Survival Improves Among Wait-listed Heart Transplant Candidates

There was an almost 99% increase in the 1-year survival rate among 95,323 candidates on the United Network for Organ Sharing, or UNOS, waiting list for a heart transplant when comparing 1987-1990 with 2011-2017, according to unadjusted and adjusted survival analyses, reports a study in JAMA Cardiology that came out last week.

This retrospective cross-sectional analysis mined the UNOS database for individuals at least 18 years old placed on the heart transplant waiting list between January 1, 1987, and December 2017, for a total study cohort of 95,323. The authors wanted to know if survival had increased among this patient group in light of improvements in both medical management and mechanical devices meant to help those with heart failure and the 2006 UNOS allocation policy (compared with the more recent 2018 UNOS allocation policy), which expanded regional organ sharing and allowed the sickest patients to receive the highest priority status.

Most patients (n = 72,915 [76.5%]) were men, and their mean (SD) age was 51.9 (12.0) years. With a primary outcome of death on the waiting list (as reported in the UNOS database and reported elsewhere externally), they were followed to 1 of 3 outcomes:

• Death
• Transplant
• List removal from clinical improvement

One-year survival rates increased among wait-listed candidates across the board for changes in listing preferences, changes in mechanical circulatory support indications, and candidates with and without ventricular assist devices (VADs), as well as from the decade prior to the decade after the 2006 UNOS allocation policy. Data were stratified by 6 eras: 1987-1990, 1991-1995, 1996-2000, 2001-2005, 2006-2010, and 2011-2017.

From 2011 to 2017, there was a 67.8% rate of 1-year survival compared with 34.1% during 1987 to 1990 (difference in proportions, 0.34%; 95% CI, 0.32%-0.36%; P < .001) among those patients who listing preferences changed. Meanwhile, compared with 1996 to 2000 during which candidates with VADs had a 10.2% 1-year survival on the transplant wait list, 2011 to 2017 saw this rate jump to 70.0% (difference in proportions, 0.60%; 95% CI, 0.58%-0.62%; P < .001), or a 586% increase.

“To account for various listing criteria across different regions and to account for changing listing preferences and policies during the study period, we attempted to depict the intrinsic risk of death for candidates on the waiting list and study it across the different eras,” the authors noted.

Other results show that 1-year survival among patients without VADs improved 23.4% between 1996 to 2000 and 2011 to 2017: from 53.9% to 66.5%, respectively (difference in proportions, 0.13%; 95% CI, 0.12%-0.14%; P < .001).

Comparing the decade prior to the decade after the 2006 UNOS allocation policy saw a 25.0% rise in 1-year survival, from 51.1% to 63.9%, respectively (difference in proportions, 0.13%; 95% CI, 0.12%-0.14%; P < .001); a 40.4% rise in 3-year survival, from 31.2% to 43.8% (difference in proportions, 0.13%; 95% CI, 0.11%-0.14%; P < .001); and a 40.6% rise in 5-year survival, from 21.9% to 30.8% (difference in proportions, 0.09%; 95% CI, 0.08%-0.10%; P < .001).

Additional results demonstrate the following comparing the periods of 2001-1005 with 2011-2017:

1. Patients with functional status above 50% (need occasional help, can’t carry out normal activities, have some symptoms of disease, can carry out normal activities with minor symptoms, no evidence of disease) increased in 2011-2017 vs 2001-2005.
2. Patients with functional status of 50% or below (need a lot of help and medical care, are disabled, are severely disabled and need hospitalization, require hospitalization/active treatment, are near death) increased in 2011-2017 vs 2001-2005.

Overall, there was a continuous decrease in deaths while on the wait list, from 1987-1990 (the reference period) to 2011-2017.

“Our data suggest that survival on the waiting list is increasing faster than survival after transplantation,” the authors concluded. “Continued improvement in outcomes for heart failure therapy among patients on the waiting list may support continued attention to balancing the survival benefit of existing supportive therapies against the indication for heart transplantation.”

Reference

Bakhtiyar SS, Godfrey EL, Ahmed S, et al. Survival on the heart transplant waiting list. JAMA Cardiol. Published online August 12, 2020. doi:10.1001/jamacardio.2020.2795