AbstractObjectivesTo investigate the outcomes of deferred coronary revascularization in patients with non‐significant in‐stent restenosis (ISR) by physiological assessment.BackgroundThe pathophysiology and natural history of ISR is markedly different from de‐novo stenoses. There is a paucity of data on the safety of deferral of revascularization of ISR using physiological assessment.MethodsIn this single centre study, using a propensity‐score matched analysis, we compared the long‐term clinical outcomes of patients with ISR and de‐novo disease deferred based on intracoronary physiology. Matching was on a 1:2 basis of ISR to de‐novo stenosis. The primary end point was major adverse cardiovascular events (MACE) a composite of all‐cause mortality, target lesion revascularization or target vessel myocardial infarction at 36 months.ResultsMatched cohorts of 56 ISR and 112 de‐novo stenoses were analyzed. The median percentage stenosis was 50% in both groups (p = 0.403). Deferral was based on fractional flow reserve (FFR). The mean FFR was 0.86 across both groups (p = 0.942). At 36‐months, freedom from MACE was similar between groups; 86.2% versus 92.8% log rank p=0.180 for ISR and de‐novo lesions, respectively. Neither were there differences in the individual components of MACE.ConclusionsDeferral of coronary revascularization in patients with ISR based on its functional impact is associated to similar long‐term safety as in de‐novo coronary stenosis.