The clinical significance of moderate coronary stenosis is a fundamental to the choice of treatment. The gold standard is invasive fractional flow reserve (FFR) studying by quantitative coronary angiography (QCA). The role of 256 slices coronary computed tomography angiography (CCTA) one-beat acquisition is insufficiently studied and may be an important factor to predict the clinical significance of moderate coronary stenosis.

To identify morphological CCTA predictors for the clinical significance of moderate coronary artery stenosis.

A total of 61 arteries (43 consecutive patients) underwent CCTA and QCA associated with a lesion-specific FFR measurement were retrospectively analyzed. CCTA was performed on a 256-slices CT one-beat acquisition, three-phase injection protocol by using smart shot dual injector. Stenosis from 50–69% were considered as moderate. FFR≤0.80 was considered as functionally significant.

The mean age was 67.9±10.1, BMI 27.3±4.4kg/m² and 75% were males. Twenty-nine percent patients (18 arteries) have clinically significant moderate stenosis with FFR≤0.8; 23% (n=14) have moderate but not clinically significant stenosis (FFR>0.80) and 48% (n=29) were presented by 30–49% stenosis. All of stenosis<50% by CCTA were functionally non-significant with FFR>0.8 (P<0.05, 100% negative predictive value (NPV)). As CT-predictors for the clinical significance of moderate coronary stenosis (FFR≤0.8) were revealed: stenosis length≥16mm (sensitivity (ss) 78%, specificity (sp) 79%, PPV 82%, NPV 73%, P=0.004) and multiple stenosis in calcified arteries with the stenosis's length≥16mm (sp 86%, PPV 85%, P=0.012).

CCTA plays an important role for noninvasive assessment of clinical significance of moderate coronary stenosis. Moderate stenosis are clinically significant (FFR≤0.8) if their length is more than 16mm in calcified arteries, particularly in culprit arteries with multiple stenosis.