January 14, 2013
Rates of mortality and morbidity for patients on a waiting list for a heart transplant decreased from 1999 to 2011, according to study results.
Researchers studied 33,073 heart transplant candidates registered on the United Network for Organ Sharing (UNOS) waiting list from 1999 to 2011. Patients were divided into five groups: those without left ventricular assist devices in urgency status 1A, 1B and 2, those with pulsatile-flow LVADs and those with continuous-flow LVADs. Researchers also investigated outcomes in patients requiring biventricular assist devices (BIVADs), total artificial heart VADs and temporary VADs.
For this study, the researchers defined two eras, based on approval of the first continuous-flow LVAD for bridge-to-transplant in the United States in 2008.
Omar Wever-Pinzon, MD, of the U.T.A.H. Cardiac Transplant Program, University of Utah Health Sciences Center, and colleagues reported that mortality was lower in the current era compared with the first era (2.1% vs. 2.9% per month; P<.0001). In the first era, the mortality rate for pulsatile-flow LVAD patients was higher than in status 2 (HR=2.15; P<.0001) and was similar to status 1B (HR=1.04; P=.61). During the current era, the mortality rate of patients with continuous-flow LVADs was similar to status 2 (HR=0.8; P=.12) and lower compared with status 1A and 1B (HR=0.24 and HR=0.47, respectively; P<.0001 for both). Status upgrade for LVAD-related complications occurred in 28% of patients studied and was associated with an increase in mortality risk (HR=1.75; P=.0001).
“Our data show that almost 30% of LVAD supported transplant candidates develop a complication that justifies a higher urgency status listing and that once this occurs, the risk of death or de-listing is markedly increased,” the researchers wrote. According to results, patients on the waiting list at the highest risk for adverse outcomes include those who require biventricular support and support with pulsative or non-durable mechanical assist devices.
“These results may help to guide optimal allocation of donor hearts,” they concluded.