What is Coronary Artery Vasospasm?
Coronary artery vasospasm (CAVS) is a condition where the coronary arteries, the blood vessels that supply your heart, constrict or tighten up. This can lead to a complete or near-total blockage of blood flow in the vessel. Back in 1959, a doctor named Myron Prinzmetal identified this condition, which differs from a type of chest pain known as classic Heberden angina that was first described in 1772.
This blood vessel tightening disease can cause a sudden shortage of blood to the heart, leading to various types of chest pain symptoms, ranging from stable (predictable) chest pain to severe, sudden chest pain, known as acute coronary syndrome. The causes of CAVS vary—it’s not a one-size-fits-all condition and it doesn’t necessarily follow the conventional risk factors that contribute to the development of coronary artery disease.
What Causes Coronary Artery Vasospasm?
The contraction or tightening of the arteries that supply blood to the heart, known as coronary artery vasospasm (CAVS), can be triggered by various factors. These include interference from the body’s involuntary nervous system, inflammation, stress from oxidation, impediment in the lining of the blood vessels, excessive contraction of the smooth muscle cells in the artery wall, genetic susceptibility, and lifestyle habits.
In a 1959 study conducted on 25 dogs by Prinzmetal and his colleagues, they observed the changes that occurred when they blocked and then reopened a large artery near the outer layer of the heart. They discovered that this led to symptoms of chest pain and discomfort (angina), changes in the heart rhythm indicating a lack of oxygen in the related region, and a bulging of the oxygen starved area during the heart’s contraction phase. They suggested that this is what happens when an artery near the heart’s surface goes into spasms.
Risk Factors and Frequency for Coronary Artery Vasospasm
Coronary artery vasospasm, also known as CAVS, is most prevalent in individuals aged 40 to 70. However, after the age of 70, its incidence tends to decrease. It’s interesting to note that this condition varies globally. For instance, it’s more common in the Japanese population compared to Western populations. Adding on, multiple spasms, identified through specific testing, are more frequently observed in the Japanese community, making up 23% of cases, compared to Caucasians, where it’s 7.5%.
In Germany, a study was conducted involving patients suspected of having obstructive coronary artery disease (CAD), a condition where the arteries supplying blood to the heart become blocked. The shocking result was that one in every four patients didn’t have any visible issue in the arteries. When these individuals were further tested with a substance known as acetylcholine, half of them were confirmed to be dealing with CAVS instead.
Signs and Symptoms of Coronary Artery Vasospasm
Approximately 20% to 30% of people who have chest pain and are tested for blockages in the heart’s arteries, using a procedure called a coronary angiogram, have normal arteries. These individuals may or may not have noticeable symptoms. If they do have symptoms, they might experience chest pain similar to that caused by reduced blood flow to the heart when their arteries go into spasm.
This pain, caused by spasms of the coronary arteries (CAVS), often happens when the person is resting, especially late at night or early in the morning. The pain might also cause them to struggle with physical activity, especially in the morning. The chest pain can feel like a crushing weight in the middle of the chest, and might extend to the jaw or arm. It’s usually relieved by placing a nitroglycerin tablet under the tongue.
When examining a patient showing these symptoms, doctors should do a complete cardiovascular examination. This starts by checking vital signs like heart rate and blood pressure to make sure the patient is stable. After that, they should listen to the heart to check its rhythm, rate, any heart murmurs, and additional heart sounds like S3 or S4. They should also listen to the patient’s lungs, checking for any abnormal sounds like crackles that could be a sign of fluid buildup in the lungs (pulmonary edema).
Testing for Coronary Artery Vasospasm
If you experience an episode that may be related to coronary artery vasospasm (CAVS), a condition leading to chest pain, your doctor may conduct an electrocardiogram (ECG). This test traces your heart’s electrical activity and can show changes that suggest a blocked blood vessel. This includes ST elevation, a specific pattern that your doctor can identify on the ECG reading, and ST depression in different areas of the ECG.
An ECG could also reveal other characteristics related to CAVS, like negative T waves and negative U waves. T waves and U waves are specific parts of the ECG reading, and changes in these waves can help the doctor make a diagnosis.
If you are given a fast-acting heart medication, like a nitrate, during the episode and the changes on the ECG go away, it can help confirm the diagnosis. However, the ECG might also show only ST depression in some cases.
You might also have a blood test to check for proteins, called biomarkers, that indicate heart damage. These include troponin I or troponin C and creatinine kinase. However, these markers may not always be high in patients with CAVS.
The definitive test for confirming CAVS is coronary angiography with provocative testing. This involves taking an X-ray image of your heart’s blood vessels and then causing them to narrow just like they would in a spasm. This can be done by administering certain drugs that cause vasoconstriction (a tightening of blood vessels). These substances, usually methylergonovine or acetylcholine, will test your heart’s reaction. If your coronary arteries narrow significantly and you show the same symptoms and ECG changes as during an episode, then this confirms the diagnosis of CAVS. Further medicine can then be given to reverse the effects of the substances used in the test.
Treatment Options for Coronary Artery Vasospasm
In treating patients with heart conditions, medical treatment and lifestyle changes are key. The first step in treatment often involves prescribing nitrates or calcium channel blockers. Nitrates help to relax the blood vessels by increasing the production of a molecule called cGMP. If the heart’s arteries spasm, causing them to narrow abruptly (a condition known as Coronary artery vasospasm or CAVS), calcium channel blockers can also be used to decrease the amount of calcium entering the body’s smooth muscle cells.
Various alternative therapies have been looked into, including a range of drugs and supplements, such as nicorandil, statins, fasudil, aspirin, magnesium, vitamins C and E, iloprost, alpha-receptor blockers, selective serotonin receptor inhibitors, and selective thromboxane A2 synthetase inhibitors. However, while these options have shown some success, their results have been inconsistent. Therefore, they need further study before we can consider them as main treatments like nitrates and calcium channel blockers. We typically avoid prescribing beta-blockers, as they can lead to angina caused by blood vessel spasms.
Usually, CAVS can be alleviated by drugs that help dilate, or open up, the blood vessels. However, in about 20% of CAVS patients, the disease seems to resist drug therapy, even long-term treatment. In these cases, treatments involving inflation of a small balloon in the blood vessel (percutaneous balloon angioplasty) have not produced good results. Treatment with a procedure called percutaneous coronary intervention, alongside long-term medicine, has been studied. But it has been observed that even after the procedure, some patients experience spasms in other areas. So, the use of coronary stents alongside long-term medication is only considered in patients with significant narrowing due to CAVS.
The use of devices called implantable cardioverter-defibrillators in CAVS patients who experience fast or irregular heart rhythms is still uncertain. However, some reports suggest that implanting the device in patients who survive serious heart rhythm problems due to CAVS can lead to positive outcomes.
What else can Coronary Artery Vasospasm be?
Coronary artery vasospasm (CAVS) can be tricky to identify due to its varied symptoms, which might be confused with other heart-related conditions. Sometimes, CAVS may cause chest pain, changes in ECG results, and increased levels of cardiac biomarkers. However, this is not always the case.
Similar symptoms might indicate different health issues, such as blockages in the coronary arteries (known as obstructive atherosclerotic coronary artery disease), pericarditis or myopericarditis (inflammation of the heart’s protective layers), primary arrhythmias (irregular heartbeats), and stress-induced cardiomyopathy (a condition where the heart muscle becomes weak).
Therefore, doctors need to consider these other conditions when trying to diagnose CAVS correctly.
What to expect with Coronary Artery Vasospasm
Between 4% and 19% of patients usually experience recurring angina attacks, or chest pain. It’s been found that older age and an impaired heart’s left ventricle function may lead to worse medical outcomes in patients with acute coronary syndrome brought about by coronary artery vasospasm, a condition wherein the heart’s arteries spasm, limiting blood flow.
Elevated hs-CRP levels, a marker of inflammation in the body, can also suggest a higher risk of death, nonfatal heart attacks, and recurring bouts of angina that may require further heart examination via coronary angiography. Despite these risks, the prognosis, or future medical outlook, is generally favorable if patients continue to take prescribed calcium channel blockers – a type of medication used to treat hypertension and manage chest pain – and address risk factors such as smoking.
Possible Complications When Diagnosed with Coronary Artery Vasospasm
Coronary artery vasospasm (CAVS) can lead to several complications, which are:
- Life-threatening heart rhythm problems
- Heart attack
- Sudden death due to heart-related issues
Preventing Coronary Artery Vasospasm
Patients should be advised to change lifestyle habits that can trigger coronary artery spasms, such as smoking. The aim of the treatment should be to start and maintain the highest doses of calcium channel blockers that the patient can safely handle. It’s important to stress the importance of sticking to their medication plan and to let them know about the risks of having recurrent coronary artery spasms if they don’t follow their medication schedule closely.
