Combined assessment of fractional flow reserve, resting full-cycle ratio, and resting ratio of distal coronary to aortic pressure for clinical outcomes.

Background: Fractional flow reserve (FFR) and non-hyperemic indices are invasive standards for evaluating functional significance of coronary stenosis. However, data are limited about outcomes in vessels with concordant and discordant physiological results, particularly with a ratio of distal coronary to aortic pressure (Pd/Pa) at rest.

Methods: This was a single-center, retrospective, observational study. Coronary physiological indices including FFR, resting full-cycle ratio (RFR), and resting Pd/Pa were invasively evaluated in vessels with intermediate coronary artery stenosis. FFR ≤0.80, RFR ≤0.89, and resting Pd/Pa ≤0.92 were considered physiologically positive. Vessels were divided into three groups according to the results of FFR, RFR, and resting Pd/Pa: concordant positive (all positive for FFR, RFR, and resting Pd/Pa), concordant negative (all negative for FFR, RFR, and resting Pd/Pa), and discordant groups. The primary endpoint was target vessel failure (TVF) defined as a composite of cardiac death and target vessel myocardial infarction and unplanned revascularization.

Results: Of 987 vessels included, 311 (31.5 %), 263 (26.6 %), and 413 (41.9 %) were in the concordant positive, discordant, and concordant negative groups. During a median follow-up period of 417 (208-756) days, TVF occurred more frequently in the concordant positive group, followed by the discordant and concordant negative groups (7.7 % vs. 4.6 % vs. 2.4 %, p = 0.004). TVF increasingly accrued during long-term follow-up, while discordant results of RFR and resting Pd/Pa did not result in worse outcomes compared with negative RFR and resting Pd/Pa.

Conclusion: The combined assessment of FFR with RFR and resting Pd/Pa stratified TVF risks in vessels with intermediate coronary stenosis.