BACKGROUND: Invasive physiological assessment of myocardial bridges (MBs) is largely unsettled. Unlike fractional flow reserve (FFR), instantaneous wave-free ratio (iFR) is a diastole-specific index. As such, its value might not be hampered by systolic pressure overshooting and negative systolic pressure gradient caused by the compression of the tunneled coronary artery. METHODS AND RESULTS: We prospectively enrolled 20 patients with angina and/or positive noninvasive stress test, absence of significant coronary artery stenosis, and angiographic suspicion/evidence of MB in the left anterior descending artery. According to a prespecified protocol, all patients underwent functional intracoronary evaluation with FFR at rest and after dobutamine (up to 20 μg kg-1 min-1) and atropine (1 mg) intravenous infusion. iFR at baseline and dobutamine-induced hyperemic wave-free period pressure ratio were also recorded. FFR values ≤0.80 and iFR values ≤0.89 were considered indicative of hemodynamic significance of MB. At baseline, no MB was hemodynamically significant according to FFR, whereas iFR was below the cutoff value in all but 7 patients. During inotropic challenge, median FFR did not change significantly (0.87-0.86, P=0.59). CONCLUSIONS: Physiological evaluation of MBs with iFR seems to be more consistent with patients' symptoms and noninvasive test results compared with FFR.
BACKGROUND: Invasive physiological assessment of myocardial bridges (MBs) is largely unsettled. Unlike fractional flow reserve (FFR), instantaneous wave-free ratio (iFR) is a diastole-specific index. As such, its value might not be hampered by systolic pressure overshooting and negative systolic pressure gradient caused by the compression of the tunneled coronary artery. METHODS AND RESULTS: We prospectively enrolled 20 patients with angina and/or positive noninvasive stress test, absence of significant coronary artery stenosis, and angiographic suspicion/evidence of MB in the left anterior descending artery. According to a prespecified protocol, all patients underwent functional intracoronary evaluation with FFR at rest and after dobutamine (up to 20 μg kg-1 min-1) and atropine (1 mg) intravenous infusion. iFR at baseline and dobutamine-induced hyperemic wave-free period pressure ratio were also recorded. FFR values ≤0.80 and iFR values ≤0.89 were considered indicative of hemodynamic significance of MB. At baseline, no MB was hemodynamically significant according to FFR, whereas iFR was below the cutoff value in all but 7 patients. During inotropic challenge, median FFR did not change significantly (0.87-0.86, P=0.59). CONCLUSIONS: Physiological evaluation of MBs with iFR seems to be more consistent with patients' symptoms and noninvasive test results compared with FFR.
Authors: Harmony R Reynolds; C Noel Bairey Merz; Colin Berry; Rohit Samuel; Jacqueline Saw; Nathaniel R Smilowitz; Ana Carolina do A H de Souza; Robert Sykes; Viviany R Taqueti; Janet Wei Journal: Circ Res Date: 2022-02-17 Impact factor: 17.367
Authors: Fan Zhou; Chun Xiang Tang; U Joseph Schoepf; Christian Tesche; Maximilian J Bauer; Brian E Jacobs; Chang Sheng Zhou; Jing Yan; Meng Jie Lu; Guang Ming Lu; Long Jiang Zhang Journal: Eur Radiol Date: 2018-10-30 Impact factor: 5.315
Authors: Michael Michail; Udit Thakur; Ojas Mehta; John M Ramzy; Andrea Comella; Abdul Rahman Ihdayhid; James D Cameron; Stephen J Nicholls; Stephen P Hoole; Adam J Brown Journal: Open Heart Date: 2020-10