Coronary volume to left ventricular mass ratio in patients with diabetes mellitus

Background: Diabetes mellitus is a major risk factor for coronary artery disease (CAD) and may provoke structural and functional changes in coronary vasculature. The coronary volume to left ventricular mass (V/M) ratio is a new anatomical parameter capable of revealing a potential physiological imbalance between coronary vasculature and myocardial mass. The aim of this study was to examine the V/M derived from coronary computed tomography angiography (CCTA) in patients with diabetes.Methods: Patients with clinically suspected CAD enrolled in the ADVANCE (Assessing Diagnostic Value of Non-invasive FFRCT in Coronary Care) registry and known diabetic status were included. Coronary artery volume and left ventricular myocardial mass were analyzed from CCTA and the V/M ratio was calculated and compared between patients with and without diabetes.Results: Of the 3053 patients (age 66 +/- 10 years; 66% male) with known diabetic status, diabetes was present in 21.9%. Coronary volume was lower in patients with diabetes compared to those without diabetes (2850 +/- 940 mm(3) vs. 3040 +/- 970 mm(3), p < 0.0001), whereas the myocardial mass was comparable between the 2 groups (122 +/- 33 g vs. 122 +/- 32 g, p = 0.70). The V/M ratio was significantly lower in patients with diabetes (23.9 +/- 6.8 mm(3)/g vs. 25.7 +/- 7.5 mm(3)/g, p < 0.0001). Among subjects with obstructive CAD (n = 2191, 24.0% diabetics) and non-obstructive CAD (16.7% diabetics), the V/M ratio was significantly lower in patients with diabetes compared to those without (23.4 +/- 6.7 mm(3)/g vs. 25.0 +/- 7.3 mm(3)/g, p < 0.0001 and 25.6 +/- 6.9 mm(3)/g vs. 27.3 +/- 7.6 mm(3)/g, respectively, p = 0.006).Conclusion: The V/M ratio was significantly lower in patients with diabetes compared to non-diabetics, even after correcting for obstructive coronary stenosis. The clinical value of the reduced V/M ratio in diabetic patients needs further investigation.