Sex Differences in Instantaneous Wave-Free Ratio or Fractional Flow Reserve-Guided Revascularization Strategy.
Kim CH., Koo B-K., Dehbi H-M., Lee JM., Doh J-H., Nam C-W., Shin E-S., Cook CM., Al-Lamee R., Petraco R., Sen S., Malik IS., Nijjer SS., Mejía-Rentería H., Alegria-Barrero E., Alghamdi A., Altman J., Baptista SB., Bhindi R., Bojara W., Brugaletta S., Silva PC., Di Mario C., Erglis A., Gerber RT., Going O., Härle T., Hellig F., Indolfi C., Janssens L., Jeremias A., Kharbanda RK., Khashaba A., Kikuta Y., Krackhardt F., Laine M., Lehman SJ., Matsuo H., Meuwissen M., Niccoli G., Piek JJ., Ribichini F., Samady H., Sapontis J., Seto AH., Sezer M., Sharp ASP., Singh J., Takashima H., Talwar S., Tanaka N., Tang K., Van Belle E., van Royen N., Vinhas H., Vrints CJ., Walters D., Yokoi H., Samuels B., Buller C., Patel MR., Serruys PW., Escaned J., Davies JE.
OBJECTIVES: This study sought to evaluate sex differences in procedural characteristics and clinical outcomes of instantaneous wave-free ratio (iFR)- and fractional flow reserve (FFR)-guided revascularization strategies. BACKGROUND: An iFR-guided strategy has shown a lower revascularization rate than an FFR-guided strategy, without differences in clinical outcomes. METHODS: This is a post hoc analysis of the DEFINE-FLAIR (Functional Lesion Assessment of Intermediate stenosis to guide Revascularization) study, in which 601 women and 1,891 men were randomized to iFR- or FFR-guided strategy. The primary endpoint was 1-year major adverse cardiac events (MACE), a composite of all-cause death, nonfatal myocardial infarction, or unplanned revascularization. RESULTS: Among the entire population, women had a lower number of functionally significant lesions per patient (0.31 ± 0.51 vs. 0.43 ± 0.59; p < 0.001) and less frequently underwent revascularization than men (42.1% vs. 53.1%; p < 0.001). There was no difference in mean iFR value according to sex (0.91 ± 0.09 vs. 0.91 ± 0.10; p = 0.442). However, the mean FFR value was lower in men than in women (0.83 ± 0.09 vs. 0.85 ± 0.10; p = 0.001). In men, an FFR-guided strategy was associated with a higher rate of revascularization than an iFR-guided strategy (57.1% vs. 49.3%; p = 0.001), but this difference was not observed in women (41.4% vs. 42.6%; p = 0.757). There was no difference in MACE rates between iFR- and FFR-guided strategies in both women (5.4% vs. 5.6%, adjusted hazard ratio: 1.10; 95% confidence interval: 0.50 to 2.43; p = 0.805) and men (6.6% vs. 7.0%, adjusted hazard ratio: 0.98; 95% confidence interval: 0.66 to 1.46; p = 0.919). CONCLUSIONS: An FFR-guided strategy was associated with a higher rate of revascularization than iFR-guided strategy in men, but not in women. However, iFR- and FFR-guided strategies showed comparable clinical outcomes, regardless of sex. (Functional Lesion Assessment of Intermediate Stenosis to guide Revascularization [DEFINE-FLAIR]; NCT02053038).