Quantitative flow ratio-guided residual functional SYNTAX score for risk assessment in patients with ST-segment...

Area of Science:

• Interventional Cardiology
• Cardiovascular Imaging and Physiology
• Clinical Risk Stratification

Background:

• Incomplete revascularisation (IR) following percutaneous coronary intervention (PCI) for ST-segment elevation myocardial infarction (STEMI) is linked to increased major adverse cardiac events (MACE).
• Accurate assessment of residual ischaemia is crucial for long-term patient outcomes after PCI.

Purpose of the Study:

• To evaluate the prognostic capability of the quantitative flow ratio (QFR)-guided residual functional SYNTAX score (Q-rFSS).
• To compare the predictive performance of Q-rFSS against traditional scoring methods for MACE in STEMI patients undergoing PCI.

Main Methods:

• A cohort of 354 STEMI patients who underwent successful PCI was analyzed.
• Q-rFSS was calculated based on residual SYNTAX score (rSS) in vessels with QFR ≤0.8.
• The primary endpoint was MACE, defined as a composite of all-cause mortality, myocardial infarction, and ischaemia-driven revascularisation at 2 years.

Main Results:

• Functional IR (Q-rFSS ≥1) was associated with a significantly higher risk of MACE compared to functional complete revascularisation (Q-rFSS=0) (22.0% vs 7.4%).
• Q-rFSS demonstrated superior prognostic ability for MACE risk compared to rSS, evidenced by a higher area under the curve (AUC) (0.738 vs 0.648).
• The addition of Q-rFSS to clinical risk factors significantly improved risk classification and reclassification for MACE.

Conclusions:

• Functional incomplete revascularisation in STEMI patients undergoing PCI is a significant predictor of long-term MACE.
• Q-rFSS offers enhanced prognostic accuracy for predicting MACE compared to conventional rSS, improving risk stratification in this patient population.