FFR Derived From Coronary CT Angiography in STEMI

Study Questions:

What is the diagnostic performance of noninvasive fractional flow reserve (FFR) derived from coronary computed tomography angiography (CTA) (FFRCT) for the diagnosis of lesion-specific ischemia in nonculprit vessels of patients with recent ST-segment elevation myocardial infarction (STEMI)?

Methods:

For this study, coronary CTA with calculation of FFRCT and invasive coronary angiography with FFR were performed 1 month after STEMI in patients with multivessel disease. Coronary CTA and invasive coronary angiography stenosis >50% were considered obstructive. Lesion-specific ischemia was assumed if FFRCT was ≤0.80. FFR ≤0.80 was the reference standard. To evaluate the influence of vessel size, the total coronary vessel lumen volume relative to left ventricular mass (volume-to-mass ratio) was calculated and compared with that of patients with stable angina.

Results:

The study evaluated 124 nonculprit vessels from 60 patients. Accuracy, sensitivity, and specificity of FFRCT were 72%, 83%, and 66% versus 64% (p = 0.033), 93% (p = 0.15), and 49% (p < 0.001) for CTA and 72% (p = 1.00), 76% (p = 0.46), and 70% (p = 0.54) for invasive coronary angiography. Following STEMI, median volume-to-mass ratio was lower than in patients with stable angina, 53 versus 65 mm3/g (p = 0.009). In patients with volume-to-mass ratio ≥65 mm3/g (upper tertile) accuracy, sensitivity, and specificity of FFRCT were all 83% versus 56% (p = 0.009), 75% (p = 0.61), and 44% (p = 0.003) in patients with <49 mm3/g (lower tertile).

Conclusions:

The authors concluded that diagnostic performance of FFRCT for staged detection of ischemia in STEMI patients with multivessel disease is moderate.

Perspective:

This study reports that diagnostic performance of FFRCT for staged detection of ischemia in nonculprit vessels of STEMI patients with multivessel disease is modest at best. While the clinical utility of FFRCT in patients with STEMI and recent acute coronary syndrome needs further investigation, the current evidence base does not support the use of FFRCT in the post-STEMI setting.

Keywords: Acute Coronary Syndrome, Angina, Stable, Cardiac Imaging Techniques, Constriction, Pathologic, Coronary Angiography, Coronary Stenosis, Fractional Flow Reserve, Myocardial, Ischemia, Myocardial Infarction, Tomography, X-Ray Computed


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