Utility of fractional flow reserve in moderate in-stent re-stenosis and jailed side branches and comparison of fractional flow reserve with single-photon emission computed tomography-myocardial perfusion imaging in native coronary artery stenosis

Background: Functional flow reserve (FFR) is used to determine functional significance of coronary artery stenosis. FFR demonstrated discrepancy between angiographic and functional significance of jailed side branches (JSBs) as well as moderate in-stent restenosis (ISR), with only minority of such lesions having functional significance. An attempt was made to study the utility of FFR and comparison of FFR with single-photon emission computed tomography-myocardial perfusion imaging (SPECT-MPI) in native coronary artery stenoses.Methods: A total of 101 lesions in 79 patients with stable ischemic coronary artery disease were subjected to FFR and SPECT-MPI including native as well as ISR and JSB. Relation between FFR and perfusion imaging was analyzed quantitatively. Sensitivity, specificity, positive predictive value, and negative predictive value were used for diagnostic accuracy.Results: FFR was ≤≤ 0.75 in majority of the lesions having >70% stenosis. Most of the lesions having reversible perfusion defect had FFR ≤≤ 0.80. There was a significant negative correlation between summed difference score (SPECT-MPI) with FFR value. As FFR value decreased, summed difference score increased. Sensitivity and specificity did not differ much when FFR cutoff was taken as 0.75 or 0.80.Conclusion: There was a significant negative correlation between FFR and sum difference score (SPECT-MPI). Sensitivity and specificity of SPECT-MPI did not differ much when FFR value cutoff was taken as 0.75 or 0.80.