Coronary no-reflow in the modern era: a review of advances in diagnostic techniques and contemporary management

ABSTRACT

Introduction: Atherosclerotic coronary artery disease, in particular acute myocardial infarction (AMI), is a leading cause of morbidity and mortality globally. Percutaneous coronary intervention (PCI) is the mainstay of treatment for obstructive coronary artery disease and AMI through the restoration of TIMI III flow. Despite good macrovascular flow, the myocardium can remain hypoperfusion due to poor microvascular perfusion, and this is referred to as ‘no-reflow’. Various treatments have been studied with variable success in both prevention and treatment of no-reflow.

Areas covered: This review outlines the cutting-edge diagnostic investigations which have been explored in no-reflow, allowing a deeper understanding of mechanism and microvascular pathological processes involved in its genesis. These include utility of novel MRI techniques and perfusion echo in conjunction with traditional approaches. Detailed review has been undertaken of both pharmacological and non-pharmacological techniques to prevent and manage microvascular dysfunction associated with no-reflow. Particular attention was paid to the evolution and successes of various mechanical protection devices.

Expert opinion: Most promising innovations in the diagnosis and management of no-reflow are evaluated, and future outlook is explored. Emerging advances in acute coronary syndrome have their findings applied a role in modifying the pathophysiology of no-reflow.

KEYWORDS:

• Review
• no reflow
• slow reflow
• microvascular obstruction
• percutaneous coronary intervention
• PCI
• protection device

Article highlights

• Advances in the recognition of no-reflow alongside the evolution in novel imaging techniques to quantify the burden of no-reflow.

• T2-weighted early gadolinium-enhanced MRI and perfusion echo are innovative approaches explored.

• Intracoronary pharmacotherapy is the mainstay of management in coronary no-reflow

• Additional benefits from the conjunctive use of non-pharmacological and structural interventions in the prevention and treatment of no-reflow.

• Detailed discussion & evidence for the use of proximal and distal embolic protection devices

• Exploration of further development of medications for use in acute coronary syndrome, and attempts to apply their potential in no-reflow pathogenesis; such as Bendavia and stem cell therapy.

Declaration of interest

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Reviewer Disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Additional information

Funding

This paper was not funded.