Prognostic Implications of Quantitative Flow Ratio-Derived Physiological 2-Dimensional Residual Disease Patterns After Stenting

Abstract

Background: Post-percutaneous coronary intervention (PCI) residual disease is associated with clinical outcomes. Nevertheless, the prognostic value of residual disease patterns remains unknown.

Objectives: This study aimed to evaluate clinical implications of 2-dimensional residual disease patterns after PCI.

Methods: One thousand six hundred seven vessels that underwent successful PCI were included. Two-dimensional residual disease patterns were determined by visual assessment or the quantitative flow ratio (QFR)-derived pull back pressure gradient index (with a cutoff value of 0.78 to define predominant focal versus diffuse disease) and instantaneous QFR gradient per unit length (with a cutoff value of ≥0.005/mm to define a major gradient). The clinical outcome was the 2-year vessel-oriented composite outcome (VOCO).

Results: Residual disease patterns were classified into 4 groups: predominant focal without and with a major gradient (group 1 [n = 1,058] and group 2 [n = 63], respectively) and predominant diffuse without and with a major gradient (group 3 [n = 318] and group 4 [n = 168], respectively). At 2 years, VOCO was lowest in group 1 (1.4% vs 5.4% in group 2 vs 4.8% in group 3 vs 8.5% in group 4, all P < 0.05), whereas there was no prognostic value for classifications by visual assessment. Physiological residual disease patterns were independently associated with VOCO and showed increased prognostic value when introduced to a model with clinical risk factors only (C index: 0.77 vs. 0.68, P = 0.008; net reclassification improvement: 0.65, P < 0.001; integrated discrimination improvement: 0.020, P < 0.001).

Conclusions: Objective analysis of post-PCI QFR pull backs using the concept of 2-dimensional residual disease patterns is feasible and superior to visual assessments. The residual disease patterns were independently associated with VOCO at 2 years.

Keywords: percutaneous coronary intervention; prognosis; pull back pressure gradient; quantitative flow ratio.