Case Review, Escalation Therapy, AMI Cardiogenic Shock
Postpartum Myocarditis Escalated to Impella 5.5® with SmartAssist®
A 33-year-old female, seven months postpartum, presented to Emergency Department in biventricular heart failure with COVID-related myocarditis and pericardial effusion. Impella CP® with SmartAssist® was placed to stabilize the patient; however, at 72 hours, with multiple high-dose inotropes and vasopressors, the patient was not showing signs of recovery. She was transferred to a tertiary facility where the heart team looked at escalation options and selected Impella 5.5 with SmartAssist to allow for continued temporary support with the potential for heart recovery. After 12 days of support with Impella 5.5 with SmartAssist, the patient was successfully weaned and explanted with native heart recovery.
Mortality on inotropes
An abundance of data highlights the negative impact of high levels of inotropic support during cardiogenic shock, correlating with an increase in mortality. Patients presenting with cardiac power output (CPO) under 0.6 watts and on two high-dose inotropes carry a morality risk of about 65%, compared to patients with similar CPO and no inotropes, whose mortality risk is about 37%. Survival to discharge for a patient in cardiogenic shock depends greatly on the ability of the heart to generate pressure and flow. As illustrated in this case study, mechanically supporting the failing heart and aggressively weaning down inotropes to optimize CPO may reduce mortality in cardiogenic shock.
Another principle illustrated in this case study is that heart teams should consider escalation if a patient is worsening or not showing signs of recovery after 48 to 72 hours. Protocols can provide heart teams with a systematic approach to decision-making. Hospitals may choose to escalate temporary support to an Impella 5.0® or Impella 5.5 with SmartAssist, to place a durable LVAD for longer-term support, or to move forward with a heart transplant.
Unilateral vs bilateral support
Protocols can also help improve survival by helping to determine whether the patient needs left, right, or biventricular support. Consider right-side support with Impella RP® if CPO is ≤0.6 watts (or ≤0.8 watts with inotropes/pressors), and the pulmonary artery pulsatility index (PAPi) is ≤0.9, indicative of RV dysfunction. Consider left-side support escalation to Impella 5.0 or Impella 5.5 with SmartAssist, or transfer to LVAD/transplant center, for patients with the same CPO but PAPi >0.9.
In this case study, because the team identified the need for escalation of care and made the decision to transfer the patient to a tertiary center for implant of the Impella 5.5 with SmartAssist, the patient was able to recover her heart and be discharged home to continue to enjoy life with her family.