Post-stress left ventricular ejection fraction drop in patients with diabetes: a gated myocardial perfusion imaging study
1 Institute of Biostructure and Bioimaging, National Council of Research, Napoli, Italy
2 Department of Translational Medical Sciences, University Federico II, Napoli, Italy
3 SDN Foundation, Institute of Diagnostic and Nuclear Development, Napoli, Italy
4 Department of Advanced Biomedical Sciences, University Federico II, Napoli, Italy
BMC Cardiovascular Disorders 2013, 13:99 doi:10.1186/1471-2261-13-99Published: 14 November 2013
To evaluate the relevance of stress-induced decrease in left ventricular ejection fraction (LVEF) in patients with type-2 diabetes.
A total of 684 diabetic patients with available rest and post-stress gated myocardial perfusion single-photon emission computed tomography (MPS) data were enrolled. An automated algorithm was used to determine the perfusion scores using a 17-segment model. LVEF drop was considered significant if the post-stress LVEF was ≥5% below the rest value. Follow-up data were available in 587 patients that were followed for the occurrence of cardiac death, nonfatal myocardial infarction, or unstable angina requiring revascularization.
A post-stress LVEF drop ≥5% was observed in 167 (24%) patients. Patients with LVEF drop had higher summed stress score (p < 0.05), summed difference score (p < 0.001), and rest LVEF (p < 0.001) compared to patients without. Conversely, summed rest score, a measure of infarct size, was comparable between the two groups. At multivariable analysis, summed difference score and rest LVEF were independent predictors (both p < 0.001) of post-stress LVEF drop. Myocardial perfusion was abnormal in 106 (63%) patients with post-stress LVEF drop and in 296 (57%) of those without (p = 0.16). The overall event-free survival was lower in patients with post-stress LVEF drop than in those without (log rank χ2 7.7, p < 0.005). After adjusting for clinical data and MPS variables, the hazard ratio for cardiac events for post-stress LVEF drop was 1.52 (p < 0.01).
In diabetic patients stress-induced ischemia is an independent predictor of post-stress LVEF drop; however, a reduction in LVEF is detectable also in patients with normal perfusion. Finally, post-stress LVEF drop increases the risk of subsequent cardiac events in diabetic patients.