Fractional flow reserve in acute coronary syndromes and in stable ischemic heart disease: clinical implications

Applied coronary physiology for planning and guidance of percutaneous coronary interventions. A clinical consensus statement from the European Association of Percutaneous Cardiovascular Interventions (EAPCI) of the European Society of Cardiology

The clinical value of fractional flow reserve and non-hyperaemic pressure ratios are well established in determining an indication for percutaneous coronary intervention (PCI) in patients with coronary artery disease (CAD). In addition, over the last 5 years we have witnessed a shift towards the use of physiology to enhance procedural planning, assess post-PCI functional results, and guide PCI optimisation. In this regard, clinical studies have reported compelling data supporting the use of longitudinal vessel analysis, obtained with pressure guidewire pullbacks, to better understand how obstructive CAD contributes to myocardial ischaemia, to establish the likelihood of functionally successful PCI, to identify the presence and location of residual flow-limiting stenoses and to predict long-term outcomes. The introduction of new functional coronary angiography tools, which merge angiographic information with fluid dynamic equations to deliver information equivalent to intracoronary pressure measurements, are now available and potentially also applicable to these endeavours. Furthermore, the ability of longitudinal vessel analysis to predict the functional results of stenting has played an integral role in the evolving field of simulated PCI. Nevertheless, it is important to have an awareness of the value and challenges of physiology-guided PCI in specific clinical and anatomical contexts. The main aim of this European Association of Percutaneous Cardiovascular Interventions clinical consensus statement is to offer up-to-date evidence and expert opinion on the use of applied coronary physiology for procedural PCI planning, disease pattern recognition and post-PCI optimisation.

Acute coronary syndromes and multivessel coronary artery disease

Patients with acute coronary syndromes (ACS) and multivessel coronary artery disease are frequently encountered during clinical practice and those patients are at higher risk of subsequent acute cardiovascular events. In patients presenting with both ST-segment elevation myocardial infarction and non-ST-segment elevation acute coronary syndromes, complete revascularization is associated with decreased risk of major adverse cardiovascular events. Nevertheless, the optimal timing of the intervention and treatment modality are still in discussions. Furthermore, non-culprit lesions assessment based on stenosis severity, either on visual or on functional evaluation, may not provide information about vulnerable plaques prone to thrombosis. Therefore, insights from intracoronary imaging could further identify high-risk plaque and patients at higher risk of future adverse events. This article aims to provide an overview of current guideline recommendations, envisioning future perspectives for the treatment of patients with ACS and multivessel disease.

Management of non-culprit coronary plaques in patients with acute coronary syndrome

Approximately 50% of patients with ST-segment elevation myocardial infarction (STEMI) have multivessel coronary artery disease, a condition associated with an increased incidence of recurrent ischaemic events and higher mortality. Based on recent evidences, a strategy of staged percutaneous coronary intervention (PCI) of obstructive non-culprit lesions should be considered the gold standard for the management of these patients. However, several issues remain still unresolved. Indeed, what is the optimal timing of staged PCI is not completely defined. Moreover, assessment of intermediate non-culprit lesions represent still a clinical conundrum, as pressure-wire indexes do not seem able to correctly identify those patients in whom deferral is safe. Intracoronary imaging may help to identify untreated non-culprit lesions containing vulnerable plaques that may portend a higher risk of future cardiovascular events. However, there are hitherto no studies demonstrating that preventive PCI of vulnerable plaques or more intensive pharmacological treatment is associated with an improved clinical outcome. In this review, we discuss the recent evolving concepts about management of non-culprit plaques in STEMI patients, proposing a diagnostic and therapeutic algorithm to guide physicians in clinical practice. We also underscore the several knowledge gaps to address in future studies.

Collapse

Optical Coherence Tomography for In Vivo Identification, Characterization and Optimal Treatment of Spontaneous Recanalization of Coronary Thrombus

BACKGROUND/AIM

Spontaneous recanalization of coronary thrombus (SRCT) is a rare in vivo appearance, with a nonspecific angiographic aspect. The aim of this study was to investigate the importance of optical coherence tomography (OCT) use for SRCT identification, characterization of pathogenic mechanisms and optimal treatment.

PATIENTS AND METHODS

We retrospectively analyzed all patients with angiographic suspicion of SRCT who underwent coronary angiography for suspected coronary artery disease and afterward investigated by OCT imaging.

RESULTS

We identified 28 cases with angiographic suspicion of SCRT (0.41% of CA) and confirmed it in 4 patients (0.05% of CA). OCT provided insight about the underlying SRCT mechanism: possible complicated atherosclerotic plaques in two cases and, respectively, spontaneous coronary artery dissection in other two cases. OCT provided accurate lesion assessment and offered optimal PCI materials selection.

CONCLUSION

Besides providing the diagnosis, OCT also improved characterization of SRCT pathogenic mechanisms, in the four confirmed SRCT cases, supporting the role of coronary wall in situ complications, namely dissection of an atherosclerotic plaque or spontaneous dissection of a normal coronary wall.

Real-Life Benefit of OCT Imaging for Optimizing PCI Indications, Strategy, and Results

Background: The aim of this study was to evaluate the benefit of standard practice Optical Coherence Tomography (OCT) imaging, as a complement to coronary angiography (CA), for optimizing the indications, strategy, and results of percutaneous coronary interventions (PCI). Methods: We retrospectively analyzed 182 patients with OCT imaging in a single tertiary center. Results: OCT use had a low prevalence (3.1% of 4256 CAs and 1.7% of 3027 PCIs). OCT was used post-CA in 71.5% and post-PCI in 28.5% of cases, mainly in acute coronary syndromes—95.6%. OCT was performed for borderline lesions in 43.4% of cases; lesion severity was reassessed as severe and led to PCI in 64.5% of them. OCT was performed for nonsignificant lesions in 17% of cases; lesion severity was reassessed as severe and led to PCI in 38.7% of them. OCT provided optimal selection for PCI strategy in 11% of cases. OCT identified suboptimal PCI results in 54% left main PCIs and in 48% bifurcation PCIs with optimal CA; PCI optimization was performed. In the only seven patients with suboptimal PCI, OCT revealed an optimal result in four cases, thus avoiding unneccessary optimization. In 27.3% of patients with post-CA OCT and PCI result “systematic” OCT control, a PCI optimization was indicated. Conclusion: OCT supplied a major benefit in 86.2% of cases, especially by identifying significant coroanry stenosis in CA borderline and nonsignificant lesions; OCT led to PCI indication in two-thirds and, respectively, one-third of these cases. In the post-PCI context, OCT led to an indication of PCI optimization in half of the complex left main and bifurcation lesions, as well as in a quarter of “systematic” post-PCI OCT controls.