Review
Copyright ©The Author(s) 2015. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Cardiol. Dec 26, 2015; 7(12): 861-874
Published online Dec 26, 2015. doi: 10.4330/wjc.v7.i12.861
Myocardial perfusion echocardiography and coronary microvascular dysfunction
Giuseppe Barletta, Maria Riccarda Del Bene
Giuseppe Barletta, Maria Riccarda Del Bene, Cardio-Thoracic and Vascular Department, Azienda Ospedaliero-Universitaria Careggi, Largo Brambilla, 50134 Florence, Italy
Author contributions: Barletta G and Del Bene MR equally contributed to this paper with conception and design of the study, literature review and analysis, drafting and critical revision and editing, and final approval of the final version.
Conflict-of-interest statement: No potential conflicts of interest. No financial support.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Giuseppe Barletta, MD, FESC, Cardio-Thoracic and Vascular Department, Azienda Ospedaliero-Universitaria Careggi, Largo Brambilla, 50134 Florence, Italy. barlettagius@tiscali.it
Telephone: +39-333-3298907 Fax: +39-55-7947578
Received: June 14, 2015
Peer-review started: June 17, 2015
First decision: August 4, 2015
Revised: September 4, 2015
Accepted: October 16, 2015
Article in press: October 19, 2015
Published online: December 26, 2015
Processing time: 192 Days and 18.4 Hours
Abstract

Our understanding of coronary syndromes has evolved in the last two decades out of the obstructive atherosclerosis of epicardial coronary arteries paradigm to include anatomo-functional abnormalities of coronary microcirculation. No current diagnostic technique allows direct visualization of coronary microcirculation, but functional assessments of this circulation are possible. This represents a challenge in cardiology. Myocardial contrast echocardiography (MCE) was a breakthrough in echocardiography several years ago that claimed the capability to detect myocardial perfusion abnormalities and quantify coronary blood flow. Research demonstrated that the integration of quantitative MCE and fractional flow reserve improved the definition of ischemic burden and the relative contribution of collaterals in non-critical coronary stenosis. MCE identified no-reflow and low-flow within and around myocardial infarction, respectively, and predicted the potential functional recovery of stunned myocardium using appropriate interventions. MCE exhibited diagnostic performances that were comparable to positron emission tomography in microvascular reserve and microvascular dysfunction in angina patients. Overall, MCE improved echocardiographic evaluations of ischemic heart disease in daily clinical practice, but the approval of regulatory authorities is lacking.

Keywords: Contrast echocardiography; Myocardial perfusion; Myocardial ischemia; Microvascular angina; Coronary flow

Core tip: Diagnostic work-up of coronary heart disease is evolving to include evaluations of the coronary microcirculation in addition to the imaging of obstructive atherosclerosis of coronary arteries and its eventual effects. Functional assessments of coronary microvasculature have become the challenge. Myocardial contrast echocardiography (MCE) emerged as a promising tool several years ago to detect myocardial perfusion abnormalities and quantify coronary blood flow. MCE compared favorably with other expensive techniques, and it accurately evaluated coronary microvascular reserve and dysfunction in research studies. However, its daily use in clinical practice is not established. Therefore, the future of this technique is questionable.