Very Short Stature Predicts Morbidity and Mortality After Heart Transplant

Abstract

<h3>Purpose</h3> Short stature has been linked to increased transplant waitlist times and operative mortality after heart surgery. We aim to describe the relationship between stature and heart transplant outcomes. <h3>Methods</h3> The United Network for Organ Sharing was queried for data on adult heart transplant recipients from 2000 to 2021. Recipients were stratified into five groups by height: very short stature (height ≥2 standard deviations [SD] below the mean), short stature (≥1 and <2 SD below the mean, average stature (within 1 SD of the mean), tall stature (≥1 and <2 SD above the mean), and very tall stature (≥2 SD above the mean). Morbidity was analyzed using Kruskal-Wallis and chi square tests. Mortality was analyzed using Kaplan-Meier estimation, log-rank tests, and Cox regression. <h3>Results</h3> 2,033 (4.3%) heart transplant recipients from 2000 to 2021 had very short stature, 8,551 (18.0%) had short stature, 5,783 (12.2%) had tall stature and 667 (1.4%) had very tall stature. The very short stature group was younger, more commonly female, weighed less, had higher rates of congenital heart disease and restrictive cardiomyopathy, lower rates of pre-transplant mechanical ventilation, and lower serum creatinine than other groups (p<0.05). The very short stature group had increased 30-day mortality (8.1%, p<0.001), rejection rate (31.4%, p<0.001), postoperative stroke rate (3.9%, p=0.015), and median length of stay (16 days, p<0.001). Five-year survival rates ranged from 72.8% to 79.4% with the lowest in very short stature patients (p<0.001; Figure 1). On Cox regression, very short stature and short stature were associated with five-year mortality (HR 1.4, p<0.001 and HR=1.2, p<0.001 respectively), but donor/recipient height mismatch, weight mismatch, and predicted heart mass mismatch were not (HR 1.1, p=0.194; HR=1.0, p=0.709; and HR 1.0, p=0.772 respectively). <h3>Conclusion</h3> Very short stature is associated with increased morbidity and mortality after heart transplant. The mechanism explaining this effect requires further study.