Dr Nandakumar is one of the few cardiologists in Singapore who has worked as a consultant interventional cardiologist in a substantive position in the UK. Currently, he is a Senior Consultant Cardiologist at Mount Elizabeth Hospital and Mount Alvernia Hospital specialising in Interventional Cardiology.
DxD Session held on 25 Jul 2018.
Dr Nandakumar answered questions from readers on:
- Best treatment for blocked heart vessels
- What happens during an angioplasty
- Risks and complications associated with stent placement
- What happens after an angioplasty
There are essentially 3 treatments for blocked heart vessels – i.e.
- Medical therapy
- Angioplasty or stents, and
- Bypass surgery
However which of these options is most suitable for yourself depends on the presence of the blockages, their severity and location.
Yes, coronary artery disease can be treated with lifestyle changes - exercise along with diet/stopping smoking/losing weight and reducing stress.
However in certain kinds of coronary disease (may need both a coronary angiogram and nuclear scan) where there is a severe blockage which is causing impairment of blood flow to a significant part of the heart muscle, it maybe advisable to proceed with heart stent or bypass surgery to prevent a heart attack with poor outcomes including mortality.
A coronary angiogram is performed whenever a patient has symptoms such as breathlessness or chest pain on exertion (not always) which usually indicate poor blood flow in the heart blood vessel due to blockages.
This could a non-invasive angiogram (ie CT coronary angiogram) or an invasive coronary angiogram (gold standard test). The modality depends on the risk and if the risk is higher an Invasive coronary angiogram maybe warranted.
When deciding between medical therapy, heart stents (angioplasty) or cardiac bypass surgery, I take into account the full picture based on factors such as:
- Clinical presentation
- Patients age
- Mental and neurologic status
- Location and severity of the blockages
- Ability to take long-term blood thinning tablets and
- Other issues such as diabetes, kidney function and heart failure along with patient expectations and preferences.
I also use validated specific “scores” to help decide the strategy such as “Syntax” score. These scores however, have to be interpreted in context to be meaningful and useful.
Contrary to what you may have heard the number of stents should be determined only by the degree and extent of any narrowing and also how the procedure unfolds.
Most cardiologists do not know the coronary anatomy before the procedure unless an angiogram has been done prior. While you maybe able to predict one stent at the minimum for the severe narrowing, this is not an exact science and one cannot predict exactly how a vessel will react during the procedure.
It depends on whether the patient falls in the low, intermediate or high risk category based on:
- The severity of the narrowing (we use scores such as modified Duke Score/SYNTAX score etc )
- Heart’s pumping ability( by echocardiography) and
- Presence of other issues such as blood pressure, diabetes and high cholesterol
It also depends on whether patient is stable and the procedure is an elective procedure, or if the patient has presented suddenly with chest pain or breathlessness which drastically alters the strategy.
Dear Ah Teck,
I would suggest that you keep yourself well informed of the procedure, what it entails on the day, what are the various outcomes and what maybe the adjunct procedures you may need and how long your recovery could take based on the results of the angiography and any treatment on the day. Of course, it would be good if your next of kin is also aware of this information.
How safe is an angioplasty, and what are the main risks of having an angiogram and angioplasty in Singapore?
Both angiogram and angioplasty procedures are quite safe in this day and age.
But any invasive procedure does carry a small risk. Some of the major risks of the procedure would be risk of heart attack (0.05%), stroke (0.07%), need for emergency cardiac surgery (0.05 to 0.3%) and mortality (0.08 to 0.65%). Bleeding and damage to the artery where we access is between 0.2 to 1%.
Yes, 100% blocked arteries can be treated and many techniques exist nowadays.
If the artery can be opened up through the normal route of blood flow it is called “antegrade” technique and there are newer specialized kits available for this technique.
There are also techniques that have been developed in Japan over the years called “retrograde” technique which is a way of going through the blocked vessel in the reverse manner by approaching though other arteries.
Is it possible to remove the plaques in the heart vessel wall, instead of using heart stents to open them up?
Yes we do use devices occasionally to remove/shave/excise plaques but this is used in less than 5% of coronary angioplasties at present.
The current devices licensed for plaque removal usage in the heart are called:
- Rotablator (a nickel plated brass burr with microscopic diamond crystals on it rotating at high speed) which excises the hard plaque tissue
- Excimer laser (which uses high energy light to dissolve plaque without harming healthy tissue) and
- Orbital atherectomy (which uses a diamond coated crown rotating at high speed to kind of “sand ” the calcium away).
All procedures are carried out after a clinical assessment of risk vs benefit. As mentioned above there is always a risk to any invasive procedure and angioplasties on minor vessels just do not justify a patient undergoing the risk of an coronary angioplasty as some of the risk, though of low frequency, if they do occur can be significantly life altering.
And while treating a severe narrowing in an important vessel has a favourable prognostic benefit (ie prolongs life but this is a hidden benefit) the same does not pply to smaller vessels.
How is an angioplasty performed in Singapore, and what is the cardiologist able to do during the angioplasty procedure?
An angioplasty is performed whenever a patient has symptoms along with risk factors suggesting there is coronary disease (ie heart vessel narrowing or blockage usually due to fat deposit).
Following insertion of local anaesthetic a thin tube called catheter is inserted in the artery in the wrist (through the groin in the olden days, rare now) and threaded upto the heart. This is painless usually as the blood vessel lacks nerves to feel touch or pain though sometimes spasm can occur.
When a cardiologist is not able to insert a heart stent, this is usually due to:
- Either the artery being blocked for a long time (called a CTO or chronic total occlusion, usually with severe calcification) or
- Because the artery is very tortuous and the narrowing is in an area which is difficult to reach
In the first instance, ie CTO, where the procedure has been unsuccessful - one could reattempt the procedure with further specialised equipment, and with experts who have specialised exclusively in opening up such arteries.
In terms of recovery we generally aim for a 4 to 6 week period to get back to full activity. Usually the cardiac rehabilitation team will come to meet you if you have been admitted with a heart attack and following the angioplasty procedure they will provide guidance on the do’s and dont’s.
Cardiac Rehabilitation is a structured, holistic, 6 to 8 week program which deals with multiple facets of recovery including diet, psychological counselling to deal with the diagnosis, treatment and its aftermath, return to driving and other occupational activity, safe return to exercise and other practical questions.
Usually, after a coronary angioplasty, some patients experience a pain called “stretch pain” which can last for a few hours after the procedure provided everything else goes well. This gradually resolves.
In general, if the stent is placed well there should be no further pain. This however depends on a number of caveats i.e:
- There are no small vessels with blockages that are still present
- There are branches with have been partially blocked with stents etc.
Your father can be rest assured that after a successful heart angioplasty, he can look forward to a good quality of life and longevity provided that the coronary disease fits the criteria and the coronary angioplasty is technically sound and complete.
Some simple rules to follow after the coronary angioplasty procedure are – ensure full compliance with the medication especially the blood thinning agents.
Usually two blood thinning agents are given and these should be taken meticulously every day without fail.
When I do the procedure I always ensure there is adequate pain relief (they are big on pain relief in the UK and the cath lab sister would always be watching the patient intently and if the patient were to wince ever so slightly the pain medication was topped up immediately).
At most you may feel some initial discomfort when the local anaesthetic is inserted.
Some patients experience pain due to spasm of the artery in the wrist but we can always give medication to open up the artery and relieve the pain.
A heart stent should and will last for life. A stent after all, is a wire-mesh scaffold and functions as such. Once a stent has been placed the inner vessel wall (called endothelium) slowly grows over it until it “heals”.
Drug-coated stents ensure that this healing is not too excessive as in the days gone past, this excessive healing would lead to re-narrowing. This healing takes between 3 to 6 months and that is why you need blood thinning agents to keep your blood thin as the stent heals.
Well, as I say to my patients, putting in the heart stent is just the start of a healing journey. Your real work starts now and it needs a consistent daily effort on your part (not just the first 3 months after angioplasty and then back to the old ways!!)
Simple rules such as eating a good healthy diet, avoiding junk and comfort food, exercising regularly, maintaining an active lifestyle, sleeping well, ensuring less stress in your life (even if it means changing your job) along with regular medication and stopping smoking go a long way in keeping you away from further heart stents or procedures.
Well the term “stent failure” usually indicates either that renarrowing has occurred or that it has been blocked completely.
Complete blockage can be sudden and obviously causes chest pain, breathlessness or sweating, chest discomfort and may include all the features of a heart attack.
Re-narrowing on the other hand, usually occurs slowly over time and is marked by return of symptoms such as chest pain or breathlessness on walking.
NO – heart stents cannot be removed for any reason except in the extremely case of a stent getting infected (about 17 or so cases reported since 1986 when the first stent was implanted and of course millions of people have had stents since then).
In which case heart surgery is necessary along with antibiotics but this is so rare that neither myself nor any of my colleagues over the years (almost 17 years) have seen an infected stent.
Currently the latest generation stents are largely made of alloys such as chromium-cobalt or platinum-chromium. These have a layer of drugs coated on them and are stuck onto the stents using “polymers”.
Some stents have non-absorbable polymers and healing takes a bit longer. Some stents have fully absorbable polymers(bio-degradable) and once the drug has been released completely it becomes a “bare metal stent”. There are yet other stents where the drug is stored in small “reservoirs” and is designed to release the drug slowly.
I am afraid the evidence does point to the fact that there is a clear advantage both in terms of quality of life and mortality benefit (for instance in those patients who have a narrowing of more than 50% in the left main stem ie the major branch on the left side of the heart, only 50% will survive beyond three years on medical treatment alone).
Of course mild to moderate narrowing in a small noncritical vessel will neither confer a survival advantage nor cause a dramatic change in your quality of life.
I would say the chances of being completely angina free depends on the extent of the disease, i.e. if you have diffuse multiple blockages or one or two critical blockages.
With diffuse extensive disease, while you may improve the prognosis by treating the critical large vessels, the symptoms may still remain as many of the smaller branches may continue to cause symptoms as stents and angioplasty cannot be used in the very small branches and vessels.
I do not know of any suitable longterm less invasive alternatives to angioplasty, bar optimal medical therapy.
There are centres abroad that offer EECP ( Enhanced external counterpulsation) but bear in mind that this is recommended for incessant angina, and is only effective for microvascular disease as adjunct therapy (i.e when the disease is in the small vessels not visible to the eye on angiogram and there is no narrowing or blockage in the larger vessels).
While there are many reasons why re-narrowing can occur, recurrence of narrowing can be related to:
- Patient factors
- Stent factors
- Procedure factors
As far as patient factors are concerned, a healthy active lifestyle with good diet, adequate sleep, minimal stress and good treatment of cardiac risk factors will help to ensure that heart stent narrowing does not happen.
In general the number of heart bypass surgeries has been falling globally as heart angioplasty (heart stent) technology has improved in leaps and bounds especially over the last decade.
Surgical techniques have also improved and newer techniques such as off-pump bypass or MIDCAB are available.
However, the reason why angioplasties are more popular are because of the quick recovery and absence of the need for open surgery though there maybe a need for repeat procedures.
Yes, those with diabetes have a two to fourfold risk of developing Coronary Artery Disease (CAD) and the extent and severity of CAD depends on the duration of diabetes. Whether the extent of coronary disease will warrant a stent or other treatment depends on the results of the coronary angiogram.
As to improving the chances of not needing stents or other intervention, while it has been shown that intensive lifestyle modification and medical therapy helps to prevent and mitigate the progression of diabetes, and also helps in modifying surrogate markers such as lipids (LDL, HDL) and hypertension etc to a favourable profile (and therefore less cardiovascular events) this may not have much impact on established CAD.
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