Quantitative flow ratio as a continuous predictor of myocardial infarction

Prognostic impact of quantitative flow ratio (QFR)-consistent complete revascularization in patients with myocardial infarction and multivessel coronary artery disease

BACKGROUND

Complete revascularization is associated with improved outcomes in patients with myocardial infarction and multivessel coronary artery disease. Quantitative flow ratio (QFR) represents an emerging angiography-based tool for functional lesion assessment. The present study investigated the prognostic impact of QFR-consistent complete revascularization in patients with myocardial infarction and multivessel disease.

METHODS

A total of 792 patients with myocardial infarction and multivessel disease were enrolled in the analysis. Post-hoc QFR analyses of 1,320 nonculprit vessels were performed by investigators blinded to clinical outcomes. The primary endpoint was a composite of all-cause death, nonculprit vessel related nonfatal myocardial infarction, and ischemia-driven revascularization at 2 years after index myocardial infarction. Patients were stratified into a QFR-consistent PCI group (n = 646) and a QFR-inconsistent PCI group (n = 146), based on whether the intervention was congruent with the QFR-determined functional significance of the nonculprit lesions.

RESULTS

The primary endpoint occurred in a total of 22 patients (3.4%) in the QFR-consistent PCI group and in 27 patients (18.5%) in the QFR-inconsistent group (HR 0.17, 95% CI 0.10-0.30, P < .001).The difference in the primary endpoint was driven by reduced rates of nonfatal myocardial infarction (2.0% vs. 15.1%; HR 0.13, 95% CI 0.06-0.25; P < .001) and ischemia-driven revascularization (1.2% vs. 5.5%; HR 0.21, 95% CI 0.08-0.57; P = .001) in the QFR-consistent PCI group.

CONCLUSIONS

Among patients with myocardial infarction and multivessel disease, a QFR-consistent complete revascularization was associated with a reduced risk of all-cause mortality, nonfatal myocardial infarction, and ischemia-driven revascularization. These findings underline the value of angiography-based functional lesion assessment for personalized revascularization strategies.

Assessment of perioperative cardiac risk using preoperative quantitative flow ratio in patients with coronary artery disease undergoing noncardiac surgery: a retrospective cohort study

Background

Quantitative flow ratio (QFR) is a novel diagnostic modality for the functional testing of coronary artery stenosis, but evidence concerning the postoperative prognostic implication of QFR in noncardiac surgery (NCS) of patients with coronary artery disease (CAD) is limited. The purpose of this study was to examine the role of QFR in perioperative risk prediction in patients with coronary heart disease.

Methods

This retrospective cohort study was conducted in The First Affiliated Hospital of Wenzhou Medical University between 2013 and 2022, and consecutively included patients with CAD who had undergone NCS <1 year after coronary angiography. The primary endpoint was major adverse cardiovascular events (MACEs), which were defined as a composite of cardiovascular death, nonfatal myocardial infarction, nonfatal stroke, cardiopulmonary arrest, malignant ventricular arrhythmia (MVA), congestive heart failure, and revascularization. Univariate and multifactorial Cox regression was used to identify the independent risk factors for perioperative cardiovascular events and to construct new models. The area under the curve (AUC), net reclassification improvement (NRI), and integrated discrimination improvement (IDI) were used to compare the newly constructed model with existing traditional models.

Results

Among the 929 participants enrolled (median age 68 years; 72.0% male), the primary endpoint was met in 67 (7.2%) patients within 30 days of follow-up. There was no significant difference in the incidence of the primary endpoint between patients with QFR <0.75 and those with "gray zone" lesions (0.75≤ QFR ≤0.8) (log-rank P=0.325). Patients with QFR <0.75 and those with "gray zone" lesions (0.75≤ QFR ≤0.8) had a higher incidence of primary endpoint events compared to patients with QFR >0.8. [QFR <0.75 vs. QFR >0.8: adjusted hazard ratio (HR) =20.70, P<0.001; 0.75≤ QFR ≤0.8 vs. QFR >0.8: HR =15.99, P<0.001]. The independent predictors of MACEs events within 30 days after NCS were albumin level [HR =0.92, 95% confidence interval (CI): 0.87-0.98; P=0.008], emergency surgery (HR =4.12, 95% CI: 1.66-10.23; P=0.002), and QFR ≤0.8 (HR =15.92, 95% CI: 5.96-42.51; P<0.001). In addition, adjusting the original Revised Cardiac Risk Index (RCRI) with QFR ≤0.8 as a risk factor significantly improved the risk stratification of postoperative adverse events, with the adjusted AUC rising from 0.574 to 0.740 (P<0.001).

Conclusions

QFR ≤0.8 could independently predict perioperative cardiovascular adverse events in patients with CAD undergoing NCS and improve the predictive value of original predictive index. Gray-zone lesions (0.75≤ QFR ≤0.8) should be actively treated.

Prognostic role of discordance between quantitative flow ratio and visual estimation in revascularization guidance

Aims

Revascularization guided by functional severity has presented improved outcomes compared with visual angiographic guidance. Quantitative flow ratio (QFR) is a reliable angiography-based method for functional assessment. We sought to investigate the prognostic value of discordance between QFR and visual estimation in coronary revascularization guidance.

Methods and results

We performed offline QFR analysis on all-comers undergoing coronary angiography. Vessels with calculated QFR were divided into four groups based on the decision to perform or defer percutaneous coronary intervention (PCI) and on the QFR result, i.e.: Group A (PCI-, QFR > 0.8); Group B (PCI+, QFR ≤ 0.8); Group C (PCI+, QFR > 0.8); Group D (PCI-, QFR ≤ 0.8). Patients with at least one vessel falling within the disagreement groups formed the discordance group, whereas the remaining patients formed the concordance group. The primary endpoint was the composite endpoint of cardiovascular death, myocardial infarction, and ischaemia-driven revascularization. Overall, 546 patients were included in the study. Discordance between QFR and visual estimation was found in 26.2% of patients. After a median follow-up period of 2.5 years, the discordance group had a significantly higher rate of the composite outcome (hazard ratio: 3.34, 95% confidence interval 1.99-5.60, P < 0.001). Both disagreement vessel Groups C and D were associated with increased cardiovascular risk compared with agreement Groups A and B.

Conclusion

Discordance between QFR and visual estimation in revascularization guidance was associated with a worse long-term prognosis. Our results highlight the importance of proper patient selection for intervention and the need to avoid improper stent implantations when not dictated by a comprehensive functional assessment.