic pressure ratio (NHPR) and FFR measurements of both systems.

In this retrospective study, all angiographically intermediate coronary artery stenoses each month were assessed, using either the NAVVUS^® or the COMET^TM pressure system, to receive coronary artery physiology assessment with NHPR and FFR measurements. The crossing profile of both systems was compared regarding objective coronary artery lesion characteristics using quantitative coronary analysis evaluation.

Over a period of 4.5 years, we evaluated 213 coronary artery stenoses using one of the two coronary tools. We found a 9.2% crossing profile failure rate using the microcatheter, compared to 0.7% in the pressure wire group (p < .001). The crossing failure was significantly correlated with the presence of coronary artery calcifications and angulation (p = .042, p = .049, respectively). FFR values were comparable be- tween the two groups and were significantly lower in the presence of coronary calcifications and proportional to the degree of stenosis (p = .036, p = .010). Pressure drift was comparable.

Our observations are in line with other studies reporting the poor crossing profile of the NAVVUS^® microcatheter. NHPR and FFR measures of both systems were well correlated.