Inconsistent Ranking of Heart Transplant Recipients Unjust

Ingrid Hein

April 16, 2018

Access to heart transplantation can be unfair in the United States, with patients in some regions ranking higher in priority because cardiologists "overtreat," which makes patients look sicker and therefore more suitable for emergent intervention than others on the wait list, new research shows.

Cardiologists are not doing anything wrong; the system encourages these practices, said William Parker, MD, Pulmonary and Critical Care Fellow at the University of Chicago. "I think they all have good intentions and are trying to do what's best for their patients."

However, "it looks like certain environments call for certain practices. I'm not trying to pass judgment in this paper, it's really about pointing out the limitations of the current system," he explained. This is a market — a local market — and needs should be analyzed at a local level, he added.

We all want allocation to be on an objective scoring system, he said.

Because the system is based on treatment status, certain patients — those supported with two inotropes and a Swan-Ganz catheter, intra-aortic balloon pump, extracorporeal membrane oxygenation, or total artificial assist-device boosts — are assigned A1 recipient status, which is the highest rating. These patients jump to the top of the list for a new heart.

The problem is that some patients might actually be hemodynamically stable without these therapies, but being on them helps them to meet the A1 criteria.

It's hard to make a system that's perfectly fair.

"It's hard to make a system that's perfectly fair," Parker told Medscape Medical News. Ultimately, the goal is to have a system that is fair from a national perspective but allows you to represent your individual patient. "We need to have objective criteria to determine higher listing status. The use of inotropic agents is somewhat subjective."

The investigation into the overtreatment of heart transplant candidates by Parker and his colleagues comes just a few months before the OPTN/UNOS Thoracic Organ Transplantation Committee implements a new system for heart allocation, which will change the three-tiered ranking system to a six-tiered system.

New System in the Works

Modifications include "tightening the qualifying criteria" by requiring evidence that candidates need certain therapies to treat cardiogenic shock, as defined by the American Heart Association (AHA); restrictions on the length of time patients can be listed as status 1, 2, or 3; and a broader geographic sharing scheme.

Considering how these changes would affect the distribution of donor hearts prompted Parker to take a close look at the current system.

"I just wanted to take the new criteria and see how many with A1 status would fit. I found there were a lot of unintended consequences," he told Medscape Medical News.

When he assessed the new cardiogenic shock criteria, he found it would "reduce the priority for transplantation for 4600 adult heart transplant candidates a year nationally. These disqualifications could lead to the increased use of surgically placed devices to circumvent the shock requirement, which would place candidates at increased and unnecessary risks while they await organ transplantation," he explained.

That led him to examine treatment practices across the country, and he found huge discrepancies in what he now terms "overtreatment."

As a result, he and his colleagues conducted a study of 12,762 adults who underwent heart transplantation from 2010 to 2015 who did not meet the AHA criteria for cardiogenic shock — treatment with either high-dose inotropes or an intra-aortic balloon pump — and were potentially overtreated.

Parker presented the findings at the International Society for Heart and Lung Transplantation 2018 Scientific Sessions in Nice, France. The work is published online in the Journal of the American College of Cardiology,

The team identified 1471 patients (11.6%) — after adjustments for logistic regression, propensity score models, and center-level variables — who were treated with high-dose inotropes or intra-aortic balloon pumps even though they did not meet the AHA criteria.

Discrepancies between centers were vast. There was a 25.5% difference between top-quartile centers and bottom-quartile centers (95% confidence interval, 21% - 30%). Differences in rates of overtreatment ranged from 2% to nearly 50%.

When centers with high rates of overtreatment were plotted on a map, distinct characteristics became clear. First, they were concentrated in the three largest urban areas in the United States: New York City, Chicago, and Los Angles. And second, overtreating centers had at least two transplant centers nearby.

We see that more competition in a region is strongly associated with high rates of overtreatment. Competition is part of this story.

"We see that more competition in a region is strongly associated with high rates of overtreatment," Parker explained. "Competition is part of this story."

These findings echo those from a previous study Parker was involved in that showed that the 2006 geographic expansion of the sharing of hearts led to an increase in the use of inotropes (Circ Heart Fail. 2017;10:e004483).

Since that change, transplant programs have "used multiple inotropes to list candidates at status 1A more frequently with progressively lower doses. Concurrently, the status 1A inotrope candidate waitlist outcomes improved substantially. These trends suggest that overtreatment with multiple inotropes contributes to the current critical excess of status 1A candidates," those researchers concluded.

The new criteria, which will be implemented this year, are more objective but have the "same problems as inotrope. The new system introduces even more criteria, but is still based on subjective decisions about therapy," Parker pointed out.

"Moving to a heart allocation score is ultimately what we should strive for, and most people agree with that," he said. "If this study can move the field toward that, by showing the limitations of our therapy-based system, that would be the hope."

A "National Resource"

"Hearts that are available are a national resource; we have a fixed number of them," said Larry Allen, MD, from the University of Colorado School of Medicine in Denver, who is the coauthor of an editorial accompanying the published study.

"Fair play is not always natural. Clinicians making heart transplant allocation decisions are rarely consciously and flagrantly overtreating patients to outwit, outplay, and outlast one another, but, in the words of cognitive psychologist Dan Ariely, we all have a 'personal fudge factor'," write Allen and Prateeti Khazanie, MD, also from the University of Colorado School.

"The goal is to do the greatest amount of good, as these decisions really are a matter of life and death," Allen told Medscape Medical News.

Both Parker and Allen point to the Model for End-Stage Liver Disease (MELD) scoring system, which does not use treatment as a criterion for liver transplantation.

This study was supported in part by an institutional Clinical and Translational Science Award. Parker reports receiving support from the National Institutes of Health. Allen reports consulting for Boston Scientific, Janssen, Amgen, and Novartis. Khazanie has disclosed no relevant financial relationships.

International Society for Heart and Lung Transplantation (ISHLT) 2018 Scientific Sessions: Abstract 438. Presented April 14, 2018.

Follow Medscape on Twitter @Medscape and Ingrid Hein @ingridhein

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