3 years back had stent. my ef has been 30% since then.now icd is recomended. there is no new complain. why now?

It is unfortunate: but many physicians delay appropriate recommendations for primary preventive ICD implantation in the hopes that medical therapy will improve the patient's EF. It is unlikely to be ignorance or malfeasance or incompetence. After hoping long enough they finally realize they have to suggest an invasive procedure for their patient's protection. 3 years is a little long but unfortunately not unusual.

That is odd: first, be sure that you have been on optimal therapy for ischemic heart disease that would also give your ef a chance to improve. Standard therapy is beta-blocker (carvedilol), ace inhibitor, Asa, statin & possibly aldactone (spironolactone). Second new blockages as a cause, albeit asymptomatic, need to be excluded. Then if EF still @ or below 30%, iCD warranted by the guidelines and possibly bi-v pacer too.