Figure 1
Rapid graft failure due to competitive flow. While the severe RCA lesion limits flow and explains her unstable angina, the intermediate and long proximal lesion in the LAD artery does not limit flow but instead produces a sizable pressure gradient and low FFR because of normal myocardial perfusion. See the main text for a full description of the case. RCA: right coronary artery; LAD: left anterior descending, FFR: fractional flow reserve; LCx: left circumflex; CABG: coronary artery bypass grafting; PCI: percutaneous coronary intervention; LCA: left coronary artery; RIMA-OM: right internal mammary artery-obtuse marginals; LIMA: left internal mammary artery
Figure 2
Conceptual roadmap. Examples represent a montage from various clinical cases and absolute values are taken from published literature. No difference in absolute perfusion (mL/min/g) exists between the LAD and non-LAD territories.5 However, the LAD supplies more mass,4 leading to greater absolute flow (mL/min). Consequently, the FFR in a normal vessel is lower for the LAD than non-LAD.6 LAD: left anterior descending; LV: left ventricle; FFR: fractional flow reserve
Table 1
Epicardial target vessels for revascularization. CT: computed tomography, FFR: fractional flow reserve, LAD: left anterior descending, LCx: left circumflex, MI: myocardial infarction, NR: not reported, PCI: percutaneous coronary intervention, RCA: right coronary artery
| AUTHOR | VESSELS | ACRONYM | GROUP | MEAN FFR | LAD | LCX | RCA |
|---|---|---|---|---|---|---|---|
| Stalikas*4 | 948 | CT mass | 43% | 29% | 26% | ||
| Piccolo†8 | 29695 | 41% | 25% | 33% | |||
| Valgimigli9 | 29696 | 47% | 23% | 30% | |||
| Pooled | 59391 | Typical PCI | 44% | 24% | 32% | ||
| Biscaglia10 | 1899 | FIRE | 31% | 36% | 33% | ||
| Stähli†11 | 991 | MULTISTARS AMI | 39% | 35% | 26% | ||
| Mehta12 | 5342 | COMPLETE | 40% | 36% | 24% | ||
| Böhm†13 | 1966 | FULL REVASC | 0.76‡ | 42% | 34% | 24% | |
| Lee14 | 752 | FRAME-AMI | 0.79‡ | 44% | 29% | 27% | |
| Puymirat†15 | 1479 | FLOWER-MI | 0.79‡ | 45% | 31% | 24% | |
| Pooled | 12429 | Nonculprit during acute MI | 40% | 35% | 26% | ||
| Collison16 | 260 | TARGET | Severe lesions | 0.59 | 58% | 17% | 26% |
| Xaplanteris§17 | 888 | FAME 2 | FFR ≤ 0.80 | 0.60 | 64% | NR | NR |
| Al-Lamee18 | 200 | ORBITA | Severe lesions | 0.69 | 71% | 13% | 16% |
| Collet19 | 1043 | PPG | FFR ≤ 0.80 | 0.68 | 73% | 12% | 16% |
| Sonck20 | 123 | P3 | FFR ≤ 0.80 | 0.66 | 76% | 11% | 13% |
| Shin21 | 341 | FFR ≤ 0.80 | 0.68 | 77% | 7% | 16% | |
| Pooled** | 1964 | Physiology trials | 72% | 12% | 17% |
[i] * Median values for mass do not exactly sum to 100%
† Percentages exclude left main and bypass graft target vessels
‡ FFR measured in lesions randomized to a physiologic strategy, including deferred lesions
§ Only reported percentage of proximal or mid LAD lesions
** Excluding the FAME 2 trial as its target vessel reporting was incomplete
Figure 3
Two cases with large pressure gradients from different mechanisms. The upper patient has mild-to-moderate angiographic disease plus normal myocardial perfusion, leading to an FFR of 0.58 with diffuse PPG indicating medical treatment. The lower patient has a severe lesion with reduced myocardial perfusion, leading to an FFR of 0.50 with focal pressure gradient when advancing the wire (“push-up”) that was successfully treated by stent placement. See the main text for a full description of each case. FFR: fractional flow reserve; PPG: pressure pullback gradient; PCI: percutaneous coronary intervention; LAD: left anterior descending; PET: positron emission tomography
Table 2
Epicardial target vessels for revascularization with focal versus diffuse disease. CT: computed tomography, FFR: fractional flow reserve, LAD: left anterior descending, MI: myocardial infarction, PCI: percutaneous coronary intervention
| AUTHOR | VESSELS | ACRONYM | GROUP | MEAN FFR | FINAL FFR | LAD |
|---|---|---|---|---|---|---|
| 948 | CT mass | 43% | ||||
| Pooled | 59391 | Typical PCI | 44% | |||
| Pooled | 12429 | Nonculprit during acute MI | 40% | |||
| Collet24 | 52 | TARGET | 0.64 | 0.83 | 87% | |
| Rajkumar25 | 81 | ORBITA | 0.78 | 0.89 | 84% | |
| Collet19 | 528 | PPG | 0.72 | 0.84 | 90% | |
| Mizukami26 | 77 | P3 | 0.70 | 0.86 | 90% | |
| Shin21 | 55 | 0.71 | 0.83 | 82% | ||
| Pooled | 793 | Diffuse* disease | 0.72 | 0.85 | 88% | |
| Collet24 | 51 | TARGET | 0.59 | 0.89 | 39% | |
| Rajkumar25 | 83 | ORBITA | 0.60 | 0.90 | 63% | |
| Collet19 | 515 | PPG | 0.63 | 0.89 | 55% | |
| Mizukami26 | 39 | P3 | 0.58 | 0.91 | 46% | |
| Shin21 | 150 | 0.69 | 0.87 | 71% | ||
| Pooled | 838 | Focal* disease | 0.63 | 0.89 | 57% |
[i] * Criteria for diffuse versus focal disease as follows: TARGET: focal indicated a pressure pullback gradient of 0.66 or greater; ORBITA: focal indicated a 0.03 or greater drop in iFR over 15 mm during pullback; PPG: focal indicated a pressure pullback gradient of 0.62 or greater; and P3: focal indicated a pullback pressure gradient greater than 0.73