Background: The correlation between angiographic or intravascular ultrasound (IVUS) variables and fractional flow reserve (FFR) in patients with single left anterior descending artery (LAD) lesion has not been studied. The current study aimed at determining the best cutoff value of angiographic and IVUS parameters for defining FFR < 0.80 in patients with LAD lesion.
Methods: Quantitative coronary analysis, IVUS and FFR measurements were undergone in 169 patients with single LAD lesion. The best angiographic and IVUS cutoff value and their predictive value for FFR < 0.80 were compared using area under the receiver-operator characteristic curve (AUC) in overall patients or in subgroups stratified by lesion sites.
Results: FFR < 0.80 was found in 99 lesions (58.6%). Minimal lumen area (MLA), and plaque burden (PB) were two predictors of FFR < 0.80. Lesion length had less value in predicting FFR < 0.80. The cutoff value of PB and MLA for FFR < 0.80 was 75.4% and 3.03 mm(2). MLA and PB had similar high diagnostic value for proximal (cutoff value 3.04 mm(2) and 76.5%) and distal LAD lesion (2.82 mm(2) and 80.6%). Combination of MLA (2.82 mm(2)) and PB (80.6%) had increased diagnostic value for distal LAD lesion.
Conclusions: MLA and plaque burden had equivalent diagnostic value for FFR < 0.80 when lesion localized in LAD. The predictive value of combination of MLA and plaque burden for distal LAD lesion was strengthened.