Case Review, Hemodynamics, AMI Cardiogenic Shock, Right Heart Failure
Impella RP® Support for Univentricular Shock
Navin Kapur, MD, FAHA, FACC, FSCAI, presents a case of univentricular shock in a 60-year-old patient with late presentation RVMI and 3 vessel disease. This case illustrates a hemodynamics-based decision-making process leading to optimal patient outcome.
Dr. Kapur, an interventional heart failure specialist at Tufts Medical Center, explains that his surgical team was concerned about hemodynamic data showing massively elevated RA pressure, elevated wedge pressure, pulmonary artery pulsatility index of far less than 1.0, and RA wedge pressure ratio far greater than 0.8 for an RVMI case. Echo revealed RV dilatation. The patient developed bradycardic arrest. Would this patient have challenges coming off pump during coronary bypass surgery? Could this patient be revascularized?
Dr. Kapur explains how this patient was referred for left heart cath and possible PCI. Angiography revealed occluded RCA, left circumflex disease, and LAD disease. Dr. Kapur notes that we usually think of left-side support first for typical high-risk PCI cases. Many support strategies were possible: balloon pump, Impella CP® heart pump, Impella RP® in addition to left-side support, or ECMO for biventricular failure.
Relying on hemodynamic data, as they do for most mechanical support cases, Dr. Kapur and his team put in a PA cath and a Langston® Dual Lumen Catheter to get simultaneous LV and AO pressures. They saw evidence of diastolic equalization, high RA pressure, low PA pulse pressure, and flat LV diastolic tracing, indicating profound right ventricular failure with intact pericardium. They determined that the patient needed right-side support.
Dr. Kapur and his team implanted an Impella RP. They hadn’t previously done an isolated Impella RP multivessel PCI for a patient with worsening right ventricular failure sliding into cardiogenic shock. Should they add LV support as well? He discusses how he returned to examining the patient’s hemodynamics. Watching the LV tracing while the patient was supported with Impella RP, he saw that LVEDP didn’t change, indicating that the left ventricle was able to tolerate restoration of preload by Impella RP. With adequate hemodynamic support, Dr. Kapur and his team proceeded with PCI with the goal of complete revascularization.
Dr. Kapur explains that he left the Impella RP in the patient post PCI. Six hour later, with the patient producing 6 L of urine, he was assured hemodynamics were rapidly improving. Although the patient became dependent on RP support, Dr. Kapur describes how he was able to wean the patient off support within 24 hours.
Repeat echo at 2-week follow up showed normal RV dimensions and RV function. “Really a nice case of revascularization and recovery for this patient,” Dr. Kapur concludes.
Thus Dr. Kapur chose an effective univentricular solution with Impella RP for this patient with univentricular failure. As other physicians frequently report when using Impella RP, he saw LV and aortic pressures increase after just a few heartbeats on support. A key aspect of this management strategy was having a goal, which in this case was decongestion of end organs, as evidenced by good urine output at 6 hours.
RA pressure alone correlates with outcomes in cardiogenic shock, Dr. Kapur explains. If you have an elevated RA pressure, it is a target of therapy. Getting RA pressure down while maintaining systemic perfusion is one of the most important predictors of better outcomes for patients.