Diagnostic accuracy of instantaneous wave-free ratio at rest and during dobutamine provocation to assess myocardial bridging relevance

Abstract Background Diastolic fractional flow reserve (d-FFR) during dobutamine provocation (DOB) was found to be a more reliable physiological index for the functional assessment of myocardial bridging (MB). However, d-FFR calculation is complicated and time-consuming, therefore several authors have suggested use instantaneous wave-free ratio (iFR) overcome these issues. Purpose The aim our study assess diagnostic performance iFR at rest DOB with exercise-induced ischemia as reference. Methods Twenty-four symptomatic patients (17 males, mean age 58±8 years) MB systolic compression ≥50% diameter stenosis on left anterior descending (LAD) artery were included. Exercise stress-echocardiography test (SE), both in distal segment LAD peak (30–50μg/kg/min), performed all patients. Optimal cut-off values resting hyperemic assessed using SE. Results Exercise-SE positive 7/24 (29%). area-under-the-receiver-operating-characteristic curve (ROC-AUC) 0.64 (95% CI: 0.400–0.885) d-FFR, 0.62 0.378–0.866) iFR, 1.000 0.999–1.000) DOB, 0.96 0.895–1.000) DOB. No significant difference ROC-AUC observed between (p=0.243). best value <0.76 similar sensitivity negative predictive (100 vs. 100% both), but lower specificity identifying associated (94% 82%; 88% 70%, respectively). Compared ischemia, accuracy 96% (kappa=0.903, p<0.001) (kappa=0.731, p<0.001), respectively. Conclusions showed identify functionally when compared ischemia. Funding Acknowledgement Type funding sources: None.