Dec. 22, 2023
If left untreated, patients with pulmonary hypertension (PH) resulting from left heart disease (LHD) have a life expectancy of less than five years, according to a study in the American Journal of Cardiology. Although the survival rate in patients with WHO Group 2 pulmonary hypertension has improved, treatment has shifted from short-term functional changes to improvements in long-term outcomes.
Up until now, the therapy for patients with end-stage heart failure was placement of a durable left ventricular assist device (LVAD) or transplantation. The LVAD is surgically implanted into the left ventricle to pump blood. However, complications like infections, stroke and bleeding can limit survival, and antibody development can affect organ transplantation candidacy. Furthermore, the survival to transplant, due to increased waitlist times, is not ideal for patients with durable LVAD.
Today, Mayo Clinic in Jacksonville, Florida, uses the Impella 5.5 temporary heart pump as a bridge to transplant or heart recovery, improving the prognosis for patients with end-stage heart failure. The Impella 5.5 is a temporary, axillary-placed heart pump that assists the pumping action of the heart.
The Impella 5.5 has transformed our practice and the outcomes for our patients. No longer are patients restricted to their beds, waiting for their lifesaving transplants. They now ambulate in the ICU and participate in physical therapy, all while their organs are optimized with better blood flow. Physicians are now able to consider transplant as a viable option in patients previously deemed too old or too sick.
"Our observations showed a sustained improvement in kidney function where kidney transplantation was not required in a subset of patients with the Impella 5.5."
A 2023 study in the Journal of Geriatric Cardiology looked at the one-year survival rate of patients over age 50 with advanced heart failure who underwent orthotopic heart transplantation (OHT) using the Impella 5.5. In this study, 38 patients age 50 or older were supported with the Impella 5.5 as a bridge to transplant. Ten patients underwent heart and kidney transplantation within this cohort. The median age at OHT was 63 years (range 58 to 68 years), with 32 male (84%) and six female (16%) patients.
Etiology was divided into ischemic (63%) and nonischemic (37%) cardiomyopathy. The baseline median ejection fraction was 19% (range 15% to 24%). Most patients were in blood group O (60%), and 50% had diabetes.
95% post-transplant survival rate
The average duration of axillary pump support was 27 days (range 6 to 94 days). The median duration of follow-up is 488 days (range 185 to 693 days). For patients who have reached the one-year follow-up time frame (22 of 38 patients, 58%), the one-year post-transplant survival is 95%.
Rohan M. Goswami, M.D., an advanced heart failure and transplant cardiologist at Mayo Clinic in Jacksonville, Florida, and one of the study's lead authors says, "Our ability to quantify a meaningful clinical, physiologic and functional change in patients using the Impella 5.5 as a bridge to transplant is a big step forward for the field. Optimization of patients prior to transplantation is key to improved outcomes." Dr. Goswami explains that, ideally, the pump could optimize a heart so much that a patient could forgo a transplant and potentially recover. He is leading a clinical trial that evaluates biomarkers and artificial intelligence to predict native heart recovery for patients with acute or chronic heart failure.
Impaired kidney function also is often associated with acute decompensation of chronic heart failure. As a result, there have been 2,561 simultaneous heart and kidney transplantations in the United States since 1988. In 2021, a total of 349 simultaneous heart and kidney transplantations were performed.
A retrospective study published in Scientific Reports reviewed patients with acute or chronic heart failure and kidney disease. These study participants were considered for combined heart and kidney transplant supported by temporary mechanical circulatory support with Impella 5.5 between January 2020 and February 2021.
Methods
All participants had chronic heart failure diagnosed, on average, at least seven years before their admission for acute decompensated heart failure. The median participant age was 67, with one female and five males, and the average BMI was 31. This cohort included blood types O, A and B.
During the study review period, 57 participants underwent heart transplantation, of which 20 participants (35%) with cardiogenic shock used the Impella 5.5 as a bridge to organ transplantation. Six patients received work-ups for heart and kidney transplant while supported with Impella 5.5.
"Our observations showed a sustained improvement in kidney function where kidney transplantation was not required in a subset of patients with the Impella 5.5," says Dr. Goswami.
Results
The Impella 5.5 helps optimize patient outcomes for those with advanced kidney disease who are awaiting organ transplantation in cardiogenic shock. The results of the study show that axillary mechanical circulatory support resulted in renal recovery across all patients. There was further improvement in the six patients who had significant renal dysfunction. These patients demonstrated marked kidney function improvement and eventually needed only heart transplants, eliminating the need for renal transplants. Additional studies with larger cohorts should be considered.
For more information
McLaughlin V. Managing pulmonary arterial hypertension and optimizing treatment options: Prognosis of pulmonary artery hypertension. American Journal of Cardiology. 2013;111(supp):10C.
Paghdar S, et al. One-year survival in recipients older than 50 bridged to heart transplant with Impella 5.5 axillary approach. Journal of Geriatric Cardiology. 2023;20:319.
Jang JM, et al. Axillary mechanical circulatory support improves renal function prior to heart transplantation in patients with chronic kidney disease. Scientific Reports. 2023;13:19671.
Refer a patient to Mayo Clinic.