Predictive Value of Resting Pd/Pa for Fractional Flow Reserve Assessed with Monorail Pressure Microcatheter in Real-World Practice

• Main Authors: Keng Tat Koh, MBBS, Asri Said, MD, Khaw Chee Sin, MBBS, Oon Yen Yee, MBBS, Erwin Mulia, MD, Tan Chen Ting, MD, Francis Shu Eng Pbeng, MBBS, Ho Kian Hui, MD, Voon Chi Yen, MBBS, Cham Yee Ling, MBBS, Khiew Ning Zan, MBBS, Nor Hanim Mohd Amin, MD, Alan Fong Yean Yip, MBChB, Ong Tiong Kiam, MBBS
• Format: Article
• Language: English
• Published: Compuscript 2019-07-01
• Series: Cardiovascular Innovations and Applications
• Subjects: fractional flow reserve; monorail pressure catheter; resting time-averaged distal coronary pressure to mean aortic pressure ratio
• Online Access: https://www.ingentaconnect.com/content/cscript/cvia/2019/00000004/00000002/art00004
• ISSN: 2009-8618; 2009-8782

Background and Objectives: The aims of this study were (1) to examine the diagnostic accuracy of resting time-averaged distal coronary pressure (Pd) to mean aortic pressure (Pa) ratio to predict hyperemic fractional flow reserve (FFR) and (2) to identify a resting Pd/Pa value that can preclude the need for hyperemic FFR assessed with use of a monorail pressure catheter. Methods: A total of 191 stenoses were assessed. After exclusions, 157 FFR data sets from 103 patients were analyzed. Results: Resting Pd/Pa showed poor agreement with hyperemic FFR (r=0.619, P<0.001). The receiver operating characteristic curve for resting Pd/Pa with reference to hyperemic FFR of 0.80 or less showed an area under the curve of 0.800 (95% confidence interval 0.732–0.868, P<0.001), with the greatest diagnostic accuracy of 74.5% for resting Pd/Pa of less than 0.85. Resting Pd/Pa of 0.96 or greater had a sensitivity of 100% and a negative predictive value of 100%, and resting Pd/Pa of 0.82 or less had a specificity of 98.9% and a positive predictive value of 94.1% to predict abnormal FFR of 0.80 or less. These results were consistent regardless of the vessels studied, the location of lesions, and the severity of stenosis. Conclusions: Resting Pd/Pa showed poor agreement with hyperemic FFR assessed with use of a monorail pressure microcatheter. However, resting Pd/Pa of 0.96 or greater had excellent sensitivity and negative predictive value to predict normal hyperemic FFR, and resting Pd/Pa of 0.82 or less had excellent specificity and positive predictive value to predict abnormal hyperemic FFR.