Coronary artery spasm: What is it and what are the treatment options?

An under-diagnosed condition called coronary artery spasm, also known as Variant angina or Prinzmetal angina, causes chest pain for many people. Professor Colin Berry explains the condition to Senior Cardiac Nurse Emily McGrath.

A 3D illustration of coronary artery spasm

What is coronary artery spasm?

It is chest tightness or pain caused by tightening of a heart artery. There can also be arm or jaw pain.

These symptoms may occur spontaneously or due to cold weather, exercise or stress.

These symptoms may occur spontaneously or due to cold weather, exercise or stress. In some cases they may be linked to the menstrual cycle. Unlike angina caused by fatty plaques that block arteries to the heart, it’s caused by a spasm of the muscle layer in the wall of the blood vessel, which leads to a temporary artery blockage.

Some patients have both coronary artery spasm and microvascular angina (issues with the smallest arteries that supply the heart), or even have it alongside blockages caused by fatty plaques.

Is it the same thing as Prinzmetal angina or vasospastic angina?

Yes - it is also called vasospastic angina, and has historically been known as Prinzmetal angina or variant angina. 

How is coronary artery spasm diagnosed?

An angiogram is used to give an X-ray image of the heart arteries, while a doctor injects a dose of a chemical called acetylcholine, which should cause blood vessels to relax. If the blood vessel instead constricts (vasospasm), we can diagnose coronary artery spasm.

What causes coronary artery spasm?

There are chemicals in the body that cause the blood vessels to tighten and other chemicals that cause the blood vessels to relax. Stress can cause constriction of the coronary arteries if there is too much of the tightening chemicals and not enough relaxing chemicals. The spasm may be linked to areas of inflammation within the blood vessel wall.

What are the treatment options for coronary artery spasm?

It is treated with a calcium channel blocker such as verapamil or diltiazem. These drugs work by stopping calcium being absorbed into the muscle cells of your blood vessels, which has the effect of relaxing the blood vessels. ACE inhibitors and statins may also help blood vessel health.

What is the outlook for these patients?

For some, it goes away on its own. For others, it persists for many years. In some cases, the vasospasm can cause not just angina, but a heart attack, a significant and life-threatening event.

Who gets coronary artery spasm?

Women and men may be equally affected. The condition can affect any age but especially those aged over 50.

What support is available?

There is currently very little support for this group of patients. Many are misdiagnosed, have to deal with recurrent chest pain for months and may be told there is no further help. These patients can feel unsupported and don’t realise many people have the same problem. There is a Facebook group for people with coronary artery spasm or you can connect with others in the BHF HealthUnlocked community.

How common is coronary artery spasm?

We have recently carried out the BHF- funded Coronary Microvascular Angina (CorMicA) study. The study found that half of patients having a coronary angiogram do not have any blockages in their heart arteries.

Four out of five patients with angina and no blocked heart artery had coronary artery spasm or microvascular angina, or both. Of these, approximately 17 per cent have coronary artery spasm on its own.

The study found that half of patients having a coronary angiogram do not have any blockages in their heart arteries.

A further 20 per cent have it combined with microvascular angina. So at least one in three of the patients with angina, but with no blockages, have coronary artery spasm. (The other affected patients have microvascular angina without coronary artery spasm.)

It’s also possible to have a CT scan which shows that the coronary arteries are clear. However, the CT scan cannot show whether there are small vessel problems or vasospasm. A normal CT scan result may give false reassurance. This means they may not get the best treatment.

Our CorMicA study was the first to show that routinely testing for these conditions clarifies the diagnosis, and means that the best, personalised treatment can be given. This leads to improvements in angina and quality of life.


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