ORIGINAL ARTICLE Relationship between myocardial perfusion abnormalities and contractile impairment in anginal patients Alessia Gimelli, MD, a Riccardo Liga, MD, b Assuero Giorgetti, MD, a Mirta Casagranda, RT, a and Paolo Marzullo, MD a,c a Fondazione Toscana Gabriele Monasterio, Pisa, Italy b University Hospital of Pisa, Pisa, Italy c CNR, Institute of Clinical Physiology, Pisa, Italy Received Apr 25, 2014; accepted Jun 24, 2014 doi:10.1007/s12350-014-9950-0 Background. A relationship between left ventricular (LV) contractile impairment and myocardial perfusion abnormalities has been suggested. Methods and Results. Three-hundred and thirty-seven patients underwent myocardial perfusion imaging at CZT and coronary angiography. On scintigraphic images, the summed difference score (SDS) and LV-ejection fraction (EF) were computed. Patients were categorized as follows: Group-1 (LV-EF < 40%; 71 patients), Group-2 (LV-EF ‡ 40% and < 55%; 77 patients), and Group-3 (LV-EF ‡ 55%; 189 patients). Significant coronary artery disease (CAD; ‡50% stenosis) was recognized in 159/337 (47%) patients. Interestingly, while in Group- 3 subjects an inverse relationship between SDS values and post-stress LV-EF was evident (P < .001), Group-1 patients presented a significant association between an increased SDS and more elevated post-stress LV-EF values (P 5 .009). Similarly, despite in the overall population an increasing severity of CAD was associated with higher SDS values (P < .001), this rela- tionship disappeared in Group-1 patients (P 5 .298). At multiple regression analysis, after correction for CAD, LV dysfunction was negatively associated with an elevated SDS (P 5 .018). Conversely in patients with normal LV function and no history of myocardial infarction, CAD extent, and functional measures of stress-induced myocardial ischemia were strictly correlated. Conclusions. Independently from CAD, a significantly impaired LV function associates with a lower prevalence of reversible ischemia. (J Nucl Cardiol 2014;21:1181–90.) Key Words: LV dysfunction Æ CZT Æ summed difference score Æ coronary artery disease INTRODUCTION Myocardial perfusion imaging (MPI) on single- photon emission computed tomography (SPECT) still plays a central role in the evaluation of patients with known or suspected coronary artery disease (CAD). 1-3 To this respect, while the occurrence of stress- induced myocardial ischemia is generally believed to be secondary to the presence of significant CAD, 1 relevant alterations of myocardial perfusion may develop in patients with non-obstructive coronary narrowings or even normal coronaries. 4 On the other hand, in some categories of patients, such as in those with significantly reduced left ventricular (LV) systolic function, revers- ible myocardial ischemia may be relatively limited despite the presence of extensive CAD. 5,6 In those subjects, the limited perfusion abnormalities at SPECT- MPI are coupled by a significant paucity of stress- induced anginal symptoms. 5 However, despite an asso- ciation between increasing extent of LV scar and reduced myocardial ischemic burden at MPI has been suggested, 3,5 a better understanding of the relationship between LV systolic dysfunction and myocardial induc- ible ischemia is needed. Alessia Gimelli and Riccardo Liga have contributed equally to this study. Reprint requests: Alessia Gimelli, MD, Fondazione Toscana Gabriele Monasterio, Pisa, Italy; gimelli@ftgm.it 1071-3581/$34.00 Copyright Ó 2014 American Society of Nuclear Cardiology. 1181