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: Among the 381 patients, 92 (24.1%) were women. Women were older, had lower estimated glomerular filtration rate (eGFR), a 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

Comparison of Fractional Flow Reserve with Resting Non-Hyperemic Indices in Patients with Coronary Artery Disease

Guidelines recommend using hyperemic (FFR) and non-hyperemic (iFR/RFR) methods of evaluating coronary artery stenoses in patients with coronary artery disease. However, in some cases, achieved results indicating significant ischemia may differ between those methods. Thus, we sought to identify predictors of such a discrepancy. Data were collected on all consecutive patients with chronic coronary syndrome hospitalized between 2020 and 2021. For 279 patients (417 vessels), results for both FFR and iFR/RFR were available. Values of ≤0.80 for FFR and ≤0.89 for iFR/RFR were considered positive for ischemia. Discordant measurements of FFR and iFR/RFR were observed in 80 (19.2%) patients. Atrial fibrillation was the only predictor of the overall FFR and iFR/RFR discordance - OR (95%CI) 1.90 (1.02–3.51); p = 0.040. The chance of positive FFR and negative iFR/RFR decreased independently with age - OR (95%CI) 0.96 (0.93–0.99); p = 0.024. On the contrary, insulin-treated diabetes mellitus was the predictor of negative FFR and positive iFR/RFR discrepancy - OR (95%CI) 4.61 (1.38–15.40); p = 0.013. In everyday clinical practice, iFR/FFR correlates well with FFR. However, discordance between these methods is quite common. Physicians should be aware of the risk of such discordance in patients with atrial fibrillation, advanced age, and insulin-treated diabetes mellitus