Prognostic implications of stress-induced transient ischemic dilation of the left ventricle in patients with systolic dysfunction and fixed perfusion defects

PurposeTo verify whether stress-induced transient ischemic dilation (TID) of the left ventricle may help refine prognostic assessment of patients with resting systolic dysfunction and fixed perfusion defects.MethodsTwo hundred seventy patients with resting ejection fraction ≤ 50% and fixed perfusion defects on exercise (n = 180) or dipyridamole (n = 90) ECG-gated single-photon emission computed tomography (SPECT) were followed-up for the combined endpoint of death, acute coronary syndrome, and clinically-driven revascularization. The TID ratio was defined as the ratio of LV volumes at stress and rest.ResultsDuring a median time of 24 months, 47 events (10 deaths, 20 acute coronary syndromes and 17 revascularization) were observed. After adjusting for clinical and stress testing variables, the unfeasible exercise test [hazard ratio (HR) 1.82, 95% confidence interval (CI) 1.02, 3.24] and the highest quartile of TID ratio [HR 1.93, 95% CI 1.05, 3.54] were the only independent predictors of outcome. The highest quartile of TID ratio was associated to significantly lower percent of event-free survival.ConclusionsLeft ventricular TID ratio helps refine outcome prediction in patients with resting systolic dysfunction and fixed perfusion defects, thus reducing risk of a false negative result.