Combined pressure and flow measurements to guide treatment of coronary stenoses

<p><strong>Objectives:</strong> The aim of this study was to assess clinical outcomes after combined pressure and flow assessment of coronary lesions.</p> <p><strong>Background:</strong> Although fractional flow reserve (FFR) remains the invasive reference standard for revascularization, approximately 40% of stenoses have discordant coronary flow reserve (CFR). Optimal treatment for these disagreements remains unclear.</p> <p><strong>Methods:</strong> A total of 455 subjects with 668 lesions were enrolled from 12 sites in 6 countries. Only lesions with reduced FFR and CFR underwent revascularization; all other combinations received initial medical therapy.</p> <p><strong>Results:</strong> Fourteen percent of lesions had FFR&lt;=0.8 but CFR&gt;=2.0 while 23% of lesions had FFR&gt;0.8 but CFR&lt;2.0. During 2-year follow-up, the primary endpoint of composite all-cause death, myocardial infarction, and revascularization in lesions with FFR&lt;=0.8 but CFR&gt;=2 (10.8% event rate) compared with lesions with FFR&gt;0.8 and CFR&gt;=2 (6.2% event rate) exceeded the prespecified +10% noninferiority margin (P = 0.090). Target vessel failure models using both continuous FFR and continuous CFR found that only higher FFR was associated with reduced target vessel failure (Cox P = 0.007) after initial medical treatment. Central core laboratory review accepted 69.8% of all tracings with mean differences of &lt;0.01 for FFR and &lt;0.02 for CFR, indicating no material impact on clinical measurements or outcomes.</p> <p><strong>Conclusions:</strong> All-cause death, myocardial infarction, and revascularization after 2 years was not noninferior between lesions with FFR&lt;=0.8 but CFR&gt;=2 and lesions with FFR&gt;0.8 and CFR&gt;=2. These results do not support using invasive CFR&gt;=2 to defer revascularization for lesions with reduced FFR if the patient would otherwise be a candidate on the basis of the entire clinical scenario and treatment preference.</p>