BACKGROUND: Current guidelines recommend intervention for symptomatic aortic stenosis, but the management of asymptomatic aortic stenosis remains controversial. As left ventricular global longitudinal strain (GLS) has been shown to predict cardiovascular outcome, we sought to find whether its use could guide the assessment of risk in these patients. METHODS AND RESULTS: We prospectively followed 79 patients with severe asymptomatic aortic stenosis (39 men; mean age, 77 ± 12 years; aortic valve [AV] area index, 0.36 cm(2)/m(2)). In addition to standard echocardiography, speckle strain was measured to assess GLS. Patients were followed for cardiac death and AV replacement driven by symptom development. A multivariable Cox regression was performed to identify associations with events. During 23 ± 20 months, 3 patients had cardiac death and 49 underwent AV replacement. Event-free survival was 72 ± 5% at 1 year, 50 ± 5% at 2 years, and 24 ± 5% at 4 years. Death and AV replacement were predicted by GLS (hazard ratio [HR], 1.14 [95% CI, 1.01-1.28]; P=0.037), as well as extent of AV calcification (HR, 2.44 [95% CI, 1.17-5.12]; P=0.018), peak transaortic pressure gradient (HR, 1.03 [95% CI, 1.01-1.04]; P<0.001), valvulo-arterial impedance (HR, 1.32 [95% CI, 1.04-1.67]; P=0.045), and Society of Thoracic Surgeons Predicted Risk of Morbidity and Mortality (HR, 0.95 [95% CI, 0.90-1.00]; P=0.052). A mean absolute GLS <15% was associated with a significant excess mortality, and this measurement added incremental prognostic value to the Society of Thoracic Surgeons Predicted Risk of Morbidity and Mortality, transaortic peak pressure gradient, AV calcification, and valvulo-arterial impedance. CONCLUSIONS: GLS is associated with outcomes in patients with severe asymptomatic aortic stenosis, incremental to other clinical and echocardiographic variables.