Correlation between abnormal microvascular perfusion and quantitative flow ratio after primary PCI in patients with...

Area of Science:

• Cardiology
• Interventional Cardiology
• Cardiovascular Imaging

Background:

• Timely assessment of microvascular perfusion (MVP) is crucial for ST-segment elevation myocardial infarction (STEMI) patient outcomes.
• Primary percutaneous coronary intervention (PPCI) aims to restore blood flow but microvascular function can remain impaired.

Purpose of the Study:

• To evaluate the clinical utility of contrast-flow quantitative flow ratio (cQFR) in assessing abnormal MVP.
• To determine the prognostic implications of cQFR for long-term mortality in STEMI patients after successful PPCI.

Main Methods:

• Two independent cohorts were analyzed: a diagnostic cohort (n=186) for cQFR-MVP correlation and a prognostic cohort (n=1931) for long-term mortality assessment.
• Abnormal MVP was assessed using myocardial contrast perfusion echocardiography (MCE).
• Patients in the prognostic cohort were followed for at least 2 years, with all-cause mortality as the primary outcome.

Main Results:

• cQFR showed moderate correlation with MCE-assessed abnormal MVP in the diagnostic cohort (AUC=0.709).
• A cQFR cutoff of 0.875 demonstrated 81.6% specificity and 50.9% sensitivity for predicting abnormal MVP.
• In the prognostic cohort, cQFR < 0.875 was associated with significantly higher long-term mortality (8.0% vs 3.8%, p < 0.001) and identified as an independent predictor (aHR=2.132).

Conclusions:

• cQFR is a valuable tool for predicting abnormal MVP in STEMI patients post-PPCI.
• A cQFR value below 0.875 independently predicts both abnormal MVP and increased long-term mortality risk, offering significant prognostic information.