Role of Functional Evaluation of Intermediate Coronary Artery Lesions with Fractional Flow Reserve in Clinical Decision Making

Abstract

Introduction
Coronary angiography often misjudges intermediate (50-70%) lesions. Fractional flow reserve (FFR) accurately assesses their physiological significance to safely guide revascularization. Addressing limited local evidence, this Nepalese study evaluates role of FFR in determining lesion severity and guiding treatment decisions.

Methods
This quantitative, cross-sectional study evaluated 43 patients with intermediate coronary lesions undergoing coronary angiography (CAG) at the Manmohan Cardiothoracic Vascular and Transplant Centre, Institute of Medicine, over one year. Patients with prior fibrinolytic treatment, connective tissue disorders, or skip lesions were excluded. Initially, revascularization or medical management was planned based on visual CAG stenosis. Next, resting full-cycle ratio (RFR) and FFR were measured. Significant lesions (FFR ≤0.80, RFR ≤0.89) received percutaneous coronary intervention (PCI); others received medical therapy. This study analysed how FFR/RFR altered initial visually-guided treatment plans.

Results
This study evaluated 43 intermediate coronary lesions (median age 66; 74% male) mostly presenting with chronic coronary syndrome. It compared visually estimated treatment plans after CAG against RFR/FFR-guided management. Visual assessment planned medical therapy for 88% (n=38) and intervention (PCI) for 12% (n=5). Functional assessment altered management strategy in 18 cases, deferring all five initially planned interventions to medical therapy and upgrading 13 medical management cases to revascularization. 

Conclusions
Functional assessment (FFR/RFR) prevented suboptimal treatment of intermediate lesions. By altering planned management after CAG, FFR showed a promising role in optimal revascularization for intermediate coronary lesions.