Diabetes mellitus and long-term safety of FFR and iFR-based coronary revascularization deferral

Introduction and objectives: The safety of physiology-based revascularization in patients with diabetes mellitus has been scarcely investigated. Our objective was to determine the safety of deferring revascularization based on the fractional flow reserve (FFR) or the instantaneous wave-free ratio (iFR) in diabetic patients. Methods: Single-center, retrospective analysis of patients with intermediate coronary stenoses in whom revascularization was deferred based on FFR > 0.80 or iFR > 0.89 values. The long-term rate of major adverse cardiovascular events, a composite of all-cause mortality, myocardial infarction, and target vessel revascularization (TVR), was assessed in diabetic and non-diabetic patients at the follow-up. The rate of TVR based on the type of physiological index used to defer the lesion was also evaluated. Results: We evaluated 164 diabetic (214 vessels) and 280 non-diabetic patients (379 vessels). No significant differences in the rate of major adverse cardiovascular events was seen between diabetic and non-diabetic patients (20.1% vs 13.2%; P = .245) at a median follow-up of 43 months. All-cause mortality and cardiac death were not statistically different between both groups in the adjusted analysis (P > .05). A trend towards a higher rate of myocardial infarction was seen in diabetic patients (6.7% vs 2.9%; P = .063). However, the rate of target vessel myocardial infarction was similar in both groups (P = .874). Overall, TVR was similar in diabetics and non-diabetics (4.7% vs 4.2%; P = .814); however, when analyzed based on the physiological index, numerically, diabetics had a higher rate of TVR when the FFR was used in the decision-making process compared to when the iFR was used (6.4% vs 0.0%; P = .064). Conclusions: Deferring the revascularization of intermediate stenoses in patients with DM based on the FFR or the iFR is safe regarding the risk of TVR or target vessel myocardial infarction, with a rate of events at the long-term follow-up similar to that seen in non-diabetic patients.