Figura 1. Caudal anteroposterior view. The left main coronary artery and the proximal and mid third...

Figura 2. Right cranial view. The red arrows show the thinning of the distal segment of the anterior...

Figura 3. Left anterior oblique view. The red arrows show the thinning of the distal segment of the ...

Figura 4. Left caudal view. This image shows the left main coronary artery, proximal and mid segment...

Figura 5. Left anterior oblique view. This image shows the right coronary artery with no lesions.

Figura 6. Coronary angiotomography. This image shows (with red arrows) the left main coronary artery...

Figura 7. Coronary angiotomography. This image shows (with red arrows) the circumflex artery, which ...

Figura 8. This image indicates (with red arrows) the right coronary artery, which is patent and wit...

Figura 9. Intramural hematoma formation is the most frequent mechanism of spontaneous coronary disse...

Figura 10. Schematic images of the different anatomical types of spontaneous coronary dissection.

Introduction

Ischemic heart disease, and acute myocardial infarction (AMI) in particular, is one of the leading causes of death worldwide. While atherosclerotic disease is the most common cause of AMI, it is important to highlight that there are other less frequent but still relevant etiologies, such as spontaneous coronary dissection (SCAD) and coronary vasospasm, among others1, 2.

SCAD emerges from acute coronary syndrome (ACS), although in many cases it is underdiagnosed2, 3. It has historically been associated with pregnancy and the peripartum period4, 5; however, with the widespread use of high-sensitivity troponins and access to early angiographic studies, SCAD has been identified as a potential relatively frequent cause of acute coronary events in the general population, especially in young women6.

This diagnostic advancement has favored a better understanding of SCAD, leading to increased detection of cases that could have been misinterpreted or not correctly diagnosed in the past.

CLINICAL CASE REPORT

We present the case of a 38-year-old woman with a history of overweight (body mass index: 27) and hypertension. She reported using oral contraceptives and drinking alcohol socially, but denied using illegal substances. She had no history of miscarriage or venous/arterial thrombosis.

She was admitted to the Department of Hemodynamics after being referred by another healthcare center for a diagnostic coronary angiography for presenting with an acute coronary syndrome with transient ST-segment elevation in the anterolateral region.

At the time of assessment, she was asymptomatic for angina or dyspnea; she was hypertensive (blood pressure: 160/90 mmHg), and showed no signs of pump failure. The electrocardiogram showed sinus rhythm at 95 beats per minute, a PR interval of 200 ms, and a QRS complex of 100 ms with an axis at +15°; T waves +/- DI-AVL and from V3 to V6, with good R progression in precordial leads.

Given her presentation, coronary angiography was conducted via right transfemoral access with a 6-Fr introducer, which revealed interesting findings (Figures 1 to 5):

• The left main coronary artery showed no lesions.

• The anterior descending artery showed diffuse thinning in the distal bed, with a diameter less than one millimeter.

• The circumflex artery showed a tubular narrowing in its mid-third, with extraluminal contrast extravasation and delayed clearance.

• The right coronary artery had no significant lesions.

The findings were interpreted as spontaneous coronary dissection (SCAD) of the anterior descending and circumflex arteries. Since the patient was asymptomatic, with TIMI grade 3 coronary artery flow and no signs of ischemia at rest, the case was discussed internally by the Cardiology team, and a decision was made not to proceed with coronary angioplasty. The patient started treatment with aspirin 100 mg/day, beta-blockers, and angiotensin II receptor antagonists. She showed favorable progression, with a good response to the treatment.

During follow-up, the patient was assessed through coronary CT angiography, which showed patent coronary arteries with no pathological images (Figures 6 to 8).

DISCUSSION

Spontaneous coronary dissection (SCAD) is an often-underdiagnosed condition primarily affecting young women. It accounts for up to 4% of all acute coronary syndromes and up to 35% of all AMI cases in women under 50 years old1.

Two main mechanisms have been proposed regarding the development of SCAD: the first, from inside out, involves a tear of the arterial intima; the second, from outside in, suggests spontaneous hemorrhage from the vasa vasorum within the arterial wall6. Between these two alternatives, the predominant mechanism is yet to be established (Figure 9).

The predisposition to SCAD in young women without traditional cardiovascular risk factors suggests a multifactorial origin that may include genetic factors, hormonal influence, acquired or inherited arterial disease, and even systemic inflammatory diseases, often exacerbated by precipitating or stressful environmental factors6.

Coronary angiography is the first-line study. One of the limitations of invasive angiography is that it is a two-dimensional luminography that does not provide specific images of the arterial wall. However, it is important to mention that a radiolucent flap, a double lumen, and contrast retention are anatomical alterations that should raise suspicion of this condition7, 8, 9.

Coronary angiography can be complemented with other diagnostic intracoronary imaging techniques such as intravascular ultrasound (IVUS) or optical coherence tomography (OCT)10.

There are different angiographic patterns that need to be identified. These are grouped in the Yip-Saw classification11, which divides these characteristics into 3 types (Figure 10). 

• Type I SCAD: Contrast penetrates the false lumen, showing an apparent double lumen with a typical dissection flap. Sometimes, there is contrast retention after contrast clearance. 

• Type II SCAD: This is characterized by diffuse and long vessel stenosis (generally greater than 20 mm) in the mid-distal segments of the artery. It is divided into 2 subtypes:

-  Subtype II A: Restoration of normal arterial diameter is observed distally to the dissection. 

-  Subtype II B: Stenosis extends to the more distal segments of the artery. 

• Type III SCAD: These are local stenoses that resemble atherosclerotic lesions. 

This spontaneous coronary dissection (SCAD) classification reveals that Type I accounts for less than one-third of cases and is associated with a lower risk of clinical progression under conservative management as well as fewer complications during invasive treatment. In contrast, Types II and III offer greater clinical challenges due to their similarity to atherosclerotic lesions. Type II is the most common classification (around 67% of cases)12.

In a registry that included 750 patients with SCAD, Saw et al found that the anterior descending artery (AD) is the most affected vessel, with a prevalence of 52.1%, followed by the circumflex artery (Cx) (37.8%) and the right coronary artery (RCA) (23.2%). The left main coronary artery (LMCA) was affected in 1.5% of cases. In most cases, lesions affect the mid to distal segments of the coronary arteries, with proximal involvement being rare (less than 10% of cases). Multivessel SCAD occurred in 13% of cases12.

There are no randomized clinical trials that conclusively determine the superiority of invasive or conservative management of spontaneous coronary dissection (SCAD). However, evidence from large series suggests a preference for conservative treatment.

The initial treatment of SCAD in the acute phase focuses on preserving or restoring myocardial perfusion, avoiding thrombolytics due to the risk of further dissection or intramural hematoma (IMH) extension.

Coronary revascularization is indicated in cases of left main coronary artery involvement, persistent ischemia, recurrent chest pain, sustained ventricular arrhythmia, or hemodynamic instability13, 14, 15.

Percutaneous coronary angioplasty (PCI) is the preferred revascularization strategy, despite the challenges it poses depending on operator experience, from recognizing SCAD to the technique used for advancing the guidewire into the true lumen to avoid further dissection or hematoma extension that could compromise the vessel lumen or affect side branches if accessed from the false lumen. In cases where the initial strategy is invasive treatment, the use of intravascular imaging such as OCT or IVUS is mandatory. Its use to diagnose this condition involves certain risks that must be carefully considered (e.g., entering the false lumen, further dissection/hematoma extension, among others)16.

Distal dissections can be managed conservatively if coronary flow is adequate and there is no significant obstruction.

Myocardial revascularization surgery should be considered for patients with left main coronary artery SCAD or when PCI has been unsuccessful or is technically unfeasible13.

Regarding dual antiplatelet therapy, it is reserved for patients treated with PCI, while others may not benefit from this strategy and could even have worse outcomes in the medium and long term.

In cases of SCAD during pregnancy, the management approach is similar to that adopted for other patients, with additional considerations to optimize maternal and fetal care. This scenario requires a multidisciplinary approach and minimization of fetal radiation exposure during invasive angiographic studies.

In the case presented, the diagnosis was interpreted as SCAD of the anterior descending and circumflex arteries. It is important to mention that this diagnosis was not confirmed using intravascular imaging (such as OCT or IVUS) to avoid potential complications of intracoronary instrumentation for purely diagnostic purposes.

CONCLUSION

We presented the case of a young woman admitted for acute coronary syndrome, where angiographic findings confirmed the suspicion of multivessel Type 2 SCAD affecting the AD and Cx arteries. In the absence of hemodynamic instability, left main coronary involvement, or recurrent ischemia, we opted for conservative treatment. The favorable evolution of this patient and her follow-up studies have shown that this was a safe and effective option.

This case underscores the importance of considering coronary dissection as a potential cause of acute coronary syndromes, especially in young women. It also highlights the need for a high diagnostic suspicion in this patient group, particularly in the absence of typical cardiovascular risk factors.

Coronary angiography, despite its limitations, remains the gold standard for diagnosis, and it can be supported by other intravascular imaging methods to achieve a definitive diagnosis or rule out differential diagnoses that may appear similar, angiographically speaking.

We emphasize the role of a conservative approach in managing patients who are hemodynamically stable and show no evidence of persistent ischemia. This approach aims to avoid unnecessary invasive procedures, which may have poor success rates and involve a higher risk of complications.

1. Schwarze, M., Abarca, B., Contreras, R., Rodríguez, P., Roa, I., & Schwarze, H. (2021). Infarto agudo al miocardio secundario a disección coronaria espontánea biarterial: Reporte de un caso y revisión de literatura. Revista Chilena de CardiologíA, 40(1), 59-64.

2. Collet J-P, Thiele H, Barbato E, et al. 2020 ESC Guidelines for the management of acute coronary syndromes in patients presenting without persistent ST-segment elevation. European Heart Journal.2021;42(14):1289-1367.

3. Hayes SN, Kim ESH, Saw J, et al. Spontaneous coronary artery dissection: current state of the science: a scientific statement from the American Heart Association. Circulation. 2018;137(19).

4. Akyuz A, Alpsoy S, Akkoyun DC. Spontaneous coronary artery dissection and woven coronary artery: three cases and a review of the literature. Korean Circ J. 2013;43(6):411.

5. Maeder M, Ammann P, Drack G, Rickli H. Pregnancy-associated spontaneous coronary artery dissection: impact of medical treatment: Case report and systematic review. ZS Kardiologie. 2005;94(12):829-835.

6. Saw J, Mancini GBJ, Humphries KH. Contemporary review on spontaneous coronary artery dissection. Journal of the American College of Cardiology. 2016;68(3):297-312.

7. Saw J. Coronary angiogram classification of spontaneous coronary artery dissection: coronary angiogram classification of spontaneous coronary artery dissection. Cathet Cardiovasc Intervent. 2014;84(7):1115-1122.

8. Adlam D, Alfonso F, Maas A, et al. European Society of Cardiology, acute cardiovascular care association, SCAD study group: a position paper on spontaneous coronary artery dissection. European Heart Journal. 2018;39(36):3353-3368.

9. Maeder M, Ammann P, Angehrn W, Rickli H. Idiopathic spontaneous coronary artery dissection: incidence, diagnosis and treatment. International Journal of Cardiology. 2005;101(3):363-369.

10. Alfonso F, Canales E, Aleong G. Spontaneous coronary artery dissection: diagnosis by optical coherence tomography. European Heart Journal. 2009;30(3):385-385.

11. Yip A, Saw J. Spontaneous coronary artery dissection—a review. Cardiovasc Diagn Ther. 2015;5:37–48. 12. 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;40:1188–97. 

12. Krittanawong C, Gulati R, Eitzman D, Jneid H. Revascularization in patients with spontaneous coronary artery dissection: where are we now? JAHA. 2021;10(13).

13. Lettieri C, Zavalloni D, Rossini R, Morici N, Ettori F, Leonzi O, Latib A, et al.. Management and long-term prognosis of spontaneous coronary artery dissection. Am J Cardiol. 2015;116:66–73.

14. Tweet MS, Eleid MF, Best PJ, Lennon RJ, Lerman A, Rihal CS, et al.. Spontaneous coronary artery dissection: revascularization versus conservative therapy. Circ Cardiovasc Interv. 2014;7:777–786.

15. Alfonso F., Bastante T., Rivero F., Cuesta J., Benedicto A., Saw J., & Gulati R. Spontaneous coronary artery dissection. Circ J, 2014. 78( 9): 2099-110.

Para descargar el PDF del artículo
Spontaneous coronary dissection, a rarely suspected entity

Haga click aquí