Predictors Associated With Prognosis of Patients on the Waiting List for Heart Transplantation

Aim    To identify predictors associated with the prognosis of patients on the heart transplant waiting list (HTWL) corresponding to UNOS class 2.Material and methods    A HTWL database for 2010-2021 was retrospectively evaluated. The study included patients (n=162) who at the time of inclusion into the HTWL met UNOS class 2 and reached the endpoint of death, heart transplantation (HT), or exclusion from the HTWL due to an improvement of their condition. Mean age was 48±13 (from 11 to 67) years, 80% (n=130) were men, and body weight index was 24.9±4.4 kg/m2. Patients were divided into two groups: group 1 (n=131), patients who left the HTWL (improvement of CHF functional class) and patients who maintained the UNOS class 2 until HT; group 2 (n=31), patients who transferred from UNOS class 2 to UNOS class 1B/1A or died while on the HTWL.Results    Patients of group 2 had lower systolic BP compared to patients of group 1 (100±17, mm Hg vs. 107±17 mm Hg, respectively, p=0.03). In group 1 compared to group 2, there was a higher proportion of patients with obesity, 29 (22%) vs. 1 (3%) (p=0.02). Laboratory blood tests: absolute lymphocyte count (2.0±0.7×109/L and 1.6±0.9×109/L, p=0.03), serum albumin (42±5 g/l and 40±6 g/l, p=0.03), red cell distribution width (RDW) (16±4% and 18±4%, p=0.01); sodium concentration (139±4 and 136±4 mmol/l, p=0.009). Patients from group 2 had a higher pulmonary vascular resistance (PVR) (4.0±2.4 Wood units vs. 3.2±1.4 Wood units, p=0.01) at baseline. A predictive model (p<0.001) was developed to determine a probability of prognosis in HTWL. The model sensitivity was 75% and the specificity was 67%. High PVR was a predictor that worsened the prognosis in HTWL; higher serum concentrations of sodium and albumin increased the probability of a favorable outcome in HTWL.Conclusion    During the period of waiting for HT, 19% of patients that met UNOS class 2 experienced deterioration of their condition (transitioned to UNOS 1) or died. The most important predictors for a better outcome in patients on HTWL who meet UNOS class 2 were higher serum levels of sodium and albumin and low pulmonary vascular resistance.