The prognostic value of combined fractional flow reserve and TIMI frame count measurements in patients with stable angina pectoris and acute coronary syndrome.

BACKGROUND

The aim of this study was to evaluate the prognostic value of different fractional flow reserve (FFR) cutoff values and corrected thrombolysis in myocardial infarction frame (TIMI) count (CTFC) measurements in a series of consecutive patients with moderate coronary lesions, including patients with unstable angina, myocardial infarction, and/or positive noninvasive functional test findings.

METHODS

We included 162 consecutive coronary patients in whom revascularization of a moderate coronary lesion was deferred based on a FFR value ≥0.75. Patients were divided according to the results of the intracoronary pressure and flow measurements into four groups: group A: 0.75 ≤ FFR ≤ 0.85 and CTFC > 28 (n=22), group B: 0.75 ≤ FFR ≤ 0.85 and CTFC ≤ 28 (n = 55), group C: 0.85 < FFR and CTFC > 28 (n = 19), and group D: 0.85 < FFR and CTFC ≤ 28 (n = 66). Adverse cardiac events and the presence of angina were evaluated at follow-up.

RESULTS

At a mean follow-up of 18 ± 10 months, cardiac event rate in patients with 0.75 ≤ FFR ≤ 0.85 and FFR > 0.85 were 22% and 9%, respectively (P = 0.026) and also, a trend was observed toward a higher cardiac event rate in case of an abnormal CTFC (CTFC > 28) compared to a normal CTFC (24% vs 12%, P = 0.066). Furthermore, a significantly higher cardiac event rate was observed when group A was compared to group D (31.8% vs 7.6%, respectively, P = 0.004).

CONCLUSION

Patients with potential microvascular dysfunction and borderline FFR values should be interpreted with caution, and management strategies should be guided not only by pressure measurement, but also by possibly supplementary clinical risk stratification and noninvasive tests.