Sex Differences in Adenosine-Free Coronary Pressure Indexes

Study Questions:

Are there sex differences in adenosine-free coronary pressure indexes?


This was a substudy from the CONTRAST (Can Contrast Injection Better Approximate FFR Compared to Pure Resting Physiology?) study comparing the diagnostic accuracy of contrast fractional flow reserve (cFFR), instantaneous wave-free ratio (iFR), and resting distal/proximal coronary pressure ratio (Pd/Pa) with FFR in 547 men and 216 women.


There was no significant difference in sensitivity of cFFR, iFR, and Pd/Pa between men and women (cFFR 77.5% vs. 75.3%, p = 0.69; iFR 84.9% vs. 79.4%, p = 0.30; Pd/Pa 78.8% vs. 77.3%, p = 0.78) or specificity (cFFR 94.3% vs. 95.8%, p = 0.56; iFR 75.6% vs. 80.1%, p = 0.38; Pd/Pa 80.6% vs. 78.7%, p = 0.69) between the indexes. cFFR was more accurate compared to the other indexes in both men and women.


There are no significant sex differences in the diagnostic accuracy of the three adenosine-free coronary pressure indexes when compared to FFR.


This is a retrospective analysis comparing the accuracy of the three adenosine-free coronary pressure indexes against FFR in men and women. Although women were less likely to have ‘functionally’ significant stenosis (FFR <0.80), it is reassuring that there were no significant sex-based differences in diagnostic accuracy of any of the indexes. However, a limitation of the study was that the comparator was FFR (considered the gold standard by the authors) and not clinical endpoints. Given known anatomic (muscle mass) and pathophysiologic (less epicardial disease in women) differences between men and women, adequately powered randomized clinical trials evaluating physiologic indexes in women are needed.

Keywords: Adenosine, Constriction, Pathologic, Contrast Media, Fractional Flow Reserve, Myocardial, Sensitivity and Specificity, Sex Characteristics

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