# Quantitative Flow Ratio-Guided vs. Angiography-Guided Percutaneous Coronary Intervention: A Systematic Review and Meta-Analysis of One-Year Clinical Outcomes

## TL;DR

This study compares the one-year outcomes of heart procedures guided by a new technique called QFR versus traditional angiography, finding similar results but highlighting the need for more research.

## Contribution

The study provides a systematic review and meta-analysis comparing QFR-guided and angiography-guided PCI outcomes, emphasizing the need for further high-quality trials.

## Key findings

- QFR-guided PCI showed numerically lower but not statistically significant risks of MACEs, revascularization, and rehospitalization compared to angiography-guided PCI.
- High heterogeneity was observed in MACEs and revascularization outcomes, suggesting variability across studies.
- Low risk of bias was found in most studies, but larger trials are needed to confirm results.

## Abstract

Background: Quantitative Flow Ratio (QFR) is a novel, wire-free, and hyperemia-free physiological assessment for guiding Percutaneous Coronary Intervention (PCI), which may offer advantages over traditional angiography-guided PCI. This systematic review with meta-analysis compares clinical outcomes after one year in patients who underwent QFR-guided versus angiography-guided PCI. Methods: This study was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and was registered on 4 November 2024 in PROSPERO (ID: CRD42024609799). A systematic search was performed across multiple databases to identify clinical trials comparing QFR-guided and angiography-guided PCI. Random-effects models were used to assess one-year outcomes of major adverse cardiovascular events (MACEs), revascularization, and rehospitalization, with heterogeneity measured using I2, H2, and Cochran’s Q statistics. Study quality was evaluated using the Cochrane Risk of Bias 2 (RoB 2) tool. Results: Compared to traditional angiography-guided PCI, QFR-guided PCI was associated with numerically lower but statistically non-significant risks of MACEs (risk difference: −0.08, 95% CI: −0.20 to 0.04), revascularization (risk difference: −0.02, 95% CI: −0.08 to 0.03), and rehospitalization (risk difference: −0.02, 95% CI: −0.08 to 0.04) over one year. Substantial heterogeneity was observed for MACEs (I2 = 84.95%, H2 = 6.64) and revascularization (I2 = 94.18%, H2 = 17.18), whereas rehospitalization exhibited low heterogeneity (I2 = 17.17%, H2 = 1.21). The risk of bias was assessed by the RoB 2 tool, which revealed low to some concern risk of bias across key domains. Conclusions: Quantitative Flow Ratio (QFR) has demonstrated comparable one-year clinical outcomes to traditional angiography for PCI guidance, with a trend toward improved results. However, the high heterogeneity among studies and the risk of bias necessitate the need for larger, high-quality trials to validate these findings.