Focal vs diffuse

Focal and diffuse coronary atheroma and Fractional Flow Reserve

A 54 yo man is referred for coronary angiography for crescendo angina since 1 week (Canadian classification grade 3). The EKG and cardiac enzymes are normal. He had a history of NSTEMI 8 months ago with single long instable lesion in mid-LAD treated with 2 DES (24mm x 3.0 + 16mm x 3.0). Atheroma was then noted in proximal LAD. The patient was asymptomatic until then, took bi-antiplatelet therapy, betablocker, ACE-inhibitor and high-dose statin (80mg atorvastatin) with negative stress test (120W). The angiogram (figure1, video 1 suppl) showed progression of proximal LAD atheroma without restenosis in mid-LAD stents. Fractional Flow Reserve in mid-LAD was 0.50 and careful pullback to the 5F guiding catheter shows an initial gentle slope before a steep step of 0.22 units (0.60 to 0.82). We concluded that ischemia was severe and mainly related to rapid progression of proximal LAD lesion and we decided to fix it with a new stent. However we anticipated a suboptimal functional result as diffuse disease was present all along the LAD. The future stent, if correctly implanted, would eliminate the 0.22 step only. Maths predicted then 0.50+0.22 = 0.72 as final FFR. A 12 mm x 3.0 DES was inflated in the prox LAD with satisfactory angio result (Figure 2 and video2 suppl) and final FFR with pullback confirmed 0.74. The patient was discharged the day after with 5mg nitrate patch on top of his previous treatment. He was warned as well as his general practitioner that mild stable effort angina may occur in some occasion and might be accepted as the result of diffuse atheroma infiltration in the LAD. With a four-year follow-up the patient is still uneventful.

Take Home Message:
FFR post PCI is an important criteria for functional result of revascularization and should systematically be measured (1). Pullback FFR helps to detect and anticipate diffuse atheroma with focal stenosis amid (2). It helps to explain some situations with residual ischemia and helps to personalize medical therapy (3).

References

1. Agarwal SK, Kasula S, Hacioglu Y, et al Utilizing Post-Intervention Fractional Flow Reserve to Optimize Acute Results and the Relationship to Long-Term Outcomes. JACC Cardiovasc Interv. 2016 ;9(10):1022-31.
2. Collet C, Sonck J, Vandeloo B et al. Measurement of Hyperemic Pullback Pressure Gradients to Characterize Patterns of Coronary Atherosclerosis. J Am Coll Cardiol. 2019;74(14):1772-1784
3. Al-Lamee R, Howard JP, Shun-Shin MJ, et al..Fractional Flow Reserve and Instantaneous Wave-Free Ratio as Predictors of the Placebo-Controlled Response to Percutaneous Coronary Intervention in Stable Single-Vessel Coronary Artery Disease. Circulation. 2018 Oct 23;138(17):1780-1792

Figure 1: LAD angiogram with severe proximal stenosis and diffuse atheroma without restenosis in mid-LAD. Simultaneous FFR tracing in mid-LAD (middle) and 1mm/sec manual pullback tracing (bottom)

Figure 2: Final angiogram after 12 mm X 3.0 mm DES in proximal LAD with simultaneous FFR tracing showing residual ischemia related to diffuse disease