Utilidad de la reserva fraccional de flujo obtenida mediante guía intracoronaria de presión en la valoración de lesiones angiográficamente moderadas en el síndrome coronario agudo

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 Acute Myocardial Infarction: A Guide for Non-Culprit Lesions?

In patients presenting with ST-segment elevation myocardial infarction (STEMI) and multi-vessel disease (MVD), the optimal therapy for non-culprit lesions is still a matter of debate. While guidelines discourage a concomitant treatment of infarct- and non-infarct-related arteries, recent studies document advantages of a complete (preventive) revascularization during primary percutaneous coronary intervention. Such an approach, however, may result in overtreatment, because angiography does not provide robust information about the functional severity of MVD. Fractional flow reserve (FFR) measurements can be a valuable guide for non-culprit lesions in acute myocardial infarction, but so far, only the reliability and safety of FFR measurements have been established in this setting. The clinical implications of an FFR-guided treatment strategy in STEMI patients with MVD are currently being tested in a large randomized trial.

Long-term Prognosis of Patients With Non-ST-segment Elevation Acute Myocardial Infarction and Coronary Arteries Without Significant Stenosis

INTRODUCTION AND OBJECTIVES

There is debate regarding the prognostic significance of the absence of significant coronary lesions in patients with non-ST-segment elevation acute myocardial infarction. We investigated long-term prognosis in a contemporary cohort of these patients.

METHODS

Retrospective observational study of 5203 patients with acute coronary syndrome. Propensity score matching was used to create 2 groups of 367 patients with non-ST-segment elevation acute myocardial infarction matched by the absence or presence of significant coronary lesions. In the matched cohort, we determined the impact of the absence of significant coronary lesions on mortality or readmission for acute coronary syndrome for 4.8 (2.6) years after discharge.

RESULTS

Mortality or readmission for acute coronary syndrome was lower among patients without significant lesions (26.4% vs 32.7%; P = .09). Mortality in both groups was 19.1%. In contrast, patients without significant lesions had a lower incidence of readmission for acute coronary syndrome (2.0/100 vs 3.9/100 person-years; P = .003). The incidence of mortality or readmission for acute coronary syndrome was similar in patients without significant lesions and those with significant 1-vessel disease (26.4% vs 27.5%; P = .19), but lower than that in patients with 2-vessel disease (37.8%; P = .007) and 3-vessel disease or left main coronary artery disease (41.1%; P = .002).

CONCLUSIONS

Patients with non-ST-segment elevation acute myocardial infarction and coronary arteries without significant lesions have similar long-term mortality but lower readmission rates for acute coronary syndrome than patients with significant lesions. Mortality or readmission for acute coronary syndrome is similar in patients without significant lesions and patients with 1-vessel disease, but lower than in patients with disease in 2 or more vessels.

The instantaneous wave-free ratio (iFR) for evaluation of non-culprit lesions in patients with acute coronary syndrome and multivessel disease

BACKGROUND

Adenosine administration is currently required for evaluation of stenosis severity with fractional flow reserve (FFR). The instantaneous wave-free ratio (iFR) was recently introduced as an adenosine-free alternative in patients with stable CAD. The aim of the present study was to replicate the findings of previous iFR studies using an independent calculation algorithm and to evaluate the iFR for the assessment of non-culprit vessels in patients with acute coronary syndrome (ACS).

METHODS AND RESULTS

53 patients with ACS (65%) and at least one non-culprit intermediate lesion and 29 (35%) with stable CAD were included. A total of 123 stenoses were evaluated with both FFR and iFR. Classification match of iFR in ACS was not inferior to stable CAD (79.5% in ACS and 84.4% in CAD; p=0.497). Accordingly, no difference was observed in iFR/FFR correlation between ACS and stable CAD (r=0.66 in ACS vs. r=0.69 in CAD). Overall, a significant correlation was found between iFR and FFR (r=0.68; p<0.001) with a good diagnostic efficiency at ROC analysis (area under the curve: 0.87). In addition, neither the localization of the stenosis within the coronary tree (p=0.147) nor the time interval from the acute event (p=0.550) significantly influenced the concordance of iFR with FFR.

CONCLUSIONS

The iFR is a promising method for the assessment of non-culprit lesion severity in patients with acute coronary syndrome.

Clinical outcomes after intravascular ultrasound and fractional flow reserve assessment of intermediate coronary lesions. Propensity score matching of large cohorts from two institutions with a differential approach

AIMS

Assessment of intermediate coronary lesions can be done with fractional flow reserve (FFR) and intravascular ultrasound (IVUS). There are no randomised trials and only a small registry from one centre is available but this is subject to important bias. We sought to evaluate the clinical outcomes of an FFR strategy compared with an IVUS strategy for intermediate lesion assessment.

METHODS AND RESULTS

We compared the outcome of patients assessed with FFR and IVUS in two centres with a differential approach. After propensity score matching 400 pairs of patients were included. Revascularisation was done when FFR was <0.75 or minimum lumen area was <4 mm2 in vessels >3 mm, and <3.5 mm2 in vessels 2.5-3 mm, along with plaque burden >50%. After FFR and IVUS, 72% and 51.2% of lesions, respectively, were left untreated (p<0.001). At one and two years no significant differences in MACE-free survival were observed in overall groups (97.7% at one year and 93.1% at two years in the FFR group and 97.7% at one year and 95.6% at two years in the IVUS group; p=0.35) and among those with deferred intervention (97.9% at one year and 94.2% at two years in the FFR group and 96.5% at one year and 93.6% at two years in the IVUS group; p=0.7).

CONCLUSIONS

IVUS and FFR may be safely used to defer revascularisation of intermediate lesions. IVUS induces a higher degree of revascularisation but much lower than previously reported and does not affect the clinical outcome.

[Update in interventional cardiology]

This article contains a detailed review of the most important studies on interventional cardiology reported in either publications or presentations. With regard to coronary interventions, ST-elevation myocardial infarction is highlighted because of the ongoing substantial expansion in primary angioplasty programs. Drug-eluting stents, especially new-generation stents, continue to be the focus of numerous studies. Clinical outcomes in diabetic patients with left main coronary artery or multivessel disease are also dealt with by much research. In addition, intracoronary diagnostic techniques, particularly optical coherence tomography, is reviewed. Finally, there is increasing interest in the percutaneous treatment of structural heart disease, particularly percutaneous aortic valve implantation.