Influence of sex on the functional assessment of myocardial ischemia

BACKGROUND: Fractional flow reserve (FFR) and non-hyperemic resting pressure ratios, such as instantaneous wave-free ratio (iFR) and resting full-cycle ratio (RFR), are recommended for evaluating the significance of angiographically intermediate coronary stenoses. Despite their usefulness, approximately 20% of assessed lesions exhibit discordance between FFR and iFR/RFR. AIMS: The role of sex in this discrepancy remains uncertain; thus, we aimed to investigate its impact on the discordance between FFR and iFR/RFR. METHODS: We reviewed 417 consecutive intermediate stenotic lesions from 381 patients, stratified by sex and assessed with both FFR and iFR/RFR. FFR ≤0.80 and iFR/RFR ≤0.89 were considered positive for ischemia. RESULTS: Of the 381 patients, 92 (24.1%) were women. Women were older, had a lower estimated glomerular filtration rate (eGFR), higher ejection fraction, and were more likely to have peripheral artery disease than men. Median FFR and iFR/RFR values were lower in men than in women (FFR 0.86 vs. 0.80; P <0.001; iFR 0.92 vs. 0.90; P = 0.049). However, overall discordance prevalence was similar for both sexes (20.6% vs. 15.1%; P = 0.22). In men, eGFR, insulin-treated diabetes mellitus, and arterial hypertension were predictors of positive FFR | negative iFR/RFR discordance, while eGFR, insulin-treated diabetes mellitus, atrial fibrillation, and chronic obstructive pulmonary disease were predictors of negative FFR | positive iFR/RFR discordance. No factors associated with either discordance were identified in women. CONCLUSIONS: FFR and iFR/RFR results indicating significant ischemia were more common in men than women when assessing intermediate coronary stenoses. Nevertheless, sex did not predict discordant results.