Assessment of coronary fractional flow reserve using a monorail pressure catheter: the first-in-human ACCESS-NZ trial.

AIMS: FFR measurements have been limited by the handling characteristics of pressure wire (PW) systems, and by signal drift. This first-in-human study evaluated the safety and efficacy of a new monorail catheter (Navvus) to assess coronary FFR, compared to a PW system. METHODS AND RESULTS: Resting measurements were acquired with both systems. After initiating IV adenosine, FFR was measured with the PW alone, simultaneously using both systems, and again with PW alone. Any zero offset of PW or Navvus was then recorded. Navvus measured FFR in all patients in whom a PW recording was obtained (50 of 58 patients); there were no complications related to Navvus. Navvus FFR correlated well with PW FFR (r=0.87, slope 1.0, intercept -0.02). Within PW measurement accuracy, in no cases did Navvus FFR classify lesion significance differently from PW FFR. PW signal drift was significantly greater than Navvus (0.06±0.12 vs. 0.02±0.02, p=0.014). CONCLUSIONS: Navvus and PW FFR correlated well. Navvus had less sensor drift. This new catheter-based system offers an alternative method for measuring FFR, with some potential advantages over PW.

First-in-human evaluation of a sirolimus-eluting coronary stent on an integrated delivery system: the DIRECT study.

AIMS: The DIRECT study is a first-in-human evaluation of the safety and efficacy of the Svelte sirolimus-eluting coronary stent mounted on a fixed-wire, "all-in-one" integrated delivery system (IDS) in patients with de novo coronary artery lesions. The system permits easy delivery, deployment and post-dilatation of a cobalt-chromium stent eluting sirolimus from a fully bioabsorbable amino acid coating. The stent on its IDS has a very low profile, and is designed specifically to facilitate direct stenting. METHODS AND RESULTS: Patients with symptomatic ischaemic heart disease and a single de novo native coronary lesion suitable for percutaneous coronary intervention were prospectively enrolled at four New Zealand sites. The lesion length had to be <23 mm and the vessel reference diameter 2.5-3.5 mm. The primary safety and efficacy endpoints were target vessel failure (TVF) and angiographic in-stent late lumen loss (LLL) at six months, respectively. Twenty-nine of 30 enrolled patients completed six-month follow-up. TVF occurred in two patients (7%). The in-stent LLL was 0.22 ± 0.27 mm. No patient had clinically-driven target lesion revascularisation. Intravascular ultrasound neointimal volume was 3.3 ± 4.4 mm3 and volume obstruction was 2.7 ± 4.5% at six months. Optical coherence tomography showed 98 ± 4% strut coverage at a depth of 0.12 ± 0.06 mm. No patient developed stent thrombosis. CONCLUSIONS: Percutaneous coronary intervention using the Svelte sirolimus-eluting coronary stent mounted on an IDS appears safe and effective in de novo coronary artery lesions, with minimal in-stent proliferation and excellent stent strut coverage at six months.