How long does a heart stent last? Do they need to be replaced?

It all depends:  Stents will last forever if they are made of some sort of metal as most are. There is a new product on the market, a new heart stent that dissolves in the artery three years after being implanted. It is yet to be used in clinically, and it will be a while (years) before its risks & benefits will be known.

(From: Scrutiny of Stent Problems Turns to Doctors, WSJ, May 29, 2007)

So, your question is not about stent durability, but about keeping the coronary artery opened up in the location where it was deployed. Because a stent destroys the artery locally, there will be scar tissue that rapidly grows over the stent. In addition, there is a strong tendency for clots to form at the site where the stent damages the arterial wall. Since platelets are involved in the clotting process, patients must take anti-platelet therapy afterwards, usually clopidogrel (Plavix) for six months and aspirin indefinitely.

Neither stents nor coronary artery bypass surgery treat atherosclerosis, the disease process that causes coronary artery disease with obstructive blockages. That means you may be developing new obstructions elsewhere, even after a successful intervention.

That said, there is about a 10-15% failure rate of stents to stay open and more than 40% of patients with a stent will need another procedure within a year, despite the use of expensive medications. This is in sharp contrast with a bypass operation that has a >95% success rate.  While stents are more or less successful as treatment of anginal symptoms, they do not protect against future heart attacks or prolong life, again as opposed to bypass surgery.

If you have coronary artery disease, it is important to choose the right treatment that should in all cases include life style modifications (diet & exercise) and medications that include cholesterol meds (the only way presently to stop progression of atherosclerosis – a process that will take years). It has been shown that in most patients with stable symptoms, this last option, called “Optimal Medical Therapy”, is actually a better treatment option than Stenting.

Patients with extensive (“3 vessel”) disease that may include a “Left main stenosis”, diminished heart function and/or Diabetes do much better with a bypass operation. In situations where time is of the essence, such as an acute heart attack, a stent is may the best option if treatment is quickly enough. The same is probably also true for patients with only “one or two” vessel disease, although there are mini bypass operations that offer an equal if not superior treatment because it promises a much better long term protection.

Hope this helps,

Dr T