One of the major developments in the field of cardiovascular medicine over the past 40 years has been the treatment of narrowing in arteries of the heart by non-invasive means, that is, without the need to surgically open the chest and do a major operation. This is known as percutaneous coronary intervention (PCI). Heart Institute of the Caribbean (HIC) is a leading provider of this service in Jamaica. Most of these procedures involve the use of stents “coronary stenting”. This week we shall discuss the role of coronary stenting in the management of heart disease.

What is a coronary stent?

Narrowing of the arteries that supply blood to the heart “coronary artery disease” is a common cause of heart disease worldwide. Management of this disease involves prevention, control of risk factors and medications. In addition, we have the ability to mechanically treat narrowing of blood vessels in one of two ways. The surgical approach is to bypass surgery where new pathways are created for blood to flow around the areas of narrowing. Coronary intervention or PCI is a procedure in which wires and balloons are advanced to an area of narrowing through blood vessels and used to dilate a stenosis or blockage. In most cases, a stent is used to ensure that the area remains open after the procedure. A stent is simply a scaffolding of metal. It can be visualised as “chicken wire” rolled into the shape of a tube. A stent is manufactured over a balloon such that when the balloon is inflated/expanded, the metal stent is pressed into the vessel wall preventing the wall from closing after the procedure.

Who needs a coronary stent?

As mentioned above, in treating patients with coronary disease, we have three methods available to us, medical management only, medical management with coronary stenting and medical management with coronary bypass surgery. The vast majority of patients with coronary artery disease are managed medically and we reserve coronary stenting or coronary bypass surgery for patients in one of two clinical scenarios. The first scenario is patients who are at increased risk of cardiac complications or death. This group includes patients who present with heart attacks, patients with increasing or unstable chest pain from coronary disease, patients with heart failure and certain arrhythmias. The second scenario is patients who are on maximal medical management but who still have symptoms related to coronary disease.

How does my cardiologist decide between stenting and bypass surgery?

There is a trade off that we consider between bypass surgery and coronary stenting. Bypass surgery has a higher risk for complications at the time of the procedure than coronary stenting. Bypass surgery, however, has the advantage of being able to treat a wider extent of narrowing than coronary stenting, particularly in patients with many areas of narrowing. There are characteristics of the heart arteries that make stenting less successful, for example, small vessels, narrowing at branch points, the presence of calcium and total vessel occlusion. Stenting has the advantage of being easier to do in patients with multiple medical problems who may not tolerate open heart surgery. The recovery period and return to normal life is also much shorter with a stenting procedure. The major downside to stenting procedures is the increased risk of recurrent narrowing when treating many blockages and the possible need for repeated procedures. Another limitation is the need for prolonged use of medications to prevent clotting after a stenting procedure which may pose a problem for patients who need other surgical procedures or have a substantial risk of bleeding.

The primary consideration in choosing between bypass and stenting is the extent and nature of narrowing in the arteries of the heart. Other considerations would include patient characteristics and co-morbidities. As a rule, the less the extent of blockages the more coronary stenting would be favoured. That is, it is unusual to do bypass surgery for only one area of narrowing. As the extent of the narrowing increases it is more likely that bypass surgery would be suggested. It should be said, however, that as coronary stenting technology has progressed, it has become feasible to treat more extensive degrees of narrowing than previously. Patients who might have undergone bypass surgery 20 years ago are currently being treated with stenting procedures. There are however groups of patients that receive greater benefit from bypass surgery. These include patients with poor heart function, diabetics with extensive disease, and certain disease anatomy. Both procedures are routinely performed at HIC with zero surgical- or procedure-related mortality and low major complication rates.

What are the complications of a coronary stenting procedure?

The rate of complications at the time of the procedure is extremely low, less than one per cent in competent hands. Complications include bleeding at the puncture site, allergic reactions, abnormal heart rhythms, change in kidney function and exceedingly rare risks of heart attack stroke or death. The long-term risk of restenosis of the narrowed area is about four per cent if one area is treated but trends higher as more areas are treated.

Can I return to a normal life after coronary stenting?

For most patients, particularly those who had only one area of narrowing that has been successfully treated, they return to life as normal. They will, however, have to make lifestyle changes to reduce the risk of development of more areas of narrowing. These include regular exercise, diet low in saturated fat, avoidance of cigarette smoking, and control of risk factors, including hypertension. Patients who receive drug-eluting stents will need to take medications (usually aspirin and a second anti-platelet drug) to prevent clotting in the area of the stent for three months to one year after the procedure. It is extremely important to take this continuously and only discontinue or pause this treatment after consulting with your cardiologist. There is also the need for continued treatment with other medications to lower blood cholesterol and improve heart function.

Dr Ernest Madu, MD, FACC, and Dr Paul Edwards, MD, FACC are Consultant Cardiologists at Heart Institute of the Caribbean (HIC) and HIC Heart Hospital. Correspondence to info@caribbeanheart.com or call 876-906-2107