Physiology-Based Revascularization of Left Main Coronary Artery Disease

Figures

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  Figure 1. A practical example of a LM lesion with downstream disease. A patient with effort angina had a LM lesion (∗) which appeared angiographically at least moderate, but also a severe lesion at the level of the mid LAD (∗∗). The LCx showed some disease but was clearly the least affected daughter branch of the LM. iFR distal to LAD was 0.35, indicating flow-limiting disease upstream, but assessment of the iFR along the course of the LAD revealed that the drop in iFR was mainly caused by the mid LAD lesion. In the proximal part of the LAD, the iFR was 0.92, suggesting that the LM lesion was not physiologically significant. iFR in the LCx was 0.92 in the proximal part and 0.96 in the distal part, which seemed to confirm this. However, since the disease in the LAD was so severe that it may also have been flow-limiting at rest, stable resting conditions may have been absent and, theoretically, the iFR might have been lower at that level if the downstream disease was not so critical. FFR towards LAD was 0.44, also indicating critical disease upstream. FFR towards LCx was 0.80, borderline significant. Since the disease in LAD was severe and the value was below 0.85, the LM lesion might still…

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  Figure 2. Our approach for intermediate LM lesions. Current approach to intermediate left main lesions in our center. The authors have a low threshold to use IVUS at any stage in the evaluation and treatment of LM lesions because of its proven added value as explained in the text. LM: left main; iFR: instantaneous wave-free ratio; FFR: fractional flow reserve; IVUS: intravascular ultrasound; ACS: acute coronary syndrome; CTO: chronic total occlusion; MLA: minimal lumen area; FU: follow-up.