Does TAVR alter coronary hemodynamics and affect the accuracy of hyperemic indices in patients with severe aortic stenosis and coronary artery disease?
Diastolic resting indices (such as iFR) are more reliable than hyperemic indices for assessing coronary stenosis severity in patients with severe aortic stenosis, as they are not confounded by the stenotic valve.
Systolic and hyperemic coronary flow increased significantly post-TAVR; consequently, hyperemic indices that include systole underestimated coronary stenosis severity in patients with severe AS. Flow during the wave-free period of diastole did not change post-TAVR, suggesting that indices calculated during this period are not vulnerable to the confounding effect of the stenotic aortic valve.
Ahmad et al. (2018) studied this question.