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

Purpose: To 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. Methods: Two 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. Results: During 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. Conclusions: Left 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.