Automated Pixel-Wise Quantitative Myocardial Perfusion Mapping by CMR to Detect Obstructive Coronary Artery Disease and Coronary Microvascular Dysfunction: Validation Against Invasive Coronary Physiology

JACC Cardiovasc Imaging. 2019 Oct;12(10):1958-1969. doi: 10.1016/j.jcmg.2018.12.022. Epub 2019 Feb 13.

Abstract

Objectives: This study sought to assess the performance of cardiovascular magnetic resonance (CMR) myocardial perfusion mapping against invasive coronary physiology reference standards for detecting coronary artery disease (CAD, defined by fractional flow reserve [FFR] ≤0.80), microvascular dysfunction (MVD) (defined by index of microcirculatory resistance [IMR] ≥25) and the ability to differentiate between the two.

Background: Differentiation of epicardial (CAD) and MVD in patients with stable angina remains challenging. Automated in-line CMR perfusion mapping enables quantification of myocardial blood flow (MBF) to be performed rapidly within a clinical workflow.

Methods: Fifty patients with stable angina and 15 healthy volunteers underwent adenosine stress CMR at 1.5T with quantification of MBF and myocardial perfusion reserve (MPR). FFR and IMR were measured in 101 coronary arteries during subsequent angiography.

Results: Twenty-seven patients had obstructive CAD and 23 had nonobstructed arteries (7 normal IMR, 16 abnormal IMR). FFR positive (epicardial stenosis) areas had significantly lower stress MBF (1.47 ± 0.48 ml/g/min) and MPR (1.75 ± 0.60) than FFR-negative IMR-positive (MVD) areas (stress MBF: 2.10 ± 0.35 ml/g/min; MPR: 2.41 ± 0.79) and normal areas (stress MBF: 2.47 ± 0.50 ml/g/min; MPR: 2.94 ± 0.81). Stress MBF ≤1.94 ml/g/min accurately detected obstructive CAD on a regional basis (area under the curve: 0.90; p < 0.001). In patients without regional perfusion defects, global stress MBF <1.82 ml/g/min accurately discriminated between obstructive 3-vessel disease and MVD (area under the curve: 0.94; p < 0.001).

Conclusions: This novel automated pixel-wise perfusion mapping technique can be used to detect physiologically significant CAD defined by FFR, MVD defined by IMR, and to differentiate MVD from multivessel coronary disease. A CMR-based diagnostic algorithm using perfusion mapping for detection of epicardial disease and MVD warrants further clinical validation.

Keywords: CMR; cardiovascular magnetic resonance; coronary artery disease; index of microcirculatory resistance; microvascular dysfunction; myocardial blood flow.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't
  • Validation Study

MeSH terms

  • Adenosine / administration & dosage
  • Adult
  • Aged
  • Case-Control Studies
  • Coronary Angiography
  • Coronary Artery Disease / diagnostic imaging*
  • Coronary Artery Disease / physiopathology
  • Coronary Stenosis / diagnostic imaging*
  • Coronary Stenosis / physiopathology
  • Coronary Vessels / diagnostic imaging*
  • Coronary Vessels / physiopathology
  • Female
  • Fractional Flow Reserve, Myocardial*
  • Humans
  • Magnetic Resonance Imaging*
  • Male
  • Microcirculation*
  • Middle Aged
  • Myocardial Perfusion Imaging / methods*
  • Predictive Value of Tests
  • Reproducibility of Results
  • Vascular Resistance
  • Vasodilator Agents / administration & dosage

Substances

  • Vasodilator Agents
  • Adenosine