Outcome of coronary lesions with deferred revascularization due to negative fractional flow reserve in subjects with acute coronary syndrome

Long-term outcome after deferred revascularization due to negative fractional flow reserve in intermediate coronary lesions

Objectives

The aim was to assess long‐term outcome after deferring intervention of coronary lesions with a fractional flow reserve (FFR) value of >0.80 in a real‐world patient population and then to identify factors associated with deferred target lesion failure (DTLF).

Background

Deferring coronary interventions of intermediate lesions based on FFR measurement is safe, irrespective of the extent of coronary artery disease. However, FFR values near the cut‐off of >0.80 may have less favorable outcome.

Methods

A retrospective analysis was performed in patients with deferred coronary intervention based on FFR value >0.80. The primary endpoint was DTLF, a composite of acute coronary syndrome (ACS) and any coronary revascularization, related to the initially deferred stenosis.

Results

A total of 600 patients, mean age of 66 ± 10 years, and 751 coronary lesions with negative FFR values (mean 0.88 ± 0.04) were included. The mean follow‐up was 27 ± 15 months. DTLF occurred in 44 patients (7.3%), revascularization in 42 (7%), and ACS without revascularization in 2 patients (0.3%). Patients with DTLF more often had diabetes mellitus, previous coronary artery bypass grafting, multivessel disease (MVD), and lower FFR at inclusion. Multivariable regression analysis showed that lower deferred FFR values [FFR 0.81–0.85: hazard ratio (HR) 2.79 (95% CI [confidence interval]; 1.46–5.32), p .002], MVD [HR 1.98 (95% CI; 1.05–3.75), p .036], distal lesions [HR 2.43 (95% CI; 1.29–4.57), p .006], and lesions located in a saphenous vein graft (SVG) [HR 6.35 (95% CI; 1.81–22.28), p .004] were independent predictors for DTLF.

Conclusions

The long‐term rate of DTLF of initially deferred coronary lesions was 7.3%. Independent predictors for DTLF are lower deferred FFR value, the presence of MVD, distal lesions, and lesions in SVG.

Quantitative Flow Ratio Identifies Nonculprit Coronary Lesions Requiring Revascularization in Patients With ST-Segment-Elevation Myocardial Infarction and Multivessel Disease

BACKGROUND

The nonculprit lesion (NCL) management in ST-segment-elevation myocardial infarction patients with multivessel disease is debated. We sought to assess whether quantitative flow ratio (QFR), a noninvasive tool to identify potentially flow-limiting lesions, may be reliable in this scenario.

METHODS AND RESULTS

The present proof-of-concept study is based on a 3-step process: (1) identification of the QFR reproducibility in NCLs assessment (cohort A, n=31); (2) prospective validation of QFR diagnostic accuracy in respect to fractional flow reserve (cohort B, n=45); and (3) investigation of long-term clinical outcomes of NCLs stratified according to QFR (cohort C, n=110). A blinded core laboratory computed QFR values for all NCLs. Cohort A showed a good correlation and agreement between QFR values at index (acute) and at staged (subacute, 3-4 days later) procedures (r=0.98; 95% confidence interval, 0.96-0.99; mean difference, 0.004 [-0.027 to 0.34]). The inter-rater agreement was κ=0.9. In cohort B, fractional flow reserve and QFR identified 16 (33%) and 17 (35%) NCLs potentially flow limiting. Sensitivity, specificity, negative, and positive predictive values were 88%, 97%, 94%, and 94%. The area under the receiver operating characteristics curve was 0.96 (95% confidence interval, 0.89-0.99). Finally, in cohort C, we identified 110 ST-segment-elevation myocardial infarction patients where at least 1 NCL was left untreated. Patients with NCLs showing a QFR value ≤0.80 were at higher risk of adverse events (hazard ratio, 2.3; 95% confidence interval, 1.2-4.5; P=0.01).

CONCLUSIONS

In a limited and selected study population, our study showed that QFR computation may be a safe and reliable tool to guide coronary revascularization of NCLs in ST-segment-elevation myocardial infarction patients.

Fractional Flow Reserve-Guided Strategy in Acute Coronary Syndrome. A Systematic Review and Meta-Analysis

Background

There are limited data on the prognosis of deferral of lesion treatment in patients with acute coronary syndrome (ACS) based on fractional flow reserve (FFR).

Objectives

To provide a systematic review of the current evidence on the prognosis of deferred lesions in ACS patients compared with deferred lesions in non-ACS patients, on the basis of FFR.

Methods

We searched Medline, EMBASE, and the Cochrane Library for studies published between January 2000 and September 2017 that compared prognosis of deferred revascularization of lesions on the basis of FFR in ACS patients compared with non-ACS patients. We conducted a pooled relative risk meta-analysis of four primary outcomes: mortality, cardiovascular (CV) mortality, myocardial infarction (MI) and target-vessel revascularization (TVR).

Results

We identified 7 studies that included a total of 5,107 patients. A pooled meta-analysis showed no significant difference in mortality (relative risk [RR] = 1.44; 95% CI, 0.9-2.4), CV mortality (RR = 1.29; 95% CI = 0.4-4.3) and TVR (RR = 1.46; 95% CI = 0.9-2.3) after deferral of revascularization based on FFR between ACS and non-ACS patients. Such deferral was associated with significant additional risk of MI (RR = 1.83; 95% CI = 1.4-2.4) in ACS patients.

Conclusion

The prognostic value of FFR in ACS setting is not as good as in stable patients. The results demonstrate an increased risk of MI but not of mortality, CV mortality, and TVR in ACS patients.

Network meta-analysis comparing iFR versus FFR versus coronary angiography to drive coronary revascularization

AIMS

Instantaneous free-wave ratio (iFR) has been recently demonstrated non-inferior to fractional flow reserve (FFR) to drive coronary revascularization; however, no study has compared iFR versus coronary angiography (CA). We performed a network meta-analysis to evaluate efficacy and safety of iFR- versus CA-guided strategy.

METHODS AND RESULTS

We searched for randomized trials and studies with propensity score matching in The Cochrane Collaboration Central Register of Controlled Trials, EMBASE, and MEDLINE/Pubmed. CA, FFR, and iFR were the three competitive arms, MACE (a composite endpoint of death, myocardial infarction [MI], and target vessel revascularization [TVR]) was the primary endpoint, while its single components the secondary ones. Subgroup analysis was performed for patients presenting with stable coronary artery disease. Eight studies were selected: 4126 patients were evaluated with FFR, 2160 with iFR, and 2214 with CA, acute coronary syndrome (ACS) was the most frequent admission diagnosis. After 12 months, rates of MACE and all-cause death did not differ between groups (respectively OR 1.04 and OR 0.86 for iFR vs FFR). Both FFR and iFR reduced TVR compared to CA (respectively OR 0.68 and OR 0.70). In patients with stable CAD both FFR and iFR reduced risk of subsequent MI compared to CA (respectively OR 0.66 and OR 0.79).

CONCLUSION

Compared to CA alone, both FFR and iFR are safe and effective in guiding coronary revascularization at 12 months. In patients with stable CAD, both FFR and iFR-guided revascularization reduce the risk of subsequent MI at 12 months.

Role of fractional flow reserve in the evaluation and management of patients with acute coronary syndrome

PURPOSE OF REVIEW

The aim of this review is to appraise the clinical and prognostic value and pitfalls of FFR across different spectra of ACS presentations and lesion subsets.

RECENT FINDINGS

Preponderance of evidence on this subject is from observational nonrandomized studies with conflicting results and short-term outcomes. Multiple recent studies evaluating the role of FFR-based deferral in non-STE ACS from a potentially culprit lesion have demonstrated poor long-term prognosis as related to future risk of target vessel failure (myocardial infarction/revascularization). The prognostic power of nonischemic FFR seems favorable in clear nonculprit ACS lesions.

SUMMARY

Fractional flow reserve evaluation can be helpful in clinical decision-making for certain subsets of ACS patients and lesions. Definite ACS-producing lesions should not be evaluated using FFR due to altered pathophysiology and distinct mechanisms underlying the disease process. In uncertain culprit lesions, FFR may be useful with complementary intracoronary imaging.

Fractional flow reserve in 2017: current data and everyday practice

INTRODUCTION

Fractional flow reserve (FFR) is an objective physiological index utilized in coronary angiography. It expresses the blood flow in the presence of a coronary artery stenosis as a fraction of the normal blood flow and gives information regarding the functional significance of the lesion. FFR guided percutaneous coronary intervention (PCI) has been shown to be superior to angiography guided PCI in several trials and registries. In addition, it appears that the use of FFR may also be preferable from an economic perspective. Areas covered: This article will cover the physiological principles underpinning FFR, the landmark clinical trials that have established its diagnostic utility and the current recommendations for the use of the procedure in daily practice. We will also examine potential future directions for the technology and try to predict how its use will evolve in the next five years. Expert commentary: We see FFR as an essential diagnostic tool in the modern catheterization laboratory, enabling physicians to make optimal decisions regarding percutaneous coronary intervention for an individual patient. It must be stated however that FFR is an adjunctive invasive functional tool that must be used in conjunction with sensible clinical history and exam findings pertaining to the individual patient. We expect that the results of FAME3 will further establish the role of FFR in risk stratifying patients with 3 vessel disease by utilizing a functional SYNTAX score.