If an LAD is occluded in the proximal segment and the patient is having stenting 'considered' rather than 'emergency', then I think we can safely assume that patient has developed collaterals. If this were not the case, the patient would be in dire straits with huge areas of tissue death.
Usually, the protocol is to treat symptoms with medication. If medication is not tolerated or effective then a stent is a conderation, if stent can not be implanted then a by-pass is the only option. All 3 therapies only treat the symptoms and are not a cure. So it seems logical to go with the procedure with the least risk.
I have a fully occluded LAD for the past 6 years, and my therapy is medication with no problems...exercise tolerance, no pain, etc. The LAD's occlusion has developed a natural by-pass with collateral vessels. If you have a completely blocked LAD there has to be other vesssels feeding the deficit of blood flow that the LAD should provide.
If medication relieves symptoms, and based on what you have posted, there would not be any danger to forgo intervention. You may want to talk to another cardiologist, preferably a non-interventional cardiologist for a second opinion. If there are collateral vessels by-passing the occlusion, there is a medical point of view not to open a completely blocked vessel as it may compromise the collateral flow. The information is meant only to provide a perspective you can discuss with your doctor. There may be other considerations.