A little more than 6 years ago, I had a stent implanted in the RCA, a totally blocked LAD and a 72% occluded circumflex no treatment other than medication. The surgeon did not want to operate with a by-pass of the LAD because the location normally supplied the LAD was being supllied blood from other souces and a bridge around the blockage (collaterials) provided a natural bypass. For the years since, I have had no problems and feel well.
Generally, if medication can dilate vessels sufficiently there may be no need for a stent. Evidence that medication is effective is to not have any symptoms, but a stent implant is really of not much concern as the risk for any complications are low...the risk would be a blood clot that could cause a heart attack, collapse of stent, stent migration, infection at the site of entry for the cath, and possible cath pentration of the lining of the vessel during the procedure.
Ed has provided the generally accepted regimen to slow or stop any progression of coronary vessel disease.
Thanks for your question, and if you have any further questions you are welcome to respond. Take care and I wish your father the best.
The LAD is a very important vessel and if they recommend stenting, I would personally have it done. The usual life style changes should be looked at, such as healthy diet, regular exercise, cholesterol level control and medicated if necessary, blood pressure monitoring. Finally stress levels, anxious people tend to get more heart problems and should find ways to reduce those levels in their lives.