Fractional flow reserve (FFR) requires maximal hyperemia and retains accuracy in patients under stable conditions even in patients with microcirculatory impairment including those with aortic stenosis. Because of the dependence on adenosine hyperemia, resting or non-hyperemic translesional pressure ratios (NHPR) have replaced FFR measurements to some degree. In the quest for the best, the first NHPR, the instantaneous wave-free ratio (iFR) has produced offspring. Diastolic sub-cycle (DPR/dPR [diastolic pressure ratio] and DFR [diastolic hyperemia-free ratio]) or whole cardiac cycle (Pd/Pa [distal pressure over aortic pressure] and resting full-cycle ratio [RFR]) pressure ratios are proprietary, and all were found to be numerically (except for Pd/Pa) and clinically equivalent . NHPRs, whether acquired over the whole cardiac cycle or only a portion of diastole, depend on stable resting flow for accuracy and reproducibility . Should coronary microcirculatory disease (e.g., left ventricular hypertrophy [LVH] in aortic stenosis [AS]) with potential different resting flow rates produce differences in NHPRs? Specifically, does the hair-splitting of the diastolic cycle differentiate NHPRs in patients with AS?