Long-term prognostic value of left ventricular dyssynchrony assessment by phase analysis from myocardial perfusion imaging

OBJECTIVE: To assess the value of left ventricular (LV) dyssynchrony, using phase analysis of nuclear single-photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) as independent predictor of cardiac events. METHODS: Phase analysis using Emory Cardiac Toolbox was applied on gated rest MPI scans to assess LV dyssynchrony in a total of 202 patients. Follow-up was obtained in 197 patients (97.5%). Major adverse cardiac events (MACE) (cardiac death and hospitalisation for any cardiac reasons, including worsening of heart failure, non-fatal myocardial infarction, unstable angina and coronary revascularisation) were determined using the Kaplan-Meier method. Cox proportional hazard regression was used to identify independent predictors of cardiac events. RESULTS: At a median follow-up of 3.2 ± 1.2 years, 41 patients had at least one event, including 5 cardiac deaths. LV dyssynchrony (n = 35) was associated with a significantly higher incidence of MACE (p<0.001) and proved to be an independent predictor of cardiac events. CONCLUSION: LV dyssynchrony assessed by phase analysis of gated SPECT-MPI is a strong predictor of MACE independent of other known predictors such as perfusion defects or decreased LV ejection fraction.