Diabetes reduces left ventricular ejection fraction-irrespective of presence and extent of coronary artery disease

Background: It is not clear whether diabetes reduces systolic left ventricular function (left ventricular ejection fraction, LVEF) irrespective of coronary artery disease (CAD). The aim of this study was to compare the LVEF between diabetic and non-diabetic patients with respect to the extent of CAD. Methods and results: Consecutive patients undergoing stress myocardial perfusion SPECT (MPS) were evaluated. MPS was interpreted using a 20-segment model with a five-point scale to define summed stress score (SSS), summed rest score, and summed difference score. LVEF was measured by gated SPECT and then compared with respect to diabetic status and SSS categories. Of 2635 patients, data of 2400 was available. Of these, 24% were diabetic, mean age was 64 +/- 11y, and 31% were female. Diabetics had a significantly lower LVEF compared with non-diabetics regardless of the extent of CAD: 53 +/- 13 and 55 +/- 13% respectively (P=0.001). Diabetics and non-diabetics did not differ significantly in the distribution of SSS categories. Diabetes was an independent predictor of decreased LVEF (odds ratio 1.6, 95% confidence interval 1.2-2.0; P<0.001). Conclusion: Diabetics had a lower LVEF than non-diabetics. This difference could be demonstrated regardless of CAD extent and might in part explain their generally worse cardiac survival compared with non-diabetics on an epidemiological level. In addition, this finding points to discussed mechanisms other than CAD lowering LVEF in diabetics.