'Left Main Angioplasty Eliminates The Need For Immediate Bypass Surgery'

Left main angioplasty is the procedure to remove the blocks in the left main coronary artery (the first part of the larger of two coronary arteries normally found in humans). Earlier, the only solution for treating such blockages was bypass surgery. In India, only a few hospitals are practicing it, as it is considered to be an expensive procedure. Dr Marc Silvestri, Interventional Cardiologist at the Rambot Hospital, Aix en Provence, France, was recently in India at Dr L H Hiranandani Hospital and Bombay Hospital, Mumbai, to perform various interventions, including left main angioplasties. Dr Silvestri, who has performed 300 left main angioplasties, spoke to Jayata Sharma about left main angioplasty and the recent controversy surrounding Drug Eluting Stents (DES)

What brings you to Mumbai?

I have come here to give lectures and to perform live interventions, including cases of left main angioplasties. At Hiranandani Hospital, I performed the procedure along with interventional cardiologist Dr Ganesh Kumar. I made my first trip to India in 1986 with my wife for tourism purposes. Later, I taught angioplasty at my institution to an Indian doctor from Ahmedabad in 1995. Recently, my visits are more for professional reasons.

How difficult is it to perform left main angioplasty?

It is like any other angioplasty procedure, local anesthesia via femoral approach.

What is the difference between protected and unprotected left main angioplasty?

It is obviously two different situations. Protected left main is when the patient has already been operated and so has at least one bypass graft patent to protect the vascularisation of the heart. At the opposite, unprotected left main is when there is no protection of other conduits or grafts. Hence, the procedure is much more difficult in the second case and with different prognosis.

When and where was the first case of left main angioplasty conducted? Who is the pioneer of left main angioplasty?

It is a paradox, but the second angioplasty performed in the world was by Dr Andreas Gruentzig, the inventor of angioplasty in 1977 in Switzerland. But he concluded very quickly that performing only ballon angioplasty was not sufficient and also not an appropriate procedure for left main disease. Sadly, stents were not available then.

French, Korean and some American cardiologists are considered to be the first to have attempted left main angioplasties. I personally published an important paper in 2000 giving the pioneer experience of our group who started left main angioplasty very early (1993).

How many countries are currently conducting left main angioplasty?

Many countries are performing left main angioplasties. The reasons are easy availability of stents and results published by pioneer teams on left main angioplasties, which make surgeons feel more comfortable.

Why was left main angioplasty considered unsafe earlier?

Before the availability of stents, the only use of balloon angioplasty provided bad immediate results because of elastic recoil of the artery wall, dissection, thrombosis and thus poor outcome for the patient.

Apart from stents, what are the reasons for left main angioplasty to be seen as a safe procedure now?

Better anticoagulation and antiplatelet regimen, improvement of devices and increasingly skilled operators.

Other than revascularisation, which are the other conditions where left main angioplasty is needed?

It is not required for any other medical condition.

Patients with left main coronary artery stenosis have usually been excluded from off-pump bypass because of concerns about their ability to tolerate beating-heart grafting. Please comment.

This is a very technical issue. In brief, during open-heart surgery the heart stops beating and is under assistance with a machine (pump). It takes some time to start this machine, so if there is any complication during left main surgery, it will be safer for the patient with left main disease to start operation directly with the pump on. This is also controversial for some surgeons who have a lot of experience with off pump surgery.

Why is left main angioplasty considered to be the Mount Everest of coronary angioplasty?

Left main is a vital vessel. The whole heart vascularisation is under the dependence of this very important coronary vessel. This means, the operator must be very skilled with years of experience, particularly in the distal localisation, which is a bifurcation. The patient's blood pressure can drop very quickly during the procedure, so these kinds of surgeries need very precise gesture.

Till now, the only option for left main revascularisation, whether it is triple vessel or not, was bypass surgery. Now, angioplasties are replacing surgery. Why?

There are numerous reasons why left main angioplasty is preferred. Main rationale being that there is no need of anaesthesia, it does not require to open the chest and hospital stay is very short for the patient. All these reasons result in lower hospital mortality and morbidity.

How have stents made left main angioplasty a safer procedure?

With the introduction of stents, numerous complex surgeries have been made easy to perform. Stents ensure optimal initial result, they can avoid emergency bypass, and most important, they reduce restenosis rate. Earlier, restenosis rate, with the conventional stents, was around 30 per cent.

What kind of stents gives better results in left main angioplasty?

Well, in this race, DES win by a good margin over bare metal stents (BMS). DES are actually responsible for reduction of restenosis between five-ten per cent. This proves to be a boon, because the operator does not need to repeat intervention. Thus, stents become really competitive with open heart surgery.

What is the number of left main angioplasties done worldwide?

Around 3,000 left main angioplasties are already officially recorded in various medical journals. However, the number of surgeries actually performed all over the world is much more because most of operator stay conservative and wait for further trial results.

DES has lately been the point of concern after a path breaking finding by the World Congress of Cardiology (WCC), Barcelona. Has this affected its usage in France?

There is no problem of using DES so much in France, as we have always been conservative about using DES. We have strict regulations and our Government has issued guidelines stating that DES is to be used only when we have evidence-based data showing the patient will get benefit with this device. Not all patients and not all lesions or blockages require DES.

So, where is the use of DES a cause for concern?

DES has become a controversy mainly in the US, where cardiologists were using DES for almost 100 per cent of their cases. The report regarding the hazards of using excessive DES has come in light showing higher mortality and higher myocardial infarction rate. However, the methodology of this metaanalysis published is controversial and need further trials to prove that really.

Has the controversy surrounding DES affected its usage in left main angioplasties?

No. De facto, there is no significant scientific data to affirm that.

How often do you use DES?

I am using DES on 60 per cent of my patients. The rest 40 per cent can be successfully treated by using BMS or any other alternative required.

Which are the stents of the future?

Bio-absorbable stents are a good bet. However, as they are still under trial, I think they will not be available until the next five years at least. Bio-absorbable stents can prove to be better as the chances of late thrombosis with these is almost nil.

The future stents will also perhaps be a combination of several drugs, but they must be safe and non-thrombogenic. That is because stents thrombosis kills the patient but not restenosis, which is a progressive phenomenon.

Currently, which type of stents are the safest bet?

Most of stents are made in stainless steal or cobalt-chromium, which can cause inflammatory reactions and can be responsible of restenosis (reblockage of the artery mostly within six months).

Definitely, titanium stents are very promising. In fact, randomised studies are ongoing to compare DES and titanium stents. Although, both the stents are equally effective, the titanium one seems much safer. I personally prefer using titanium stents, when I have to use a conventional BMS, as this is the only inert metal, which does not have any side effects or proves allergic on any individual reactions.

jayata@expresshealthcaremgmt.com