Dissertation/Thesis Abstract

Spontaneous Coronary Artery Dissection (SCAD): Utility of Echocardiography
by Tweet, Marysia Susan, M.S., College of Medicine - Mayo Clinic, 2020, 41; 28027192
Abstract (Summary)

Background: Spontaneous coronary artery dissection (SCAD) is an important cause of myocardial infarction and sudden cardiac death predominantly among women. Previously considered a rare cause of acute coronary syndrome, recent increase in awareness and use of intracoronary imaging during diagnostic coronary angiography has improved the recognition of SCAD. Much uncertainty remains regarding SCAD pathophysiology, natural history and outcomes. Adverse events after a SCAD diagnosis including recurrent SCAD are substantial, and predictors of adverse events are unknown. While echocardiography is frequently used to evaluate SCAD patients, there are limited published data regarding echocardiographic findings.

Methods: We aimed to prospectively perform and analyze transthoracic echocardiography in patients diagnosed acutely with SCAD at the Mayo Clinic or seen in the outpatient Mayo Clinic SCAD Clinic. We interpreted any prior pre- or post-SCAD echocardiogram studies for comparison. Part 1 of the project focused on the echocardiographic parameters at the time of acute SCAD. Part 2 of the project assessed the correlation of coronary tortuosity with echocardiographic parameters.

Results: Among 34 patients recruited for a prospective echocardiogram during an acute SCAD, most (94%) were women with a mean age of 52.4 years at time of SCAD. Twenty-one (62%) of patients had fibromuscular dysplasia, and 31 (91%) had coronary tortuosity. Overall, the mean left ventricular ejection fraction (LVEF) was within normal limits of 58 ± 8 (range 40–70), and 25 (73.5%) patients had an LVEF of 55% or greater. Despite the normal or near-normal LVEF, twenty-four (71%) patients had regional wall motion abnormalities (RWMA), 23 of whom had left ventricular apex RWMA. Twelve (36%) patients had apical akinesis (≥ 2 segments).

Of the 117 participants with research echocardiograms performed in follow-up after an acute SCAD at a median of 11 months (IQR 3.9, 41), 95 (81.2%) met criteria on coronary angiography as having coronary tortuosity and 20 (17.1%) did not (2 were undetermined). In total, the mean age at time of echocardiography was 50 years. Most (79, 69%) participants had normal left ventricular geometry, although 13 (11%) had left ventricular enlargement. Eleven (9.6%) patients had concentric remodeling, 5 (4.4%) had concentric hypertrophy, and 19 (16.7%) had eccentric hypertrophy. The mean left ventricular ejection fraction was 59% with a mean wall motion score index of 1.2. Only 10 (8.5%) of patient had a LVEF less than 50%. Fourteen (12.4%) participants had abnormal diastolic function. There was no significant valve disease. There was no difference in left ventricular geometry, mass index, or pulse wave tissue Doppler systolic velocities between the patients who had coronary tortuosity compared to those who did not, but this may be due to lack of power since most patients had coronary tortuosity, many had FMD, and all had a history of SCAD.

Conclusions: The majority of patients presenting with SCAD have normal or near-normal echocardiogram parameters. Despite the majority having a normal left ventricular ejection fraction, most also had persistent regional wall motion abnormalities including akinesis or dyskinesis of the left ventricular apex. This subgroup may require additional monitoring for future complications. Additionally, coronary tortuosity did not correlate with echocardiographic parameters such as left ventricular geometry, left ventricular mass index and systolic function.

Indexing (document details)
Advisor: Hayes, Sharonne N.
Commitee: Morrow, Melissa, Olson, Timothy, Jenkins, Sarah
School: College of Medicine - Mayo Clinic
Department: Clinical and Translational Science
School Location: United States -- Minnesota
Source: MAI 82/3(E), Masters Abstracts International
Subjects: Health sciences
Keywords: Cardiac, Echocardiography, Myocardial infarction, Women
Publication Number: 28027192
ISBN: 9798678108463
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