Dr. Dharam Kumbhani
I was honored to represent UT Southwestern at multiple venues during #AHA21. One of the sessions in which I participated discussed the contemporary management of cardiogenic shock. My presentation was on hemodynamic support in this condition, and I delineated my top five fundamental principles on use of such devices for this indication.
As background, the use of mechanical circulatory support (MCS) devices for cardiogenic shock has skyrocketed over the past decade. Interestingly, there appears to be a fivefold variation in the use of Impella across hospitals for comparable patients. The first step of hemodynamic support is to have a thorough understanding of the patient’s shock profile, for which a right heart catheterization is indispensable. Patients with elevated right- and left-sided filling pressures likely have biventricular failure and may have different considerations from those who have low filling pressures and likely have hypovolemic shock. The three goals for patients needing hemodynamic support are maximizing circulatory support, providing ventricular support, and maintaining coronary perfusion. In this regard, the SCAI shock classification is helpful. The timing and choice of MCS (matching MCS to severity of shock) is also critically important; if a patient is sliding into “hemometabolic” shock (shock with metabolic derangements), an intra-aortic balloon pump (IABP) is unlikely to help; early ECMO may be more appropriate in that setting.
It goes without saying that operators should be comfortable with the various devices available to them and understand their limitations and pitfalls. IABP, for instance, has a class III recommendation in the 2018 European guidelines for use in cardiogenic shock complicating myocardial infarction; despite this, however, IABP remains widely used, likely due to its ease and rapidity of deployment and because it gives some operators peace of mind when tackling complex coronary lesions. Similarly, although Impella is widely used, there are no randomized controlled trials that show superior outcomes compared with IABP. Indeed, at least two large observational studies have shown Impella use to be associated with a higher risk of complications including stroke, bleeding, and vascular complications. Mitigating vascular complications to the extent possible is an important skill set for implanting physicians, as is being facile with newer techniques such as axillary access, same-side access for PCI, etc. We also discussed how management of cardiogenic shock is a true team effort, requiring close collaboration between interventional cardiologists, advanced heart failure specialists, cardiac intensivists, and cardiac surgeons. Observational studies suggest that a shock team approach is associated with higher PA catheter use, more appropriate MCS use (and paradoxically, a lower MCS use overall), and potentially lower mortality.
Without doubt, tremendous strides have been made in the management of patients with cardiogenic shock, and this session and my talk highlighted many of the important clinical issues to consider for the use of mechanical circulatory support in this setting.