Pressure wire versus microcatheter for FFR measurement: a head-to-head comparison.

AIMS: Recently developed microcatheters can be used instead of a pressure wire for fractional flow reserve (FFR) measurement. We sought to assess the haemodynamic and clinical impact of using a larger profile device to measure FFR. METHODS AND RESULTS: Our prospective registry included 77 consecutive patients who underwent invasive FFR measurement of intermediate coronary stenoses between June 2015 and July 2016. FFR values were obtained first using a pressure wire only (FFRw), second using a Navvus microcatheter (FFRMC), and finally using the wire with the microcatheter still in the stenosis (FFRw-MC) during intravenous adenosine infusion. Eighty-eight stenoses were suitable for a thorough head-to-head comparison. Mean FFRw (0.83±0.08) was significantly higher than mean FFRMC (0.80±0.10) and FFRw-MC (0.80±0.10). Mean FFRMC and FFRw-MC did not differ significantly. Bland-Altman analysis showed a bias of -0.03±0.05 for lower FFRMC values compared to FFRw values. Using a threshold of 0.80 for FFR, the indication for revascularisation would have differed when based on FFRMC versus FFRw in 20/88 (23%) of the lesions and 18/77 (23%) of the patients. CONCLUSIONS: FFR measured using a microcatheter overestimates stenosis severity, leading to erroneous indication for revascularisation in a sizeable proportion of cases.

Clinical implications of guiding catheter extubation during fractional flow reserve measurements.

BACKGROUND: Fractional flow reserve (FFR) is defined by the maximal coronary flow ratio with and without stenosis. AIMS: We hypothesized that guiding catheter intubation in coronary ostia during FFR measurements may underestimate FFR value by limiting the increase of coronary flow during maximal hyperaemia. METHODS: Between June 2013 and January 2014, we prospectively included all patients with i.v. adenosine FFR measurements. FFR was measured with the guiding catheter intubated in the coronary ostia (FFRint) and extubated in the aorta (FFRext). We calculated the ratio between coronary ostium assessed by quantitative coronary angiography and guiding catheter surfaces, defined as the free ostial lumen ratio. RESULTS: In total, 151 lesions in 104 patients were included; 121 lesions and 88 patients were eligible for analysis. Mean±SD FFRext was significantly lower compared with FFRint; 0.82±0.08 and 0.84±0.08, respectively (P<0.001). Revascularization indication changed in 14 patients (16%). The difference induced by guiding extubation correlated significantly with the free ostial lumen ratio (R2=0.06, P=0.008). CONCLUSION: FFR value is significantly lower when the guiding catheter is extubated. The smaller the coronary ostium, the greater the difference observed between FFRext and FFRint. Guiding extubation during FFR measurements changed the revascularization indication in 16% of cases.

Outcome impact of coronary revascularization strategy reclassification with fractional flow reserve at time of diagnostic angiography: insights from a large French multicenter fractional flow reserve registry.

BACKGROUND: There is no large report of the impact of fractional flow reserve (FFR) on the reclassification of the coronary revascularization strategy on individual patients referred for diagnostic angiography. METHODS AND RESULTS: The Registre Français de la FFR (R3F) investigated 1075 consecutive patients undergoing diagnostic angiography including an FFR investigation at 20 French centers. Investigators were asked to define prospectively their revascularization strategy a priori based on angiography before performing the FFR. The final revascularization strategy, reclassification of the strategy by FFR, and 1-year clinical follow-up were prospectively recorded. The strategy a priori based on angiography was medical therapy in 55% and revascularization in 45% (percutaneous coronary intervention, 38%; coronary artery bypass surgery, 7%). Patients were treated according to FFR in 1028/1075 (95.7%). The applied strategy after FFR was medical therapy in 58% and revascularization in 42% (percutaneous coronary intervention, 32%; coronary artery bypass surgery, 10%). The final strategy applied differed from the strategy a priori in 43% of cases: in 33% of a priori medical patients, in 56% of patients undergoing a priori percutaneous coronary intervention, and in 51% of patients undergoing a priori coronary artery bypass surgery. In reclassified patients treated based on FFR and in disagreement with the angiography-based a priori decision (n=464), the 1-year outcome (major cardiac event, 11.2%) was as good as in patients in whom final applied strategy concurred with the angiography-based a priori decision (n=611; major cardiac event, 11.9%; log-rank, P=0.78). At 1 year, >93% patients were asymptomatic without difference between reclassified and nonreclassified patients (Generalized Linear Mixed Model, P=0.75). Reclassification safety was preserved in high-risk patients. CONCLUSION: This study shows that performing FFR during diagnostic angiography is associated with reclassification of the revascularization decision in about half of the patients. It further demonstrates that it is safe to pursue a revascularization strategy divergent from that suggested by angiography but guided by FFR.

Transulnar versus transradial artery approach for coronary angioplasty: the PCVI-CUBA study.

OBJECTIVES: To compare in terms of efficacy and safety the transulnar to the transradial approach for coronary angiography and angioplasty. BACKGROUND: Opposite to the transradial approach, which is now widely used in catheterization laboratories worldwide, the ulnar artery approach is rarely used for cardiac catheterization. METHODS: Diagnostic coronarography, followed or not by angioplasty, was performed by transulnar or transradial approach, chosen at random. A positive (normal) direct or reverse Allen's test was required before tempting the radial or the ulnar approach, respectively. MACE were recorded till 1-month follow-up. Doppler ultrasound assessment of the forearm vessels was scheduled for all the angioplastied patients. RESULTS: Successful access was obtained in 93.1% of patients in the ulnar group (n = 216), and in 95.5% of patients in the radial group (n = 215), P = NS. One hundred and three and 105 angioplasty procedures were performed in 94 and 95 patients in ulnar and radial group, with success in 95.2% and 96.2% of procedures in ulnar and radial group, respectively (P = NS). Freedom from MACE at 1-month follow-up was observed in 93 patients in both groups (97.8% for ulnar group and 95.8% for radial group), P = NS. Asymptomatic access site artery occlusion occurred in 5.7% of patients after transulnar and in 4.7% of patients after transradial angioplasty. A big forearm hematoma, and a little A-V fistula were observed, each in one patient, in the ulnar group. CONCLUSION: The transulnar approach for diagnostic and therapeutic coronary interventions is a safe and effective alternative to the transradial approach, as both techniques share a high success rate and an extremely low incidence of entry site complications. The transulnar approach has the potential to spare injury to the radial artery in anticipation of its use as a coronary bypass conduit.