# Predictive value of the inconsistency between the residual and post-PCI QFR for prognosis in PCI patients

## TL;DR

This study shows that when the actual improvement in blood flow after heart stent placement is less than expected, patients face a higher risk of future heart issues.

## Contribution

The study introduces ΔQFR as a novel metric to assess PCI outcomes and identifies it as a predictor of long-term prognosis.

## Key findings

- The underanticipated ΔQFR group had significantly higher target vessel failure (TVF) rates than the consistent group.
- A ΔQFR ≤ −0.1 was identified as an independent risk factor for TVF.
- Nonlinear relationship between ΔQFR and TVF risk was observed using restricted cubic spline regression.

## Abstract

To investigate the prognostic value of the consistency between the residual quantitative flow ratio (QFR) and postpercutaneous coronary intervention (PCI) QFR in patients undergoing revascularization.

This was a single-center, retrospective, observational study. All enrolled patients were divided into five groups according to the ΔQFR (defined as the value of the post-PCI QFR minus the residual QFR): (1) Overanticipated group; (2) Slightly overanticipated group; (3) Consistent group; (4) Slightly underanticipated group; and (5) Underanticipated group. The primary outcome was the 5-year target vessel failure (TVF).

A total of 1373 patients were included in the final analysis. The pre-PCI QFR and post-PCI QFR were significantly different among the five groups. TVF within 5 years occurred in 189 patients in all the groups. The incidence of TVF was significantly greater in the underanticipated group than in the consistent group (P = 0.008), whereas no significant differences were found when comparing the underanticipated group with the other three groups. Restricted cubic spline regression analysis showed that the risk of TVF was nonlinearly related to the ΔQFR. A multivariate Cox regression model revealed that a ΔQFR≤ −0.1 was an independent risk factor for TVF.

The consistency between the residual QFR and post-PCI QFR may be associated with the long-term prognosis of patients. Patients whose post-PCI QFR is significantly lower than the residual QFR may be at greater risk of TVF. An aggressive PCI strategy for lesions is anticipated to have less functional benefit and may not result in a better clinical outcome.