Use of fractional flow reserve versus stress perfusion scintigraphy in stent restenosis

Fractional flow reserve (FFR) is a valid surrogate for hemodynamic significance in stenotic native coronary arteries. The aim of this study was to examine the value of FFR compared to stress perfusion myocardial scintigraphy (SPMS) in patients with coronary stent restenosis. We studied 42 patients, aged 62 ± 10 years, with stent restenosis 5.3 ± 1.6 months after coronary stent implantation. All patients had a single coronary lesion of intermediate severity (diameter stenosis 40–70%). FFR measurement, SPMS, and quantitative angiography of the stent stenosis were performed in all patients. The mean percentage in stent diameter stenosis was 53 ± 9%. FFR was 0.77 ± 0.15. In 20 patients FFR was below 0.75. Nineteen patients had reversible perfusion defects in SPMS. FFR showed good diagnostic accuracy for the detection of reversible perfusion defects in SPMS (AUROC 0.86, 95% CI 0.74–0.98). The percentage of agreement of SPMS and FFR was 88%, with the best cutoff value of 0.75 for FFR. A FFR value of 0.75 is not only valid for diagnosing significant native coronary stenosis, but also for stent restenosis. Thus, FFR measurement should be taken into account when making decisions regarding patients with stent restenosis.