Relationship between myocardial perfusion abnormalities and contractile impairment in anginal patients

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 = .009). Similarly, despite in the overall population an increasing severity of CAD was associated with higher SDS values (P < .001), this relationship disappeared in Group-1 patients (P = .298). At multiple regression analysis, after correction for CAD, LV dysfunction was negatively associated with an elevated SDS (P = .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.