Fractional flow reserve- and intravascular ultrasound-guided strategies for intermediate coronary stenosis and low lesion complexity in patients with or without diabetes: a post hoc analysis of the randomised FLAVOUR trial.

Background: A recent randomised trial demonstrated fractional flow reserve (FFR) guidance for percutaneous coronary intervention (PCI) was non-inferior to intravascular ultrasound (IVUS) guidance regarding clinical outcomes, with a lower frequency of PCI.
Aims: We sought to evaluate the prognosis of FFR versus IVUS guidance for PCI of intermediate coronary artery stenosis and low lesion complexity in diabetic and non-diabetic patients.
Methods: This study is a prespecified post hoc analysis from the FLAVOUR trial. The primary outcome was major adverse cardiac events (MACE) at 24 months, defined as a composite of death, myocardial infarction or any revascularisation. The secondary outcomes were target vessel failure (TVF) and each component of MACE and TVF at 24 months.
Results: Among 1,682 randomly assigned patients, 554 (32.9%) had diabetes, and the mean SYNTAX score was 8.64±6.03 at baseline. The FFR group had a lower PCI rate than the IVUS group in both diabetic (48.2% vs 69.1%; p<0.001) and non-diabetic (42.6% vs 63.3%; p<0.001) patients. At 24 months, there was no difference in the cumulative incidence of MACE between the FFR and the IVUS groups in either diabetic (9.3% vs 8.3%; p=0.90) or non-diabetic (7.5% vs 8.6%; p=0.50) patients. The cumulative incidence of TVF was also comparable between the FFR and the IVUS groups regardless of diabetic status.
Conclusions: In patients with intermediate coronary stenosis and low lesion complexity, regardless of diabetic status, FFR guidance had no significant differences in MACE or TVF with a lower frequency of PCI compared with IVUS guidance.