Trends in LDL-C following coronary angiography involving assessment by fractional flow reserve in obstructive vs non-obstructive coronary artery disease

BACKGROUND: We sought to determine whether management of LDL-C following invasive angiography and assessment by fractional flow reserve (FFR) differs between those with obstructive vs non-obstructive CAD. METHODS: Retrospective study of 721 patients undergoing coronary angiography involving assessment by FFR between 2013 and 2020 at a single academic center. Groups with obstructive vs non-obstructive CAD by index angiographic and FFR findings were compared over 1 year of follow-up. RESULTS: Based on index angiographic and FFR findings, 421 (58%) patients had obstructive CAD vs 300 (42%) with non-obstructive CAD, mean (±SD) age 66±11 years, 217 (30%) women, and 594 (82%) white. There was no difference in baseline LDL-C. At 3-months follow-up, LDL-C was lower than baseline in both groups, with no between group difference. In contrast, at 6-months, median (Q1, Q3) LDL-C was significantly higher in non-obstructive vs obstructive CAD (LDL-C 73 (60, 93) vs 63 (48, 77) mg/dL, respectively (p = 0.003), (p = 0.001 in multivariable linear regression)). At 12-months, LDL-C remained higher in non-obstructive vs obstructive CAD (LDL-C 73 (49, 86) vs 64 (48, 79) mg/dL, respectively, although not statistically significant (p = 0.104)). The rate of high-intensity statin use was lower among those with non-obstructive CAD vs obstructive CAD at all time points (p < 0.05). CONCLUSIONS: After coronary angiography involving FFR, there is intensification of LDL-C lowering at 3-months follow-up in both obstructive and non-obstructive CAD. However, by 6-months follow-up LDL-C is significantly higher among those with non-obstructive CAD vs obstructive CAD. Following coronary angiography involving FFR, patients with non-obstructive CAD may benefit from greater attention to LDL-C lowering to reduce residual ASCVD risk.