Outcomes of use of inotropes at waitlisting through heart transplant: the UNOS experience

Abstract Introduction While awaiting transplantation, patients are at high risk for severe deterioration of their condition unresponsive to conventional heart failure medications, requiring other forms of therapeutic intervention. However, in patients where machinal circulatory support (MCS) is not a feasible option, inotropic therapy becomes a critical alternative. Inotropes, such as dobutamine and milrinone, help to enhance heart contractility and stabilize hemodynamics, thereby acting as a bridge to transplant for patients ineligible for MCS. We sought to evaluate the trends and outcomes of patients on inotropes while waitlisted and investigate the effect of inotropes at the time of HT on mortality and post-operative clinical outcomes. Methods A retrospective analysis of the United Network for Organ sharing (UNOS) registry (2000-2021) was performed, and patients were grouped according to the presence or absence of inotropes at the time of transplantation. Independent samples t-test was performed for between-group comparisons of continuous variables, while Pearson chi-squared test compared categorical variables. Univariable logistic regression was used to assess the impact of use of inotropes on in-hospital outcomes, while univariable Cox regression was performed to assess their role on survival. Results A decrease of inotrope use throughout the waitlist period was noted over time (b: -0.02, p0.001) . Differences in recipient characteristics between the two groups are summarized in the table. No difference was noted in terms of 1- and 5- year mortality. Use of inotropes at the time of HT was associated with decreased 30-day mortality (OR 0.74; 95% CI: 0.62-0.88, p=0.001) and need for post-operative dialysis (OR: 0.88; 95% CI: 0.79, 0.98, p=0.017). No difference was found in terms of post-operative stroke (OR: 0.90; 95% CI: 0.72, 1.12, p=0.354) and post-operative permanent pacemaker implantation (OR: 0.85; 95% CI: 0.66, 1.09, p=0.20). Conclusions Continuous use of inotropes after waitlisting is associated with lower 30-day mortality and does not lead to worse long-term outcomes. Thus, continuation of inotropes to bridge patients to transplantation can be considered a viable option when mechanical support is not feasible.