Coronary Microcirculation: The Next Frontier in the Management of STEMI

Area of Science:

• Cardiology
• Interventional Cardiology
• Cardiovascular Research

Background:

• Primary percutaneous coronary intervention (PCI) has improved ST-segment elevation myocardial infarction (STEMI) outcomes.
• Inadequate reperfusion in the coronary microcirculation, known as coronary microvascular dysfunction (CMD), persists in up to 50% of STEMI patients post-PCI.
• CMD is linked to poorer clinical prognosis and increased infarct size.

Purpose of the Study:

• To review the incidence, assessment methods, and prognostic implications of CMD after primary PCI in STEMI patients.
• To highlight the clinical utility of invasive CMD assessment in the catheterization laboratory.
• To discuss therapeutic strategies targeting coronary microcirculation in STEMI.

Main Methods:

• Review of existing evidence on CMD occurrence and assessment post-primary PCI.
• Overview of invasive assessment technologies: thermodilution, Doppler-based methods, and functional coronary angiography.
• Examination of hemodynamic parameters: coronary flow reserve (CFR), index of microcirculatory resistance (IMR), hyperemic microvascular resistance (HMR), and pressure at zero flow (PzF).

Main Results:

• CMD is a frequent complication following primary PCI in STEMI, associated with adverse outcomes.
• Invasive hemodynamic assessment provides valuable prognostic information.
• Various methods exist for assessing CMD, with ongoing development in functional angiography.

Conclusions:

• Invasive assessment of CMD at the end of primary PCI is clinically relevant for STEMI management.
• Understanding and addressing CMD is essential for improving patient prognosis after myocardial infarction.
• Further research into therapeutic interventions targeting the coronary microcirculation is warranted.