The Influence of Epicardial Resistance on Microvascular Resistance Reserve
Authors' conclusion
MRR, unlike CFR, is minimally influenced by epicardial resistance, and thus should be considered the more specific index of microvascular function.
Study context
- Population
- Patients after proximal left anterior descending artery stenting64 measurements of each
- Participants
- 16 patients
- Comparison
- Coronary flow reserve (CFR) vs microvascular resistance reserve (MRR) across 4 grades of artificial epicardial stenosis
- Outcome
- Response of CFR and MRR to increasing epicardial resistance
Methodological detailsartificial graded stenosis (balloon inflation within stent), continuous thermodilution
- Artificial graded stenosis (balloon inflation within stent)
- Continuous thermodilution
Main finding
As reported in the abstract
| Group | CFR | MRR |
|---|---|---|
| No stenosis | 2.5 ± 0.9 | 3.0 ± 1.0 |
| Mild | 2.2 ± 0.8 | 3.0 ± 1.0 |
| Moderate | 1.8 ± 0.7 | 2.9 ± 1.0 |
| Severe | 1.4 ± 0.6 | 2.8 ± 1.0 |
CFR
No stenosis2.5 ± 0.9
Mild2.2 ± 0.8
Moderate1.8 ± 0.7
Severe1.4 ± 0.6
MRR
No stenosis3.0 ± 1.0
Mild3.0 ± 1.0
Moderate2.9 ± 1.0
Severe2.8 ± 1.0
- CFR decrease per 0.1 decrease in fractional flow reserve (FFR)
- 0.3 (P < 0.001)
- MRR decrease per 0.1 decrease in FFR
- 0.05 (P < 0.001)
Further findings
Hyperemic coronary flow by stenosis grade
| Outcome | No stenosis | Mild | Moderate | Severe |
|---|---|---|---|---|
| FFR by stenosis grade | mean 0.82 ± 0.05 | mean 0.72 ± 0.04 | mean 0.61 ± 0.05 | mean 0.48 ± 0.09 |
- FFR by stenosis grade — Significant sequential decrease
- P < 0.001
- Hyperemic coronary flow by stenosis grade — Linear decrease
- P < 0.001
Original publication
The Influence of Epicardial Resistance on Microvascular Resistance Reserve. J Am Coll Cardiol. Published 14 May 2024. doi:10.
Composed by AI from the published abstract and checked against it. How Briefs are made →