Related Experiment Video
Updated: Feb 11, 2026
Interventional Diagnostic Procedure: A Practical Guide for the Assessment of Coronary Vascular Function
Published on: March 15, 2022
Comprehensive physiological evaluation of epicardial and microvascular coronary domains using vascular conductance
Nina W van der Hoeven1, Guus A de Waard, Alicia Quirós
1Department of Cardiology, VU University Medical Center, Amsterdam, the Netherlands.
Insights
A new method simultaneously assesses epicardial (CEPI) and microvascular conductance (CMICRO) for coronary artery disease. High CEPI effectively identifies significant stenoses, while CEPI lower than CMICRO indicates ischemia.
Area of Science:
- Cardiovascular physiology
- Interventional cardiology
- Medical diagnostics
Background:
- Current assessment of coronary circulation relies on pressure ratios and resistance.
- Simultaneous assessment of epicardial (CEPI) and microvascular conductance (CMICRO) offers a unified approach in comparable units.
- Developing an integrated method is crucial for evaluating both epicardial and microvascular disease severity.
Purpose of the Study:
- To develop and validate a novel integral method for assessing the functional severity of epicardial and microvascular coronary artery disease.
- To enable simultaneous evaluation of coronary epicardial (CEPI) and microvascular conductance (CMICRO).
- To provide a comprehensive assessment of blood deliverability across both coronary domains.
Main Methods:
- Intracoronary pressure and Doppler flow velocity measurements were performed in 403 vessels from 261 patients with stable coronary artery disease.
- Hyperemic pressure-flow velocity (PV) relationships were analyzed to derive epicardial (CEPI) and microvascular conductance (CMICRO).
- Receiver operating characteristic (ROC) curves were used to evaluate the diagnostic performance of CEPI in identifying significant stenoses.
Main Results:
- Median CEPI was significantly higher than CMICRO (4.2 vs. 1.3 cm/s/mmHg, p<0.001).
- Microvascular conductance (CMICRO) was independent of stenosis severity (p=0.797).
- Epicardial conductance (CEPI) demonstrated excellent diagnostic efficiency for significant stenoses (AUC 0.93); CEPI < CMICRO predicted decreased flow and pressure, indicating ischemia (AUC 0.90).
Conclusions:
- A comprehensive assessment of separate epicardial (CEPI) and microvascular conductance (CMICRO) is feasible.
- CEPI exhibits high diagnostic accuracy for detecting clinically relevant coronary stenoses.
- A condition of CEPI < CMICRO signifies myocardial ischemia due to reduced distal flow and pressure, with CMICRO useful for assessing microvascular disease severity.
Aims:
Assessment of the coronary circulation has been based largely on pressure ratios (epicardial) and resistance (micro-vessels). Simultaneous assessment of epicardial (CEPI) and microvascular conductance (CMICRO) provides an intuitive approach using the same units for both coronary domains and expressing the actual deliverability of blood. The aim of this study was to develop a novel integral method for assessing the functional severity of epicardial and microvascular disease.
Methods And Results:
We performed intracoronary pressure and Doppler flow velocity measurements in 403 vessels in 261 patients with stable coronary artery disease. Hyperaemic mid-to-late diastolic pressure and flow velocity (PV) relationships were calculated. The slope of the aortic PV indicates the overall conductance and the slope of the distal PV relationship represents CMICRO. The intercept with the x-axis represents zero-flow pressure (Pzf). CEPI was derived from microvascular and overall conductance. Median CEPI was higher compared to CMICRO (4.2 [2.1-8.0] versus 1.3 [1.0-1.7] cm/s/mmHg, p<0.001). CMICRO was independent of stenosis severity (1.3 [1.0-1.7] in FFR ≤0.80 versus 1.4 [1.0-1.8] in FFR >0.8, p=0.797). ROC curves (using FFR and HSR concordant vessels as standard) demonstrated an excellent ability of CEPI to characterise significant stenoses (AUC 0.93). When CEPI
Conclusions:
A comprehensive assessment of separate CEPI and CMICRO was feasible. CEPI has a remarkable diagnostic efficiency to detect a clinically relevant stenosis. When CEPI
Related Concept Videos
02:26Conservation of Protein Domains Over Different Proteins
A limited set of protein domains often duplicate and recombine during evolution. These domains can be organized in different combinations to...
01:29Physiology of the Genitourinary System I: Renal Blood Flow and Glomerular Filtration
01:28Conduct Disorder
01:19Conduction System of the Heart
The pacemaker cells are located in two primary nodes: the sinoatrial (SA) node and the atrioventricular (AV) node. The SA node pacemaker cells can autonomously depolarize, triggering an action potential that leads to the...
03:24Seedless Vascular Plants
01:29Three Developmental Domains
Physical Development
Physical processes, also known as maturation, encompass the biological changes that occur across an individual's life. These changes begin with genetic inheritance and continue through various stages, including growth in height and weight,...