Impact of intravascular ultrasound parameters on revascularization decision in grey zone fractional flow reserve: data from IRIS FFR registry

Abstract

Abstract Background The optimal revascularization strategy for coronary stenosis with grey-zone fractional flow reserve (FFR) value (0.75-0.80) is still debated. This study investigated the prognostic impact of the lesion characteristics measured by intravascular ultrasound (IVUS) in grey-zone FFR. Methods A total of 734 native coronary stenoses with grey-zone FFR in 734 patients from the prospective multicenter IRIS-FFR registry were simultaneously evaluated by IVUS. The primary outcome was a composite of cardiac death, myocardial infarction and target vessel revascularization. Results Among the 734 patients, revascularization was deferred for 293 patients and performed for 441. During a median follow-up of 4.4 years, the primary outcome occurred in 31 (10.6%) patients in deferred group and 42 (9.5%) in performed group. With the best cut-off values of 2.62 mm2 (area under curve 0.64) and 75% (area under curve 0.63), respectively, the minimal lumen area (MLA) and plaque burden (PB) at the MLA site were significant predictors of the primary outcome in the deferred group, whereas they were not predictive in the performed group. Revascularization performed group showed lower incidence rate of the primary outcome than deferral group in 348 patients with smaller MLA (<2.62 mm2) and larger PB (>75%) (19.3% vs. 36.8%, hazard ratio 0.58, 95% confidence interval [CI] 0.34-0.91, P=0.017), whereas other patients showed similar incidence rate of primary outcome between two groups (15.7% vs. 19.8%, hazard ratio 0.78, 95% CI 0.47-1.31, P=0.35). Conclusions For coronary stenoses with grey-zone FFR and smaller MLA and larger PB measured by IVUS, revascularization was associated with better clinical outcomes than deferral. The incorporation of FFR and IVUS may improve the revascularization decision in native coronary stenoses with grey-zone FFR.