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.