Objective To evaluate the predictive value of the quantitative flow ratio (QFR) combined with early exercise tolerance testing (CPET) for long-term prognosis after coronary intervention. Methods Patients with unstable angina (UA) and 50–90% stenosis scheduled for elective PCI were randomly assigned to the QFR group (undergoing intervention if QFR < 0.80) or the conventional group (empirical PCI). Cardio-Pulmonary Exercise Test (CPET) was performed 1–3 weeks postoperatively to record the anaerobic threshold (AT), peak metabolic equivalent (MET), peak oxygen uptake (peakVO2), VE/VCO2 slope, oxygen uptake/work rate (VO2/WR), oxygen uptake/heart rate (VO2/HR), Weber cardiac function classification, and cardiac reserve function. One-year follow-up assessed MACE events (including cardiovascular death, non-fatal arrhythmia, ischemia-driven revascularization, and rehospitalization for unstable angina). Results The QFR group demonstrated superiority over the conventional group in key CPET parameters including AT, peak MET, peak VO2, and VO2/HR (p < 0.05). Ischemia-driven revascularization was significantly lower in the QFR group (8.6% vs 19.5%, p = 0.046), with significantly shorter stent lengths (20 mm vs 26 mm, p = 0.001) and higher postoperative QFR values (0.92 vs 0.90). Logistic regression analysis demonstrated that improved QFR values significantly reduced MACE risk. PeakVO2 was an independent protective factor for MACE (OR = 0.47, p = 0.017). ROC curve analysis revealed that the QFR curve had an area under the curve (AUC = 0.928), peakVO2 AUC = 0.948). Optimal cutoff values were set at QFR = 0.885 and peakVO2 = 16.8 mL kg−1 min−1. Patients were reclassified into four groups based on these cutoffs: dual-normal, single-abnormal, and dual-abnormal groups. Logistic regression analysis showed combined indicator p = 0.081 < 0.05, with combined indicator AUC 0.977 indicating good calibration (HL P = 0.624, Brier 0.049). Decision curve analysis demonstrated superiority over single-indicator models. Conclusion QFR-guided PCI enables precise ischemia localization, reduces implantations, and enhances exercise tolerance. Combining QFR with peakVO2 accurately identifies high-risk patients, and intensive rehabilitation improves long-term outcomes.

Predictive value of the QFR combined with early exercise tolerance testing for long-term prognosis after coronary intervention

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2026年5月30日

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Qi Deng,
Qincong Chen,
Yongfeng Zhao,
Jingjie Dong,
Jianming Tang,
Rubing Wu,
Shengqiang Du,
Feihu Jia,
Shuo Wang

摘要

Objective

To evaluate the predictive value of the quantitative flow ratio (QFR) combined with early exercise tolerance testing (CPET) for long-term prognosis after coronary intervention.

Methods

Patients with unstable angina (UA) and 50–90% stenosis scheduled for elective PCI were randomly assigned to the QFR group (undergoing intervention if QFR < 0.80) or the conventional group (empirical PCI). Cardio-Pulmonary Exercise Test (CPET) was performed 1–3 weeks postoperatively to record the anaerobic threshold (AT), peak metabolic equivalent (MET), peak oxygen uptake (peakVO₂), VE/VCO₂ slope, oxygen uptake/work rate (VO₂/WR), oxygen uptake/heart rate (VO₂/HR), Weber cardiac function classification, and cardiac reserve function. One-year follow-up assessed MACE events (including cardiovascular death, non-fatal arrhythmia, ischemia-driven revascularization, and rehospitalization for unstable angina).

Results

The QFR group demonstrated superiority over the conventional group in key CPET parameters including AT, peak MET, peak VO₂, and VO₂/HR (p < 0.05). Ischemia-driven revascularization was significantly lower in the QFR group (8.6% vs 19.5%, p = 0.046), with significantly shorter stent lengths (20 mm vs 26 mm, p = 0.001) and higher postoperative QFR values (0.92 vs 0.90). Logistic regression analysis demonstrated that improved QFR values significantly reduced MACE risk. PeakVO₂ was an independent protective factor for MACE (OR = 0.47, p = 0.017). ROC curve analysis revealed that the QFR curve had an area under the curve (AUC = 0.928), peakVO₂ AUC = 0.948). Optimal cutoff values were set at QFR = 0.885 and peakVO₂ = 16.8 mL kg⁻¹ min⁻¹. Patients were reclassified into four groups based on these cutoffs: dual-normal, single-abnormal, and dual-abnormal groups. Logistic regression analysis showed combined indicator p = 0.081 < 0.05, with combined indicator AUC 0.977 indicating good calibration (HL P = 0.624, Brier 0.049). Decision curve analysis demonstrated superiority over single-indicator models.

Conclusion

QFR-guided PCI enables precise ischemia localization, reduces implantations, and enhances exercise tolerance. Combining QFR with peakVO₂ accurately identifies high-risk patients, and intensive rehabilitation improves long-term outcomes.