Team Approach to the Management of Shock: Clinical Decisions Q&A and Transfer, Escalation and Weaning Cases (Part 4)

Q&A Session

In this Q&A session, Daniel Burkhoff, MD, Bartley Griffith, MD, Babar Basir, DO, and Benham Tehrani, MD, discuss loss of pulsatility, ECMO training, training for spoke hospitals, and the choice between Impella RP® and VA ECMO.

Pulsatility 

Addressing a question about the impact of loss of pulsatility, Dr. Burkhoff responds, “The question of loss of pulsatility is really critical and signifies something completely different when you’re on Impella® and when you’re on ECMO.” He states that loss of pulsatility occurs when the left ventricle fails to eject “and we call that LV-aortic pressure uncoupling,” he explains, “because now the aortic pressure is higher than the left ventricular pressure and there’s no ejection and no aortic valve opening.” 

For patients supported with ECMO, a closed aortic valve means that blood is trapped in the left ventricle with the potential for stasis of blood in the LV and aortic root. For patients supported with Impella, a closed aortic valve, Dr. Burkhoff explains, “tells you that the Impella is actually doing what it’s supposed to do, which is decrease the LV workload, decrease the preload, and elevate the pressure in the arterial system.” Impella maintains blood flow within the atrium, the ventricle, and the proximal aorta. Dr. Griffith provides additional insights on the combined use of ECMO and Impella. 
 

ECMO Training

Addressing a question about how interventional cardiologists can be trained and certified in the use of ECMO, Dr. Basir emphasizes that ECMO training for interventionalists may be less about placement and more about long-term management of ECMO. He points interventionalists to professional societies and CAMP PCI™. Dr. Tehrani echoes that interventionalists are likely already familiar with the procedural techniques of large bore access and complication management, but will require training in the management aspects of understanding hemodynamics, venting, pulsatility, weaning and escalation. 
 

Spoke Site Training

Dr. Tehrani addresses a question about the training that spoke sites receive regarding treating and transferring patients to hub facilities, noting that telehealth during the COVID era has helped facilitate communication with spokes. He explains that resources and operator experience vary among spoke facilities and that some easily implant Impella while IABP is the only resource at others. The key is understanding the capabilities of sites and providing support and resources and escalating once patients arrive at the hub center.
 

Impella RP® vs VA ECMO

Addressing a question about his decision to use Impella RP rather than VA ECMO in a case he previously described, Dr. Basir explains that the initial hemodynamic changes that occurred with the Impella CP® and the improvement in cardiac power output (CPO) in that case reassured him that Impella RP would be sufficient. Had he not seen the improvement in CPO after placing Impella CP, Dr. Basir states, “then using an ECpella strategy [combining Impella support with ECMO] probably would have been my go-to.” 

Dr. Burkhoff adds that when deciding whether to use Impella RP or VA ECMO, clinicians should consider whether the patient requires supplemental oxygen, and “the mandate to use ECMO would really be based on the need for arterial oxygenation.” Dr. Griffith, an ECMO proponent with limited Impella RP experience, acknowledges that approaches are evolving, but adds, “there’s nothing like a decompressed left ventricle on ECMO to let you get a good night’s sleep.”

“I think it comes down to timing,” Dr. Tehrani responds, explaining that when the patient is in extremis, ECMO may be the only option. However, with early recognition that the right side is not responding in a patient without significant impairment of oxygen, he believes that adding Impella RP to left side Impella support (a strategy called “Bipella™” support) is an excellent choice, avoiding the additional access site required for ECMO.

Transfer, Escalation and Weaning Case Presentations

AMI Cardiogenic Shock Case from Dr. Villablanca

Pedro Villablanca, MD, MSc, FACC, FSCAI, an interventional cardiologist and structural heart intervention specialist at Henry Ford Hospital, presents the case of a 52-year-old female presenting with chest pain and cardiac arrest. The patient went into complete heart block during PCI, and Impella CP® was inserted, but she developed limb ischemia. She was transferred directly to the cath lab at Henry Ford Hospital where a right heart cath revealed possible RV dysfunction with low CPO and low CI. The team evaluated the access options for escalation of support, determining that transcaval delivery of Impella 5.0® was the best option. 

Dr. Villablanca describes access and insertion in detail, explaining that the team delivered the Impella 5.0 before removing the Impella CP. He then describes dry closure with MANTA®* and restoration of flow to the patient’s leg.  The patient improved significantly after 4 days of Impella 5.0 support.
*MANTA is a registered trademark of Teleflex Incorporated

Acute on Chronic Shock Case from Dr. Kiernan

Michael Kiernan, MD, MS, MBA, medical director of the ventricular assist device program and assistant professor at Tufts University School of Medicine, presents the case of a 51-year-old male with acute decompensated heart failure and longstanding chronic kidney disease. He also had limited social support, which figured into later treatment decisions. He presented to an outside facility with deteriorating renal function and severely deranged hemodynamics. The patient was medically treated and discharged home on inotropic support with a planned referral to Tufts for consideration of heart/kidney transplant. He was readmitted with progressive dyspnea and edema. 

Dr. Kiernan discusses the clinical spectrum and hemodynamics of heart failure and shock, emphasizing that patients presenting with acute on chronic heart failure can respond very differently to pharmacologic and mechanical therapeutic interventions than patients presenting with AMI shock.

Dr. Kiernan describes the patient as clearly very sick with end-stage heart disease, recurrent presentations with severely reduced CI, and shock despite a normal blood pressure. He then acknowledges the availability of several treatment options and emphasizes the importance of involving a multidisciplinary heart team and allowing hemodynamics to guide therapy. He also explains the discordance between physical exam and invasive hemodynamics, highlighting the use of a PA catheter and hemodynamics to guide therapy so that clinicians aren’t falsely reassured by a patient’s blood pressure, as was the case with this patient.

This patient was determined to have primarily LV-dominant cardiogenic shock and was transferred urgently to the hybrid cath lab at Tufts. With heart recovery unlikely in an inotrope-dependent patient, and the barriers associated with this patient’s limited social support, the team decided to buy time and use Impella 5.5® as a bridge to decision. 

Case Discussion

Both case presentations entailed use of an Impella 5.0/Impella 5.5. In Dr. Villablanca’s case, Impella 5.0 was placed urgently and transcavally to rescue the patient. Addressing the question of what alternatives he would have had without transcaval experience, Dr. Villablanca explains that he could have done right or left subclavian, although he notes the potential for arm ischemia with axillary subclavian insertion. Or he suggests waiting for the surgical team to perform a surgical cut-down.

Dr. Kiernan addresses the question of perioperative management of patients requiring an Impella 5.5 by emphasizing the need for an experienced team— a cardiac anesthesiologist, interventional cardiologist, and cardiac surgeon—to discuss strategies in advance of the procedure. He also stresses the importance of placing the PA catheter before the patient arrives in the OR so that the team can use hemodynamics to guide therapy during the procedure.