# Intra-operative Risk Factors Affecting Mortality after Heart Transplantation: A Referral Center Experience in Iran

## TL;DR

This study from Iran identifies intra-operative risk factors that increase mortality after heart transplants in both children and adults.

## Contribution

The study provides new insights into specific intra-operative risk factors affecting post-transplant mortality in a single-center, long-term cohort.

## Key findings

- Reoperation due to bleeding and defibrillation significantly increased one-month mortality risk in both children and adults.
- ECMO use and ICU stay were associated with higher one-year mortality.
- Readmission had a protective effect against one-month mortality.

## Abstract

Heart transplantation is the preferred treatment for end-stage heart failure. This study investigated the intra-operative risk factors affecting post-transplantation mortality.

This single-center retrospective cohort study examined 239 heart transplant patients over eight years, from 2011-2019, at the oldest dedicated cardiovascular center, Shahid Rajaee Hospital (Tehran, Iran). The primary evaluated clinical outcomes were rejection, readmission, and mortality one month and one year after transplantation. For data analysis, univariate logistic regression analyses were conducted.

In this study, 107 patients (43.2%) were adults, and 132 patients (56.8%) were children. Notably, reoperation due to bleeding was a significant predictor of one-month mortality in both children (OR=7.47, P=0.006) and adults (OR=172.12, P<0.001). Moreover, the need for defibrillation significantly increased the risk of one-month mortality
in both groups (children: OR=38.00, P<0.001; adults: OR=172.12, P<0.001). Interestingly, readmission had a protective effect against one-month mortality in
both children (OR=0.02, P<0.001) and adults (OR=0.004, P<0.001). Regarding one-year mortality, the use of extracorporeal membrane oxygenation (ECMO) was associated with a
higher risk in both children (OR=7.64, P=0.001) and adults (OR=12.10, P<0.001). For children, reoperation due to postoperative hemorrhage also increased the risk (OR=5.14, P=0.020),
while defibrillation was a significant risk factor in both children and adults (children: OR=22.00, P<0.001; adults: OR=172.12, P<0.001).
The median post-surgery survival was 22 months for children and 24 months for adults.

There was no correlation between sex and poorer outcomes. Mortality at one month and one year after transplantation was associated with the following risk factors: the use of ECMO,
reoperation for bleeding, defibrillation following cross-clamp removal, and Intensive Care Unit (ICU) stay. Readmission, on the other hand, had a weak protective effect.