Diagnostic accuracy of quantitative angiographic and intravascular ultrasound parameters predicting the functional significance of single de novo lesions

Objectives: The current study aimed at determining the best cutoff value of angiographic and intravascular ultrasound (IVUS) parameters for defining fractional flow reserve (FFR) <0.8 in patients with single coronary artery lesion.

Background: The correlation between angiographic or IVUS variables and FFR in patients with single coronary artery lesions has not been studied yet.

Methods: Quantitative coronary analysis and IVUS and FFR measurements were used in 323 patients with a single lesion. The best angiographic and IVUS cutoff values and their predictive value for FFR<0.8 were compared using area under the receiver-operator characteristic curve (AUC).

Results: FFR<0.8 was in 54.2%. Minimal lumen area (MLA), plaque burden (PB), lesion length (LL) and lesion at left anterior descending artery (LAD) were four predictors of FFR<0.8. LL had less value in predicting FFR<0.8. The cutoff values of PB and MLA for FFR<0.8 were 72.7% and 2.97 mm(2). MLA and PB had similar high diagnostic value for vessel size ≥ 3 mm (cutoff values: 3.02 mm(2) and 80.7%), proximal LAD lesion (cutoff values: 3.04 mm(2) and 76.5%) and unstable angina (2.82 mm(2) and 71.9%). Combination of MLA (2.82 mm(2)) and PB (80.6%) had increased diagnostic value for distal LAD lesion. Only PB (71%) had higher diagnostic value for diabetic patients. MLA and PB could not predict FFR<0.8 for vessel size<3mm, and non-LAD lesion.

Conclusion: Best cutoff value of MLA and PB for FFR<0.8 in patients with a single lesion is patient-, vessel size- and lesion location-oriented. PB has strengthened diagnostic accuracy for diabetic patients.