Assessment of left ventricular mechanical dyssynchrony in long standing type II diabetes mellitus patients with normal gated SPECT MPI.

Objectives: The assessment of left ventricular dyssynchrony (LVD) using phase analysis of gated SPECT-MPI is well established. Multiple factors like diabetes, hypertension and dyslipidaemia could potentially affect the phase analysis, however their implication is not fully understood. Aim of the present study was to evaluate the LVD in long standing type II diabetes mellitus (DM) in patients with no perfusion abnormalities and adequate left ventricular ejection fraction (LVEF >60%) on gated SPECT-MPI.

Methods: We retrospectively analysed 146 (86 diabetic and 60 non-diabetic) consecutive patients with normal gated SPECT-MPI (SSS <4) and adequate LVEF >60%. Sixty non-diabetic patients (30 female) with low/intermediate probability of coronary artery disease serve as control for evaluation of phase analysis. Eighty-six diabetic patients (43 female) having diabetes for more than 5 years duration, the mean age of 61.4±11.4 years were on treatment for DM. LVD was determined from the cut-off values (蠅 mean + 2SD) obtained for phase standard deviation (PSD) and histogram bandwidth (HBW) from the control subjects. Multivariate logistic regression analysis was used to evaluate correlation between various confounding factors.

Results: LVD was detected in 24 patients (28%) in DM patients group, with the pre-defined cut-off values for PSD (>10.77) and HBW (>35.5) derived from control population. Multivariate logistic regression analysis revealed that duration of DM, hypertriglyceridemia, overweight/obesity and long-term complications (nephropathy, neuropathy, retinopathy) were independently associated with LVD, with long-term complications being the highest risk factor (OR:58.9; 95%CI 10.37-334.46, p<0.001). For sequential logistic regression models, an overall fit model based on clinical variables including age and DM duration (χ2 = 10.42) was improved by addition of overweight/obesity, smoke, alcohol and hypertriglyceridemia (χ2 = 15.14, p < 0.05), and further improved by addition of long term complications (χ2 = 42.47, p < 0.001) as variables.

Conclusion: Duration of DM, hypertriglyceridemia, overweight/obesity and long term diabetic complications were closely associated with LVD in DM patients with no perfusion abnormalities and adequate LVEF. Our findings suggest, diabetic patients have higher incidence of LVD and may require aggressive management despite absence of perfusion abnormalities and adequate LVEF.