RESUMO
BACKGROUND AND OBJECTIVES: Angiographic assessment of coronary stenosis severity using quantitative coronary angiography (QCA) is often inconsistent with that based on fractional flow reserve (FFR) or intravascular ultrasound (IVUS). We investigated the incidence of discrepancies between QCA and FFR or IVUS, and the outcomes of FFR- and IVUS-guided strategies in discordant coronary lesions. METHODS: This study was a post-hoc analysis of the FLAVOUR study. We used a QCA-derived diameter stenosis (DS) of 60% or greater, the highest tertile, to classify coronary lesions as concordant or discordant with FFR or IVUS criteria for percutaneous coronary intervention (PCI). The patient-oriented composite outcome (POCO) was defined as a composite of death, myocardial infarction, or revascularization at 24 months. RESULTS: The discordance rate between QCA and FFR or IVUS was 30.2% (n=551). The QCA-FFR discordance rate was numerically lower than the QCA-IVUS discordance rate (28.2% vs. 32.4%, p=0.050). In 200 patients with ≥60% DS, PCI was deferred according to negative FFR (n=141) and negative IVUS (n=59) (15.3% vs. 6.5%, p<0.001). The POCO incidence was comparable between the FFR- and IVUS-guided deferral strategies (5.9% vs. 3.4%, p=0.479). Conversely, 351 patients with DS <60% underwent PCI according to positive FFR (n=118) and positive IVUS (n=233) (12.8% vs. 25.9%, p<0.001). FFR- and IVUS-guided PCI did not differ in the incidence of POCO (9.5% vs. 6.5%, p=0.294). CONCLUSIONS: The proportion of QCA-FFR or IVUS discordance was approximately one third for intermediate coronary lesions. FFR- or IVUS-guided strategies for these lesions were comparable with respect to POCO at 24 months. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02673424.
RESUMO
OBJECTIVES: This study sought to investigate the clinical, electrocardiographic, and physiological relevance of main and side branches in coronary bifurcation lesions. BACKGROUND: Discrepancy exists between stenosis severity and clinical outcomes in bifurcation lesions. However, its mechanism has not been fully evaluated yet. METHODS: Sixty-five patients with left anterior descending coronary artery (LAD) bifurcation lesions were prospectively enrolled. Chest pain and 12-lead electrocardiogram were assessed after 1-min occlusion of coronary flow and coronary wedge pressure (Pw) was measured using a pressure wire. RESULTS: ST-segment elevation was more frequent during LAD occlusion (92%) than during diagonal branch occlusion (37%) (p < 0.001). Pain score was also higher with the occlusion of LAD than with the diagonal branch (p < 0.001). However, both Pw and Pw/aortic pressure (Pa) were lower in the LAD than in diagonal branches (Pw: 21.0 ± 6.5 vs. 26.7 ± 9.4, p < 0.0001; Pw/Pa: 0.22 ± 0.07 vs. 0.27 ± 0.08, p = 0.001). The corrected QT interval was prolonged with LAD occlusion (435.0 ± 39.6 ms to 454.0 ± 45.4 ms, p < 0.0001) but not with diagonal branch occlusion. There was no difference in vessel size between the diagonal branches with and without ST-segment elevation during occlusion. Positive and negative predictive values of vessel size (≥2.5 mm) to determine the presence of ST-segment elevation were 48% and 72%, respectively. CONCLUSIONS: Diagonal branch occlusion caused fewer anginas, less electrocardiogram change, less arrhythmogenic potential, and higher Pw than did a LAD occlusion. These differences seem to be the main mechanism explaining why aggressive treatment for side branches has not translated into clinical benefit in coronary bifurcation lesions. (Comparison Between Main Branch and Side Branch Vessels; NCT01046409).