Coronary Artery Disease: When stents aren’t enough and surgery is needed.

Coronary artery disease is one of the most important heart conditions for Singaporeans to understand because it can develop quietly for years before causing chest pain, breathlessness, or a heart attack. It happens when the coronary arteries, the blood vessels that supply oxygen-rich blood to the heart muscle, become narrowed or blocked by a buildup of plaque made of fat, cholesterol, calcium, and inflammatory cells. For many people, medicines, lifestyle changes, and procedures such as angioplasty with stent placement can improve symptoms and reduce risk. But there are situations where stents are not enough, and bypass surgery becomes the better, and sometimes the safer, option.

For Singapore residents, this topic matters in practical ways. Many people here live active, busy lives, commute long hours, eat a mix of hawker and home-cooked meals, and manage common risk factors such as high blood pressure, diabetes, high cholesterol, and smoking history. Coronary artery disease does not always announce itself with dramatic symptoms. Some people first find out during a routine check-up, an ECG, a treadmill test, or after a heart attack. Understanding when stents may not solve the problem can help patients and families ask better questions, make informed decisions, and recognise why doctors sometimes recommend coronary artery bypass grafting, commonly called bypass surgery or CABG.

How coronary artery disease develops and why it can become complex

Coronary artery disease, often shortened to CAD, develops when the artery walls thicken and narrow due to atherosclerosis, the gradual accumulation of plaque. If the plaque is stable, a person may have no symptoms or only mild discomfort on exertion. If the plaque ruptures, a clot can form suddenly and block blood flow, which can trigger a heart attack. The severity of disease is not only about one blocked segment. It also depends on how many arteries are involved, where the narrowings are located, whether the left main coronary artery is affected, and how well the heart muscle is functioning.

Doctors typically assess CAD using symptoms, blood tests, ECG, echocardiography, stress testing, coronary CT angiography in selected cases, and invasive coronary angiography when necessary. Coronary angiography is a dye-based X-ray test that shows the inside of the arteries. It remains the standard way to define the anatomy before deciding whether medical therapy, stenting, or surgery is best. In Singapore, this assessment is commonly done in tertiary hospitals and specialist cardiac centres, where the heart team may include cardiologists, cardiothoracic surgeons, anaesthetists, and nurses who discuss the most appropriate treatment path.

Why symptoms alone do not tell the full story

Chest tightness is the best-known symptom, but CAD can also cause shortness of breath, fatigue, reduced exercise tolerance, upper abdominal discomfort, jaw pain, or discomfort in the arm or back. Some people, especially those with diabetes, may have less typical symptoms. A person may feel “fine” at rest but become breathless climbing stairs at a station or walking briskly in the heat. That does not necessarily mean the disease is mild. A single tight narrowing in a critical location can be more dangerous than several lesser narrowings in less important branches.

When stents work well, and when they may not be enough

Stents are tiny mesh tubes inserted through a catheter to open narrowed coronary arteries and keep them open. The procedure is called percutaneous coronary intervention, or PCI. In the right setting, PCI can relieve angina, restore blood flow during a heart attack, and shorten recovery time compared with open-heart surgery. For a single, straightforward blockage, especially in a vessel that is suitable for catheter treatment, a stent can be an excellent option.

However, stents are not always the best solution. The heart team may recommend bypass surgery instead when the disease is too extensive, too complex, or located in an area where long-term outcomes are better with surgery. This does not mean stents are ineffective. It means the anatomy and the overall clinical picture may favour another approach. In medical decision-making, the question is not “Which procedure is newer?” but “Which treatment offers the safest and most durable result for this particular patient?”

Situations where PCI may be limited

Some common reasons stents may not be enough include:

• Multiple blocked arteries, especially when several major vessels are affected
• Significant left main coronary artery disease, which involves the main vessel supplying a large portion of the heart
• Diffuse disease, where long stretches of artery are narrowed rather than one short blockage
• Complex lesions, including heavily calcified arteries, chronic total occlusions, or difficult branching patterns
• Diabetes with multivessel coronary artery disease, where surgery often provides better long-term outcomes in selected patients
• Reduced pumping function of the heart, especially when combined with severe coronary disease

In these situations, placing several stents may not address the full burden of disease, may carry higher risk, or may not provide durable relief. Restenosis, which means re-narrowing of the artery after treatment, is less common with modern drug-eluting stents than in the past, but complex disease can still lead to repeat procedures. Bypass surgery can offer a more complete revascularisation, meaning blood supply is restored to more of the heart muscle using grafts that route blood around the blocked segments.

Why location matters as much as the number of blockages

A blockage in a large proximal segment, such as the left main or the proximal left anterior descending artery, can affect a much larger area of heart muscle than a blockage in a smaller branch vessel. Even a single lesion may be serious if it is in a critical location. This is why treatment decisions are based on coronary anatomy, symptoms, test results, heart function, and overall surgical risk, not just a simple count of “one blockage” versus “three blockages.”

What bypass surgery does differently

Coronary artery bypass grafting, or CABG, is an operation that creates a new route for blood to reach the heart muscle. Surgeons use a blood vessel graft, often taken from the internal mammary artery in the chest, the radial artery in the arm, or a vein from the leg, and connect it beyond the blocked segment. Blood then flows through the graft to nourish the heart tissue downstream of the obstruction.

Bypassing the blockage does not remove the plaque itself. Instead, it routes blood around the problem. This can be especially useful when multiple arteries are diseased or when the artery walls are so diffusely narrowed that putting in a stent would not restore a good result. CABG is performed under general anaesthesia and requires a longer recovery than PCI, but for the right patient it can provide more complete revascularisation and better symptom control over time.

How surgeons decide which grafts to use

The choice of graft matters. The left internal mammary artery, when used to bypass the left anterior descending artery, has excellent long-term durability and is a cornerstone of bypass surgery. Vein grafts can also be effective but may have lower long-term patency than arterial grafts. In some cases, surgeons may use multiple arterial grafts depending on the patient’s age, anatomy, diabetes status, kidney function, and overall risk profile. The aim is to build a durable blood supply to the heart with the least risk possible.

Beating heart versus conventional bypass

Some CABG operations are performed with a heart-lung machine, while others are done on a beating heart without cardiopulmonary bypass in selected patients. The surgical approach depends on the individual case and the surgeon’s assessment. There is no one-size-fits-all method. The key is whether the chosen technique can provide safe, complete, and lasting revascularisation.

How doctors decide between stents and surgery in Singapore

In Singapore, CAD treatment generally follows established cardiovascular practice standards used internationally, with decisions adapted to the individual patient’s anatomy, symptoms, and risk factors. Patients may first see a general practitioner, then a cardiologist, and if needed, a cardiothoracic surgeon. For complex disease, a multidisciplinary heart team discussion is especially valuable. This team-based approach reflects good clinical practice because coronary artery disease is not just a plumbing problem, it is a whole-patient condition influenced by diabetes, kidney disease, blood pressure control, medication adherence, and lifestyle.

Doctors often consider several factors when deciding whether a stent or bypass surgery is more appropriate:

• How many arteries are blocked and how severe the narrowings are
• Whether the left main artery is involved
• Whether the disease is focal or diffuse
• Whether the patient has diabetes
• Whether the heart’s pumping function is reduced
• Whether the patient has had previous stents or previous bypass surgery
• Whether symptoms persist despite optimal medication
• The patient’s overall surgical risk, including age, kidney function, lung disease, and frailty

In practice, a patient may be told that PCI is technically possible, but CABG may provide a more complete and durable solution. Another patient, especially one with a single short blockage and otherwise normal arteries, may be an excellent candidate for a stent. Both recommendations can be correct. The best choice depends on the disease pattern, not on which procedure sounds simpler.

What to ask your doctor if surgery is suggested

Patients in Singapore often want clear, practical answers before agreeing to surgery. Useful questions include: Why is surgery better for my case? How many arteries are blocked? Is the left main artery involved? What type of grafts will be used? What are the expected benefits in my situation? What risks should I understand? How long is the hospital stay and the recovery period? What changes should I make after discharge? These questions can help patients and families feel more confident and involved in the decision.

Recovery, long-term care, and what life looks like after treatment

Whether treatment is done with a stent or bypass surgery, coronary artery disease remains a chronic condition that requires ongoing care. The procedure treats the current blockage pattern, but it does not cure the underlying tendency to develop plaque. Long-term management usually includes cholesterol-lowering therapy, often with statins, blood pressure control, diabetes management, antiplatelet medication when prescribed, smoking cessation, exercise, and dietary adjustments. Cardiac rehabilitation can be extremely helpful after a heart event or surgery, because it combines supervised exercise, education, and lifestyle support.

After bypass surgery, recovery takes time. Patients may need to manage chest discomfort from the surgical wound, breathing exercises, and gradual return to activity. Walking is usually encouraged early, but heavy lifting and strenuous exertion are restricted for a period as advised by the surgical team. People with desk jobs may return earlier than those whose work involves physical labour, but the timeline varies. In Singapore, many patients also have to plan around caregiving responsibilities, public transport, and work expectations, so realistic discharge planning matters.

Lifestyle changes that fit Singapore living

Practical heart-healthy habits do not require dramatic changes overnight. Small, sustainable steps can make a real difference. These include choosing smaller portions of fried foods, limiting sugary drinks, reducing salt-heavy sauces, increasing vegetables, and selecting leaner protein more often. For exercise, brisk walking in a park, swimming, or cycling on safe routes can be appropriate when cleared by the doctor. If weather or schedules make outdoor activity difficult, indoor walking at malls or community centres can still help. For smokers, stopping smoking is one of the most important actions to reduce future cardiovascular risk.

It also helps to keep medical follow-up regular. Many Singaporeans juggle work, family, and health appointments, but blood pressure, cholesterol, and diabetes control should not be left to chance. Missing medicines or stopping them early after PCI or CABG can increase risk. Patients should always follow the prescribed regimen and clarify any side effects, bruising, dizziness, or bleeding concerns with a doctor.

Recognising urgent symptoms and seeking timely care

Chest pain that feels heavy, tight, or crushing, especially if it spreads to the arm, jaw, back, or is associated with sweating, nausea, or shortness of breath, needs urgent medical assessment. Symptoms that occur at rest, worsen over minutes, or do not improve quickly should not be ignored. In Singapore, emergency services are available, and timely treatment can save heart muscle. People with known coronary artery disease should know their warning signs and have a clear plan for when to seek help.

Even after stenting or bypass surgery, new symptoms should be reviewed promptly. A procedure reduces risk, but it does not eliminate the possibility of future disease progression in other segments of the coronary arteries. Early assessment can identify whether symptoms are related to the heart, medication issues, anaemia, lung disease, reflux, or another cause.

Coronary artery disease is manageable, but it deserves respect. Stents are highly useful in many patients, yet they are not a universal answer. When the disease is complex, widespread, or located in critical segments, bypass surgery may offer a better path to symptom relief and long-term heart protection. The right decision comes from careful assessment, honest discussion, and a treatment plan tailored to the individual. For Singaporeans, the key message is straightforward: if your doctor recommends surgery instead of another stent, it is often because the anatomy and evidence suggest that surgery offers the better balance of safety, durability, and heart function preservation. A thorough conversation with your cardiologist and, when appropriate, your cardiothoracic surgeon can clarify the best next step for your heart health.

Medical note: This article provides general health information for awareness and education. It is not a substitute for personalised medical advice, diagnosis, or treatment. If you have chest pain, shortness of breath, or symptoms suggestive of a heart problem, seek prompt medical assessment.