[Coronary physiology in the catheter laboratory]

Area of Science:

• Cardiovascular Physiology
• Interventional Cardiology

Background:

• Coronary flow regulation primarily occurs in microcirculation resistance vessels.
• Functional significance of epicardial stenosis depends on interaction with downstream microcirculation.
• Visual assessment alone can lead to misinterpretation and incorrect revascularization decisions.

Purpose of the Study:

• To highlight the importance of physiological measurements in assessing coronary stenosis.
• To emphasize the role of iwFR and FFR in guiding revascularization decisions.
• To discuss novel methods for virtual planning and risk stratification in coronary artery disease.

Main Methods:

• Utilizing physiological measurements like instantaneous wave-free ratio (iwFR) and fractional flow reserve (FFR).
• Employing co-registration and coronary mapping for virtual percutaneous coronary intervention planning.
• Conducting invasive flow measurements for risk stratification in acute coronary syndrome.

Main Results:

• Physiological measurements accurately detect complex interactions between epicardial stenosis and microcirculation.
• ESC guidelines recommend iwFR and FFR (Class IA) for intermediate stenoses with unclear hemodynamic relevance.
• Despite recommendations, physiological measurements are not routinely used in clinical practice.

Conclusions:

• Accurate assessment of coronary stenosis requires integrating hemodynamic data with anatomical information.
• Novel techniques like co-registration and coronary mapping enhance planning for complex interventions.
• Invasive flow measurements are vital for risk stratification and management of acute coronary syndrome patients.