Related Experiment Video
Updated: May 18, 2026
Oxygenation-sensitive Cardiac MRI with Vasoactive Breathing Maneuvers for the Non-invasive Assessment of Coronary Microvascular Dysfunction
Published on: August 17, 2022
CMR of microvascular obstruction and hemorrhage in myocardial infarction
1Division of Cardiology, Department of Medicine, Johns Hopkins Medical Institutions, 600 N. Wolfe Street/Carnegie 568, Baltimore, MD 21287, USA. kwu@jhmi.edu
Abstract:
Microvascular obstruction (MO) or no-reflow phenomenon is an established complication of coronary reperfusion therapy for acute myocardial infarction. It is increasingly recognized as a poor prognostic indicator and marker of subsequent adverse LV remodeling. Although MO can be assessed using various imaging modalities including electrocardiography, myocardial contrast echocardiography, nuclear scintigraphy, and coronary angiography, evaluation by cardiovascular magnetic resonance (CMR) is particularly useful in enhancing its detection, diagnosis, and quantification, as well as following its subsequent effects on infarct evolution and healing. MO assessment has become a routine component of the CMR evaluation of acute myocardial infarction and will increasingly play a role in clinical trials of adjunctive reperfusion agents and strategies. This review will summarize the pathophysiology of MO, current CMR approaches to diagnosis, clinical implications, and future directions needed for improving our understanding of this common clinical problem.
Insights
Microvascular obstruction (MO), a complication of reperfusion therapy for heart attacks, indicates a poor prognosis. Cardiovascular magnetic resonance (CMR) is crucial for detecting, diagnosing, and quantifying MO, aiding in understanding its impact on heart recovery.
Area of Science:
- Cardiology
- Medical Imaging
Background:
- Microvascular obstruction (MO), also known as no-reflow, is a complication of acute myocardial infarction reperfusion.
- MO is linked to adverse left ventricular (LV) remodeling and poorer patient outcomes.
- While several imaging methods exist, cardiovascular magnetic resonance (CMR) offers superior detection, diagnosis, and quantification of MO.
Purpose of the Study:
- To review the pathophysiology of MO.
- To outline current CMR approaches for MO diagnosis and assessment.
- To discuss the clinical implications and future research directions for MO.
Main Methods:
- Review of existing literature on microvascular obstruction.
- Focus on the role and techniques of cardiovascular magnetic resonance (CMR) in MO assessment.
- Synthesis of information regarding MO pathophysiology, diagnosis, and clinical impact.
Main Results:
- CMR is highly effective for detecting, diagnosing, and quantifying MO after myocardial infarction.
- MO assessment via CMR is integral to evaluating infarct evolution and healing.
- MO evaluation is becoming standard in CMR for acute myocardial infarction and relevant clinical trials.
Conclusions:
- Microvascular obstruction is a significant predictor of adverse outcomes post-myocardial infarction.
- CMR provides essential insights into MO, guiding patient management and therapeutic strategies.
- Further research is needed to fully understand and manage MO, improving reperfusion therapy effectiveness.
Related Concept Videos
01:21Imaging Studies for Cardiovascular System IV: CMRI
01:29Cardiomyopathy IV: Restrictive Cardiomyopathy
01:23Mitral Regurgitation II: Clinical Features and Diagnostic Tests