Heart artery blockage is a common concern among patients who visit a cardiologist. When symptoms of blocked arteries start to appear, many people worry about whether they will eventually need a stent or bypass surgery. The decision depends on several factors, including the severity of the blockage, risk levels and how the heart is coping with reduced blood flow.
At Gerard Leong Cardiology Clinic, our patients often seek clarity on what treatment option is best for their situation. The goal is never to rush people into procedures. Instead, our cardiologists use a structured evidenced based approach to evaluate the most appropriate treatment option for the most optimal outcome- whether lifestyle management with medication alone or if stenting or bypass surgery is needed to achieve it. This article explains how cardiologists make that decision and what patients should understand about each option.
Key Takeaways
- Stents and bypass surgery are recommended when a heart artery blockage significantly restricts blood flow or when symptoms cannot be controlled with medication.
- A cardiologist evaluates symptoms of blocked arteries, imaging results and functional tests to determine if a blockage is dangerous.
- Stents are often suitable for one or two blocked arteries, while bypass surgery is usually preferred for complex or multi-vessel disease.
- Diagnostic tests such as CT angiography, coronary angiography, FFR and iFR help cardiologists make accurate and personalised treatment decisions.
- Even after a stent or bypass, lifestyle changes and long term medication remain essential to protect future heart health.
What Happens When Heart Arteries Become Blocked
Heart arteries supply oxygen-rich blood to the heart muscle. Over time, cholesterol, fat and calcium build up in the artery walls, forming plaque. This condition is known as coronary artery disease.
How Blockages Develop
Heart artery blockages do not form overnight. They develop slowly over many years due to changes within the artery walls. This gradual process explains why some people remain symptom-free for a long time, even when plaque is already building up.
Plaque Formation Inside the Arteries
Plaque begins to accumulate when cholesterol, fat and calcium settle along the inner lining of the coronary arteries. Over time, this build-up causes the artery walls to thicken and harden. As the plaque enlarges, the space inside the artery becomes narrower, reducing the amount of blood that can pass through easily.
Why Blockages Become Dangerous Over Time
As the artery continues to narrow, the heart receives less oxygen-rich blood, especially during physical activity when the heart demands more oxygen. This reduced supply can lead to symptoms such as chest discomfort, breathlessness or fatigue.
If the plaque becomes unstable and ruptures, a blood clot may form suddenly at the site. A complete blockage can occur within minutes, which is the most common cause of a heart attack. This progression highlights the importance of early detection, monitoring and timely treatment to prevent serious complications.
Why Symptoms Occur
Symptoms occur when the heart struggles to get enough blood to keep up with daily activities. The most common symptoms and signs on exertion or at rest include:
- Chest discomfort or pain or pressure
- Shortness of breath
- Fatigue
- Pain in the jaw, neck, arm or back
- Light headedness
- Cold sweats that cannot be explained or accounted for
However, some people experience no symptoms at all. This is known as silent heart artery blockage. It is common in individuals with diabetes.
How Cardiologists Diagnose Heart Artery Blockages
To determine whether a stent or bypass is necessary, the cardiologist must first confirm how severe the blockage is and how it affects heart function.
Clinical Evaluation
The cardiologist asks about:
- When the symptoms started
- What triggers the symptoms or discomfort
- Whether rest improves the symptoms or discomfort
- The frequency and intensity of chest pain or discomfort
Risk Assessment
Risk factors that increase the likelihood of severe artery blockage include:
- Diabetes
- Smoking
- High blood pressure
- High cholesterol
- Family history of heart disease
Diagnostic Tests Used to Assess Blockages
Electrocardiogram (ECG)
An ECG records the electrical signals that travel through the heart with every heartbeat. It helps identify abnormal rhythms, previous silent heart attacks and areas of the heart that may not be receiving enough oxygen. Although it does not show the arteries directly, it is an important first step in evaluating chest pain or unexplained breathlessness.
Echocardiogram
An echocardiogram uses ultrasound waves to create live images of the heart. It allows the cardiologist to assess how well the heart muscle contracts and relaxes, whether the valves are functioning properly and whether any part of the heart is weakening due to reduced blood flow. This test is especially useful for understanding the impact of a blockage on overall heart function.
Stress Tests
A stress test evaluates how the heart performs when it is required to work harder, either through physical exercise or medication that simulates exertion. If certain areas of the heart do not receive enough blood during stress, it may indicate a significant blockage. This test helps identify whether symptoms are related to coronary artery disease and guides further investigation.
CT Coronary Angiography (CTCA)
A non-invasive scan that provides detailed images of the coronary arteries. It helps identify:
- Plaque build up
- The type of plaque
- Severity of narrowing
Coronary Angiography with and without Intravascular Ultrasound (IVUS)
Coronary angiography is considered the gold standard for diagnosing heart artery blockages. A thin catheter is inserted through the wrist or groin to inject dye into the coronary arteries. X-ray images then reveal the exact location, size and complexity of any narrowing. Accuracy is enhanced with IVUS interrogation of suspicious blockages.
This test is essential when determining and planning appropriate interventions such as stenting or bypass surgery to re-establish coronary blood flow.
FFR and iFR
Fractional Flow Reserve (FFR) and Instantaneous Wave Free Ratio (iFR) measure the pressure differences across a blockage to assess whether it is truly restricting blood flow. This is important because some blockages may appear severe on imaging but do not significantly affect circulation. FFR and iFR help ensure that stents are placed only when necessary, allowing cardiologists to make safe and targeted treatment decisions.
Comparing Diagnostic Tests for Heart Artery Blockages
Test | Purpose | Strengths | Used When |
ECG | Checks electrical activity | Quick and widely available | Initial evaluation |
Echocardiogram | Assesses heart function | Non invasive | Suspected heart weakness |
Stress Test | Evaluates blood flow under stress | Good for detecting exertional symptoms | When symptoms occur during activity |
CTCA | Visualises plaque and narrowing | Detailed anatomical images | Early detection or screening |
Coronary Angiography | Confirms severity of blockages | Gold standard | When planning stent or bypass |
Intravascular Ultrasound (IVUS) | Assess severity of blockages using ultrasound waves | Enhances further accuracy of coronary angiography | When blockage is borderline significant, especially in the determination on need for stent or bypass
When blockage is borderline |
FFR/iFR | Determines functional severity | Highly accurate |
When a Stent Becomes Necessary
A stent may be recommended when the blockage disrupts blood flow enough to cause symptoms or pose a risk of heart attack.
1. Symptoms Affect Quality of Life
A stent is often recommended when symptoms interfere with daily activities despite medication. If chest pain, breathlessness or physical discomfort continue to limit normal tasks such as walking, climbing stairs or performing light exercise, it may indicate that the artery is too narrow to supply sufficient blood. When lifestyle modifications and medication are no longer effective, placing a stent can relieve symptoms and help patients regain confidence in their daily routines.
2. One or Two Vessel Disease
Stents are particularly effective when only one or two arteries are affected and the blockages are localised. In these cases, the narrowing is usually short, predictable and technically straightforward to treat. Stenting helps restore blood flow quickly without the need for major surgery, allowing patients with limited disease to resume normal activities sooner. This approach is often preferred when the remaining arteries appear healthy and heart function is well preserved.
3. Heart Attack or Unstable Symptoms
During a heart attack or when symptoms become unstable, time is critical. An artery may be severely or suddenly blocked, preventing oxygen from reaching part of the heart muscle. In such situations, a stent is inserted urgently to restore blood flow and minimise long-term damage. Quick intervention reduces the risk of complications and improves recovery outcomes. Stents are also used when symptoms escalate rapidly, such as chest pain occurring even at rest or sudden breathlessness.
4. Abnormal Functional Tests
In some cases, a blockage may not look severe on imaging, but functional tests reveal that blood flow is significantly reduced. FFR and iFR help measure the pressure difference across the narrowed area, showing whether the heart is struggling to receive enough oxygen. If these tests confirm that the blockage is restricting circulation, placing a stent can prevent worsening symptoms and reduce the risk of future heart events. This ensures treatment is given only when truly needed, based on accurate and personalised measurements.
When Bypass Surgery Is Recommended
Bypass surgery is usually recommended when the pattern of heart artery blockage is more severe or complex. Instead of opening the artery from within, bypass surgery creates a new route for blood to flow around the blocked area, ensuring the heart receives the oxygen it needs. Cardiologists consider several specific scenarios when bypass may offer safer or more effective results than a stent.
1. Multi-Vessel Disease
Bypass surgery is often advised when three or more major coronary arteries are significantly narrowed. In multi-vessel disease, blockages tend to occur in different locations and affect several parts of the heart.
Treating each artery with multiple stents may not provide the same long-term benefit as bypass surgery. Bypass can restore strong, consistent blood flow to multiple areas of the heart at once, which helps improve symptoms and reduces the risk of future complications.
2. Left Main Artery Blockage
The left main coronary artery supplies a large portion of the heart muscle, making it one of the most critical vessels. When this artery becomes severely narrowed, the risk of a major heart attack rises substantially. Because of the importance of this vessel, bypass surgery is often recommended over stenting, as it provides a more durable and reliable solution. A bypass graft ensures that a stable flow of blood continues to reach the areas of the heart that depend on this vital artery.
3. Complex Artery Structure
Some blockages are simply too difficult to treat effectively with stents. When the narrowing is long, heavily calcified or located at a branch point involving multiple arteries, the structure becomes more challenging. In these cases, stents may not expand fully or remain stable over time.
Bypass surgery offers a safer and more predictable option because the surgeon can create an alternate pathway that avoids the difficult area altogether. This approach ensures better long term outcomes for patients with complex anatomy.
4. Patients with Diabetes
People with diabetes are more likely to develop widespread and aggressive coronary artery disease. Their blockages often involve multiple vessels and may progress faster than in individuals without diabetes.
Research consistently shows that bypass surgery provides better long-term survival and fewer repeat procedures for diabetic patients with multi-vessel disease. By offering more complete restoration of blood flow, bypass surgery helps protect heart function and reduces the risk of future cardiac events.
Do All Blockages Require Treatment?
Not all heart artery blockages automatically require a stent or bypass. Some can be safely managed with optimal medical management- OMT- this involves lifestyle adjustments- total lifestyle management- and medications. This is especially when the narrowing is not severe or when blood flow to the heart remains adequate.
Cardiologists assess the overall pattern of disease, the patient’s symptoms and the results of functional tests before deciding whether optimal medical management therapy alone is appropriate.
When Medication Is Enough
Medication is often suitable when the blockage is mild or moderate and does not heavily restrict blood flow. If symptoms remain manageable and do not interfere significantly with daily activities, a cardiologist may recommend continuing with optimal medical management therapy while monitoring the condition closely.
Lifestyle Changes That Support Heart Health
Cardiologists emphasise the importance of total lifestyle management (TLM) regardless of whether a stent or bypass is required.
Important Changes Include:
- Quitting smoking
- Being physically active, gradually increasing to regular exercise, while avoiding over-exertion.
- Eating a heart-friendly diet
- Managing or preventing on-set of diabetes
- Managing blood pressure
- Reducing stress
- Maintaining healthy weight
Lifestyle changes above in total lifestyle management. TLM can help prevent future blockages and improve long-term outcomes.
How Medication Helps
Medication supports heart health in several important ways.
- Anti-angina medicines help ease chest discomfort by improving blood flow to the heart muscle.
- Cholesterol-lowering drugs reduce plaque build-up and stabilise existing plaque, lowering the risk of plaque rupture, and thus heart attacks and sudden cardiac death.
- Blood pressure medication helps protect the artery walls from strain and prevents further narrowing.
- Blood thinners reduce the likelihood of blood clots forming inside already narrowed arteries, which is essential for preventing heart attacks.
Together, these medications help control symptoms, improve quality of life and lower the risk of sudden cardiac death and potential future complications. When taken consistently and combined with healthy lifestyle practices, optimal medical management therapy can be an effective and long-term option for many patients.
Getting the Right Support from a Cardiologist in Singapore
If you have been diagnosed with a heart artery blockage, choosing between a stent, bypass or optimal medical management therapy alone can feel overwhelming. A thorough evaluation by a cardiologist in Singapore ensures you receive the safest and most suitable treatment plan.
At Gerard Leong Cardiology Clinic, we provide clear explanations and personalised care based on your symptoms, test results and long-term health goals. If you are experiencing symptoms of blocked arteries or have concerns about your heart health, we encourage you to seek professional guidance so that we can help you make informed and confident decisions about your treatment.
Frequently Asked Questions
Can a mild blockage become severe over time?
Yes, blockages can progress, especially if risk factors like smoking, high cholesterol, diabetes or high blood pressure are uncontrolled.
Is a stent noticeable inside the body?
No, you will not feel the stent. It stays inside the artery permanently.
Can I travel after getting a stent?
Most patients can travel after recovery, but it is best to check with your cardiologist first.
Is bypass surgery a permanent solution?
Bypass grafts can last many years, but new blockages can still form if lifestyle risks that drives the underlying coronary heart disease are not addressed.
Can exercise help with heart artery blockages?
Regular exercise improves circulation and strengthens the heart, but it must be done safely under medical advice if blockages are present.