Impaired strain in diabetic patients with stable coronary artery disease assessed by cardiac magnetic resonance

Abstract Background Type 2 diabetes mellitus (T2DM) can contribute or lead to myocardial structural derangement by multiple mechanisms, including ischemic cardiomyopathy and, more rarely and of difficult evaluation, diabetic cardiomyopathy. Early stages of myocardial dysfunction can be assessed by strain analysis with cardiac magnetic resonance feature tracking (CMR-FT), however, there is no studies that examined deformation parameters in diabetic patients with stablished coronary artery disease (CAD). Purpose We sought to compare the strain parameters of patients with and without T2DM with stable CAD. Methods Patients with stable multivessel CAD and preserved left ventricular ejection fraction (LVEF), included in the MASS V trial, underwent contrast-enhanced cardiac magnetic resonance before revascularization procedures. Patients were stratified according to T2DM diagnosis at baseline. Feature tracking was performed using short-axis cine images and 2- and 4-chamber long-axis images. The left ventricular endocardial and epicardial contours of the end diastole phase were manually delineated in all images. Automatically tracking contours were performed to calculate left ventricular global longitudinal (LVGLS), circumferential (LVGCS) and radial (LVGRS) strain (FIGURE 1). Results Of 202 patients studied, 88 (44%) were diabetic and 114 (56%) non-diabetic. Baseline characteristics were similar between groups (age 70 ± 10 vs 69 ± 11; 69% vs 68% males; LVEF 65 ± 13 vs 67 ± 9). Mean Syntax score was 21.2 ± 8.5 vs 20.4 ± 8.5 (P=0.52) in diabetic and non-diabetic, respectively. There were no differences in left ventricle volumes, mass and LVEF. Mean LGE mass was 2.3 ± 0.9 vs 1.9 ± 0.9 grams (P=0.32) respectively in T2DM and control groups. Strain values were all reduced in T2DM patients, as shown in FIGURE 2 (LVGLS: -15.5% ± 2.3% vs -17.5% ± 2.7%, P=0.02; LVGCS: -15.4% ± 2.6% vs -17.4% ± 3.0%, P=0.03; LVGCS: 25.9% ± 5.9% vs 29.5% ± 7.2%, P=0.01). Multivariable analyses adjusted for age, sex, BMI, hypertension, Syntax score and LGE mass showed no differences in the results. Conclusion In this study, T2DM was associated with impaired deformation parameters (decreased left ventricular global longitudinal, circumferential, and radial strain). These findings suggest myocardial dysfunction in diabetic patients when compared to control subjects in the setting of stable multivessel CAD.FIGURE 1FIGURE 2