Use of Mechanical Left ventricuLar Unloading in Complex Higher-risk Indicated Procedures

During the last three to four decades percutaneous coronary intervention (PCI) tools and techniques have improved immensely. Currently, PCI is the most widely used approach for myocardial revascularization. In general, elective PCI is considered a safe and relatively low-risk procedure.

However, patients with left main or complex coronary lesions or impaired left ventricular function remain at high risk for peri-procedural and post-procedural hemodynamic instability and death.

Mechanical circulatory support (MCS) devices, such as intra-aortic balloon pump (IABP) and Impella (Impella 2.5 and CP), have emerged as potential tools to avoid hemodynamic instability during these CHIP coronary interventions. These devices have shown to improve hemodynamics / cardiac output during complex PCI procedures, although the benefit of mechanical circulatory support in CHIP PCI remains debated and no clear benefit on patient outcomes has been shown. A recent large scale analysis favoured Impella as opposed to IABP. The use of these devices, especially Impella, is associated with increased risk for complications such as bleeding. The use of MCS for optimizing peri-procedural hemodynamic support needs to be balanced out against the potential risk for MCS related complications.

Recently the PulseCath iVAC 2L was introduced. This is a pulsatile pump, placed in the left ventricle, that ejects blood into the ascending aorta at a flow up to 2L/min. Theoretically, pulsatility maintains the physiological vascular responses and endothelial function at the level of the -systemic and -micro circulation and might offer benefit when compared to continues flow devices such as Impella. In contrast, IABP (which also offers pulsatile support), lacks the possibility of active unloading. Therefore, the combination of those features in the PulseCath iVAC2L is unique.

Recent studies performed with the PulseCath iVAC2L in the setting of CHIP PCI demonstrated hemodynamic advantages with afterload reduction, increased stroke volume and higher cardiac output. Also, the device was deemed safe in terms of complications. Samol et al. showed in a prospective cohort study that the use of IVAC2L was non-inferior to Impella in terms of feasibility and safety, even if complications occur. Other advantages of the IVAC2L are its relatively simple use and lower costs when compared to other mechanical circulatory support devices such as the Impella family. Considering that the IVAC2L is powered by an IABP console, the possibility of widespread use adds an even greater advantage.

So far, MCS facilitated CHIP has not been proven beneficial compared to a conservative (non-supported) high-risk procedure. Although high-risk criteria parameters such as coronary anatomy (location and complexity), co-morbid conditions, and concomitant cardiac disease (structural or valvular disease, left ventricular dysfunction) are well known, no intrinsic value of each of these components is determined. The recent PULSE trial shed some light on this gap of knowledge by showing possible additional hemodynamic benefit for patients with mitral regurgitation, who presented with an acute coronary syndrome (ACS) and who had higher cardiac filling pressures at baseline. Therefore, MCS-facilitated high-risk PCI might be beneficial if used in ACS patients or patients with (left-sided) congestion (stabilized acutely decompensated heart failure) with low hemodynamic tolerance. However, due to the low number of patients enrolled and non-randomized nature of this study, conclusions should be drawn with caution. To this day, no randomized controlled trials have been executed with the PulseCath iVAC2L in this subset of CHIP patients who are thought to benefit from an MCS-facilitated PCI. Its place in the setting of CHIP PCI remains to be elucidated.

Research hypothesis:

Prophylactic percutaneous mechanical left ventricular unloading by insertion of the PulseCath iVAC2L during complex coronary stenting (complex left main disease or equivalent or last remaining vessel) at risk for prolonged procedural ischemia in patients with severely reduced LV function is superior to a mechanical unassisted PCI procedure.