MUGA (Multiple Gated Acquisition) is a nuclear test which accurately calculates the pumping function of the heart over multiple heart beating cycles gated (timed with the ECG) so that the machine can know when the heart is contracting and dilating). It does not give information whether blood flow to the heart muscle is adequate and whether pumping will improve if blood flow is restored (Viable myocardium). AIIMS has all modalities to detect viable myocardium like dobutamine echo test, Seatamibi, PET, MRI. So if your doctor is not looking at viability there must be a good reason.
Many a time the damaged part of the heart muscle is markedly thinned out (this can be known on a simple Echocardiogram)and unlikely to recover function. The medicines are fine.