Post-PCI Global QFR and Long-Term Outcomes in ACS: Findings From the FAVOR III China Trial.

BACKGROUND

The prognostic utility of residual pressure wire-based physiological assessment after percutaneous coronary intervention (PCI) has been demonstrated.

OBJECTIVES

The aim of this study was to investigate the prognostic value of the residual global Murray law-based angiographic quantitative flow ratio (μQFR) in an acute coronary syndrome (ACS) population.

METHODS

In this post hoc analysis from the FAVOR III China (Comparison of Quantitative Flow Ratio Guided and Angiography Guided Percutaneous Intervention in Patients With Coronary Artery Disease) trial, off-line μQFR was computed for 3 major coronary arteries. Residual global μQFR was calculated as the sum of postprocedural μQFR values for treated vessels and preprocedural values for nontreated vessels. ACS patients (including those with ST-segment elevation myocardial infarction, non-ST-segment elevation myocardial infarction, and unstable angina) were categorized into high-risk (less than or equal to the cutoff value) and low-risk (greater than the cutoff value) groups according to residual global μQFR. The primary endpoint was 3-year major adverse cardiac events (MACE), the composite of all-cause death, myocardial infarction, or ischemia-driven revascularization.

RESULTS

Among 2,428 ACS patients, 2,241 (92.3%) had analyzable μQFR, with a cutoff value of 2.71. High-risk patients (n = 407 [18.2%]) had a greater incidence of 3-year MACE (21.2% vs 10.4%; adjusted HR [aHR]: 1.53; 95% CI: 1.10-2.13; P = 0.01) and MACE excluding periprocedural myocardial infarction (16.2% vs 7.8%; aHR: 1.72; 95% CI: 1.17-2.53; P = 0.006) compared with the low-risk group. The prognostic effect of residual global μQFR was consistent across QFR- and angiography-guided subgroups (P for interaction = 0.35). Patients with low residual ischemia derived the best outcomes after QFR-guided PCI (MACE 8.8% vs 11.9% for angiography-guided PCI; HR: 0.73; 95% CI: 0.55-0.97).

CONCLUSIONS

Residual global μQFR is a robust angiographic index for post-PCI ischemia burden and long-term risk stratification. In patients with ACS, QFR-guided PCI achieving low residual global ischemia was associated with the most favorable 3-year prognosis.