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Evaluation of Coronary Flow Reserve After Myocardial Ischemia Reperfusion in Rats
Published on: June 28, 2019
Microcirculation function assessment in acute myocardial infarction: A systematic review of microcirculatory
Marta Silva1, Luis Paiva1,2,3, Rogério Teixeira1,2,3
1Faculdade de Medicina, Universidade de Coimbra, Coimbra, Portugal.
Background:
Up to 50% of acute myocardial infarction (MI) patients present with microvascular dysfunction, after a successful percutaneous coronary intervention (PCI), which leads to worse clinical outcomes. The main purpose of this study is to provide a critical appraisal of the emerging role of invasive microvascular resistance indices in the MI setting, using the index of microcirculatory resistance (IMR), hyperemic microvascular resistance (HMR) and zero-flow pressure (Pzf).
Methods:
We systematically explored relevant studies in the context of MI that correlated microcirculation resistance indices with microvascular dysfunction on cardiac magnetic resonance (CMR), microvascular dysfunction occurring in infarct related arteries (IRA) and non-IRA and its relation to clinical outcomes.
Results:
The microcirculation resistance indices correlated significantly with microvascular obstruction (MVO) and infarct size (IS) on CMR. Although HMR and Pzf seem to have better diagnostic accuracy for MVO and IS, IMR has more validation data. Although, both IMR and HMR were independent predictors of adverse cardiovascular events, HMR has no validated cut-off value and data is limited to small observational studies. The presence of microvascular dysfunction in non-IRA does not impact prognosis.
Conclusion:
Microvascular resistance indices are valuable means to evaluate microcirculation function following MI. Microvascular dysfunction relates to the extent of myocardial damage and clinical outcomes after MI.
Systematic Review Registration:
[https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021228432], identifier [CRD42021228432].
Insights
Microvascular resistance indices like IMR and HMR help assess microvascular dysfunction after myocardial infarction (MI). This dysfunction correlates with heart damage and impacts patient outcomes, highlighting their clinical value.
Area of Science:
- Cardiovascular Medicine
- Interventional Cardiology
- Biomedical Engineering
Background:
- Microvascular dysfunction affects up to 50% of acute myocardial infarction (MI) patients post-percutaneous coronary intervention (PCI).
- This dysfunction is linked to poorer clinical outcomes, necessitating better assessment methods.
- Invasive microvascular resistance indices are emerging as critical tools for evaluating microcirculation in MI.
Approach:
- Systematic review of studies correlating microcirculation resistance indices with microvascular dysfunction.
- Assessment of indices including index of microcirculatory resistance (IMR), hyperemic microvascular resistance (HMR), and zero-flow pressure (Pzf).
- Correlation analysis with microvascular obstruction (MVO), infarct size (IS) on cardiac magnetic resonance (CMR), and clinical outcomes.
Key Points:
- Microcirculation resistance indices significantly correlate with MVO and IS on CMR.
- IMR shows more validation data, while HMR and Pzf suggest higher diagnostic accuracy for MVO/IS.
- Both IMR and HMR are independent predictors of adverse cardiovascular events, though HMR lacks validated cut-offs.
Conclusions:
- Invasive microvascular resistance indices are valuable for evaluating microcirculation function post-MI.
- Microvascular dysfunction is directly related to myocardial damage extent and clinical prognosis after MI.
- Further research is needed to establish validated cut-offs for indices like HMR.
