Introduction and objectives: The fractional flow reserve (FFR) has been shown to be a valid and useful measure in the functional assessment of coronary stenoses of intermediate severity. Our aim was to determine the usefulness of FFR assessment in diabetic patients, in whom determination of the FFR can be influenced by microvascular dysfunction.
Methods: Between 1997-2004, FFR assessment was used to evaluate 222 consecutive coronary lesions judged by an interventional cardiologist to be of intermediate severity (ie, 40%-70%). Intravenous adenosine (140 microg/kg per min) was used to achieve maximum hyperemia. The occurrence of cardiac events (ie, death, non-fatal acute myocardial infarction, and target lesion revascularization) was compared in diabetics and nondiabetics in whom FFR assessment gave a negative result and intervention was deferred. The mean follow-up period was 30+/-21 months.
Results: Revascularization was deferred for 144 lesions (in 136 patients) in which the FFR was >/=0.75. Of these, 42 lesions (29.2%) were in diabetics (40 patients). The proportion of patients who were female or who had hypertension, dyslipidemia or multivessel disease was greater in the diabetic group. There was no difference in indications for coronary angiography. In both groups, the most frequently investigated vessel was the left anterior descending coronary artery. The mean FFR was 0.87+/-0.06, and there was no difference between the groups. On long-term follow-up, there was no difference in the rate of death or acute myocardial infarction. Overall, 8.8% of nondiabetics and 14.3% of diabetics with a negative FFR test result required target lesion revascularization (P=.32).
Conclusions: Our results indicate that deferring percutaneous coronary intervention in diabetics with a moderately severe coronary artery stenosis and an FFR >/=0.75 is safe.