Abstract
Byline: Kashif Shaikh, Creighton Univ, Omaha, NE; April Kinninger, The Lundquist Ins., Torrance, CA; Suraj Dahal, Lundquist Institute, Torrance, CA; Suvasini Lakshmanan; Ilana Golub; VENKATA M ALLA, CHI, omaha, NE; Jonathon Leipsic, UBC, Vancouver, Canada; Matthew Budoff, Torrance, CA Introduction: Cross-sectional studies have shown the association of atherosclerotic plaque burden and FFRCT. However, the relationship between changes in anatomic CCTA parameters and FFRCT has not been evaluated. In the present study, we sought to study the natural history of FFRCT and to observe the impact of coronary plaque characteristics on intracoronary hemodynamics over time as assessed by noninvasive CCTA. Methods: Patients who had undergone baseline and follow-up CCTA were included. Coronary plaque scores and vessel stenosis severity were quantified on CCTA. Multivariate linear regression was used to examine the association of change in the per vessel FFRCT, average distal FFRCT, and the most diseased vessel FFRCT with total plaque score(TPS), coronary artery calcium(CAC), total segment stenosis (TSS), segment involvement score (SIS). Results: Final analysis included 101 subjects (83% male; age 65.5 Ø 10.1 years). After adjusting for several cardiovascular risk factors, on a per-vessel basis involving the most significant lesion, a 1 unit increase in TPS resulted on average in a 0.008 decrease in FFR in the most diseased vessel, p=0.004, after adjusting for several risk factors. Using the average FFRCT of the distal LAD, RCA, and LCX, a 1 unit increase in TPS results on average in a 0.004 decrease in the distal average FFR, p=0.026. A 1 unit increase in TPS results on average in 0.005 decrease in the RCA distal pins of FFR, p=0.033 (Table 1). There are no significant associations of the LCX and LAD FFR with TPS. There are no significant associations of the change in FFRCT with TSS, SIS or CAC progression. Conclusion: Worsening atherosclerotic plaque burden is associated with worsening physiology as assessed on CCTA as assessed by FFRCT. Therapies that stabilize or regress plaque may improve overall physiology. Further prospective trials are required to validate these findings.