Long‐Term Clinical Outcomes of Nonhyperemic Pressure Ratios: Resting Full‐Cycle Ratio, Diastolic Pressure Ratio, and Instantaneous Wave‐Free Ratio

Abstract

Background Nonhyperemic pressure ratios (NHPRs) such as instantaneous wave‐free ratio, resting full‐cycle ratio, or diastolic pressure ratio have emerged as invasive physiologic indices precluding the need for hyperemic agents. The current study sought to evaluate the long‐term prognostic implications of NHPRs compared with fractional flow reserve (FFR). Methods and Results NHPRs were calculated from resting pressure tracings by an independent core laboratory in 1024 vessels (435 patients). The association between NHPRs and the risk of 5‐year vessel‐oriented composite outcomes (VOCO, a composite of cardiac death, vessel‐related myocardial infarction, and ischemia‐driven revascularization) were analyzed among 864 deferred vessels. Lesions with positive NHPRs (instantaneous wave free ratio, resting full‐cycle ratio, and diastolic pressure ratio ≤0.89) or FFR (≤0.80) showed significantly higher risk of VOCO at 5 years than those with negative NHPRs or FFR, respectively. Discriminant ability for 5‐year VOCO was not different among NHPRs and FFR (C‐index: 0.623–0.641, P for comparison=0.215). In comparison of VOCO among the groups with deferred concordant negative (NHPRs−/FFR−), deferred discordant (NHPRs+/FFR− or NHPRs−/FFR+), and revascularized vessels, the cumulative incidence of VOCO were 7.5%, 14.4%, and 14.8% (log‐rank PP=0.964). Conclusions Currently available invasive pressure‐derived indices showed similar prognostic implications for vessel‐related events at 5 years. Deferred lesions with discordant results between NHPRs and FFR did not show higher risk of vessel‐related events at 5 years than revascularized vessels. Registration URL: https://www.clini​caltr​ials.gov; Unique identifiers: NCT01621438, NCT01621438.