Use of Resting Non-hyperemic Indices for Avoidance of Fractional Flow Reserve Measurement: The Goal of 100% Accuracy

• Published in: The Journal of invasive cardiology 2016-07, Vol.28 (7), p.265-270
• Main Authors: Ammar, Khawaja Afzal, Kazmi, Syed Shahab, Ahmad, Mirza Nubair, Ahmad, Mirza Mujadil, Riaz, Arsalan, Husain, Imran, Husain, Fatima, Allaqaband, Suhail, Bajwa, Tanvir, Gupta, Anjan
• Format: Article
• Language: English
• Subjects: Adenosine - administration & dosage; Aged; Arterial Pressure - physiology; Cardiac Catheterization - methods; Coronary Stenosis - diagnosis; Coronary Stenosis - physiopathology; Coronary Vessels - diagnostic imaging; Coronary Vessels - pathology; Coronary Vessels - physiopathology; Diagnostic Errors - prevention & control; Female; Fractional Flow Reserve, Myocardial - physiology; Hemodynamics; Humans; Hyperemia - physiopathology; Male; Middle Aged; Predictive Value of Tests; Retrospective Studies; Severity of Illness Index; Vasodilator Agents - administration & dosage
• ISSN: 1557-2501

Recent studies have suggested that fractional flow reserve (FFR) measurement can be avoided by using similar ranges of baseline mean coronary pressure (Pd) to mean aortic pressure (Pa) ratio (0.88-0.95). Further studies have suggested that too many significant coronary stenoses are misclassified based on these ranges. We hypothesized that with a certain range of baseline Pd/Pa, 100% positive predictive value (PPV) and negative predictive value (NPV) can be achieved to avoid misclassification. We retrospectively evaluated the pressure tracings of 555 consecutive intermediate coronary stenotic lesions that had undergone FFR measurement in the cardiac catheterization laboratory of a tertiary-care center. The baseline Pd/Pa was manually measured and correlated with final FFR. The operating test characteristics were calculated using an abnormal FFR of ≤0.80 as the criterion standard for the presence of hemodynamic, significant coronary stenosis. The area under the receiver-operating characteristics curve of baseline Pd/Pa for predicting FFR was 0.89, very similar to published results for instantaneous wave-free ratio and Pd/Pa. However, a significant number of lesions were mischaracterized (ie, using a baseline Pd/Pa of ≤0.88 to >0.95, there were 22 misclassifications, with 6 false-positive and 16 false-negative results). At a Pd/Pa of ≤0.86, 100% PPV was achieved, and 100% NPV was achieved at >1.00. A baseline Pd/Pa of ≤0.86 is associated with a PPV of 100%, which can avoid the misclassification errors seen in prior studies. This provides a more clinically useful application of baseline Pd/Pa.