Medically Reviewed By: Dr Paul Lim – MBBS, M.Med (Int Med), MRCP (UK), FAMS (Cardiology)
Coronary Artery Disease Symptoms, Tests & Treatment
Coronary artery disease is the gradual narrowing of the arteries that supply your heart muscle, and at every stage there is something worth doing about it. Been told you have a narrowing, or worried it runs in the family? Dr Paul Lim is easy to talk to, and will set out plainly what your arteries are doing and what your options are.
Dr Paul Lim Chun Yih
Senior Consultant Cardiologist & Electrophysiologist
CT Coronary Calcium Score — S$403.30 (NETT, incl. GST). A short scan that shows whether calcified plaque has already formed in your heart’s arteries, and grades how much of it there is. Available at our Orchard clinic.
What Is Coronary Artery Disease?
Your heart is a muscle, and it needs its own blood supply. Three arteries sit on its surface and deliver it.
The three coronary arteries
Those three vessels are the coronary arteries, and each one feeds a different territory:
- The left anterior descending artery (LAD) runs down the front of the heart and supplies the front wall and most of the main pumping chamber. It covers the largest territory, so a narrowing here carries the most weight.
- The left circumflex artery (LCx) curves around the left side to supply the side and back walls.
- The right coronary artery (RCA) runs down the right side, supplying the right chamber, the underside of the heart and, in most people, the heart’s natural pacemaker and its wiring.
Coronary artery disease is what happens when fatty material builds up inside their walls, thickening them from within and leaving a narrower channel for blood to pass through. The medical name for that build-up is atherosclerosis, and the material itself is called plaque.
- Heart muscle
- Coronary arteries and blood flow
- Plaque narrowing the artery
What happens when one narrows
At rest, a partly narrowed artery usually copes. The trouble starts when the heart is asked to work harder. Climb a flight of stairs and the muscle needs more oxygen; a healthy artery widens to supply it, while a narrowed one cannot. That shortfall between supply and demand is called ischaemia, and when you can feel it, it is called angina.
Why a mild narrowing can still matter
Plaque matters for a second reason that has nothing to do with how narrow the artery is: it can rupture. A clot then forms at the site within minutes and can block the artery outright. That is a heart attack, and it happens most often in arteries that were only moderately narrowed, in people who had never felt a thing.
- 1. Narrowed, but stable Blood still gets past. This can sit unchanged for years.
- 2. The cap tears The surface splits open. Size has little to do with it.
- 3. A clot blocks it Within minutes the artery shuts. That is a heart attack.
The same condition, several names
Four names for the same disease turn up on reports and referral letters: coronary artery disease (CAD), coronary heart disease (CHD), ischaemic heart disease (IHD) and atherosclerotic heart disease.
The same process affects the arteries to the brain, where it causes stroke, and to the legs, where it causes peripheral arterial disease. Finding it in one place is a reason to look at the others.
How common it is in Singapore
Symptoms of Coronary Artery Disease
The pattern matters more than the sensation. Discomfort that arrives with effort and settles with rest is the signature.
Angina, the classic symptom
People rarely call it pain. The words that come up in clinic are tightness, heaviness, pressure, a band around the chest, or a weight sitting on it. It is usually felt centrally, behind the breastbone, and it can spread to the jaw, neck, shoulder, either arm, or through to the back.
What makes it recognisable is the pattern:
- Brought on by exertion. Stairs, a slope, carrying shopping, hurrying for a bus.
- Worse in the cold, after a big meal, or under stress.
- Eases within a few minutes of stopping. The single most useful clue.
- Reproducible. The same effort brings on the same discomfort.
When it is not chest discomfort at all
A substantial minority never get the textbook chest tightness, and what they do get is easy to put down to age or being out of condition:
- Breathlessness on exertion where there was none a year ago.
- Unusual fatigue, or a quiet drop in what you can manage.
- Jaw, neck, shoulder or arm discomfort that comes with effort and goes with rest.
- Nausea, sweating or light-headedness during exertion.
- Indigestion-like burning that exercise brings on and antacids do not touch.
This matters most in people with diabetes, where nerve damage can blunt the warning, and in the elderly. In women, chest discomfort is still the commonest symptom, as it is in men, though women may be more likely to describe it in other terms, or to notice breathlessness alongside it. If you are explaining away a change in what you can do, that is worth a conversation.
When there are no symptoms
Silent coronary artery disease is common. An artery can narrow a long way before the heart complains, because the body compensates: you slow down without noticing, take the lift, stop doing the thing that brought the discomfort on. A plaque that has not yet limited flow gives you nothing to feel, and can still burst.
Which is the argument for looking rather than waiting. If you have high cholesterol, high blood pressure, diabetes, a smoking history or an early family history, your risk can be measured now rather than discovered later.
Emergency — Call 995 or go to A&E
Do not wait, and do not drive yourself, if you have:
- Chest pain or tightness lasting more than a few minutes, or coming and going
- Chest discomfort that does not settle with rest
- Chest discomfort with sweating, nausea, or severe breathlessness
- Discomfort spreading to the arm, jaw, neck or back
- Fainting or collapse
Book a cardiologist appointment
Arrange prompt review if:
- Chest tightness comes on with exertion and eases with rest
- You are more breathless on stairs or slopes than you used to be
- Angina you already know about is happening more often, or with less effort
- A scan or ECG report has raised the possibility of coronary disease
- You are concerned, or would like a second opinion on a result
Worth assessing, not alarming
Reasons to check your risk while you feel well:
- A parent or sibling with heart disease before 55 (men) or 65 (women)
- High cholesterol, raised blood pressure or diabetes
- A current or past smoking history
- You are over 40 and have never had your cardiovascular risk measured
Recognise yourself in any of that? Find out whether your arteries are behind it.
Angina: Stable, Unstable and Variant
Angina, or angina pectoris, is the symptom rather than the diagnosis. Which type you have changes how urgently it needs attention.
Stable angina
Angina with a predictable pattern. A known amount of effort brings on a known amount of discomfort, which settles within minutes of resting or after a glyceryl trinitrate (GTN) spray, and it has usually been the same for weeks or months. It still needs assessment and treatment, since the disease behind it progresses, but it is not an emergency.
Unstable angina
The pattern has changed, and that change is the warning: a plaque has become unstable and a clot is forming on it. Unstable angina sits alongside heart attack under the heading acute coronary syndrome, and it needs emergency assessment.
Treat any of these as an emergency:
- Angina that comes on at rest, or wakes you from sleep
- Angina triggered by much less effort than it used to take
- Episodes that are more frequent, more severe or lasting longer
- Discomfort that no longer settles with rest or with your GTN spray
- Chest discomfort you have never had before, lasting more than a few minutes
Call 995 rather than arranging an appointment, and do not drive yourself to hospital.
| Stable angina | Unstable angina | |
|---|---|---|
| What brings it on | A predictable level of exertion or stress | Less effort than before, or nothing at all |
| How long it lasts | Usually under 10 minutes | Longer, or it does not stop |
| Response to rest or GTN | Settles reliably | Poor response, or none |
| Pattern over time | Unchanged for weeks or months | Recently worse, more frequent or new |
| What to do | Book a cardiologist appointment | Call 995 or go to A&E |
Variant (Prinzmetal) angina
An artery can go into spasm and narrow sharply with little plaque present, which is variant or Prinzmetal angina. It strikes at rest, often in the early hours, and can affect people who look low-risk on paper. Treatment is medication that relaxes the artery, not a stent.
Angina with normal arteries
Some people have genuine angina while an angiogram shows arteries that are largely clear. The problem lies in vessels too small for the scan to see, and it is called microvascular angina. It is commoner in women. The symptom is real, it has a name, and it has treatment.
Chest tightness that arrives with exertion and eases with rest? Have it assessed by Dr Paul Lim.
Causes and Risk Factors
Plaque does not appear overnight. It accumulates across decades, and most of what drives it can be measured and changed.
How a plaque forms
It begins with damage to the lining of the artery. High blood pressure, tobacco smoke, high blood sugar and LDL cholesterol all injure it, and once it is damaged, fat works its way into the wall. The body seals the deposit over with a fibrous cap and, in time, calcium.
That is the whole of treatment in miniature. Less LDL in the blood means less material getting in, which is why lowering cholesterol works. A thicker cap means a plaque less likely to burst, which is why stabilising one matters as much as widening the channel.
Risk factors you can change
-
High LDL cholesterol The biggest driver you can do something about.
-
Smoking and vaping Damages the artery lining and makes clots likelier.
-
High blood pressure Stresses the artery wall day in, day out.
-
Type 2 diabetes Speeds the process up and blunts the warning symptoms.
-
Central obesity Weight carried around the middle in particular.
-
Physical inactivity Worsens nearly every other item here.
-
Poor sleep and sleep apnoea Often untreated, and it raises blood pressure.
-
Chronic stress Raises pressure, and drags other habits with it.
Risk factors you cannot change
-
Age Risk climbs steadily from the forties onwards.
-
Family history A parent or sibling affected before 55 (men) or 65 (women).
-
Sex Men develop it earlier; women catch up after menopause.
-
Ethnicity Risk differs at the same cholesterol reading.
-
Lipoprotein(a) Inherited, missed by a standard panel, measured once.
-
Kidney and inflammatory disease Chronic kidney disease, rheumatoid arthritis and similar.
An inherited risk factor is a reason to start looking earlier, not a verdict. Family history changes when you screen and how firmly the modifiable factors are treated.
How Coronary Artery Disease Is Diagnosed
No single test answers every question. Which one you need depends on whether you have symptoms, and on how likely the disease is before any test is done.
A consultation starts with the story, because the pattern of the symptoms carries real diagnostic weight, and continues with the tests that fit the question being asked.
The tests, and what each one answers
-
ECG A few minutes. Often normal here, so it cannot clear you, but it can show a past silent heart attack.
-
Treadmill stress test · S$218 Walking on an incline while the ECG runs. Reveals narrowing that rest conceals.
-
2D echocardiogram Ultrasound of the pumping. Segments that move poorly suggest muscle already damaged.
-
CT calcium score · S$403.30 No injection, no treadmill. A score of zero is genuinely reassuring if you have no symptoms.
-
CT coronary angiogram · S$1,384.30 Dye plus CT. Shows whether narrowing is there and how severe.
-
Invasive coronary angiogram In hospital, through a fine catheter. The reference standard, and a stent can go in at the same sitting.
What 50% or 70% narrowing means
A CT or invasive angiogram describes each narrowing as a percentage: how much of the vessel’s width the plaque has taken up. These are the conventions used to describe a narrowing, not thresholds that decide treatment on their own.
| Narrowing | Usually called | What it usually means |
|---|---|---|
| Under 50% | Mild, or non-obstructive | Plaque is present but flow is not limited. It rarely causes angina, and it is still a reason to treat cholesterol and the other risk factors, because a plaque this size can rupture. |
| 50–69% | Moderate | Borderline. Whether it limits flow depends on the artery and how much muscle lies below it, so it is often settled with a functional test rather than the picture alone. |
| 70% or more | Severe, or obstructive | Flow-limiting in most cases, and the usual cause of angina on exertion. Where symptoms persist despite treatment, opening the artery is considered. |
| Left main, 50% or more | Significant left main disease | Treated as severe at a lower percentage, because this single vessel supplies most of the muscle. |
A percentage is a measurement, not a verdict. What follows depends on your symptoms, which artery is involved, how much muscle sits below the narrowing, and what a functional test shows.
How many arteries are involved
The other half of the report is how widely the disease is spread. Single vessel disease means one of the three arteries is significantly narrowed, double vessel disease two, and triple vessel disease all three. Left main disease is counted separately, since a narrowing there affects everything downstream of it.
The count matters because it shapes what is recommended. A single narrowing is often managed with medication, or with a stent where symptoms persist. Triple vessel disease and left main disease are the settings in which bypass surgery is more often the better option, particularly for people with diabetes.
Blood tests that inform the picture
Blood tests do not find a narrowing. They measure what is driving it, and they set the targets treatment aims at: a lipid panel first, then apolipoprotein B, lipoprotein(a), hs-CRP and HbA1c where they add something.
Every tier of our heart screening packages bundles these with a consultation, and the upper tiers add CT imaging.
Not sure which of these tests you need? Ask Dr Paul Lim, who will pick the one that answers your question.
Treatment for Coronary Artery Disease
Treatment has two jobs that run in parallel: relieve the symptoms, and reduce the chance of a heart attack. The second is the one that changes outcomes.
Lifestyle, which does more than people expect
- Stopping smoking. The highest-value change available, and it starts paying within weeks.
- Regular aerobic activity, about 150 minutes a week. Ask first if you have symptoms.
- Diet. Less saturated fat and refined carbohydrate; more vegetables, whole grains, nuts and oily fish.
- Weight around the waist, which shifts blood pressure, blood sugar and triglycerides together.
- Sleep and stress, including treatment for sleep apnoea.
Our guide to building a stronger heart covers these in practical detail.
Medication
The combination depends on your risk, your other conditions and what you tolerate.
- To lower cholesterol: a statin, which also stabilises plaque, with ezetimibe or a PCSK9 inhibitor added if LDL stays above target.
- To stop clots forming: an antiplatelet, usually low-dose aspirin. After a stent you take two rather than one, aspirin plus clopidogrel, ticagrelor or prasugrel, which is called dual antiplatelet therapy. It runs for a defined period, commonly around six months, or about a year after a heart attack, before stepping back to a single drug. Your cardiologist sets the duration.
- To lower blood pressure: an ACE inhibitor, ARB, beta-blocker or calcium channel blocker.
- To ease the angina itself: a beta-blocker or calcium channel blocker daily, and a GTN spray for episodes.
- For diabetes: some of the newer drugs lower cardiac risk beyond their effect on blood sugar.
Never stop or change a cardiac medication on your own, and never stop either antiplatelet after a stent without asking the doctor who prescribed it. Stopping the second one early is a leading cause of a stent clotting off.
Opening a narrowed artery: angioplasty and stents
Where a narrowing limits blood flow, or symptoms persist despite treatment, the artery itself may need attention:
- Coronary angioplasty and stenting (percutaneous coronary intervention, or PCI). A balloon widens the narrowed segment, and a heart stent, which is a small metal scaffold, holds it open. The catheter goes in through the wrist or groin, and the hospital stay is usually short.
- Coronary artery bypass grafting (CABG). Open surgery routing blood around the narrowings, using vessels taken from the chest, arm or leg. Usually preferred for triple vessel or left main disease, and for people with diabetes and extensive disease.
A stent restores flow through the segment it sits in. It does not treat the rest of the artery, which is why the tablets and the habits carry on afterwards.
Dr Paul Lim assesses coronary artery disease, arranges the imaging and manages the medical treatment. Where angioplasty or bypass surgery is indicated, he refers on to an interventional cardiologist or cardiac surgeon and continues your follow-up care.
Holding a scan result, or would simply like a second opinion on the plan? Sit down with Dr Paul Lim.
Can Coronary Artery Disease Be Reversed?
Partly. What is achievable is more encouraging than the word “reversed” suggests.
What does not go away
Plaque that has calcified does not dissolve. In that literal sense the disease does not go away, and no diet or supplement clears a calcified artery.
What treatment does change
Lowering LDL hard halts progression in most people, and shrinks the softer part of a plaque modestly. What matters more is that the plaque changes character: the cap thickens and it becomes far less likely to burst. Since bursting is what causes heart attacks, a stabilised plaque is a much safer one even when the narrowing looks unchanged on a scan.
So the realistic goal is to stop it getting worse and make what is there less dangerous, which is achievable for most people with tablets and habits. People live decades with treated coronary artery disease.
A calcium score will not fall with treatment, and may rise slightly as soft plaque calcifies and stabilises. A rising score on treatment is not, on its own, evidence that treatment has failed. It is interpreted alongside your symptoms and your cholesterol figures.
Living With Coronary Artery Disease
A diagnosis usually changes your treatment and your monitoring far more than it changes your daily life.
How long you can expect to live with it
There is no single figure. It depends on how many arteries are involved, how well the heart muscle pumps, whether you have had a heart attack already, and how well cholesterol, blood pressure and diabetes are controlled from here.
The part within your control is substantial. Someone who stops smoking, gets their LDL to target and takes their treatment consistently has a materially different outlook from someone with the same scan who does none of those things. The diagnosis starts a long-term condition, not a countdown.
Exercise, work and travel
- Exercise is part of the treatment, not a risk to avoid. Agree the intensity before you push it.
- Most people return to their usual work. If yours is physically demanding, raise it at your consultation.
- Carry your GTN spray if one has been prescribed, tell someone at home where it is, and read the note on erectile dysfunction tablets below.
- Check in before long flights or trips to altitude, particularly after a recent stent or heart attack.
- Sexual activity is generally fine once you manage moderate exertion without symptoms. If you use a GTN spray, or any other nitrate, do not take an erectile dysfunction tablet such as sildenafil, tadalafil or vardenafil. Taken together they can drop your blood pressure dangerously low, and the combination has been fatal. Tell whichever doctor prescribes one that you take the other.
That interaction runs both ways. After sildenafil or vardenafil, GTN should be avoided for at least 24 hours; after tadalafil, which lasts longer, for at least 48 hours. If you develop chest pain in that window, call 995 and tell the crew what you have taken and when, so they can treat you safely without nitrates.
If you have been advised not to drive after a cardiac event or procedure, follow that advice until you have been reassessed and told it is safe. Any declaration or licensing question that follows is one for the relevant authority, so ask them directly.
Monitoring
Expect periodic review of your cholesterol, blood pressure, blood sugar and kidney function, as often as your situation warrants. Report any change in your symptom pattern rather than waiting for the next appointment.
When to See a Cardiologist
Book an assessment if any of these apply:
- Chest tightness or breathlessness that exertion brings on and rest relieves
- A drop in what you can manage physically that you have been explaining away
- A calcium score, CT angiogram or ECG report suggesting coronary disease
- A parent or sibling who had a heart attack, stent or bypass before 55 in men or 65 in women
- You are concerned, or would like a second opinion on a result
Dr Paul Lim is a Senior Consultant Cardiologist and Electrophysiologist consulting at Orchard and Jurong. A first consultation usually includes an ECG, and then whichever of an echocardiogram, treadmill stress test or CT scan fits what you describe. Still weighing it up? Our guide on when to see a cardiologist may help.
Book a Coronary Artery Disease Assessment
See Dr Paul Lim to have your symptoms, your scans and your cardiovascular risk reviewed together.
Send Us a Message
Where to Get Your Heart Arteries Checked in Singapore
Opening Hours
| Monday – Friday | 8:30 AM – 5:30 PM |
| Saturday | 8:30 AM – 12:30 PM |
| Sunday & Public Holidays | Closed |
By Appointment Only
Coronary Artery Disease FAQ
The questions people most often arrive with about narrowed heart arteries, angina and what happens next.
Can you have coronary artery disease without symptoms?
Yes, and it is common. An artery can narrow a long way while the body quietly compensates, and a plaque that has not yet limited flow gives you nothing to feel, even though it can still burst. That is why a heart attack is sometimes the first sign, and why risk assessment is offered to people who feel completely well.
Can coronary artery disease be reversed?
Partly. Calcified plaque does not dissolve, and no diet or supplement clears it. What treatment achieves is still worth having: lowering LDL hard halts progression in most people and thickens the cap over a plaque, so it is far less likely to burst. Since bursting causes heart attacks, a stabilised plaque is much safer even when the narrowing looks the same on a scan.
Is coronary artery disease hereditary?
Family history is one of the strongest risk factors, particularly a parent or sibling affected before 55 in men or 65 in women. Genes influence cholesterol, blood pressure and inflammation, and inherited conditions such as familial hypercholesterolaemia and raised lipoprotein(a) raise risk sharply. It changes when you should start looking and how firmly the rest is treated, rather than deciding the outcome.
How long can you live with coronary artery disease?
There is no single figure. It depends on how many arteries are involved, how well the heart muscle pumps, whether you have had a heart attack, and how well cholesterol, blood pressure and diabetes are controlled from here. Many people live for decades with treated coronary artery disease, and the part within your control is substantial.
Can you get coronary artery disease in your 20s or 30s?
It is uncommon but it happens. Plaque can start forming in adolescence, and symptoms this young usually point to a strong driver: familial hypercholesterolaemia, markedly raised lipoprotein(a), heavy smoking or poorly controlled diabetes. Chest tightness on exertion deserves assessment at any age, and a young person with a strong family history should have cholesterol and Lp(a) measured.
Do I need a stent if I have coronary artery disease?
Not necessarily. Many people are treated with medication and lifestyle change alone. A stent is considered when a narrowing limits blood flow, when symptoms persist despite treatment, or during a heart attack or unstable angina. It restores flow through the segment it occupies but does not treat the rest of the artery, so the tablets continue afterwards.
What does 70% blockage in a heart artery mean?
It means plaque has taken up about 70% of the width of that artery. At that size it usually limits blood flow once the heart works hard, which is why it is the point where angina on exertion becomes likely and opening the artery starts to be considered. Under 50% is called mild, or non-obstructive, and rarely causes symptoms, though it is still a reason to treat cholesterol. Between 50 and 69% is borderline. The left main artery is the exception, where 50% counts as significant.
Is a blocked artery the same as heart block?
No, and the similar wording confuses a lot of people. A blocked artery is coronary artery disease, a problem in the vessels supplying the heart muscle, and it causes angina or a heart attack. Heart block is a fault in the heart’s electrical wiring, so the signal is delayed or fails to get through, and it causes a slow pulse, fatigue or fainting. Different tests, different treatments.