To SIPAT or Not to SIPAT: The Stanford Integrated Psychosocial Assessment for Transplant

Abstract

The Stanford Integrated Psychosocial Assessment for Transplant (SIPAT) is a tool used to standardize and objectify the pre-transplant evaluation. We sought to assess whether the SIPAT score is associated with outcomes of acute cellular rejection (ACR), graft failure (GF) and survival. Retrospective study in HTx recipients between 01/2008 and 05/2019 at a single institution. Post-transplant outcomes included: incidence of ACR, GF, and death, comparing HTx recipients with a SIPAT score <21 [acceptable] vs. ≥21 [minimally acceptable]. The KM method was used to assess survival, and a competing risk model was used for GF. Cox proportional hazard regression was applied to quantify the association of ACR (a time dependent variable) with mortality, adjusted for demographic characteristics. Independent estimating equations were used to assess the association of the SIPAT score with longitudinal biopsy ACR grades RESULTS: Overall 393 HTx recipients had a SIPAT evaluation. Patients included were more likely Caucasian (55.5%) and male (70.2%), with a median age of 55.2 (46-61.7) years. The median (IQR) SIPAT score was 14 (10-19) and 68 patients (17.2%) had a SIPAT score ≥ 21. Women were more likely to have a low (acceptable) SIPAT score (33% vs. 16%, p-value = 0.008). Recipients with a SIPAT score ≥21 were not at higher risk for ACR (p= 0.99) (Figure 1A), when adjusted for recipients' demographics. Between-group differences in survival and graft failure were not statistically significant (5-year survival: ≤21 vs. >21, 84.5% [79.3%, 88.5%] vs. 81.6% [65.0%, 90.8%], p= 0.74; 5-year GF CIF: ≤21 vs. >21, 6.5% [3.9%, 10.9%] vs. 10.2% [3.7%, 28.2%], p= 0.65 [GF]). The study did not show evidence that minimally acceptable recipients, according to psychosocial criteria, experienced an increased risk of rejection, graft failure or death. While the SIPAT tool has become an integral tool for heart transplant evaluation, a high SIPAT score alone may not be sufficient to risk stratify candidates.