Gradual Versus Abrupt Reperfusion During Primary Percutaneous Coronary Interventions in ST-Segment-Elevation...

Area of Science:

• Cardiology
• Interventional Cardiology
• Cardiovascular Research

Background:

• Microvascular damage from edema and hemorrhage is a key issue in ST-segment-elevation myocardial infarction (STEMI) reperfusion.
• Primary percutaneous coronary intervention (PCI) can abruptly restore pressure and flow, potentially worsening microvascular injury.
• Investigating methods to mitigate reperfusion injury during primary PCI is crucial for STEMI management.

Purpose of the Study:

• To evaluate if pressure-controlled reperfusion via gradual reopening of the infarct-related artery can limit microvascular injury in STEMI patients undergoing primary PCI.
• To compare the effects of pressure-controlled reperfusion with delayed stenting (PCRDS) versus standard immediate stenting (IS) on coronary microvascular function and infarct size.

Main Methods:

• A randomized trial comparing PCRDS (n=10) with IS (n=10) in STEMI patients with occluded infarct-related arteries.
• PCRDS involved initial reperfusion with a 1.5-mm balloon followed by pressure control for 30 minutes before stenting.
• Coronary hemodynamics, including intracoronary pressure and Doppler flow velocity, were continuously assessed. The primary endpoint was zero flow pressure after a 60-minute monitoring period.

Main Results:

• PCRDS resulted in significantly lower distal intracoronary pressures compared to IS (71.2±9.37 mmHg vs. 90.13±12.09 mmHg, P=0.001).
• Microvascular resistance was significantly lower in the PCRDS group (1.83±0.53 vs. 2.83±0.56 mmHg·s·cm⁻¹, P=0.001), indicating better microcirculatory function.
• The primary endpoint, zero flow pressure, was significantly lower in PCRDS (41.46±17.85 mmHg vs. 76.87±21.34 mmHg, P=0.001), and myocardial infarction size was smaller (peak Troponin T: 5395±2991 ng/mL vs. 8874±1927 ng/mL, P=0.006).

Conclusions:

• Pressure-controlled reperfusion with delayed stenting (PCRDS) effectively preserves coronary microvascular integrity in STEMI patients undergoing primary PCI.
• This technique leads to smaller myocardial infarction sizes compared to standard immediate stenting.
• PCRDS is a safe and effective alternative, demonstrating improved outcomes without increased procedural complications.