Quantitative flow ratio-guided residual functional SYNTAX score for risk assessment in patients with ST-segment elevation myocardial infarction undergoing percutaneous coronary intervention

A Visualized Nomogram for Predicting Prognosis in Elderly Patients after Percutaneous Coronary Intervention

Background

Revascularized patients still experience adverse cardiovascular events. This is particularly true for elderly patients over the age of 65, as they often have more co-morbid vascular conditions. It is important to develop a tool to assist clinicians in comprehensively assessing these patients' prognosis. The objective of this study is to create a comprehensive visual nomogram model combining clinical and physiological assessments to predict outcomes in elderly patients undergoing percutaneous coronary intervention (PCI).

Methods

This study is a retrospective investigation of patients who underwent PCI between January 2016 and December 2017. A total of 691 patients with 1461 vessels were randomly divided into a training (n = 483) and a validation set (n = 208). A multivariate Cox regression model was employed using the training set to select variables for constructing a nomogram. The performance of the nomogram was assessed through the receiver operating characteristic curve (ROC) and calibration curves to evaluate its discrimination and predictive accuracy. To further assess the clinical usefulness, Kaplan-Meier curve analysis and landmark analysis were conducted.

Results

Independent risk factors, including diabetes mellitus (DM), post-PCI quantitative flow ratio (QFR), previous myocardial infarction (MI), and previous PCI, were contained in the nomogram. The nomogram exhibited a good area under the curve (AUC) ranging from 0.742 to 0.789 in the training set, 0.783 to 0.837 in the validation set, and 0.764 to 0.786 in the entire population. Calibration curves demonstrated a well-fitted curve in all three sets. The Kaplan-Meier curves showed clear separation and the patients with higher scores in the nomogram model exhibited a higher incidence of target vessel revascularization (TVR) (7.99% vs. 1.24% for 2-year, p < 0.001 and 13.54% vs. 2.23% for 5-years, p < 0.001, respectively).

Conclusions

This study has developed the visually intuitive nomogram to predict the 2-year and 5-year TVR rates for elderly patients who underwent PCI. This tool provides more accurate and comprehensive healthcare guidance for patients and their physicians.

Progress in the Application of the Residual SYNTAX Score and Its Derived Scores

The residual SYNTAX score (rSS) is employed for the quantification of residual coronary lesions and to guide revascularization. rSS can be combined with other examinations to evaluate the severity of vascular disease and play an evaluative and guiding role in various scenarios. Furthermore, combining rSS with other indicators, benefits prognosis evaluation, and rSS-derived scores have been increasingly used in clinical practice. This article reviews the progress in the clinical application of rSS and its derived scores for complex coronary arteries and other aspects, based on relevant literature.

Effects of percutaneous coronary intervention and diabetes mellitus on short- and long-term prognosis assessed by the three-vessel quantitative flow ratio

AIMS

We aimed to investigate the impact of percutaneous coronary intervention (PCI) and diabetes mellitus (DM) on short- and long-term prognosis in patients with coronary artery disease using three-vessel quantitative flow ratio (3 V-QFR) assessment.

METHODS

A retrospective analysis of 2440 vessels in 1181 patients who underwent PCI was performed. The patients were categorized according to the presence or absence of DM and the median 3 V-QFR. The primary outcome was the occurrence of major adverse cardiac events (MACE), defined as a combination of cardiovascular death, myocardial infarction, and ischemia-driven revascularization, over a 5-year period.

RESULTS

The pre-PCI and post-PCI 3 V-QFR values for the entire population were 2.37 (2.04-2.56) and 2.94 (2.82-3.00), respectively. Landmark analysis showed that the incidence of MACE was comparable among all groups within the first year (log-rank p = 0.088). Over the course of 2 years, the incidence of MACE was higher in both groups with a post-PCI 3 V-QFR < 2.94 (log-rank p < 0.001). However, from 2 to 5 years, patients with DM had higher rates of MACE (log-rank p = 0.013).

CONCLUSIONS

In the short term, a low post-PCI 3 V-QFR is a predictor of high risk for MACE. However, in the long term, DM emerges as the dominant risk factor.

Outcomes of Functionally Complete vs Incomplete Revascularization: Insights From the FAVOR III China Trial

BACKGROUND

Functional complete revascularization (FCR) after percutaneous coronary intervention (PCI) as determined by the residual functional SYNTAX score (rFSS) based on pressure wire fractional flow reserve assessment has been associated with an improved prognosis.

OBJECTIVES

This study sought to determine the rates and clinical implications of FCR as assessed by the quantitative flow ratio (QFR), and to determine the outcomes of pre-PCI QFR guidance compared with standard angiography guidance in patients achieving and not achieving FCR after PCI.

METHODS

In the randomized, sham-controlled, blinded, multicenter FAVOR (Comparison of Quantitative Flow Ratio Guided and Angiography Guided Percutaneous Intervention in Patients with Coronary Artery Disease) III China trial, QFR-guided PCI reduced the 1-year rate of major adverse cardiac events (MACE) compared with angiography-guided PCI. In the present prespecified substudy, the incidence of MACE was compared according to the presence of post-PCI FCR (rFSS = 0 based on core laboratory-assessed QFR) in the QFR-guided and angiography-guided groups.

RESULTS

Among 3,781 patients with available rFSS assessments, 3,221 (85.2%) achieved FCR, including 88.1% after QFR guidance and 82.2% after angiography guidance (P < 0.001). Patients with FCR had a markedly lower rate of 1-year MACE compared with those with functional incomplete revascularization (FIR) (rFSS ≥1) (5.1% vs 19.7%; P < 0.001). Prognostic models including the rFSS had higher discrimination and reclassification ability than those with the anatomic residual SYNTAX score. The relative risks for 1-year MACE with QFR-guided compared with the angiography-guided lesion selection were consistent in patients achieving FCR (4.1% vs 6.3%; HR: 0.65; 95% CI: 0.47-0.88) and in those with FIR (18.7% vs 20.4%; HR: 0.90; 95% CI: 0.61-1.32) (P_interaction = 0.19).

CONCLUSIONS

In this large-scale trial, achieving FCR after PCI was associated with markedly lower 1-year rates of MACE. Compared with standard angiography guidance, QFR-guided PCI lesion selection improved the likelihood of achieving FCR and improved 1-year clinical outcomes in patients with both FCR and FIR.

Quantitative Flow Ratio or Angiography for the Assessment of Non-culprit Lesions in Acute Coronary Syndromes: Protocol of the Randomized Trial QUOMODO

Background

Approximately 50% of the patients undergoing percutaneous coronary intervention (PCI) for acute coronary syndromes (ACS) have additional stenotic lesions in non-infarct-related coronary arteries. The decision whether these stenoses require further treatment is routinely based on angiography alone. The quantitative flow ratio (QFR) is a simple non-invasive method that may help quantify the functional significance of these intermediate coronary artery lesions. The aim of our single-center, randomized superiority trial is to test the impact and efficacy of QFR, as compared to angiography, in the treatment of patients with ACS with multivessel coronary artery disease. Primary goal of the study is to investigate 1. The impact of QFR on the proportion of patients receiving PCI vs. conservative therapy and 2. whether QFR improves angina pectoris and overall cardiovascular outcomes.

Methods and Analysis

After treatment of the culprit lesion(s), a total of 200 consecutive ACS patients will be randomized 1:1 to angiography- vs. QFR-guided revascularization of non-culprit stenoses. Patients and clinicians responsible are blinded to the randomization group. The primary functional endpoint is defined as the proportion of patients assigned to medical treatment in the two groups. The primary clinical endpoint is a composite of death, non-fatal myocardial infarction, revascularization and significant angina at 12 months. Secondary endpoints include changes in the SAQ subgroups, and clinical events at 3- and 12-month follow-up.

Discussion

This study is designed to investigate whether QFR-based decision-making is associated with a decrease in angina and an improved prognosis in patients with multivessel disease.

Trial Registration Number

ClinicalTrials.gov Registry (NCT04808310).

Quantitative Flow Ratio to Predict Nontarget Vessel-Related Events at 5 Years in Patients With ST-Segment-Elevation Myocardial Infarction Undergoing Angiography-Guided Revascularization

Background In ST-segment-elevation myocardial infarction, angiography-based complete revascularization is superior to culprit-lesion-only percutaneous coronary intervention. Quantitative flow ratio (QFR) is a novel, noninvasive, vasodilator-free method used to assess the hemodynamic significance of coronary stenoses. We aimed to investigate the incremental value of QFR over angiography in nonculprit lesions in patients with ST-segment-elevation myocardial infarction undergoing angiography-guided complete revascularization. Methods and Results This was a retrospective post hoc QFR analysis of untreated nontarget vessels (any degree of diameter stenosis [DS]) from the randomized multicenter COMFORTABLE AMI (Comparison of Biolimus Eluted From an Erodible Stent Coating With Bare Metal Stents in Acute ST-Elevation Myocardial Infarction) trial by assessors blinded for clinical outcomes. The primary end point was cardiac death, spontaneous nontarget vessel myocardial infarction, and clinically indicated nontarget vessel revascularization (ie, ≥70% DS by 2-dimensional quantitative coronary angiography or ≥50% DS and ischemia) at 5 years. Of 1161 patients with ST-segment-elevation myocardial infarction, 946 vessels in 617 patients were analyzable by QFR. At 5 years, the rate of the primary end point was significantly higher in patients with QFR ≤0.80 (n=35 patients, n=36 vessels) versus QFR >0.80 (n=582 patients, n=910 vessels) (62.9% versus 12.5%, respectively; hazard ratio [HR], 7.33 [95% CI, 4.54-11.83], P<0.001), driven by higher rates of nontarget vessel myocardial infarction (12.8% versus 3.1%, respectively; HR, 4.38 [95% CI, 1.47-13.02], P=0.008) and nontarget vessel revascularization (58.6% versus 7.7%, respectively; HR, 10.99 [95% CI, 6.39-18.91], P<0.001) with no significant differences for cardiac death. Multivariable analysis identified QFR ≤0.80 but not ≥50% DS by 3-dimensional quantitative coronary angiography as an independent predictor of the primary end point. Results were consistent, including only >30% DS by 3-dimensional quantitative coronary angiography. Conclusions Our study suggests incremental value of QFR over angiography-guided percutaneous coronary intervention for nonculprit lesions among patients with ST-segment-elevation myocardial infarction undergoing primary percutaneous coronary intervention.

Clinical implication of QFR in patients with ST-segment elevation myocardial infarction after drug-eluting stent implantation

The feasibility and prognostic value of quantitative flow ratio (QFR) after percutaneous coronary intervention (PCI) in ST-segment elevation myocardial infarction (STEMI) patients have not been assessed. The aim of this study was to investigate the prognostic utility of post-PCI QFR to predict outcomes in STEMI and determine the influence of functional results, in both culprit and nonculprit lesions, after PCI. Patients undergoing PCI of culprit lesions and receiving staged procedures of nonculprit lesions after 7 days were enrolled from 2 centers and underwent post-PCI QFR. The primary outcome was the vessel-oriented composite endpoints (VOCEs), defined as vessel-related cardiovascular death, vessel-related myocardial infarction, and target vessel revascularization. Four hundred fifteen vessels (186 culprit lesions and 219 nonculprit lesions) in 186 patients were analyzed. Measured at staged PCI, the post-PCI QFR of culprit lesions was significantly lower than that of nonculprit lesions (0.92 ± 0.10 versus 0.95 ± 0.08, p < 0.001). The multivariable model demonstrated that low post-PCI QFR was an independent predictor of 2-year VOCE (20.8% versus 5.7%; hazard ratio 2.718; 95% CI 1.347-5.486; p = 0.005). In STEMI patients with a low angiography-derived index of microcirculatory resistance (≤ 40U), a good correlation and agreement between post-PCI QFR value of culprit lesions at primary and staged procedures (r = 0.942; mean difference: - 0.0017 [- 0.074 to 0.070]) was identified. In conclusion, culprit lesions suffered from suboptimal functional results more frequently compared to nonculprit lesions after PCI in STEMI patients. Low post-PCI QFR was associated with subsequent adverse clinical outcomes. After stenting, culprit lesions may feasibly be assessed through QFR without significant microvascular dysfunction.

QFR Predicts the Incidence of Long-Term Adverse Events in Patients with Suspected CAD: Feasibility and Reproducibility of the Method

AIMS

We evaluate feasibility and reproducibility of post hoc quantitative flow ratio (QFR) measurements and their prognostic predictive power during long-term follow-up.

METHODS AND RESULTS

Between 2010 and 2012, 167 patients without angiographic evidence of significant stenoses were enrolled in a prospective registry. Of these patients, 96% presented 7 years follow-up data. QFR was measured post hoc by three certified investigators. QFR analysis was feasible in 71% of left anterior descending (LAD), 72% of left circumflex (LCX), and 61% of right (RCA) coronaries for a total of 350 measurements repeated in triplicate. Coefficients of variation were 2.1% for RCA and LCX, and 2.8% for the LAD (quartile coefficients of dispersion respectively 1.5, 1.4, and 1.3). QFR ≤0.80 was recorded in 25 patients (27 vessels, in 74% of the cases LAD). A total of 86 major adverse cardiovascular and cerebrovascular events were observed in 76 patients. QFR ≤0.80 in at least one of the three vessels was the strongest predictor of events (HR 3.14, 95%CI 1.78-5.54, p = 0.0001). This association was maintained in several sensitivity analyses.

CONCLUSIONS

QFR reproducibility is acceptable, even when analysis is performed post hoc. A pathological QFR is not rare in patients without angiographic evidence of significant stenosis and is a predictor of incident events during long-term follow-up.

CONDENSED ABSTRACT

In a post hoc analysis of 167 patients without evidence of angiographic significant stenosis, the presence of QFR value ≤0.80 in at least one of the three coronary vessels showed to be the strongest predictor of major adverse cardiovascular and cerebrovascular events during long-term follow-up. QFR reproducibility have been shown to be acceptable among experienced operators.