Original title: Prognostic Value of Fractional Flow Reserve Linking Physiologic Severity to Clinical Outcomes. Reference: Nils P. Johnson et al. J Am Coll Cardiol 2014;64:1641–54.
Fractional flow reserve (FFR) has become an essential tool for guiding treatment, but its graded relationship to prognosis and its influence by medical treatment vs revascularization, remains unclear.
The hypothesis of this study is that FFR presents a continuous relationship between numerical value and prognosis, such that the lower the FFR values, the higher the risk of major events and, therefore, the larger the absolute benefit from revascularization.
9173 patients were analyzed and followed up during 16 months in average. Clinical events increased as FFR values decreased and revascularization showed greater net benefit for the lowest baseline FFR values.
FFR cutoff values as from which and interaction with prognosis was observed were between 0.75 and 0.8. FFR measured immediately after stenting showed an inverse relationship with future events (HR 0.86, CI 95% 0.80 to 0.93; p<0.001). An FFR guided strategy leads to revascularization half as often as an angiography guided strategy but with 20% less events and 10% more freedom from angina.
Conclusion
FFR proved a continuous and independent relation with future events and this can be influenced by revascularization. Lesions with the lowest FFR values receive the highest absolute benefit from revascularization. FFR measured after stenting showed an inverse relationship with risk.
Editorial Comment
FFR can be seen not only as a “biological marker” given its continuous and independent relation with prognosis, but also as a treatment goal, given that revascularization significantly change the events curve. FFR is an objective tool to balance the risk/benefit ratio in each patient, not as a dichotomy but as a continuous relationship.
SOLACI