Intracoronary electrocardiogram to guide percutaneous interventions in coronary bifurcations - a proof of concept: the FIESTA (Ffr vs. IcEcgSTA) study

AIMS: The aim of this study was to determine the accuracy of the intracoronary electrocardiogram (icECG) to detect ischemia during bifurcation lesions percutaneous coronary intervention (PCI) with fractional flow reserve (FFR) as a reference. METHODS AND RESULTS: Patients with significant bifurcation lesions defined as FFR <= 0.80 were included. FFR and icECG were performed in the main vessel (MV) and side branch (SB) before and after provisional stenting. icECG was recorded with a uninsulated proximal wire end connected to a unipolar lead. The diagnostic accuracy of icECG for the detection of ischemia in the SB after MV stenting was determined with FFR as a reference. Overall, 37 patients were included. Seventeen bifurcations had SB FFR <= 0.80 after MV stenting and 20 patients had ST-segment elevation on the icECG. There was significant correlation between SB FFR and ST-segment elevation on icECG (r=-0.533, p<0.001). The diagnostic accuracy of icECG ST-Elevation to detect functionally significant SB stenosis revealed an AUC of 0.71 (95%CI 0.64- 0.80) with a sensitivity of 88% and specificity of 75% with a positive predictive value of 75% and negative predictive value of 88%. Neither SB FFR nor icECG correlated with SB percent diameter stenosis after MV stenting. CONCLUSIONS: Intracoronary ECG has a good ability to predict functionally significant stenosis at the SB after MV stenting during bifurcation PCI. This method provides a novel strategy to assess the significance of a SB lesion without the need of a pressure wire. ClinicalTrials.gov Identifier: NCT01724957