Spontaneous coronary artery dissection is an emergency condition that arises from a spontaneous tear in the coronary arteries and can result in a heart attack or sudden death. Previously thought to be a very rare condition, it is now increasingly  recognised as an important cause of heart attack, accounting for 1 to 4% of heart attacks1–3 associating with pregnancy.

By Dr Chua Yi Yi, Senior Resident, Department of Cardiology and Assoc Prof Chin Chee Tang, Senior Consultant, Department of Cardiology, Director of Coronary Intervention Service 

Our coronary arteries are blood vessels that supply oxygen-rich blood to the heart, and allow the heart to pump blood to the rest of the body. The arterial walls are made up of thin layers of tissue and consist of three layers. When the innermost layer tears, blood can be trapped between the layers. Separation of the arterial wall layers can also occur due to bleeding from spontaneous rupture of the small vessels that supply the arterial wall. In either case, the build-up of blood between the layers of the arterial wall limits blood flow to the coronary artery which can lead to a heart attack.

Alina experienced the classic symptoms of spontaneous coronary artery dissection (SCAD) a week after giving birth in 2015, when she had the feeling of pressure building up in her chest, and into her jaws and upper arms. The symptoms went away in a couple of minutes. However, the exact symptoms returned a week later. This time, the symptoms were more severe, and she felt breathless and unwell. She immediately knew that something was wrong and called an ambulance. She was only 32 years then.

Alina was brought by the ambulance to NHCS, and rushed to the Catheterisation Laboratory (Cath Lab) for a percutaneous coronary intervention (PCI) procedure, to restore the blood flow to her heart.

Assoc Prof Chin Chee Tang was the doctor on duty at the Cath Lab when Alina was wheeled in urgently. “I knew that this would not be one of our usual heart attack cases as she was so young. And knowing that she had a baby at home made it even more stressful,” he remembered. Together with Assoc Prof Lim Soo Teik, Senior Consultant, Department of Cardiology, Director of Cardiac Catheterisation Laboratory, NHCS, they started the PCI procedure. Alina recalled being told by Assoc Prof Chin that her condition was serious but they would do everything they could to help her.

In the four-hour procedure, the team of medical staff successfully restored the blood flow in Alina's heart by placing three stents in the left coronary artery systems to repair the torn blood vessels. Following the procedure, she was cared for by the Coronary Care Unit team led by Assoc Prof Yeo Khung Keong, Deputy Chief Executive Officer (Data Science and Innovation) and Senior Consultant, Department of Cardiology, NHCS. She was prescribed with blood thinners, beta blockers, statins and heart failure medications. As her heart function (ejection fraction) was significantly reduced, she had to wear a life vest - a wearable defibrillator to automatically deliver treatment shock in case of any detection of abnormal rapid heart rhythm.

Coping with SCAD

Prior to having SCAD, Alina had been leading a healthy and active life. She was eating healthily, and exercising regularly up to two to three times a week such as swimming, jogging, yoga and fitness training. She had no history of heart disease in her family and had never smoked.

Alina was told SCAD mostly happens to women and the risk of SCAD is highest in the last weeks of a pregnancy and the first six weeks after. It was likely due to the hormonal fluctuations that the body went through during pregnancy and the postpartum period. “It is very important for every woman to be aware of her body, and that SCAD can happen to anyone regardless of age and risk factors,” expressed Alina.

The road to recovery had been challenging for Alina, as she was a new first-time mom when the SCAD episode happened. “I was dealing with two traumas – one from having SCAD, and the other was not being able to fulfil my role as a mother,” shared Alina, recounting how she was not able to perform simple tasks like taking her baby out for a walk, or carrying him when he was crying. 

The Road to Recovery

Alina with her husband and baby – three months after her recovery.

Alina signed up for the Cardiovascular Rehabilitation and Preventive Cardiology programme at NHCS a few weeks after her discharge, which taught her gradual restorative exercises to regain her strength and confidence in her body. After about three months, her heart function improved, and she no longer needed to wear the life vest, which was a big milestone in her recovery.

Alina also researched about SCAD online, and found an online support group with mostly young women around the world who also experienced SCAD. She found that connecting and discussing with others who had the condition helped her a lot in her recovery.

“After a journey of two years, I can say that I felt better - both physically and mentally. I have accepted my limits and learned to live with the new parameters. I always say that I lost my old self forever, but I regained a new kind of normal,” shared Alina, who successfully managed to have another child post-SCAD, after further considerations and discussions with doctors.

For the Physicians

Diagnosing and Managing SCAD

Patients with SCAD may present with symptoms typical of a heart attack such as chest pain or discomfort that radiates to the neck, jaw or arm, breathlessness, nausea, dizziness, or sweating. They may also present with ventricular arrhythmias and sudden cardiac arrest.

Patients often have elevated troponin levels, and abnormalities in their electrocardiogram including ST segment changes, which is the interval between ventricular depolarisation and ventricular repolarisation. Definitive diagnosis requires invasive coronary angiogram and may require the use of adjunctive imaging such as intravascular ultrasound or optical coherence tomography.

Observational data suggests that a conservative management with medications alone is safe for most patients, and hence preferred, if applicable. Long-term medical therapy frequently includes aspirin and betablocker4. However, patients with high-risk features such as ongoing ischaemia, left main dissection, ventricular arrhythmias, or haemodynamic instability may require coronary revascularisation with PCI or coronary artery bypass surgery. Cardiac rehabilitation and psychosocial support are also important aspects of treatment5. Blood pressure should be well-controlled and high-intensity exercise and sports should be avoided. Overall, long-term prognosis is excellent, though cardiovascular events such as recurrent heart attacks, ventricular arrhythmia, cardiogenic shock, or unplanned revascularisation may occur following index presentation4.

SCAD: Most common cause of heart attack associated with pregnancy

SCAD likely occurs because of a complex interplay between predisposing conditions and precipitants. It most commonly affects young women without classical cardiovascular risk factors. Over 90% of patients with SCAD are women. SCAD is strongly associated with fibromuscular dysplasia, a nonatherosclerotic, non-inflammatory form of angiopathy that can affect any arterial bed to cause stenosis, occlusion, aneurysm, or dissection6,7.

Pregnancy and the postpartum period are also well-established risk factors. Though pregnancy-associated SCAD encompasses a relative small proportion of SCAD cases, it is the most common cause of myocardial infarction amongst patients who are pregnant or post-partum8. Other predisposing factors include other forms of arteriopathies or connective tissue disorders, use of exogenous hormones, systemic inflammatory disease, or migraine. Precipitating factors include intense exercise, retching or vomiting, severe hypertension, intense emotional stress, and recreational drugs2. While pregnancy is not recommended following an episode of SCAD, patients should consult with their doctors to further discuss on this.

1. Hayes SN, Kim ESH, Saw J, et al. Spontaneous Coronary Artery Dissection: Current State of the Science. Circulation. 2018;137(19):e523-e557. doi:10.1161/CIR.0000000000000564

2. Mahmoud AN, Taduru SS, Mentias A, et al. Trends of Incidence, Clinical Presentation, and In-Hospital Mortality Among Women With Acute Myocardial Infarction With or Without Spontaneous Coronary Artery Dissection: A Population-Based Analysis. JACC Cardiovasc Interv. 2018;11(1):80-90. doi:10.1016/j.jcin.2017.08.016

3. Saw J, Starovoytov A, Humphries K, et al. Canadian spontaneous coronary artery dissection cohort study: in-hospital and 30-day outcomes. Eur Heart J. 2019;40(15):1188-1197. doi:10.1093/eurheartj/ehz007

4. Gilhofer TS, Saw J. Spontaneous coronary artery dissection: a review of complications and management strategies. Expert Rev Cardiovasc Ther. 2019;17(4):275-291. doi:10.1080/14779072.2019.1598261

5. The First Dedicated Cardiac Rehabilitation Program for Patients With Spontaneous Coronary Artery Dissection: Description and Initial Results - PubMed. Accessed May 30, 2022. https://pubmed.ncbi.nlm.nih.gov/26923234/

6. Saw J, Aymong E, Sedlak T, et al. Spontaneous coronary artery dissection: association with predisposing arteriopathies and precipitating stressors and cardiovascular outcomes. Circ Cardiovasc Interv. 2014;7(5):645-655.  doi:10.1161/CIRCINTERVENTIONS.114.001760

7. Prasad M, Tweet MS, Hayes SN, et al. Prevalence of extracoronary vascular abnormalities and fibromuscular dysplasia in patients with spontaneous coronary artery dissection. Am J Cardiol. 2015;115(12):1672-1677. doi:10.1016/j.amjcard.2015.03.011

8. Tweet MS, Hayes SN, Codsi E, Gulati R, Rose CH, Best PJM. Spontaneous Coronary Artery Dissection Associated With Pregnancy. J Am Coll Cardiol. 2017;70(4):426-435. doi:10.1016/j.jacc.2017.05.055

This article is from Murmurs Issue 42 (January – April 2022). Click here to read other articles or issues.