Objectives: This study tried to predict in-stent restenosis by the measurement of fractional flow reserve and to evaluate the effect of diabetes mellitus control on the relationship between in-stent restenosis and fractional flow reserve.
Methods: Fractional flow reserve was measured in 62 patients (mean age 61 +/- 9 years, 32 with angina pectoris and 30 with myocardial infarction) after stent implantation. The patients were divided into three groups according to the value of HbA1c and fasting blood sugar (FBS): Group P (HbA1c > or = 6.5% or FBS > or = 126 mg/dl, n = 15), Group G (6.5% > HbA1c > or = 5.8% or 126 > FBS > or = 100 mg/dl, n = 12), and Group N (HbA1c < 5.8% and FBS < 100 mg/dl, n = 35). The relationship between fractional flow reserve at the end point of stent implantation and target lesion revascularization (TLR) was evaluated.
Results: In all patients, fractional flow reserve was 0.89 +/- 0.17 and percentage diameter stenosis was 17.6 +/- 11.6% after stent implantation. The TLR rate was 21%. Fractional flow reserve was significantly lower in patients with TLR (0.85 +/- 0.08 vs 0.91 +/- 0.06, p < 0.01). Fractional flow reserve was significantly lower in patients with TLR in Groups N and G (Group N: 0.85 +/- 0.04 vs 0.91 +/- 0.06, p < 0.05, Group G: 0.77 +/- 0.06 vs 0.91 +/- 0.05, p < 0.01). Fractional flow reserve showed no significant difference between patients with TLR and without TLR in Group P (0.85 +/- 0.10 vs 0.87 +/- 0.08, p = NS). In patients with optimal results (fractional flow reserve > or = 0.90), TLR rate was 60% in Group P, 0% in Group G and 0% in Group N.
Conclusions: Fractional flow reserve after stent implantation is useful for the prediction of TLR in patients without diabetes mellitus. However, diabetic control in patients with diabetes mellitus might be attributable to TLR rather than fractional flow reserve.