Non-atherosclerotic causes of acute coronary syndromes.

Atherosclerosis and plaque disruption have a central pathological role in the majority of patients who present with an acute coronary syndrome (ACS), but non-atherosclerotic processes are also important contributors to a substantial number of ACS events and require different diagnostic and therapeutic strategies. In the absence of obstructive coronary artery disease, intravascular imaging techniques might be needed to delineate the underlying aetiology, together with a high index of suspicion for other important causes of ACS. In this Review, we discuss five non-atherosclerotic causes of ACS, including spontaneous coronary artery dissection, coronary artery embolism, vasospasm, myocardial bridging and stress-induced cardiomyopathy (Takotsubo syndrome).

Early Natural History of Spontaneous Coronary Artery Dissection.

Background: Risks and mechanisms of extension of conservatively managed spontaneous coronary artery dissection (SCAD) remain incompletely understood. Study objectives were to (1) evaluate mechanisms of early SCAD evolution through serial angiographic analysis, and (2) determine predictors of early SCAD progression.

Methods And Results: Retrospective registry study of patients with SCAD managed with an initial conservative strategy (n=240).

Coronary endothelial function and spontaneous coronary artery dissection.

Objectives: To investigate the role of endothelial function in patients with previous spontaneous coronary artery dissection.

Background: Mechanisms underlying spontaneous coronary artery dissection, including a possible contribution from endothelial dysfunction, remain poorly understood.

Methods: This was a single center, retrospective study of patients with a prior spontaneous coronary artery dissection episode who underwent invasive endothelial function testing in the cardiac catheterization laboratory for evaluation of recurrent chest pain.

Techniques and outcomes of paravalvular leak repair after transcatheter aortic valve replacement.

Objectives: To investigate the feasibility, procedural success, and outcomes of paravalvular leak (PVL) closure in patients with prior transcatheter aortic valve replacement (TAVR).

Background: PVL after TAVR is associated with adverse patient outcomes and increased mortality. Percutaneous PVL closure has emerged as a therapeutic strategy for addressing this issue, but data for transcatheter PVL repair after TAVR remains limited.

Experience and complications associated with use of guide extension catheters in percutaneous coronary intervention.

Objectives: To investigate the utility and safety of the GuideLiner "mother-and-child" catheter system during transradial and transfemoral percutaneous coronary intervention (PCI).

Background: In patients with complex coronary anatomy, stent delivery can be challenging and result in procedural failure and complications. The GuideLiner is a coaxial guide extension system designed to enable deep vessel engagement and facilitate device delivery.