Heart Disease or Coronary Artery Disease is the largest single killer in our society. The changing life style and added to that the stresses and strains of life have made this disease an almost epidemic. In India it is fast growing and soon we will be the number one country with patients of Coronary Artery Disease. The WHO report is scaring and it points towards a total disaster. Keeping this in new we all need to take preventive steps to lessen the burden of this disease. First and foremost step towards this will be to have an organized lifestyle, regular exercise and diet control. But the next more important step will be to go for preventive check ups. The incidence of this disease is rising now in younger population so it will be advisable that anybody who is above 35 years should have all his investigations carried out from heart point of view at least once a year so that if there is any alarming sign it is tackled well in time. This particularly holds good in those persons who have a strong family history.
This is one scenario and the other is that someone is having coronary artery disease, which is significant enough to produce symptoms, and requires some treatment. In this second scenario one has to act immediately. Rather than have a wishful thinking that symptoms are not related to heart and may be due to gastric trouble or muscular pain one should immediately go for stress test and if it is positive then to see how much exactly the disease is, one undergoes angiography which is the only gold standard test to quantify this disease.
The real dilemma starts when one is found to be having significant coronary artery disease, which requires interventional treatment. As of now two types of interventions are available (both are invasive and require hospitalization).
Angioplasty and Bypass Surgery there can be situations where both can be offered as treatment of coronary artery disease and of course Bypass Surgery can be applied and is the solution in any type of situation. Angioplasty means that the diseased area of coronary artery is repaired by dilating the diseased porition with a balloon catheter and these days to support the weak dilated wall of the artery a stent is put in place for better long term patency rates.
Bypass Surgery is where surgically the disease part is bypassed with a new route of blood supply via a graft taken from the human body only in the form of vein or an artery. These days we used more and more of arterial grafts either the Internal Mammary Artery that runs at the beck of sternum or radial artery, which runs in the arms.
Angioplasty is less invasive than surgery in terms of that it is done under local anaesthesia and there are no major incisions. Bypass Surgery has also become less invasive in terms that it is being done on beating heart and no longer the heart is arrested to carry out these grafts. So the stressful effect of heart lung machine on the body is gone now and recovery is much faster. Bypass surgery is beyond doubt the long term, time tested solution which improves quality of life, prevents sudden heart attacks and freedom from second procedure is great.
In case of Angioplasty with stents also improves quality of life but the other two factors do not hold good. If the stent fails or blocks again it will lead to a fresh heart attack and also the chances of blockages second time are more with stents where a second procedure may be required early. The earlier stents had high re-blockage rate but the new generation of medicated or drug coated stents have better durability and patency rates but still they have above 9% re-blockage rate during the first year only. The procedure is beneficial only in short-term basis, in terms of no major incision, less or shorter stay in hospital and no general anaesthesia but at the cost of durability.
Bypass surgery is a proven durable treatment for coronary artery disease but when a patient is detected to have this disease there are certain situations where both the treatments can be applied and there the dilemma starts. If you look at human psyche anybody and everybody in the world will want a less traumatic treatment where angioplasty comes in mind but at the same time no one wants to suffer again and again and one wants a long term solution to the disease or to that effect eradication of disease (which though is not possible) but something close to that is possible with bypass surgery. As new route of blood flow is create via grafts, which are disease free, bypassing the diseased part of artery, which means in an indirect sense removing the diseased path from the route of blood supply to the heart.
Whenever a particular form of treatment is adopted it is backed by lot of research first in animal models and then in human beings as clinical trials. Then only it is offered to public en mass. Even after the procedure is accepted it is constantly evaluated by further trials and also it is compared to the already existing procedures or other newer procedure so that the best form of therapy can be chosen for the patient population. In this direction lot of trials were conducted on cardiology front about 15 major ones and some were compared with surgical arm. Even with the advent of drug eluting stents, bypass surgery scored over angioplasty with stents in terms of better long term results i.e. event free years and less chances of second procedure. Patients in the angioplasty arm had more incidence of major adverse coronary events after the first procedure.
What are the issues here lets have a look ! Agreed any patient will choose a less invasive treatment out of two available treatments. But here is a catch; these two terms of treatments have to be equally effective in terms of their results. In case of angioplasty vs surgery key issues are:
1. Is angioplasty in multi-vessel disease evidence based?
2. Are the limitations of angioplasty known to the patient?
3. Is it economical in multi-vessel disease as compared to surgery?
There is another major flaw. The trials on which we base our treatment are conducted on western population, which is genetically different than Asian or Indian population. In the sense that in western population the size of coronary arteries is much bigger than the Asian population like it is 4-6mm as compared to 2-4mm in Asians. So treatment applied there cannot hold good here.
As such if we look at Angioplasty vs CABG the two forms of treatment are not equivalent in terms of:
1. Bypass Surgery not only tackles culprit lesion but also deals with future lesions as it is done distal to the diseased part.
2. In certain situations angioplasty carries very high mortality like Left Main Disease.
3. Even the repeat revascularization or second procedure requirement is higher with angioplasty in multi-vessel disease or left main disease. As per two latest trials even in western population Arterial Revascularization Therapy Study (ARTS), Stent or Surgery (SOS) trials the incidence of second procedure in angioplasty group is 3 times higher than patients treated with surgery. Also the risk of death in both the trials with surgery is very low 1.2% in ARTS trial and 0.8% in SOS trial.
4. The trials included only simpler form of disease like single or double vessel but the results are being applied to multi-vessel group. The need for re-intervention in ARTS trial was 30% as compared to 9% in surgical group.
5. Again in diabetes the bypass surgery scores over angioplasty in terms of long term benefits as in ARTS trial it was 43% in angioplasty as compared to 10% in surgery patients.
6. Surgery offers more complete revascularization with better durability especially arterial grafts.
7. Left main disease is a very serious situation, which requires urgent intervention and bypass surgery so far has been the best form of treatment.
8. Another major disadvantage with drug coated stents is what we call “Late Stent Thrombosis” or sudden occlusion of the stent after a year or so when the blood thinners or antiplatelets are withdrawn or reduced and infact FDA in USA has issued a warning to all these companies for this dreaded complication.
Other myths about angioplasty safety have also been proven wrong.
1. Risk of heart attack during angioplasty is 10%
2. Risk of restenosis with in first year is 10% to 30%.
3. There is no reduction in neurological complications with this.
4. Even in trials including drug coated stents multi-vessel disease, small vessels, long lesions, diabetes and restenosis patients have been excluded but in practice they are applied in even these subset of patients also.
Recently a lot of studies have come in the reputed International Journals, two of which I quote here which have proven beyond doubt that CABG or Bypass Surgery is much superior to angioplasty in multi-vessel and left main disease and these subset of patients should only be treated with surgery for long term benefits and economics.
1. One paper was published in Annals of Thoracic Surgery Dec. 2006 entitled, “Coronary Artery Bypass Grafting is still the best treatment for Multivessel and Left Main Disease… But patients need to Know” by Dr. David P Taggart from John Radcliffe Hospital, University of Oxford, United Kingdom.
2. Does off pump or minimal invasive coronary artery bypass reduce mortality, morbidity and resource utilization when compared with percutaneous coronary Intervention? A Meta analysis of randomized trials. …In Journal of Thoracic and Cardiovascular Surgery March 2007 by David Bainbridge & Colleagues from Canada.
Both these papers have detailed about pros and cons of two procedures. In Lancet in Jan. 2006, the headline cover stated, “In view of the survival benefits shown for CABG the real controversy is why patients with symptoms and anatomy known to benefit from surgery are still submitted to angioplasty”.
Again the dilemma is summarized by Dr. Califf, Head of Interventional Cardiology at Duke University, “Stenting or Surgery” in Journal of American College of Cardiology”. It is likely that most people undergoing Coronary Angioplasty are not told the entire story when a decision is made about undergoing angioplasty. He attributes this to conflicts of self-referral and financial incentives and concludes, “Without Surgical Opinion the patient is in no position to have a rational input into the decision.”
The great father of interventional cardiology, Andreas Gruntizg, who died prematurely in a plane crash at age of 46 stated in 1979, “We estimate that only about 10-15% of candidates for bypass, surgery have lesions suitable for angioplasty. A perspective randomized trial will be necessary to evaluate the usefulness in comparison with surgical and medical management”.
So to conclude stent or surgery is not/should not be a physician’s choice. It should depend on what disease demands keeping in view the long term benefits and the economics. Pros and Cons of both the procedures should be made aware to patient in detail. Durability of treatment rather than short stay should be the goal and important factor for deciding treatment.
In the end I think the best way to remove this dilemma is have multidisciplinary team consisting of a physician, a cardiologist and a cardiac surgeon to decide about the treatment plan for coronary artery disease in a particular patient on individualized basis
