Talk to Cardiologist on Suggestion For Severe Cardiac Issue

My father age is 49.unhe 1 week pehle heart attack hua he or doctors angiography ke bad bypass ka keh rae hen..unhe high diabetes issue tha kaafi saalo se pr attack se 1 month pehle se sugar low reh thi thi abhi bhi low hi he...his weight is 105 and cholestrol bhi high he...and according to angiography one vein is completely blocked, one is blocked at centre and 3rd end has bocome narrow..so what should we do? Is bypass is safe in this condition? Ya kisi medication se blockage khatam hosakti he...mere father ka saans bhi bohat ziada phool raha he...