Real-time use of instantaneous wave–free ratio: Results of the ADVISE in-practice: An international, multicenter evaluation of instantaneous wave–free ratio in clinical practice

Abstract

ObjectivesTo evaluate the first experience of real-time instantaneous wave–free ratio (iFR) measurement by clinicians.BackgroundThe iFR is a new vasodilator-free index of coronary stenosis severity, calculated as a trans-lesion pressure ratio during a specific period of baseline diastole, when distal resistance is lowest and stable. Because all previous studies have calculated iFR offline, the feasibility of real-time iFR measurement has never been assessed.MethodsThree hundred ninety-two stenoses with angiographically intermediate stenoses were included in this multicenter international analysis. Instantaneous wave–free ratio and fractional flow reserve (FFR) were performed in real time on commercially available consoles. The classification agreement of coronary stenoses between iFR and FFR was calculated.ResultsInstantaneous wave–free ratio and FFR maintain a close level of diagnostic agreement when both are measured by clinicians in real time (for a clinical 0.80 FFR cutoff: area under the receiver operating characteristic curve [ROCAUC] 0.87, classification match 80%, and optimal iFR cutoff 0.90; for a ischemic 0.75 FFR cutoff: iFR ROCAUC 0.90, classification match 88%, and optimal iFR cutoff 0.85; if the FFR 0.75-0.80 gray zone is accounted for: ROCAUC 0.93, classification match 92%). When iFR and FFR are evaluated together in a hybrid decision-making strategy, 61% of the population is spared from vasodilator while maintaining a 94% overall agreement with FFR lesion classification.ConclusionWhen measured in real time, iFR maintains the close relationship to FFR reported in offline studies. These findings confirm the feasibility and reliability of real-time iFR calculation by clinicians.

Diagnostic Performance of the Instantaneous Wave-Free Ratio

“…During the assessment of eligibility, further 6 studies were excluded. 8,[30][31][32][33][34] Finally, a total of 23 studies were available for the analysis, 7,[9][10][11][12][13][14][15][16][17][18][19][20][21]28,29,[35][36][37][38][39][40][41] including 6381 stenoses. The study selection procedure is reported in details in Figure 1 while the Table summarizes the most relevant characteristics of the selected studies.…”

Advances in Coronary Physiology

“…ADVISE-In-Practice was the first study to use the commercially available iFR console. 66 In this international, multicenter study of 392 stenoses in 313 patients, iFR had a high classification match with FFR (80% using the FFR 0.80 cut-point; 88% with ischemic threshold of 0.75 and 92% if the FFR gray-zone was accounted for). 66 Using the hybrid approach, 61% of the patients could be spared from adenosine, with a Figure 7.…”

“…ACS, acute coronary syndrome; FFR, fractional flow reserve; iFR, instantaneous wave-free ratio; PCI, percutaneous coronary intervention. Reproduced with permission from Petraco R, et al 66 Current Developments in Pressure-Only Indices stenoses in 82 patients with ACS and stable disease, an iFR threshold of 0.92 best matched an FFR of 0.80 with a diagnostic concordance with FFR of 81.3%. 71 No difference in diagnostic efficiency between ACS patients and those with stable disease was found and all apparent discrepancies were within the FFR 0.75-0.80 gray-zone.…”

“…66 Intracoronary nitrates are used not to produce hyperemia, rather to maximize epicardial vessel diameter, and to prevent wire-induced spasm, which can induce a pseudo-stenosis. After any injection of contrast or nitrate, a short delay of 15-20 s should be allowed prior to measurement; because nitrates should be administered soon after guide catheter engagement, there is no practical delay, as this time elapses with wire preparation and passage through the catheter.…”

Coronary Functional Tests in the Catheterization Laboratory – Pathophysiological and Clinical Relevance –

“…34, 35 Notably, distal to corointermediate coronary stenoses (Figure 2). 30 For a FFR cutoff of 0.80, a predefined iFR value of 0.90 provided the optimal cutoff, with a classification match of 80%; when the originally validated 0.75 ischemic FFR cutoff was used as a reference comparison, the agreement between iFR and FFR increased to 88% with the optimal iFR cutoff being 0.85; when accounting for the known 0.75-0.80 FFR gray zone, the classification match between iFR and FFR increased to 93%. Finally, confirming previous reports, 31 a hybrid decision-making strategy with iFR and FFR could avoid the use of vasodilator in 61% of patients, while maintaining 94% overall agreement with FFR classification of lesions.…”