Medium-term follow-up of intermediate coronary stenoses left unrevascularized based on myocardial fractional flow...

Coronary stenoses of intermediate severity create difficulties in decision making when revascularization is concerned. Myocardial fractional flow reserve (mFFR), an accurate tool to identify physiological significance of individual coronary stenoses, may help solve this problem.

Fifty-eight intermediate (30-70%) coronary stenoses in 51 patients (mean age 54.4 +/- 8.9 years, 9 women) were left unrevascularized because of normal (> or = 0.75) mFFR findings and the patients were prospectively followed with regard to the occurrence of death, myocardial infarction and target vessel revascularization. The mean reference vessel diameter, percent stenosis and mFFR of the intermediate lesions were 3.3 +/- 0.3 mm, 46.8 +/- 9.2% and 0.86 +/- 0.05, respectively. Of the 58 intermediate lesions, 20 (34%) were associated with perfusion defects on thallium scan. Significant (> 70%) disease in addition to the one with the intermediate stenosis was present in I coronary artery in 24 (47%), and 2 coronary arteries in 6 (12%) patients and angioplasty of at least one significant stenosis was performed at the initial evaluation in 18 (35%) patients. Follow-up for a mean of 16.6 +/- 6.6 months disclosed no death or myocardial infarction. Target vessel revascularization was performed in 3 (6%) patients at a mean of 4 +/- 2.6 months. A control angiogram, which was performed in 12 of 18 patients who had undergone angioplasty at the initial evaluation revealed restenosis in 3 (25%) patients with no significant angiographic changes in the target intermediate stenoses. Anginal status was found to be significantly improved at follow-up.

In this study, we found that intermediate coronary stenoses with an mFFR > or = 0.75 have a favourable medium-term clinical outcome with respect to major cardiac adverse events when left unrevascularized based on mFFR findings.