Background: The global left-ventricular (LV) ejection fraction (EF) is a powerful predictor of cardiac death (CD). There are limited data on the prognostic value of regional LV function. We examined the role of visually assessed regional wall motion in risk stratification for future cardiac events.
Methods and results: A prospectively gathered database of 10,336 patients who underwent technetium (Tc)-99m sestamibi-gated single-photon emission computed tomography (SPECT) was analyzed. The summed stress score (SSS) and summed wall-motion score (SWMS) were calculated using a standard 17-segment model. The post-stress EF was generated using QGS software. The follow-up was 90.2% complete over 28.6 +/- 16 months. Patients with early (<or=60 days) revascularization were censored, leaving 8,767 for analysis. A multivariate analysis demonstrated that abnormal wall motion (SWMS >or=5) was an independent predictor of cardiac death (odds ratio = 1.78, 95% confidence interval = 1.11 to 2.85, P = .016). Among patients with an EF >or=45%, abnormal wall motion was the only gated SPECT variable that independently predicted cardiac death (odds ratio = 1.69, 95% confidence interval = 1.06 to 2.7, P = .028). In patients with an EF >or=45% and reversible perfusion defects, abnormal wall motion predicted an intermediate (2.2%/year) risk for CD, and a high (4.2%/year) risk for the combined endpoint of cardiac death and nonfatal MI.
Conclusions: Regional LV function data from gated SPECT provide important prognostic information, and may identify a subgroup of patients with preserved EF and ischemia who are at significant risk for future cardiac events.