RESEARCH ARTICLE


Influence of Coronary Artery Stenosis Severity and Coronary Collateralization on Extent of Chronic Myocardial Scar: Insights from Quantitative Coronary Angiography and Delayed-Enhancement MRI



Daniel Bexell1, 5, Randolph M Setser1, Paul Schoenhagen1, 2, Michael L Lieber3, Sorin J Brener2, Thomas B Ivanc2, Eva M Balazs2, Thomas P O`Donnell4, Arthur E Stillman1, Håkan Arheden5, Galen S Wagner6, Richard D White*, 1, 2
1 From the Departments of Diagnostic Radiology, Duke University Medical Center, Durham, NC
2 Cardiovascular Medicine, Duke University Medical Center, Durham, NC
3 Quantitative Health Sciences, Duke University Medical Center, Durham, NC
4 Cleveland Clinic, Cleveland, OH, Siemens Corporate Research, Duke University Medical Center, Durham, NC
5 Princeton, NJ, Department of Clinical Physiology, Duke University Medical Center, Durham, NC
6 Lund University, Lund, Sweden, and Division of Cardiology, Duke University Medical Center, Durham, NC


© Bexell et al.; Licensee Bentham Open.

open-access license: This is an open access article licensed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0/) which permits unrestricted, non-commercial use, distribution and reproduction in any medium, provided the work is properly cited.

* Address correspondence to this author at the Department of Radiology, University of Florida College of Medicine-Jacksonville, 655 West 8th Street, Jacksonville, FL 32209, USA; Tel: (904) 244-4224; Fax: (904) 244-8827; E-mail: richard.white@jax.ufl.edu


Abstract

Objectives:

In patients with chronic ischemic heart disease, the relationship between coronary artery lesion severity and myocardial scarring is unknown.The purpose of this study was to examine the relationship between proximal coronary artery stenosis severity, the amount of coronary collateralization, and myocardial scar extent in the distal distribution of the affected coronary artery based on both quantitative coronary angiography (QCA) and delayed-enhancement magnetic resonance imaging (DE–MRI).

Methods:

Thirty-four patients (26 males, 8 females; age range: 35-86 years) with a coronary artery containing a single, proximal stenosis ≥30% by quantitative coronary angiography (QCA) underwent DE-MRI. The relationship between stenosis severity, collateralization, and myocardial scar morphology (area, transmurality and patchiness) was examined using linear mixed-model ANCOVA.

Results:

There was a statistically significant correlation between stenosis severity and scar extent (r=0.53, p<0.01). Patients with hemodynamically significant stenoses (≥70%) exhibited significantly greater collateralization (p<0.05) and scar extent (p<0.01) than patients with <70% stenosis. However, scarring was often found in patients with stenoses <70%. Also, greater stenosis severity (93±14%) and mean scar extent (41±35%) were found in patients with collaterals than in patients without collaterals (diameter stenosis 48±10%, p<0.01) (scar extent 19±29%, p=0.01).

Conclusions:

Using QCA and DE-MRI, we demonstrate a significant relationship between coronary artery stenosis severity and myocardial scar extent, in the absence of a documented history of acute infarction. The relationship likely reflects increasing ischemia leading to scar formation in the range of angiographically significant stenosis. However, in the absence of collateralization, scar was observed without significant stenosis, especially in females.

Key Words: Coronary collateralization, coronary stenosis, magnetic resonance imaging, myocardial ischemia, myocardial scar, quantitative coronary angiography..