Stenting of a coronary artery narrowing across a bifurcation with a side branch artery may result in a significant angiographic stenosis (nipping) of the side branch. If this causes symptoms of chest pain or ischaemic ECG changes at the time of the procedure, additional angioplasty (with or without stent insertion) through the stent struts is usually undertaken to improve blood flow into the side branch, but this increases subsequent risks of restenosis and stent thrombosis in the main vessel. In the absence of symptoms or ECG abnormalities, the functional significance of side branch nipping is uncertain and opinion on whether to treat a nipped side branch remains divided.^1–4

The coronary pressure-derived fractional flow reserve (FFR) is a lesion-specific means of determining the functional significance of coronary artery narrowings, but its value in assessing side branch nipping is not known.

This pilot study aimed to assess the correlation between the FFR across nipped side branch arteries that have been crossed by main vessel stents, with the degree of angiographic narrowing at the side branch ostium. The potential role of the coronary pressure wire in guiding treatment of the nipped side branch is considered.

METHODS

This study was registered with Southampton University NHS Trust R&D Department and approved by the local ethics committee. All patients gave written informed consent.

All patients were scheduled for elective percutaneous intervention (PCI) for symptoms of chronic stable …