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Three Part Question

In [adults with acute coronary syndrome], what is the [prevalence] of [spontaneous coronary artery dissection]?

Clinical Scenario

A 42-year-old previously healthy woman presented to the emergency department with chest pain and was found to have an ST elevation myocardial infarction. Cardiac catheterization revealed a dissection in her left anterior descending artery. You wonder what is the prevalence of spontaneous coronary artery dissection (SCAD) in patients with acute coronary syndromes.

Search Strategy

Medline 1946-08/14 using OVID interface, Cochrane Library (2014), PubMed clinical queries

[(exp spontaneous coronary artery dissection)] AND [(incidence.mp) OR (prevalence.mp)]. Limit to English language

Search Outcome

39 papers were identified; five were relevant to the clinical question

Relevant Paper(s)

Author, date and country	Patient group	Study type (level of evidence)	Outcomes	Key results	Study Weaknesses
Saw J, Aymong E, Mancini GB, et al. 2014 Jul Canada	Women, age 18-50, who underwent coronary angiogram. Goal was to identify the prevalence of non-atherosclerotic coronary artery disease (NACAD), including spontaneous coronary artery dissection (SCAD) in young women.	Retrospective Review	Identify the prevalence of NACAD in young women. Identify the prevalence of subtypes of NACAD, including SCAD, in young women.	NACAD was found in 13.0% of young women undergoing coronary angiography. SCAD was the most common subtype of NACAD, accounting for 69.6% of NACAD. Overall, the prevalence of SCAD was 9.0% in young women undergoing coronary angiography.	Retrospective study limited by chart review for available data. Small population, N=177 Potential selection bias in choosing women who underwent coronary angiography. Higher acuity patients may not have survived to angiography and lower acuity patients may not have required it. Diagnosis was based on consensus of experts reviewing the angiography.
Mortensen KH, Thuesen L, Kristensen IB, et al. 2009 Nov 1 Denmark	All patients undergoing coronary angiography in 3 counties in Denmark were identified in the Denmark Heart Registry from 1997-2007. All reports using the term "dissection" were evaluated.	Retrospective Case-identification Denmark Heart Registry Study	Describe incidence of SCAD Describe predictors of SCAD Describe prognosis of SCAD	SCAD was identified in 22 of 32,869 (0.7%) of angiograms. SCAD accounted for 22 of 11.175 (2.0%) among cases of ACS. Women accounted for 77% of SCAD cases. Mean age, 48.7 +/- 8.9 years.	Retrospective study based on a patient registry. Limited ethnic diversity. Diagnosis was based on consensus of experts reviewing the angiography.
Nishiguchi T, Tanaka A, Ozaki Y, et al. 2013 Sep 11 Japan	Prospective cohort study of 326 patients with ACS confirmed by coronary angiography underwent Optical Coherence Tomography of the culprit vessel to look for SCAD.	Prospective cohort study	Describe the prevalence of SCAD in patient with ACS	SCAD was identified in 4.0% of ACS patients. Women accounted for 54% of SCAD cases.	Identification of SCAD was performed using OCT. Intracoronary thombus prevented visualization of the whole coronary structure in 61% of patients. 16 patients were withdrawn due to poor OCT images. Small sample size, N=326
Vanzetto G, Berger-Coz E, Barone-Rochette G, et al. 2009 Feb 3 France	All cases of SCAD (23 cases) were retrospectively identified in a cardiology laboratory database (out of 11,605 patients) between 2000 and 2006.	Retrospective Cohort with prospective follow-up	Assess the prevalence, clinical presentation, management, and prognosis of SCAD	Overall, the prevalence of SCAD was 0.2% (23/11,605) in patients undergoing angiography for stable CAD or ACS. SCAD is observed in as much as 10% of women under 50 years old who present with STEMI. Women accounted for 74% of SCAD cases.	Small sample size, N=23 Retrospective study based on a cardiology laboratory database.
Maeder M, Ammann P, Angehrn W, Rickli H. 2005 Jun 8 Switzerland	Coronary angiograms were reviewed in 5054 patients without atherosclerosis or associated pregnancy. The goal was to better describe the clinical presentation and treatment of idiopathic SCAD.	Prospective cohort study	To better describe the clinical presentation and treatment options for idiopathic SCAD not associated with atherosclerosis or pregnancy.	Of 5054 patients undergoing angiography, only 5 cases of idopathic SCAD were identified. All 5 cases were premenopausal females 3 of these women had no cardiac risk factors. LAD is the most common location for dissection. Treatment included heparin, anti-platelets, stents, and CABG	Small population, N=5 The number of idiopathic SCAD cases in this study is not enough to adequately characterize the clinical presentation. The study was more of a case report than a true study.

Comment(s)

Spontaneous coronary artery dissection — sometimes referred to as SCAD — is a rare emergency condition that occurs when a tear develops in the inner layer of a coronary artery. Blood seeps between the artery layers, forming a blockage. While SCAD is increasingly being recognized as an important cause of acute coronary syndrome, the prevalence is difficult to estimate. Previous publications on SCAD are based on single cases or relatively small series with retrospective design and without long-term follow-up. Variable methods are used to identify SCAD including coronary angiography, intravascular ultrasound, and optical coherence tomography. Because of these factors, the prevalence ranges significantly among the studies. One consistent finding is that women account for a majority of SCAD, particularly younger women with few or no risk factors for heart disease.

Clinical Bottom Line

SCAD is an uncommon, but important, cause for acute MI and should be considered in the differential of acute coronary syndrome, particularly in young women with no cardiac risk factors.

References

1. Saw J, Aymong E, Mancini GB, et al. Nonatherosclerotic Coronary Artery Disease in Young Women Can J Cardiol. 2014 Jul;30(7):814-9
2. Mortensen KH, Thuesen L, Kristensen IB, et al. Spontaneous Coronary Artery Dissection: A Western Denmark Heart Registry Study Catheterization and Cardiovascular Interventions 2009 Nov 1;74(5):710-7
3. Nishiguchi T, Tanaka A, Ozaki Y, et al. Prevalence of spontaneous coronary artery dissection in patients with acute coronary syndrome. Eur Heart Acute Cardiovasc Care 2013 Sep 11. doi: 10.1177/2048872613504310 [Epub ahead of print]
4. Vanzetto G, Berger-Coz E, Barone-Rochette G, et al. Prevalence, therapeutic management and medium-term prognosis of spontaneous coronary artery dissection: results from a database of 11,605 patients. Eur J Cardiothorac Surg 2009 Feb;35(2):250-4
5. Maeder M, Ammann P, Angehrn W, Rickli H. Idiopathic spontaneous coronary artery dissection: incidence, diagnosis and treatment. Int J Cardiol 2005 Jun 8;101(3):363-9