Effect of lesion length on functional significance of intermediate long coronary lesions

To assess the relationship between lesion length and other angiographic parameters on the functional significance of long coronary lesions with moderate stenosis.

Coronary revascularization is usually based on angiographic percent stenosis. Coronary stenosis length is not usually considered in daily clinical practice for revascularization decision-making. The relevance of lesion length might be greater in longer lesions with intermediate stenosis.

All coronary lesions >20 mm and of 40-70% percent stenosis assessed by intracoronary pressure wire between 2007 and 2009 were included. Interventionists performing digital quantification of lesion stenosis were blinded to the result of fractional flow reserve (FFR). Correlations between angiographic data and FFR were analyzed.

One hundred and six lesions from 103 patients were included. Reference diameter: 2.9 ± 0.56 mm; maximal stenosis: 49.0 ± 8.7%; minimal luminal diameter (MinimalLD): 1.48 ± 0.4 mm; mean luminal diameter (MeanLD): 2.3 ± 0.5 mm; mean lesion length: 28.7 ± 10.6 mm. Lesions with FFR <0.75 accounted for 33% (n = 35). Weak correlations were obtained between FFR and MinimalLD (r = 0.36; P < 0.0005), MeanLD (r = 0.24; P = 0.014), maximal stenosis (r = 0.31; P = 0.001), and mean stenosis (r = 0.018; P = 0.85); strong correlations were observed between FFR and lesion length (r = 0.63; P < 0.0005), lesion length/MinimalLD (r = 0.67; P < 0.0005), and lesion length/MeanLD (0.72; P < 0.0005). The predictive values of lesion length, lesion length/MinimalLD, and lesion length/MeanLD for FFR <0.75 were 0.86, 0.91, and 0.92, respectively.

In long lesions (>20 mm) with moderate angiographic stenosis, lesion length might be the strongest determinant of functional repercussion. Lesion length should be considered when judging the benefit of revascularization or perform functional functional measures that overcome the limitations of simple stenosis quantification.