The ratio of lesion length (LL) to the fourth power of minimal lumen diameter (LL/MLD4) displays strong accuracy for detecting coronary lesions but is less effective in patients with diabetes, according to a study published in Coronary Artery Disease.

To conduct this study, researchers performed quantitative coronary angiography and simultaneous abnormal fractional flow reserve (FFR) measurement in 324 patients (234 without diabetes and 90 with diabetes) with 335 coronary lesions.

Following analysis, the results showed that in those without diabetes, FFR was notably correlated with percent diameter stenosis (%DS) and LL/MLD4 ratio (P<0.001 for both). They noted that in the diabetes group, there was no correlation between %DS and FFR, whereas a close-to-threshold correlation was observed for the LL/MLD4 ratio (P=0.048).

Furthermore, the investigators observed a significant differentiation of LL/MLD4 ratio between those without and with diabetes (0.738 vs. 0.540; P=0.024). Moreover, they wrote, “The LL/MLD4 ratio showed higher areas under the curve than %DS (0.738 vs. 0.635; P=0.017) and LL (0.738 vs. 0.634; P=0.024) in [the] non-diabetic population, but this superiority did not exist in diabetic population.”

“We showed good diagnostic accuracy of LL/MLD4 ratio for identifying ischemic lesions in patients without diabetes,” the researchers concluded. However, “there was an impaired performance in diabetic patients, and thus FFR measurement is essential to determine their hemodynamic status.”

Keywords: diabetes mellitus, coronary lesions, coronary artery disease, coronary angiography