Between-center variation in high-priority listing status under the new heart allocation policy

Abstract

Under the new US heart allocation policy, transplant centers listed significantly more candidates at high priority statuses (Status 1 and 2) with mechanical circulatory support devices than expected. We determined whether the practice change was widespread or concentrated among certain transplant centers. Using data from the Scientific Registry of Transplant Recipients, we used mixed-effect logistic regression to compare the observed listings of adult, heart-alone transplant candidates postpolicy (December 2018 to February 2020) to seasonally matched pre-policy cohort (December 2016 to February 2018). US transplant centers (N = 96) listed similar number of candidates in each policy period (4472 vs. 4498) but listed significantly more at high priority status (25.5% vs. 7.0%, p < .001) than expected. Adjusted for candidate characteristics, 91 of 96 (94.8%) centers listed significantly more candidates at highpriority status than expected, with the unexpected increase varying from 4.8% to 50.4% (interquartile range [IQR]: 14.0%-23.3%). Centers in OPOs with highest Status 1A transplant rate pre-policy were significantly more likely to utilize high-priority status under the new policy (OR: 9.73, p = .01). The new heart allocation policy was associated with widespread and significantly variable changes in transplant center practice that may undermine the effectiveness of the new system.

Association of center-level temporary mechanical circulatory support use and waitlist outcomes after the 2018 adult heart allocation policy

“…Recent investigation by Ran et al supports the presence of such a phenomenon, noting increased center-level variation in high-priority listing status in the new era. 16 Such findings are in line with the variation in centerlevel tMCS use noted in our study and may give credence to the idea that a broad spectrum of patients may be listed as highpriority status following the policy change. To better assess equity in the effect of the policy change, standardization of criteria for the initiation of tMCS could play a critical role.…”

“…3 Interestingly, some have suggested that these findings may be a manifestation of "gaming" the new system and patient advocacy, with physicians choosing bridging modalities that optimize the odds of transplantation for their patients. 11,16 In light of these changes, we found patients listed at high-tMCS centers to exhibit higher transplantation rates and lower rates of PWO compared to those listed at low-tMCS centers. These findings build on prior literature, showing that center-level tMCS use may profoundly impact patient-level outcomes regardless of the patient bridging strategy.…”

An updated estimate of posttransplant survival after implementation of the new donor heart allocation policy

“…To control for changes in recipient demographics over time, we estimated the effect of the policy using a multivariable Cox proportional hazards regression controlling for the components of the Index for Mortality Prediction After Cardiac Transplantation (IMPACT) score using the entire study data range 15 . Because treatment practices have changed since the new policy was implemented, 16,17 we also estimated posttransplant survival before and after policy implementation by treatment support at the time of transplantation. For these subgroup analyses, high‐dose inotrope support was defined by OPTN policies as “multiple inotropes or a single high‐dose inotrope and has hemodynamic monitoring” (e.g., dobutamine at greater than or equal to 7.5 mcg/kg/min) 11 .…”

Unintended consequences of achieving equity in the new heart allocation policy

“…However, a widespread behavior shift to achieve expeditious transplantation has unfortunately been observed with a higher than expected number of patients across centers nationwide being listed with high-priority statuses (Status 1 or 2) without accompanying explanatory changes in candidate characteristics when compared to seasonally matched prepolicy cohorts. 7 Furthermore, the number of exception requests for high-priority listing has dramatically increased. Combining these factors, the new heart allocation policy has had limited success in reducing the crowding of candidates clustered at the highest priority statuses, a behavior which has been observed broadly across transplant centers in the United States.…”

“…However, a widespread behavior shift to achieve expeditious transplantation has unfortunately been observed with a higher than expected number of patients across centers nationwide being listed with high‐priority statuses (Status 1 or 2) without accompanying explanatory changes in candidate characteristics when compared to seasonally matched prepolicy cohorts 7 . Furthermore, the number of exception requests for high‐priority listing has dramatically increased.…”