The use of the acute Pd/Pa drop after intracoronary nitroglycerin infusion to rule out significant FFR: CANICA (Can intracoronary nitroglycerin predict fractional flow reserve without adenosine?) multicenter study

Objective Functional assessment of coronary artery stenosis is performed by measuring the fractional flow reserve (FFR) under hyperemic conditions (Adenosine). However, the use of adenosine portends limitations. Objective We sought to investigate the relationship and correlation between FFR and the Pd/Pa value obtained just after the intracoronary infusion (acute drop) of nitroglycerin (Pd/Pa‐NTG) and if this parameter enhances diagnostic accuracy for FFR prediction compared to the resting baseline Pd/Pa. Methods We conducted a multicenter study including prospectively patients presenting intermediate coronary artery stenosis (30–70%) evaluated with pressure wire. Resting baseline Pd/Pa, Pd/Pa‐NTG and FFR were measured. Results 283 patients (335 lesions) were included. Resting baseline Pd/Pa value was 0.72 to 1.0 (0.93 ± 0.04), Pd/Pa‐NTG was 0.60 to 1.0 (0.87 ± 0.07) and FFR 0.55 to 1.0 (0.83 ± 0.08). The ROC curves for resting baseline Pd/Pa and for Pd/Pa‐NTG, using a FFR ≤ 0.80 showed an AUC of 0.88 (95% CI: 0.84–0.92, P 0.96 and >0.88, respectively. These values were present in a 29.8% (n = 100) and a 47.1% (n = 158), of the total lesions. Scatter plots showed a better correlation and agreement points with Pd/Pa‐NTG than resting baseline Pd/Pa. The cutoff value of Pd/Pa‐NTG > 0.88 showed an excellent NPV (96.2% for FFR > 0.8 and 100% for FFR > 0.75) and sensitivity (95% for FFR > 0.8 and 100% for FFR > 0.75) which were consistently high across all the subgroups analysis. Conclusion The cutoff value of acute Pd/Pa‐NTG > 0.88 has a high NPV meaning adenosine‐FFR can be avoided in almost half of lesions. © 2015 Wiley Periodicals, Inc.