Survival in Patients Listed for Heart Transplantation
Survival in Patients Listed for Heart Transplantation
Objectives. The aim of this study was to assess the survival benefit from heart transplantation (HT), defined as reduction in the risks for 90-day and 1-year mortality on undergoing HT close to listing, in candidates stratified by their risk for waiting list mortality.
Background. Among patients listed for HT, those at higher risk for death without transplantation are also at higher risk for early post-transplantation mortality.
Methods. All patients age ≥18 years listed for HT in the United States from 2007 to 2010 were analyzed. A model was developed to predict the risk for waiting list mortality within 90 days, and listed patients were stratified into 10 risk groups (deciles). All groups were followed for 1 year to assess cumulative 1-year mortality while on the waiting list. Models of 90-day and 1-year post-transplantation mortality were developed using recipient data, and these risks were estimated at listing in all listed candidates.
Results. Of 10,159 patients listed for HT, 596 (5.9%) died within 90 days and 1,054 (10.4%) within 1 year without undergoing transplantation. Of 5,720 recipients of transplants with 1-year follow-up, 576 (10.1%) died within 1 year. The risk for death while on the waiting list within 90 days increased from 1.6% to 19% across the 10 risk groups. The survival benefit from HT increased progressively with higher risk for death without transplantation (p < 0.001 for trend), but there was no benefit in the first 6 risk groups.
Conclusions. The risk for waiting list mortality varies considerably among HT candidates. Although the survival benefit of HT generally increases with increasing risk for waiting list mortality, there is no measurable benefit in many candidates at the lower end of the risk spectrum.
Heart transplantation (HT) is an established therapy for end-stage heart failure. Although the number of patients listed for HT in the United States continues to increase, the supply of donor hearts remains relatively unchanged. To minimize mortality in patients awaiting HT, the U.S. allocation policy has prioritized sicker candidates to receive donor hearts since the early days of transplantation. In the current 3-tier system, a patient may be listed as status 2, 1B, or 1A on the basis of criteria intended to represent increasing medical urgency. These groups are then assigned progressively higher priority during allocation. Because not all candidates listed at the highest urgency status (1A) share a similar risk for death while waiting, some experts have argued for a re-examination and revision of the current allocation algorithm.
Previous studies have suggested that sicker patients among those listed for HT are also at higher risk for post-transplantation mortality. Although prioritizing donor hearts to candidates on the basis of transplantation urgency is justified as fairness or justice, whether it is also justifiable on the basis of higher survival benefit to such patients is unknown. A better understanding of the relationship of the survival benefit from HT with increasing risk for death on the waiting list will be valuable not only to the physicians caring for patients with heart failure but also to the allocation experts responsible for refining the heart allocation algorithm.
We hypothesized that the survival benefit from HT estimated at the time of listing will be higher in patients at higher risk for death while on the waiting list. The specific objectives of this study were: 1) to risk-stratify patients listed for HT on the basis of their risk for death without HT within 90 days of listing; and 2) to quantify the survival benefit of HT across risk strata of waiting list mortality.
Abstract and Introduction
Abstract
Objectives. The aim of this study was to assess the survival benefit from heart transplantation (HT), defined as reduction in the risks for 90-day and 1-year mortality on undergoing HT close to listing, in candidates stratified by their risk for waiting list mortality.
Background. Among patients listed for HT, those at higher risk for death without transplantation are also at higher risk for early post-transplantation mortality.
Methods. All patients age ≥18 years listed for HT in the United States from 2007 to 2010 were analyzed. A model was developed to predict the risk for waiting list mortality within 90 days, and listed patients were stratified into 10 risk groups (deciles). All groups were followed for 1 year to assess cumulative 1-year mortality while on the waiting list. Models of 90-day and 1-year post-transplantation mortality were developed using recipient data, and these risks were estimated at listing in all listed candidates.
Results. Of 10,159 patients listed for HT, 596 (5.9%) died within 90 days and 1,054 (10.4%) within 1 year without undergoing transplantation. Of 5,720 recipients of transplants with 1-year follow-up, 576 (10.1%) died within 1 year. The risk for death while on the waiting list within 90 days increased from 1.6% to 19% across the 10 risk groups. The survival benefit from HT increased progressively with higher risk for death without transplantation (p < 0.001 for trend), but there was no benefit in the first 6 risk groups.
Conclusions. The risk for waiting list mortality varies considerably among HT candidates. Although the survival benefit of HT generally increases with increasing risk for waiting list mortality, there is no measurable benefit in many candidates at the lower end of the risk spectrum.
Introduction
Heart transplantation (HT) is an established therapy for end-stage heart failure. Although the number of patients listed for HT in the United States continues to increase, the supply of donor hearts remains relatively unchanged. To minimize mortality in patients awaiting HT, the U.S. allocation policy has prioritized sicker candidates to receive donor hearts since the early days of transplantation. In the current 3-tier system, a patient may be listed as status 2, 1B, or 1A on the basis of criteria intended to represent increasing medical urgency. These groups are then assigned progressively higher priority during allocation. Because not all candidates listed at the highest urgency status (1A) share a similar risk for death while waiting, some experts have argued for a re-examination and revision of the current allocation algorithm.
Previous studies have suggested that sicker patients among those listed for HT are also at higher risk for post-transplantation mortality. Although prioritizing donor hearts to candidates on the basis of transplantation urgency is justified as fairness or justice, whether it is also justifiable on the basis of higher survival benefit to such patients is unknown. A better understanding of the relationship of the survival benefit from HT with increasing risk for death on the waiting list will be valuable not only to the physicians caring for patients with heart failure but also to the allocation experts responsible for refining the heart allocation algorithm.
We hypothesized that the survival benefit from HT estimated at the time of listing will be higher in patients at higher risk for death while on the waiting list. The specific objectives of this study were: 1) to risk-stratify patients listed for HT on the basis of their risk for death without HT within 90 days of listing; and 2) to quantify the survival benefit of HT across risk strata of waiting list mortality.
