Treatment of angina aims to provide immediate relief from the symptoms, prevent future attacks, and reduce your risk of having a heart attack or stroke.
If your risk is thought to be high, a combination of surgery and medication will probably be recommended. Surgery may also be recommended if medication doesn't work.
If your risk of having a heart attack or stroke is thought to be low, it should be possible to significantly reduce the risk by using a combination of medication and lifestyle changes (see preventing angina for more about lifestyle changes).
The various treatments for angina are outlined below. You can also read a summary of the pros and cons of the treatments for angina, allowing you to compare your treatment options.
Immediate relief from symptoms
Glyceryl trinitrate is a medication widely used to provide immediate relief from symptoms of angina. It can also be used as a preventative measure before doing activities known to trigger angina, such as exercise.
Glyceryl trinitrate belongs to a group of medication called nitrates. Nitrates work by relaxing and widening the blood vessels that increase the blood supply to the heart.
Glyceryl trinitrate is available in tablet form, which you dissolve under your tongue, or as a spray. You may experience headaches, flushing and dizziness soon after taking glyceryl trinitrate.
You should avoid drinking alcohol while taking glyceryl trinitrate, because it can make the side effects worse. If you experience dizziness, avoid driving and operating complex or heavy machinery.
One dose of glyceryl trinitrate usually eases the pain within two to three minutes. If the first dose does not work, a second dose can be taken after five minutes.
You should dial 999 to request an ambulance if the pain continues for five minutes after taking a second dose of glyceryl trinitrate.
Glyceryl trinitrate tablets usually expire after about eight weeks, at which point you will need a new supply. Therefore, you may prefer to use glyceryl trinitrate spray, as it lasts for longer.
Preventing angina attacks
Medication is also used to prevent angina attacks. This usually involves taking at least one type of medicine every day for the rest of your life.
Your GP or cardiologist (an expert in treating heart conditions) will usually try one medication first to see if it helps to prevent your symptoms (monotherapy). If this isn't effective, two medications may be recommended (combination therapy).
First, a beta-blocker or a calcium channel blocker is used to reduce the frequency of angina attacks. Which medication is prescribed may depend on your level of health and, in some cases, your personal preference.
Beta-blockers make the heart beat slower and with less force. This means the heart needs less blood and oxygen after exercise, which can either prevent angina or lower its frequency.
Common side effects of beta-blockers include tiredness, cold hands and feet, diarrhoea and feeling sick.
Beta-blockers can also interact with other medicines, causing adverse side effects. Check with your GP or pharmacist before taking other medicines in combination with beta-blockers, including those available over the counter.
Calcium channel blockers
Calcium channel blockers work by relaxing the muscles that make up the walls of your arteries, increasing blood supply to the heart.
Side effects of calcium channel blockers include flushed face, headaches, dizziness, tiredness and skin rashes. However, these side effects should pass within a few days once your body gets used to the medicine.
You should never drink grapefruit juice if you're taking calcium channel blockers, because they can cause a drop in your blood pressure.
If you're unable to take beta-blockers or calcium channel blockers for medical reasons, or if you find the side effects too unpleasant, your GP or cardiologist may recommend alternative medication.
Long-acting nitrates are similar to glyceryl trinitrate, except they're designed for the long-term prevention of symptoms.
Side effects include headache and a flushed face, although these should improve with time.
If you're taking long-acting nitrates, you shouldn't take sildenafil (Viagra). This is because the combination of the two can lead to a dangerous drop in blood pressure.
Ivabradine is a newer type of medication that has a similar effect to beta-blockers in that it slows down the speed of your heart beat.
However, it works in a different way to beta-blockers, which means it can often be used in people unable to take beta-blockers for medical reasons, such as those with a lung infection.
A common side effect of ivabradine is that people experience temporary flashes of brightness in their field of vision. If you have this side-effect, it may not be safe for you to drive at night. You should ask your GP for advice.
Nicorandil is a potassium channel activator that widens the coronary arteries to increase blood flow to the heart.
Potassium channel activators can often be used by people who are unable to take calcium channel blockers for medical reasons.
Side effects of nicorandil include dizziness, headaches and feeling sick.
Ranolazine works by relaxing the muscles of the heart to improve blood flow and prevent angina attacks.
Unlike the other medications used to prevent angina attacks, ranolazine doesn't affect the speed at which the heart beats, so it may be a more suitable alternative treatment for people with heart failure or an abnormal heart rhythm.
Common side effects of ranolazine include constipation, dizziness and feeling weak.
If a single medication doesn't work for you, a combination of medications will probably be recommended. This is known as combination therapy.
If combination therapy doesn't work, you may be referred for surgical treatment (see below).
In some cases, where people are unable or unwilling to have surgery, or you are waiting for surgery, three different medications may be prescribed.
Reducing the risk of heart attack and stroke
Three medications are available to help reduce the risk of a heart attack and stroke in people with angina. They are:
Statins work by blocking the effects of an enzyme in your liver used to make cholesterol. Reducing blood cholesterol levels should prevent further damage to your coronary arteries and should reduce the risk of a heart attack or stroke occurring.
Statins sometimes have mild side effects that can include constipation, diarrhoea and abdominal pain.
Low-dose aspirin is a type of medication called an antiplatelet. It's used to reduce the "stickiness" of your blood to prevent blood clots, which can reduce your risk of having a heart attack.
Side effects of low-dose aspirin are uncommon, but can include irritation of the stomach or bowel, indigestion and feeling sick.
If you're allergic to aspirin, or you're unable to take it because of another health condition that may be aggravated by it, such as a stomach ulcer, alternative antiplatelet medicines are available.
Angiotensin-converting enzyme (ACE) inhibitors
ACE inhibitors are medicines that can be used to reduce your blood pressure.
ACE inhibitors block the activity of a hormone called angiotensin II, which narrows blood vessels. As well as stopping the heart working so hard, ACE inhibitors improve the blood flow around the body.
ACE inhibitors have been known to reduce the supply of blood to the kidneys, which can reduce their efficiency. Therefore, blood and urine tests may be carried out before you start taking ACE inhibitors to make sure there are no pre-existing problems with your kidneys.
Annual blood and urine tests may also be required if you continue to use ACE inhibitors.
Side effects of ACE inhibitors include dizziness, tiredness or weakness and a persistent, dry cough, although these should pass within a few days.
You should check with your GP or pharmacist before taking any other medication in combination with ACE inhibitors.
Surgery is usually recommended if your angina symptoms fail to respond to medication. However, you'll probably need to continue taking some medication after having surgery.
The two main types of surgery used to treat angina are:
CABG or PCI?
In some circumstances it may not be possible to choose whether you have CABG or PCI. For example, PCI may not be suitable for people whose blood vessels have an unusual structure.
Both PCI and CAGB are broadly similar in their effectiveness in treating angina and preventing fatal complications in the long term, although each technique has its own set of pros and cons.
PCI doesn't involve making major incisions in the body, so the recovery time from surgery is much quicker and there's much less pain afterwards.
However, one main disadvantage of PCI is that there's a higher risk of the unblocked section of artery becoming blocked again, which would require further surgery to treat. The most recent data shows that further surgery is required in around 1 in 25 cases.
CABG is usually the preferred surgical option for people who:
- have diabetes, and/or
- are over 65 years of age, and/or
- have blockages in three or more of the blood vessels that supply the heart with blood
Research indicates that using CABG in such circumstances is more likely to prolong lifespan than using angioplasty. There's also recent evidence that people who have had a CABG usually report a slightly better quality of life in the long term.
The disadvantage of CABG is that it causes more post-operative pain than PCI and it has a longer recovery time (usually around 12 weeks, compared to about one to two weeks for PCI).
If treatment is ineffective
If the symptoms of angina don't improve despite medication and surgery (or if surgery is unsuitable), a different approach may be used. This may involve the use of psychological or behavioural treatments, such as cognitive behavioural therapy (CBT).
Treatments such as CBT can help you develop skills to cope with your condition, manage your pain and improve your symptoms.
There are some treatments that the National Institute for Health and Care Excellence (NICE) says shouldn't be offered to help manage pain in people with stable angina:
- Transcutaneous electrical nerve stimulation (TENS) – where a small, battery-operated machine is used to deliver electrical impulses into the body to relieve pain.
- Enhanced external counterpulsation (EECP) – where inflatable cuffs wrapped around the calves, thighs and buttocks are inflated in time with the rhythm of your heart. This is done to help improve blood flow into and out of your heart.
- Acupuncture – a form of ancient Chinese medicine, in which fine needles are inserted into the skin at certain points on the body.
These treatments aren't recommended, because there's a lack of evidence concerning their effectiveness and safety for people with stable angina.
If you have unstable angina (where symptoms develop unpredictably and persist even when resting), you'll immediately be given medication to prevent blood clots developing and reduce your risk of having a heart attack or stroke.
This will usually be aspirin to help thin your blood, unless there's a reason you're unable to take it, such as having a history of liver disease.
You'll probably also be prescribed another blood-thinning medication called clopidogrel, which you may need to take for at least 12 months (if you're unable to take aspirin, you'll just be prescribed clopidogrel).
You may also be given an injection of an additional blood thinning medication, such as fondaparinux or heparin.
It's likely you'll then have a series of tests to assess your risk of having a heart attack in the future (see diagnosing angina for more information).
If the risk is moderately high, an examination called a coronary angiography may be carried out to assess the size and location of the blockage in your coronary artery. If the blockage is significant, CABG or PCI can be performed.