The delta fractional flow reserve can predict lesion severity and long-term prognosis

Background: Fractional flow reserve (FFR) is a method which is used to identify the angiographically intermediate lesions requiring revascularization. However, physiological importance and clinical usability of delta (Delta) FFR, the difference between FFR in baseline conditions (FFRbase, resting) and after adenosine administration (FFRmin, hyperemic), is currently unknown. We aimed to investigate whether Delta FFR may be helpful in the identification of the lesion severity and predictability of long term prognosis. Method and results: We enrolled 123 consecutive patients with an intermediate lesion (40-70% stenosis) at LAD in this study. The patients were divided into three groups according to FFRmin results (group I: FFR > 0.80, n = 71; group II: FFR between 0.75 and 0.80, n = 28; group III: FFR < 0.75, n = 24). We followed the patients for a mean duration of 36 17 months for major adverse cardiac events (MACE). For the sensitivity and the specificity of Delta FFR to detect the lesion severity, the area under ROC curve was found as 0.873 (95% Cl: 0.788-0.958, P<0.001). When >= 15 is accepted as the cut-off value for Delta FFR, the specificity was 95%, the sensitivity was 59% for lesion severity. When we compared the predictability of MACE by FFRmin and Delta FFR, there is no difference in FFRmin groups (FFR<0.75, 0.75-0.80 and FFR>0.80) (29%, 46% and 30%, respectively, P=0.247). However, between the groups which were determined according to cut-off values for Delta FFR (Delta FFR < 10; Delta FFR, 10-15; Delta FFR >= 15) among the patients with FFR <= 0.80, MACE was significantly different (73%,44%, 11%; respectively, P=0.003). Conclusion: Delta FFR may represent the vascular ischemic compensatory capacity to a significant lesion and this response capacity shows the severity of the lesion with high specificity. Decreased and insufficient vascular response capacity to a significantly lesion relates to the poor long-term clinical prognosis. Delta FFR may be helpful in the identification of the lesion severity in the assessment of intermediate coronary lesions; it can be used as a guide for revascularization decision and in predictability of long-term clinical prognosis. (C) 2008 Elsevier Ireland Ltd. All rights reserved.