Lesion-Specific and Vessel-Related Determinants of Fractional Flow Reserve Beyond Coronary Artery Stenosis.
OBJECTIVES
The aims of the present study were: 1) to investigate the contribution of the extent of luminal stenosis and other lesion composition-related factors in predicting invasive fractional flow reserve (FFR); and 2) to explore the distribution of various combinations of morphological characteristics and the severity of stenosis among lesions demonstrating normal and abnormal FFR.


BACKGROUND
In patients with stable ischemic heart disease, FFR-guided revascularization, as compared with medical therapy alone, is reported to improve outcomes. Because morphological characteristics are the basis of plaque rupture and acute coronary events, a relationship between FFR and lesion characteristics may exist.


METHODS
This is a subanalysis of NXT (HeartFlowNXT: HeartFlow Analysis of Coronary Blood Flow Using Coronary CT Angiography), a prospective, multicenter study of 254 patients (age 64 ± 10 years, 64% male) with suspected stable ischemic heart disease; coronary computed tomography angiography including plaque morphology assessment, invasive angiography, and FFR were obtained for 383 lesions. Ischemia was defined by invasive FFR ≤0.80. Computed tomography angiography-defined morphological characteristics of plaques and their vascular location were used in univariate and multivariate analyses to examine their predictive value for invasive FFR. The distribution of various combinations of plaque morphological characteristics and the severity of stenosis among lesions demonstrating normal and abnormal FFR were examined.


RESULTS
The percentage of luminal stenosis, low-attenuation plaque (LAP) or necrotic core volume, left anterior descending coronary artery territory, and the presence of multiple lesions per vessel were the predictors of FFR. When grouped on the basis of degree of luminal stenosis, FFR-negative lesions had consistently smaller LAP volumes compared with FFR-positive lesions. The distribution of plaque characteristics in lesions with normal and abnormal FFR demonstrated that whereas FFR-negative lesions excluded likelihood of stenotic plaques with moderate to high LAP volumes, only one-third of FFR-positive lesions demonstrated obstructive plaques with moderate to high LAP volumes.


CONCLUSIONS
In addition to the severity of luminal stenosis, necrotic core volume is an independent predictor of FFR. The distribution of plaque characteristics among lesions with varying luminal stenosis and normal and abnormal FFR may explain the outcomes associated with FFR-guided therapy.
['Ahmadi|Amir|A|', 'Leipsic|Jonathon|J|', 'Øvrehus|Kristian A|KA|', 'Gaur|Sara|S|', 'Bagiella|Emilia|E|', 'Ko|Brian|B|', 'Dey|Damini|D|', 'LaRocca|Gina|G|', 'Jensen|Jesper M|JM|', 'Bøtker|Hans Erik|HE|', 'Achenbach|Stephan|S|', 'De Bruyne|Bernard|B|', 'Nørgaard|Bjarne L|BL|', 'Narula|Jagat|J|']
D000368:Aged D006328:Cardiac Catheterization D000072226:Computed Tomography Angiography D017023:Coronary Angiography D003324:Coronary Artery Disease D023921:Coronary Stenosis D003331:Coronary Vessels D005260:Female D053805:Fractional Flow Reserve, Myocardial D006801:Humans D008297:Male D008875:Middle Aged D009336:Necrosis D058226:Plaque, Atherosclerotic D011237:Predictive Value of Tests D011379:Prognosis D011446:Prospective Studies D012720:Severity of Illness Index
coronary artery stenosis stable ischemic heart disease revascularization myocardial ischemia percutaneous coronary intervention vulnerable plaque