Impact of instantaneous wave-free ratio on graft failure after coronary artery bypass graft surgery

Background: We aimed to assess an impact of instantaneous wave-free ratio (iFR) on a graft failure after coronary artery bypass grafting (CABG). Methods and results: A total of 131 coronary arteries from 88 patients who underwent invasive coronary angiography, intracoronary pressure measurements, CABG, and scheduled follow-up coronary computed tomography angiography within one year were investigated. All studied arteries had FFR <0.80. The rate of graft failure was significantly higher in vessels with negative iFR (>0.89) than in those with positive iFR (<0.89) (25.7% vs. 7.3%, p = 0.012). The graft failure rates increased as the preoperative iFR values rose (iFR <0.80, 3.3%; iFR: 0.80-0.84, 5.6%; iFR: 0.85-0.89, 16.0%; iFR: 0.90-0.94, 28.0%; and iFR: 0.95-1.00, 50.0%; p = 0.002). A cut-off value of iFR to predict graft failures was determined as 0.84 by receiver-operating characteristic curve analysis with sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of 88%, 62%, 25%, 97%, and 66%, respectively. Conclusions: The risk of graft failure becomes higher, as the preoperative iFR increases.The graft failure is significantly more frequent when a bypass graft is anastomosed on vessels with negative iFR than those with positive iFR. (C) 2020 Elsevier B.V. All rights reserved.

Automated summary

The study aimed to assess the impact of instantaneous wave-free ratio (iFR) on graft failure after coronary artery bypass grafting (CABG). The results showed that graft failure rates were significantly higher in vessels with negative iFR (>0.89) compared to those with positive iFR (<0.89).