TCT-660 Discordance between resting and hyperemic conditions in focal and diffuse disease.

Abstract

Background: Physiological discrepancies between nonhyperemic pressure ratios (NHPRs) and fractional flow reserve (FFR) are present in one-fifth of cases in clinical practice. The mechanism of pressure loss because of friction or separation has been recognized to play a pivotal role in these discrepancies. The pull back pressure gradient (PPG) can quantify coronary artery disease (CAD) patterns as either focal or diffuse. This study aimed to assess the influence of PPG on the discordance observed between NHPR and FFR. Method(s): This was a prespecified subanalysis of the PPG Global Registry, which was a prospective, multicenter, and international study. Patients planned for PCI with functionally significant lesions based on FFR (<=0.80) were included. Resting full-cycle ratio (RFR) and FFR were measured before percutaneous coronary intervention. PPG was calculated from manual FFR pull back curves. A discordance was defined as negative RFR (>0.89) but positive FFR (<=0.80). Focal and diffuse CAD were defined by the median PPG value (0.62). Result(s): Overall, 325 patients (338 vessels) were included with a mean age 65.4 +/- 9.8 years, 80% male, and 25% diabetics. In 86% of cases, pressure assessments were performed in the left anterior descending artery. Discordance with RFR- and FFR+ was identified in 67 patients (19.8%). The functional severity of discordant lesions was milder in the vessels compared to those with concordance (FFR 0.72 +/- 0.07 in concordant cases vs 0.77 +/- 0.04 in discordant cases; P < 0.001). Moreover, the PPG was significantly higher in cases of discordance (0.53 +/- 0.13 in concordant cases vs 0.57 +/- 0.14 in discordant cases; P = 0.045). Focal disease (indicated by higher PPG) in the right coronary artery was identified as a strong predictor of RFR-/FFR+ discordance (OR: 11.7; 95% CI: 3.6-38.7). Conclusion(s): Discordance between NHPR and FFR was more common in focal (high PPG) lesions and those located in the right coronary artery. This finding may highlight the features that require hyperemic invasive physiological assessment. Categories: IMAGING AND PHYSIOLOGY: Physiologic Lesion Assessment.Copyright © 2024