The effectiveness of United Network of Organ Sharing status 2 transplantation in the modern era.

BACKGROUND

The continued benefit of United Network of Organ Sharing (UNOS) status 2 transplantation in the modern era has been questioned.

METHODS

We measured deterioration to higher status designations, improvement allowing delisting, and risk of death or delisting as too ill, regardless of subsequent status, from the Scientific Registry of Transplant Recipients database. Extended Cox models were used to assess the relative hazard of status 2 transplantation vs waiting after status 2 listing. The likelihood of transplantation was measured with logistic regression.

RESULTS

We analyzed 14,153 candidates listed from 2003 to 2008. Within 1 year of initial listing, deterioration to status 1B occurred frequently (63%), while delisting as too well occurred rarely (2%-7%). Death or delisting as too ill occurred among 27% at 2 years after initial status 2 listing. Mortality at 2 years after status 2 transplantation was 13%. The hazard ratio (HR) after 180 days of status 2 transplantation vs waiting during or after initial status 2 listing was 0.41 (95% confidence interval, 0.31-0.55). The likelihood of transplantation was markedly diminished for women (odds ratio, 0.71; p < 0.001) and congenital heart disease (odds ratio, 0.24; p < 0.001). Death or delisting as too ill for women (HR, 1.7; p < 0.001) and congenital heart disease (HR, 3.2; p < 0.001) were substantially higher than in other groups.

CONCLUSIONS

Escalation of UNOS status is common and delisting as too well is uncommon after initial status 2 listing. Despite the decreasing number of transplants provided to status 2 registrants, sub-groups of patients may be at high risk of waiting at status 1A, justifying the continued use of the status 2 designation.