Long-term Outcomes of Patients Undergoing ECMO-assisted PCI

In the past four decades, there has been a widespread percutaneous coronary intervention (PCI) in coronary artery disease (CAD). Guidelines recommended that PCI is a reasonable option to improve survival, compared with medical therapy, in selected patients with low-to-medium anatomic complexity of CAD equally suitable for coronary artery bypass grafting (CABG); for complex and diffuse CAD, CABG was associated with a more significant clinical benefit. However, CABG is not always feasible due to patient preferences or the excess risk of perioperative morbidity and mortality. In selected patients with functionally significant multivessel disease (MVD) and LVEF ≤ 35% who are at high surgical risk or inoperable, PCI may be considered as an alternative to CABG. The recent 2024 European Society of Cardiology guidelines for the management of chronic coronary syndromes provided IIb B recommendation under such settings. However, such a subset of patients is considered at high risk for PCI complications due to the risk of hemodynamic collapse during balloon inflations or complex procedures.

Mechanical circulatory support (MCS) devices for elective high-risk PCI can provide hemodynamic support preventing hemodynamic failure during PCI. Several studies have suggested that intra aortic balloon pump (IABP) showed no significant benefits. Impella with a larger hemodynamic support also failed to demonstrate benefits, despite a tendency favoring the device. Venoarterial extracorporeal membrane oxygenation (VA -ECMO) is an alternative option for mechanical support, providing more extensive hemodynamic support in patients with potential or ongoing circulation failure. Initial reports on the use of VA-ECMO showed controversial results in the treatment of cardiogenic shock due to myocardial infarction. However, available evidence for the use of VA-ECMO in high-risk PCI has been restricted to retrospective small sizes; large-volume studies about the long-term outcome in this patient are limited.

ECMO requires a complex multidisciplinary approach and advanced technology. The potential benefits of hemodynamic support may be outweighed by the risk of device-associated complications, particularly bleeding and peripheral vascular events. Two studies have demonstrated that ECMO center experience may be associated with lower mortality in patients with cardiorespiratory failure. However, the relationship between operator experience and long-term outcomes post-VA-ECMO-assisted PCI in high-risk patients, and the ideal threshold to classify an operator as "experienced" have not been previously studied. Therefore, the aim of the present study was also to analyze the association between operator experience and one-year mortality post-VA-ECMO-assisted PCI.