Table 1.
Significant instantaneous wave-free ratio-(iFR®)-studies
| Advise | Verify | Clarify | Park et al[39] | Resolve | Advise in practice | Indolfi et al[42] | ADVISE II | Harle et al[44] | Van de Hoef et al[45] | DEFINE-FLAIR | iFR®-SWEDHEART | |
| First author journal and year of Publication | Sen et al[18]. J Am Coll Cardiol 2012 | Berry et al[37]. J Am Coll Cardiol 2013 | Sen et al[38]. J Am Coll Cardiol 2013 | Park et al[39]. Int J Cardiol 2013 | Jeremias et al[40]. J Am Coll Cardiol 2014 | Petraco et al[41]. Am Heart J 2014 | Indolfi et al[42]. Int J Cardiol 2015 | Escaned et al[43]. J Am Coll Cardiol-Intv 2015 | Harle et al[44]. Int J Cardiol 2015 | Van de Hoef et al[45]. Euro-Intervention 2015 | Davies et al[19]. N Engl J Med 2017 | Götberg et al[20]. N Engl J Med 2017 |
| Study design | PC, multicenter, non-randomized | PC, multicenter, non-randomized | PC, multicenter | PC, multicenter, non-randomized | RS, multicenter, non-randomized | PC, multicenter, non-randomized | PC, monocenter, non-randomized | PC, multicenter, non-randomized | PC, monocenter, non-randomized | PC, multicenter, non-randomized | PC, multicenter, randomized | PC, multicenter, randomized |
| Countries (centers) | 2 (3) | 6 (6) | 2 (3) | 1 (2) | 7 (15) | 101 (16) | 1 (1) | 8 (45) | 1 (1) | 3 (7) | 19 (49) | 3 (14) |
| Included patients | 131 | 206 | 51 | 238 | 1768 | 313 | 82 | 598 | 109 | 228 (iFR® = 66) | 2492 (iFR® = 1242) | 2037 (iFR® = 1019 |
| Stenoses | 157 | 206 | 51 | 238 | 1974 | 392 | 123 | 690 | 151 | 299 (iFR® = 85) | 3183 (iFR® = 1575) | 3004 (iFR® = 1568) |
| Hemodynamic relevant stenoses (%) | N/A | 134 (65) | N/A | 103 (43.3) | N/A | 153 (39) | 37 (30.1) | 248 (35.9) | N/A | N/A | 451 (28.6) | 457 (29.1) |
| Age in years ± SD | 62.6 ± 10.2 | 65.2 ± 10.2 | 66.2 ± 9.2 | 62.8 ± 0.6 | 63.4 ± 10.3 | 67 ± 11 | 64 ± 9 | 63.6 ± 10.8 | 67 ± 11 | 58 ± 11 | 65.5 ± 10.8 | 67.6 ± 9.6 |
| Men (%) | 83.5 | 71 | 82.4 | 68 | 74.9 | 79 | 81.7 | 68.9 | 63.9 | 68 | 77.5 | 74.2 |
| Diabetes mellitus (%) | 54 (34.4) | 50 (24) | 14 (27.4) | 66 (28) | 497 (28.1) | 94 (30) | 14 (17.1) | 209 (35) | N/A | 10 (15) | 382 (30.8) | 232 (22.8) |
| Hypertonia (%) | 88 (56.1) | 137 (67) | 18 (35.2) | 133 (56) | N/A | 232 (74) | 61 (74.4) | 471 (78.8) | N/A | 25 (38) | 873 (70.3) | 730 (71.6) |
| Smoking (%) | 34 (21.7) | 64 (31) | 15 (29.4) | 64 (27) | 520 (29.4) | 160 (51) | 49 (59.8) | 135 (22.6) | N/A | 21 (32) | 243 (19.6) | 159 (15.6) |
| One-vessel CAD (%) | 108 (68.8) | 85 (41) | N/A | N/A | N/A | 113 (36) | 50 (61) | N/A | 75 (69.4) | N/A | N/A | 452 (44.3) |
| Multi-vessel CAD (%) | 49 (31.2) | 105 (51) | N/A | N/A | 951 (53.8) | 197 (63) | 32 (39) | N/A | 33 (30.6) | N/A | 505 (40.7) | 364 (35.7) |
| Stable angina (%) | 151 (96.2) | 140 (68) | N/A | 151 (63) | 1216 (68.6) | 228 (73) | 29 (35) | 320 (53.5) | N/A | N/A | 986 (79.4) | 632 (62.0) |
| Unstable angina (%) | 6 (3.8) | 46 (22) | N/A | 84 (36) | 255 (14.4) | 85 (27) | 53 (65) | 151 (25.3) | N/A | N/A | 186 (15.0) | 211 (20.7) |
| iFR® cut-off | 0.83 | ≤ 0.83 | 0.86 | 0.9 | 0.9 | 0.9 | 0.92 | 0.89 | 0.896 | 0.9 | 0.89 | 0.89 |
| MACE-rate after 1 yr (iFR® vs FFR, P-value) | N/A | N/A | N/A | N/A | N/A | N/A | N/A | N/A | N/A | N/A | 6.8 vs 7.0 (P = 0.003) | 6.7 vs 6.1 (P = 0.007) |
| Adverse events (iFR® vs FFR, P-value) | N/A | N/A | N/A | N/A | N/A | N/A | N/A | N/A | N/A | N/A | 3.1 vs 30.8 (P < 0.001) | 3.0 vs 68.3 (P < 0.0001) |
| Diagnostic accuracy in % (iFR® vs FFR) | 93 | 68 | 92.3 | 82 | 80.4 | 80 | 81.3 | 82.5 | 83.4 | N/A | N/A | N/A |
PC: Prospective cohort study; RS: Retrospective study; FFR: Fractional flow reserve; N/A: Not available; MACE: Major adverse cardiac events.