Findings challenge donor heart allocation process

Outcomes in patients waiting for heart transplants may vary according to the length of waiting list time, findings in a study published online Jan. 29 in the Journal of the American College of Cardiology showed.

Researchers led by Tajinder P. Singh, MD, MSc, of Children’s Hospital Boston, identified all adults in the national Organ Procurement and Transplantation database waiting for a first-time heart transplant between 2007 and 2010. They evaluated post-transplant outcomes in patients who had a heart transplant between Jan. 1, 2007 and March 1, 2011, excluding patients who had multiple organs transplanted or who previously had a heart transplant. The primary outcomes were death without a transplant, whether it occurred while on the waiting list or after removal from the list, and death after transplant.

“The primary hypothesis was that survival benefit from HT [heart transplant] estimated at the time of listing will be higher in patients who are at a higher risk of death without HT,” the authors wrote.

They developed a risk prediction model of wait-list mortality within 90 days and one year of transplant and arranged participants into 10 risk groups. Patients in the first two risk groups were younger, more likely to have dilated or ischemic cardiomyopathy, were not using a ventilator or a balloon pump and had normal kidney function. The two highest risk groups had multiple risk factors, such as mechanical support and severe kidney dysfunction.

There were 10,159 patients on the waiting list for a heart transplant, and 596 (5.9 percent) died within 90 days and 1,054 (10.4 percent) died within one year without a transplant. There were 5,720 transplant recipients with a one-year follow-up, and 576 (10.1 percent) died within a year.

Mortality risk of patients on the wait list within 90 days varied from 1.6 percent to 19 percent across the risk groups. A higher risk of death without transplant was associated with an increased survival benefit, but there was no benefit in the six lowest-risk groups.

“[T]hese findings suggest that considering survival benefit from HT or improving the stratification of listed patients in prioritizing heart allocation may improve overall outcomes in patients listed for HT,” the authors wrote.