The treatment options for a heart attack depend on whether you've had an ST segment elevation myocardial infarction (STEMI), or another type of heart attack.
An ST segment elevation myocardial infarction (STEMI) is the most serious form of heart attack and requires emergency assessment and treatment. It's important you're treated quickly, to minimise damage to your heart after an STEMI.
If you have symptoms of a heart attack and an electrocardiogram (ECG) shows you have an STEMI, you'll be assessed for treatment to unblock your coronary arteries.
The treatment used will depend on when your symptoms started and how soon you can access treatment.
- If your symptoms started within the past 12 hours – you'll usually be offered primary percutaneous coronary intervention (PCI).
- If your symptoms started within the past 12 hours but you cannot access PCI quickly – you'll be offered medicine to break down blood clots.
- If your symptoms started more than 12 hours ago – you may be offered a different procedure, especially if your symptoms have improved. The best course of treatment will be decided after an angiogram and may include medicine, PCI or bypass surgery.
- If a PCI isn’t suitable for you – you may be offered a combination of medicines to prevent blood clots, called antiplatelet medicines.
Primary percutaneous coronary intervention (PCI) is the term for emergency treatment of an STEMI. It's a procedure to widen the coronary artery (coronary angioplasty).
Coronary angiography is done first, to assess your suitability for PCI.
You may also be given blood-thinning medicines to prevent further clots from forming, such as low-dose aspirin.
You may need to continue taking medicines for some time after PCI.
Coronary angioplasty is a potentially complex procedure that requires specialist staff and equipment, and not all hospitals have the facilities.
This means you'll need to be taken urgently, by ambulance, to one of the specialist centres (Heart Attack Centres) that now serve most of the UK's regions.
During coronary angioplasty, a tiny tube with a sausage-shape balloon at the end (a balloon catheter) is put into a large artery in your groin or arm. The catheter is passed through your blood vessels and up to your heart, over a fine guidewire, using X-rays to guide it.
Once the catheter is in the narrowed section of your coronary artery, the balloon is inflated to open it. Flexible metal mesh (a stent) is usually inserted into the artery to help keep it open afterwards.
Medicines to prevent blood clots
There are two types of medicines to prevent blood clots. These are called antiplatelets and anticoagulants and are usually taken as a tablet. They make blood flow through your veins more easily. This means your blood will be less likely to form a clot.
Medicines to break down blood clots
Medicines used to break down blood clots, known as thrombolytics or fibrinolytics, are usually given by injection.
Thrombolytics, or fibrinolytics, target and destroy a substance called fibrin. Fibrin is a tough protein that makes up blood clots by acting like a sort of fibre mesh that hardens around the blood.
You may also be given a medicine called a glycoprotein IIb/IIIa inhibitor if you have an increased risk of experiencing another heart attack in the future.
Glycoprotein IIb/IIIa inhibitors do not break up blood clots, but they prevent blood clots from getting bigger. They're an effective method of stopping your symptoms getting worse.
A coronary angioplasty may not be technically possible if the anatomy of your arteries is different from normal. This may be the case if there are too many narrow sections in your arteries or if there are lots of branches coming off your arteries that are also blocked.
In such circumstances, an alternative operation, known as a coronary artery bypass graft (CABG), may be considered.
A CABG involves taking a blood vessel from another part of your body (usually your chest, leg or arm) and attaching it to your coronary artery above and below the narrowed area or blockage. This new blood vessel is known as a graft.
The graft diverts blood around narrowed or clogged parts of your major arteries to improve blood flow and oxygen supply to your heart.
Treating non-ST segment elevation myocardial infarction (NSTEMI) and unstable angina
If an ECG shows you have an NSTEMI or unstable angina (the "less serious" types of heart attack), blood-thinning medicine, including aspirin and other medicines, is usually recommended.
In some cases, further treatment with coronary angioplasty or coronary artery bypass graft (CABG) may be recommended in cases of NSTEMI or unstable angina, after initial treatment with these medicines.