<qa>  What is the average echocardiography performed within 3 months before or at time of enrol- 25LVEF35, performed within 3 months before or at time of enrolment, as measured by radionuclide ventriculography, or electrocardiogram ECG-gated SPECT myocardial perfusion imaging MPI, or magnetic resonance imaging MR, computed tomography CT, or 3D or 2D echocardiography Simpsons or multidisc method only, M-mode echocardiography is not accepted. 